Bump to version 1.3.7

Under certain conditions, e.g. non-existent database files, the repository would be created
and then immediately be re-created.

Not only was this unnecessary, but HSQLDBDatabaseUpdates would attempt to export the node-local
data twice, which would cause an error due to existing .script files.

The fix is three-pronged:

1. Don't immediately rebuild the repository if it's only just been built
2. Don't export the empty node-local data if repository has only just been built
3. Don't export the node-local data if it's empty

WindowsInstaller/Qortal.aip

@@ -19,10 +19,10 @@
     <ROW Property="Manufacturer" Value="Qortal"/>
     <ROW Property="MsiLogging" MultiBuildValue="DefaultBuild:vp"/>
     <ROW Property="NTP_GOOD" Value="false"/>
-    <ROW Property="ProductCode" Value="1033:{31E3EA92-5348-4D5E-BF92-403470774E62} 2052:{FD291A77-AFE6-4511-BF5C-643D2173F4E5} 2057:{AC09453B-3F19-49E9-984D-BF167F2E29B9} " Type="16"/>
+    <ROW Property="ProductCode" Value="1033:{3F23DC7A-BC0B-4598-9FD4-C4B927A10D7F} 1049:{CF0D5DDC-7CB7-4308-8F98-DF8D2DB2D38D} 2052:{983B77E5-62CF-431C-B015-B96C5DCA6858} 2057:{BF1C757A-A3A0-4285-906A-6D8D91D74D0A} " Type="16"/>
     <ROW Property="ProductLanguage" Value="2057"/>
     <ROW Property="ProductName" Value="Qortal"/>
-    <ROW Property="ProductVersion" Value="1.2.2" Type="32"/>
+    <ROW Property="ProductVersion" Value="1.3.5" Type="32"/>
     <ROW Property="RECONFIG_NTP" Value="true"/>
     <ROW Property="REMOVE_BLOCKCHAIN" Value="YES" Type="4"/>
     <ROW Property="REPAIR_BLOCKCHAIN" Value="YES" Type="4"/>
@@ -174,7 +174,7 @@
     <ROW Component="ADDITIONAL_LICENSE_INFO_97" ComponentId="{D5544706-E2A7-424F-AEA5-3963E355AA29}" Directory_="jdk.crypto.mscapi_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_97" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_98" ComponentId="{104DBCE8-A458-4B3E-9EFA-2D8613561619}" Directory_="jdk.dynalink_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_98" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_99" ComponentId="{D02E3C37-E81A-48FA-9E28-B26B728AECD9}" Directory_="jdk.httpserver_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_99" Type="0"/>
-    <ROW Component="AI_CustomARPName" ComponentId="{761A8B87-CEA8-4F5D-82CC-552C48C9EC14}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
+    <ROW Component="AI_CustomARPName" ComponentId="{5FCFB67B-FDD0-4B15-9A58-2188092589E9}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
     <ROW Component="AI_ExePath" ComponentId="{3644948D-AE0B-41BB-9FAF-A79E70490A08}" Directory_="APPDIR" Attributes="260" KeyPath="AI_ExePath"/>
     <ROW Component="APPDIR" ComponentId="{680DFDDE-3FB4-47A5-8FF5-934F576C6F91}" Directory_="APPDIR" Attributes="0"/>
     <ROW Component="DATA_PATH" ComponentId="{EE0B6107-E244-4CDB-B195-E9038D2F1E0E}" Directory_="DATA_PATH" Attributes="0"/>
@@ -648,7 +648,7 @@
     <ROW BootstrOptKey="GlobalOptions" DownloadFolder="[AppDataFolder][|Manufacturer]\[|ProductName]\prerequisites" Options="2"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.BuildComponent">
-    <ROW BuildKey="DefaultBuild" BuildName="DefaultBuild" BuildOrder="1" BuildType="1" Languages="en_GB;zh;en" LangOpt="1" InstallationType="2" CabsLocation="1" UseLzma="true" LzmaMethod="2" LzmaCompressionLevel="4" PackageType="1" FilesInsideExe="true" ExeIconPath="qortal.ico" ExtractionFolder="[AppDataFolder][|Manufacturer]-extract\[|ProductName] [|ProductVersion]\install" LangsDialog="true" UseLargeSchema="true" Unicode="true" ExeName="[|ProductName]-[|ProductVersion]" MsiPackageType="x64" JRE64Dir="jre64_Dir"/>
+    <ROW BuildKey="DefaultBuild" BuildName="DefaultBuild" BuildOrder="1" BuildType="1" Languages="en_GB;zh;en;ru" LangOpt="1" InstallationType="2" CabsLocation="1" UseLzma="true" LzmaMethod="2" LzmaCompressionLevel="4" PackageType="1" FilesInsideExe="true" ExeIconPath="qortal.ico" ExtractionFolder="[AppDataFolder][|Manufacturer]-extract\[|ProductName] [|ProductVersion]\install" LangsDialog="true" UseLargeSchema="true" Unicode="true" ExeName="[|ProductName]-[|ProductVersion]" MsiPackageType="x64" JRE64Dir="jre64_Dir"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.DictionaryComponent">
     <ROW Path="&lt;AI_DICTS&gt;ui.ail"/>
@@ -656,6 +656,7 @@
     <ROW Path="&lt;AI_DICTS&gt;ui_en.ail"/>
     <ROW Path="&lt;AI_DICTS&gt;ui_zh.ail"/>
     <ROW Path="dictionary.ail" Options="1"/>
+    <ROW Path="&lt;AI_DICTS&gt;ui_ru.ail"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.FirewallExceptionComponent">
     <ROW FirewallException="EXE" DisplayName="[ProductName]" Enabled="1" Scope="*" Condition="((?Qortal.exe=2) AND ($Qortal.exe=3))" Profiles="0" AppPath="[#Qortal.exe]" Port="*" Protocol="ANY"/>
@@ -1128,11 +1129,14 @@
     <ROW IniFile="ApplicationType" FileName="Qortal.ini" DirProperty="APPDIR" Section="Application" Key="Application Type" Value="gui" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="ClassPath" FileName="Qortal.ini" DirProperty="APPDIR" Section="Class Path" Key="Class Path" Value="[#qortal.jar];" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="FailureCheck" FileName="Qortal.ini" DirProperty="APPDIR" Section="Application" Key="Failure Check" Value="yes" Action="0" Component_="Qortal.exe"/>
+    <ROW IniFile="JVMSource" FileName="Qortal.ini" DirProperty="APPDIR" Section="Java Runtime Environment" Key="JVM Source" Value="favor_JDK" Action="0" Component_="Qortal.exe"/>
+    <ROW IniFile="JVMType" FileName="Qortal.ini" DirProperty="APPDIR" Section="Java Runtime Environment" Key="JVM Type" Value="favor_server" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="MainClass" FileName="Qortal.ini" DirProperty="APPDIR" Section="Java Runtime Environment" Key="Main Class" Value="org.qortal.controller.Controller" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="MaximumVersion" FileName="Qortal.ini" DirProperty="APPDIR" Section="Java Runtime Environment" Key="Maximum Version" Value="any" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="MinimumVersion" FileName="Qortal.ini" DirProperty="APPDIR" Section="Java Runtime Environment" Key="Minimum Version" Value="11" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="OverrideWorkingDir" FileName="Qortal.ini" DirProperty="APPDIR" Section="Application" Key="Override WorkingDir" Value="yes" Action="0" Component_="Qortal.exe"/>
     <ROW IniFile="SingleInstance" FileName="Qortal.ini" DirProperty="APPDIR" Section="Application" Key="Single Instance" Value="yes" Action="0" Component_="Qortal.exe"/>
+    <ROW IniFile="VMProvider" FileName="Qortal.ini" DirProperty="APPDIR" Section="Java Runtime Environment" Key="VM Provider" Value="any" Action="0" Component_="Qortal.exe"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.MsiInstExSeqComponent">
     <ROW Action="AI_DOWNGRADE" Condition="AI_NEWERPRODUCTFOUND AND (UILevel &lt;&gt; 5)" Sequence="210"/>
@@ -1189,7 +1193,7 @@
     <ROW Action="Set_DATA_PATH_property" Condition="( NOT Installed )" Sequence="77"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.MsiJavaComponent">
-    <ROW Name="Qortal.exe" Launcher="Qortal.exe" MainClass="MainClass" ClassPath="ClassPath" JREMin="MinimumVersion" JREMax="MaximumVersion" IconPath="qortal.ico" AppType="ApplicationType" SingleInstance="SingleInstance" PlusList="APPDIR;" MinusList="#Qortal.exe;" MacDescription="[|CurrentJavaProductName] [|ProductVersion] © [|Manufacturer], Inc, 2019" MacBundleId="com.[|Manufacturer].[|ProductName].[|CurrentJavaProductName]" FailureCheck="FailureCheck" OverrideWkDir="OverrideWorkingDir" UACExecutionLevel="0" Platform64="true"/>
+    <ROW Name="Qortal.exe" Launcher="Qortal.exe" MainClass="MainClass" ClassPath="ClassPath" JREMin="MinimumVersion" JREMax="MaximumVersion" IconPath="qortal.ico" AppType="ApplicationType" JVMType="JVMType" SingleInstance="SingleInstance" PlusList="APPDIR;" MinusList="#Qortal.exe;" MacDescription="[|CurrentJavaProductName] [|ProductVersion] © [|Manufacturer], Inc, 2019" MacBundleId="com.[|Manufacturer].[|ProductName].[|CurrentJavaProductName]" JVMSourcePreference="JVMSource" FailureCheck="FailureCheck" OverrideWkDir="OverrideWorkingDir" UACExecutionLevel="0" VMProviderOptions="VMProvider" Platform64="true"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.MsiLaunchConditionsComponent">
     <ROW Condition="( Version9X OR VersionNT64 )" Description="[ProductName] can not be installed on [WindowsTypeNTDisplay]." DescriptionLocId="AI.LaunchCondition.NoNT" IsPredefined="true" Builds="DefaultBuild"/>

WindowsInstaller/dictionary.ail

@@ -3,95 +3,115 @@
   <!-- Control table -->
   <ENTRY id="Control.Text.CustomizeDataPathDlg#Description">
     <STRING lang="en" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
+	<STRING lang="ru" value="Вы можете выбрать место хранения блокчейна и других данных."/>
     <STRING lang="zh" value="你想把区块链数据存放在一个特定的文件夹吗？"/>
     <STRING lang="zh_TW" value="你想把区块链数据存放在一个特定的文件夹吗？"/>
   </ENTRY>
   <ENTRY id="Control.Text.CustomizeDataPathDlg#Text">
     <STRING lang="en" value="Select one of the options below, then click &quot;Next&quot;."/>
+	<STRING lang="ru" value="Выберите один из вариантов ниже, затем нажмите Далее"/>
     <STRING lang="zh" value="请选择，然后“下一步”"/>
     <STRING lang="zh_TW" value="请选择，然后“下一步”"/>
   </ENTRY>
   <ENTRY id="Control.Text.CustomizeDataPathDlg#Title">
     <STRING lang="en" value="Choose Custom Data Storage Folder?"/>
+	<STRING lang="ru" value="Выберите место хранения данных."/>
     <STRING lang="zh" value="选择数据保存的文件夹?"/>
     <STRING lang="zh_TW" value="选择数据保存的文件夹?"/>
   </ENTRY>
   <ENTRY id="Control.Text.CustomizeDbDlg#Description">
     <STRING lang="en" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
+	<STRING lang="ru" value="Вы можете выбрать место хранения блокчейна и других данных."/>
     <STRING lang="zh" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
     <STRING lang="zh_TW" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
   </ENTRY>
   <ENTRY id="Control.Text.CustomizeDbDlg#Title">
     <STRING lang="en" value="Choose Custom Data Storage Folder?"/>
+	<STRING lang="ru" value="Выберите место хранения данных."/>
     <STRING lang="zh" value="Choose Custom Data Storage Folder?"/>
     <STRING lang="zh_TW" value="Choose Custom Data Storage Folder?"/>
   </ENTRY>
   <ENTRY id="Control.Text.DataFolderDlg#Description">
     <STRING lang="en" value="This is the folder where the blockchain, and other data, will be stored."/>
+	<STRING lang="ru" value="Это папка, в которой будет храниться блокчейн и другие данные."/>
     <STRING lang="zh" value="这里是区块链及其它数据存放的文件夹"/>
     <STRING lang="zh_TW" value="这里是区块链及其它数据存放的文件夹"/>
   </ENTRY>
   <ENTRY id="Control.Text.DataFolderDlg#Text">
     <STRING lang="en" value="To store data in this folder, click &quot;[Text_Next]&quot;. To store data in a different folder, enter it below or click &quot;Browse&quot;."/>
+	<STRING lang="ru" value="Чтобы сохранить данные в этой папке, нажмите &quot;[Text_Next]&quot;. Чтобы сохранить данные в другой папке, введите ее ниже или нажмите &quot;Обзор&quot;."/>
     <STRING lang="zh" value="如果存放在这个文件夹，点 “下一步”。如果存放在其它位置，请选择“浏览”。"/>
     <STRING lang="zh_TW" value="如果存放在这个文件夹，点 “下一步”。如果存放在其它位置，请选择“浏览”。"/>
   </ENTRY>
   <ENTRY id="Control.Text.DataFolderDlg#Title">
     <STRING lang="en" value="Select Data Storage Folder"/>
+	<STRING lang="ru" value="Выберите папку для хранения данных"/>
     <STRING lang="zh" value="请选择文件存储地方"/>
     <STRING lang="zh_TW" value="请选择文件存储地方"/>
   </ENTRY>
   <ENTRY id="Control.Text.DbFolderDlg#Description">
     <STRING lang="en" value="This is the folder where the blockchain, and other data, will be stored."/>
+	<STRING lang="ru" value="Это папка, в которой будет храниться блокчейн и другие данные."/>
     <STRING lang="zh" value="This is the folder where the blockchain, and other data, will be stored."/>
     <STRING lang="zh_TW" value="This is the folder where the blockchain, and other data, will be stored."/>
   </ENTRY>
   <ENTRY id="Control.Text.DbFolderDlg#Title">
     <STRING lang="en" value="Select Data Storage Folder"/>
+	<STRING lang="ru" value="Выберите папку для хранения данных"/>
     <STRING lang="zh" value="请选择文件存储地方"/>
     <STRING lang="zh_TW" value="请选择文件存储地方"/>
   </ENTRY>
   <ENTRY id="Control.Text.NTPDialog#Description">
     <STRING lang="en" value="Reconfigure Windows for more accurate time?"/>
+	<STRING lang="ru" value="Настроить синхронизацию времени системы Windows?"/>
     <STRING lang="zh" value="重新配置Windows以获得更准确的时间？"/>
   </ENTRY>
   <ENTRY id="Control.Text.NTPDialog#Text_1">
     <STRING lang="en" value="An accurate Windows clock is required to connect to the [ProductName] network and make transactions."/>
+	<STRING lang="ru" value="Для подключения к сети Qortal и совершения транзакций требуется точная настройка времени Windows"/>
     <STRING lang="zh" value="需要准确的Windows时钟才能连接到[ProductName]网络并进行交易。"/>
   </ENTRY>
   <ENTRY id="Control.Text.NTPDialog#Text_2">
     <STRING lang="en" value="Select one of the options below, then click &quot;Next&quot;."/>
+	<STRING lang="ru" value="Выберите один из вариантов ниже, затем нажмите"/>
     <STRING lang="zh" value="请选择，然后“下一步”"/>
   </ENTRY>
   <ENTRY id="Control.Text.NTPDialog#Text_3">
     <STRING lang="en" value="Your computer&apos;s clock needs to be accurate to within 0.5 seconds."/>
+	<STRING lang="ru" value="Точность времени вашего компьютера должна составлять 0.5 секунд."/>
     <STRING lang="zh" value="您的计算机时钟需要准确到0.5秒内。"/>
   </ENTRY>
   <ENTRY id="Control.Text.NTPDialog#Title">
     <STRING lang="en" value="Windows clock accuracy"/>
+	<STRING lang="ru" value="Настройка времени системы Windows"/>
     <STRING lang="zh" value="Windows 时钟精度"/>
   </ENTRY>
   <ENTRY id="Control.Text.VerifyRemoveDlg#RemoveBlockchainCheckbox">
     <STRING lang="en" value="Remove downloaded blockchain and other data"/>
+	<STRING lang="ru" value="Удалить загруженный блокчейн и другие данные"/>
     <STRING lang="zh" value="删除您下载的区块链"/>
   </ENTRY>
   <!-- RadioButton table -->
   <ENTRY id="RadioButton.Text.CUSTOM_DB_BOOL#choose">
     <STRING lang="en" value="Choose custom data storage folder..."/>
+	<STRING lang="ru" value="Выбрать папку для хранения данных..."/>
     <STRING lang="zh" value="选择特定的文件夹存储"/>
     <STRING lang="zh_TW" value="选择特定的文件夹存储"/>
   </ENTRY>
   <ENTRY id="RadioButton.Text.CUSTOM_DB_BOOL#default">
     <STRING lang="en" value="Use default location "/>
+	<STRING lang="ru" value="Использовать папку по умолчанию"/>
     <STRING lang="zh" value="使用默认存储地点"/>
     <STRING lang="zh_TW" value="使用默认存储地点"/>
   </ENTRY>
   <ENTRY id="RadioButton.Text.RECONFIG_NTP#1">
     <STRING lang="en" value="Yes, configure Windows to use internet time servers (Recommended)"/>
+	<STRING lang="ru" value="Да, настроить синхронизацию времени Windows (Рекомендуется)"/>
     <STRING lang="zh" value="是，将Windows配置为使用多个Internet时间服务器 (推荐的)"/>
   </ENTRY>
   <ENTRY id="RadioButton.Text.RECONFIG_NTP#2">
     <STRING lang="en" value="No, I will manage clock accuracy myself"/>
+	<STRING lang="ru" value="Нет, я сам буду управлять настройками часов"/>
     <STRING lang="zh" value="不，我会自己管理时钟精度。"/>
   </ENTRY>
 </DICTIONARY>

lib/org/ciyam/AT/1.3.8/AT-1.3.8.pom

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.ciyam</groupId>
+  <artifactId>AT</artifactId>
+  <version>1.3.8</version>
+  <description>POM was created from install:install-file</description>
+</project>

lib/org/ciyam/AT/maven-metadata-local.xml

@@ -3,13 +3,14 @@
   <groupId>org.ciyam</groupId>
   <artifactId>AT</artifactId>
   <versioning>
-    <release>1.3.7</release>
+    <release>1.3.8</release>
     <versions>
       <version>1.3.4</version>
       <version>1.3.5</version>
       <version>1.3.6</version>
       <version>1.3.7</version>
+      <version>1.3.8</version>
     </versions>
-    <lastUpdated>20200812131412</lastUpdated>
+    <lastUpdated>20200925114415</lastUpdated>
   </versioning>
 </metadata>

pom.xml

@@ -3,19 +3,18 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.qortal</groupId>
 	<artifactId>qortal</artifactId>
-	<version>1.3.3</version>
+	<version>1.3.7</version>
 	<packaging>jar</packaging>
 	<properties>
 		<bitcoinj.version>0.15.5</bitcoinj.version>
 		<bouncycastle.version>1.64</bouncycastle.version>
 		<build.timestamp>${maven.build.timestamp}</build.timestamp>
-		<ciyam-at.version>1.3.7</ciyam-at.version>
+		<ciyam-at.version>1.3.8</ciyam-at.version>
 		<commons-net.version>3.6</commons-net.version>
 		<commons-text.version>1.8</commons-text.version>
 		<dagger.version>1.2.2</dagger.version>
 		<guava.version>28.1-jre</guava.version>
-		<hsqldb.version>2.5.0-fixed</hsqldb.version>
-		<hsqldb-sqltool.version>2.5.0</hsqldb-sqltool.version>
+		<hsqldb.version>2.5.1</hsqldb.version>
 		<jersey.version>2.29.1</jersey.version>
 		<jetty.version>9.4.29.v20200521</jetty.version>
 		<log4j.version>2.12.1</log4j.version>
@@ -397,12 +396,6 @@
 			<artifactId>hsqldb</artifactId>
 			<version>${hsqldb.version}</version>
 		</dependency>
-		<dependency>
-			<groupId>org.hsqldb</groupId>
-			<artifactId>sqltool</artifactId>
-			<version>${hsqldb-sqltool.version}</version>
-			<scope>test</scope>
-		</dependency>
 		<!-- CIYAM AT (automated transactions) -->
 		<dependency>
 			<groupId>org.ciyam</groupId>

run.sh

@@ -1,51 +0,0 @@
-#!/bin/sh
-
-# There's no need to run as root, so don't allow it, for security reasons
-if [ "$USER" = "root" ]; then
-	echo "Please su to non-root user before running"
-	exit
-fi
-
-# Validate Java is installed and the minimum version is available
-MIN_JAVA_VER='11'
-
-if command -v java > /dev/null 2>&1; then
-    version=$(java -version 2>&1 | awk -F '"' '/version/ {print $2}')
-    version=$(echo $version | cut -d'.' -f1,2)
-    if [ `echo "${version}>=${MIN_JAVA_VER}" | bc` -eq 1 ]; then
-        echo 'Passed Java version check'
-    else
-        echo 'Please upgrade your Java to version 11 or greater'
-        exit 1
-    fi
-else
-  echo 'Java is not available, please install Java 11 or greater'
-  exit 1
-fi
-
-# No qortal.jar but we have a Maven built one?
-# Be helpful and copy across to correct location
-if [ ! -e qortal.jar -a -f target/qortal*.jar ]; then
-	echo "Copying Maven-built Qortal JAR to correct pathname"
-	cp target/qortal*.jar qortal.jar
-fi
-
-# Limits Java JVM stack size and maximum heap usage.
-# Comment out for bigger systems, e.g. non-routers
-# or when API documentation is enabled
-# JVM_MEMORY_ARGS="-Xss256k -Xmx128m"
-
-# Although java.net.preferIPv4Stack is supposed to be false
-# by default in Java 11, on some platforms (e.g. FreeBSD 12),
-# it is overriden to be true by default. Hence we explicitly
-# set it to true to obtain desired behaviour.
-nohup nice -n 20 java \
-	-Djava.net.preferIPv4Stack=false \
-	-XX:NativeMemoryTracking=summary \
-	${JVM_MEMORY_ARGS} \
-	-jar qortal.jar \
-	1>run.log 2>&1 &
-
-# Save backgrounded process's PID
-echo $! > run.pid
-echo qortal running as pid $!

run.sh

@@ -0,0 +1 @@
+start.sh

src/main/java/org/qortal/RepositoryMaintenance.java

@@ -0,0 +1,75 @@
+package org.qortal;
+
+import java.security.Security;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
+import org.qortal.controller.Controller;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryFactory;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
+import org.qortal.settings.Settings;
+
+public class RepositoryMaintenance {
+
+	static {
+		// This must go before any calls to LogManager/Logger
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	private static final Logger LOGGER = LogManager.getLogger(RepositoryMaintenance.class);
+
+	public static void main(String[] args) {
+		LOGGER.info("Repository maintenance starting up...");
+
+		Security.insertProviderAt(new BouncyCastleProvider(), 0);
+		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
+
+		// Load/check settings, which potentially sets up blockchain config, etc.
+		try {
+			if (args.length > 0)
+				Settings.fileInstance(args[0]);
+			else
+				Settings.getInstance();
+		} catch (Throwable t) {
+			LOGGER.error("Settings file error: " + t.getMessage());
+			System.exit(2);
+		}
+
+		LOGGER.info("Opening repository");
+		try {
+			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
+			RepositoryManager.setRepositoryFactory(repositoryFactory);
+		} catch (DataException e) {
+			// If exception has no cause then repository is in use by some other process.
+			if (e.getCause() == null) {
+				LOGGER.info("Repository in use by another process?");
+			} else {
+				LOGGER.error("Unable to start repository", e);
+			}
+
+			System.exit(1);
+		}
+
+		LOGGER.info("Starting repository periodic maintenance. This can take a while...");
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			repository.performPeriodicMaintenance();
+
+			LOGGER.info("Repository periodic maintenance completed");
+		} catch (DataException e) {
+			LOGGER.error("Repository periodic maintenance failed", e);
+		}
+
+		try {
+			LOGGER.info("Shutting down repository");
+			RepositoryManager.closeRepositoryFactory();
+		} catch (DataException e) {
+			LOGGER.error("Error occurred while shutting down repository", e);
+		}
+	}
+
+}

src/main/java/org/qortal/api/Security.java

@@ -5,10 +5,20 @@ import java.net.UnknownHostException;
 
 import javax.servlet.http.HttpServletRequest;
 
-public class Security {
+import org.qortal.settings.Settings;
+
+public abstract class Security {
+
+	public static final String API_KEY_HEADER = "X-API-KEY";
 
-	// TODO: replace with proper authentication
 	public static void checkApiCallAllowed(HttpServletRequest request) {
+		String expectedApiKey = Settings.getInstance().getApiKey();
+		String passedApiKey = request.getHeader(API_KEY_HEADER);
+
+		if ((expectedApiKey != null && !expectedApiKey.equals(passedApiKey)) ||
+				(passedApiKey != null && !passedApiKey.equals(expectedApiKey)))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.UNAUTHORIZED);
+
 		InetAddress remoteAddr;
 		try {
 			remoteAddr = InetAddress.getByName(request.getRemoteAddr());
@@ -19,4 +29,5 @@ public class Security {
 		if (!remoteAddr.isLoopbackAddress())
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.UNAUTHORIZED);
 	}
+
 }

src/main/java/org/qortal/api/model/ActivitySummary.java

@@ -1,5 +1,6 @@
 package org.qortal.api.model;
 
+import java.util.Collections;
 import java.util.EnumMap;
 import java.util.Map;
 
@@ -13,17 +14,61 @@ import org.qortal.transaction.Transaction.TransactionType;
 @XmlAccessorType(XmlAccessType.FIELD)
 public class ActivitySummary {
 
-	public int blockCount;
-	public int transactionCount;
-	public int assetsIssued;
-	public int namesRegistered;
+	private int blockCount;
+	private int assetsIssued;
+	private int namesRegistered;
 
 	// Assuming TransactionType values are contiguous so 'length' equals count
 	@XmlJavaTypeAdapter(TransactionCountMapXmlAdapter.class)
-	public Map<TransactionType, Integer> transactionCountByType = new EnumMap<>(TransactionType.class);
+	private Map<TransactionType, Integer> transactionCountByType = new EnumMap<>(TransactionType.class);
+	private int totalTransactionCount = 0;
 
 	public ActivitySummary() {
 		// Needed for JAXB
 	}
 
+	public int getBlockCount() {
+		return this.blockCount;
+	}
+
+	public void setBlockCount(int blockCount) {
+		this.blockCount = blockCount;
+	}
+
+	public int getTotalTransactionCount() {
+		return this.totalTransactionCount;
+	}
+
+	public int getAssetsIssued() {
+		return this.assetsIssued;
+	}
+
+	public void setAssetsIssued(int assetsIssued) {
+		this.assetsIssued = assetsIssued;
+	}
+
+	public int getNamesRegistered() {
+		return this.namesRegistered;
+	}
+
+	public void setNamesRegistered(int namesRegistered) {
+		this.namesRegistered = namesRegistered;
+	}
+
+	public Map<TransactionType, Integer> getTransactionCountByType() {
+		return Collections.unmodifiableMap(this.transactionCountByType);
+	}
+
+	public void setTransactionCountByType(TransactionType transactionType, int transactionCount) {
+		this.transactionCountByType.put(transactionType, transactionCount);
+
+		this.totalTransactionCount = this.transactionCountByType.values().stream().mapToInt(Integer::intValue).sum();
+	}
+
+	public void setTransactionCountByType(Map<TransactionType, Integer> transactionCountByType) {
+		this.transactionCountByType = new EnumMap<>(transactionCountByType);
+
+		this.totalTransactionCount = this.transactionCountByType.values().stream().mapToInt(Integer::intValue).sum();
+	}
+
 }

src/main/java/org/qortal/api/model/CrossChainBitcoinRefundRequest.java

@@ -22,6 +22,9 @@ public class CrossChainBitcoinRefundRequest {
 	@Schema(description = "Bitcoin miner fee", example = "0.00001000")
 	public BigDecimal bitcoinMinerFee;
 
+	@Schema(description = "Bitcoin HASH160(public key) for receiving funds, or omit to derive from private key", example = "u17kBVKkKSp12oUzaxFwNnq1JZf")
+	public byte[] receivingAccountInfo;
+
 	public CrossChainBitcoinRefundRequest() {
 	}
 

src/main/java/org/qortal/api/model/CrossChainOfferSummary.java

@@ -83,4 +83,10 @@ public class CrossChainOfferSummary {
 		return this.partnerQortalReceivingAddress;
 	}
 
+	// For debugging mostly
+
+	public String toString() {
+		return String.format("%s: %s", this.qortalAtAddress, this.mode.name());
+	}
+
 }

src/main/java/org/qortal/api/model/NodeInfo.java

@@ -11,6 +11,7 @@ public class NodeInfo {
 	public String buildVersion;
 	public long buildTimestamp;
 	public String nodeId;
+	public boolean isTestNet;
 
 	public NodeInfo() {
 	}

src/main/java/org/qortal/api/model/NodeStatus.java

@@ -20,17 +20,14 @@ public class NodeStatus {
 	public final int height;
 
 	public NodeStatus() {
-		isMintingPossible = Controller.getInstance().isMintingPossible();
-		isSynchronizing = Controller.getInstance().isSynchronizing();
+		this.isMintingPossible = Controller.getInstance().isMintingPossible();
 
-		if (isSynchronizing)
-			syncPercent = Controller.getInstance().getSyncPercent();
-		else
-			syncPercent = null;
+		this.syncPercent = Controller.getInstance().getSyncPercent();
+		this.isSynchronizing = this.syncPercent != null;
 
-		numberOfConnections = Network.getInstance().getHandshakedPeers().size();
+		this.numberOfConnections = Network.getInstance().getHandshakedPeers().size();
 
-		height = Controller.getInstance().getChainHeight();
+		this.height = Controller.getInstance().getChainHeight();
 	}
 
 }

src/main/java/org/qortal/api/model/TradeBotRespondRequest.java

@@ -8,13 +8,13 @@ import io.swagger.v3.oas.annotations.media.Schema;
 @XmlAccessorType(XmlAccessType.FIELD)
 public class TradeBotRespondRequest {
 
-	@Schema(description = "Qortal AT address", example = "AH3e3jHEsGHPVQPDiJx4pYqgVi72auxgVy")
+	@Schema(description = "Qortal AT address", example = "Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
 	public String atAddress;
 
-	@Schema(description = "Bitcoin BIP32 extended private key", example = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TbTVGajEB55L1HYLg2aQMecZLXLre5YJcawpdFG66STVAWPJ")
+	@Schema(description = "Bitcoin BIP32 extended private key", example = "xprv___________________________________________________________________________________________________________")
 	public String xprv58;
 
-	@Schema(description = "Qortal address for receiving QORT from AT")
+	@Schema(description = "Qortal address for receiving QORT from AT", example = "Qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq")
 	public String receivingAddress;
 
 	public TradeBotRespondRequest() {

src/main/java/org/qortal/api/resource/AddressesResource.java

@@ -7,6 +7,7 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.parameters.RequestBody;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.math.BigDecimal;
@@ -473,6 +474,7 @@ public class AddressesResource {
 		}
 	)
 	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.INVALID_DATA, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String computePublicize(String rawBytes58) {
 		Security.checkApiCallAllowed(request);
 

src/main/java/org/qortal/api/resource/AdminResource.java

@@ -8,6 +8,7 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.parameters.RequestBody;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.io.IOException;
@@ -40,7 +41,6 @@ import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
 import org.qortal.api.ApiError;
 import org.qortal.api.ApiErrors;
-import org.qortal.api.ApiException;
 import org.qortal.api.ApiExceptionFactory;
 import org.qortal.api.Security;
 import org.qortal.api.model.ActivitySummary;
@@ -57,6 +57,7 @@ import org.qortal.network.PeerAddress;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
 import org.qortal.utils.Base58;
 import org.qortal.utils.NTP;
 
@@ -118,6 +119,7 @@ public class AdminResource {
 		nodeInfo.buildVersion = Controller.getInstance().getVersionString();
 		nodeInfo.buildTimestamp = Controller.getInstance().getBuildTimestamp();
 		nodeInfo.nodeId = Network.getInstance().getOurNodeId();
+		nodeInfo.isTestNet = Settings.getInstance().isTestNet();
 
 		return nodeInfo;
 	}
@@ -132,6 +134,7 @@ public class AdminResource {
 			)
 		}
 	)
+	@SecurityRequirement(name = "apiKey")
 	public NodeStatus status() {
 		Security.checkApiCallAllowed(request);
 
@@ -152,6 +155,7 @@ public class AdminResource {
 			)
 		}
 	)
+	@SecurityRequirement(name = "apiKey")
 	public String shutdown() {
 		Security.checkApiCallAllowed(request);
 
@@ -180,7 +184,10 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public ActivitySummary summary() {
+		Security.checkApiCallAllowed(request);
+
 		ActivitySummary summary = new ActivitySummary();
 
 		LocalDate date = LocalDate.now();
@@ -192,16 +199,13 @@ public class AdminResource {
 			int startHeight = repository.getBlockRepository().getHeightFromTimestamp(start);
 			int endHeight = repository.getBlockRepository().getBlockchainHeight();
 
-			summary.blockCount = endHeight - startHeight;
+			summary.setBlockCount(endHeight - startHeight);
 
-			summary.transactionCountByType = repository.getTransactionRepository().getTransactionSummary(startHeight + 1, endHeight);
+			summary.setTransactionCountByType(repository.getTransactionRepository().getTransactionSummary(startHeight + 1, endHeight));
 
-			for (Integer count : summary.transactionCountByType.values())
-				summary.transactionCount += count;
+			summary.setAssetsIssued(repository.getAssetRepository().getRecentAssetIds(start).size());
 
-			summary.assetsIssued = repository.getAssetRepository().getRecentAssetIds(start).size();
-
-			summary.namesRegistered = repository.getNameRepository().getRecentNames(start).size();
+			summary.setNamesRegistered (repository.getNameRepository().getRecentNames(start).size());
 
 			return summary;
 		} catch (DataException e) {
@@ -209,6 +213,30 @@ public class AdminResource {
 		}
 	}
 
+	@GET
+	@Path("/enginestats")
+	@Operation(
+		summary = "Fetch statistics snapshot for core engine",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					mediaType = MediaType.APPLICATION_JSON,
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = Controller.StatsSnapshot.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@SecurityRequirement(name = "apiKey")
+	public Controller.StatsSnapshot getEngineStats() {
+		Security.checkApiCallAllowed(request);
+
+		return Controller.getInstance().getStatsSnapshot();
+	}
+
 	@GET
 	@Path("/mintingaccounts")
 	@Operation(
@@ -221,6 +249,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public List<MintingAccountData> getMintingAccounts() {
 		Security.checkApiCallAllowed(request);
 
@@ -267,6 +296,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.REPOSITORY_ISSUE, ApiError.CANNOT_MINT})
+	@SecurityRequirement(name = "apiKey")
 	public String addMintingAccount(String seed58) {
 		Security.checkApiCallAllowed(request);
 
@@ -319,6 +349,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String deleteMintingAccount(String key58) {
 		Security.checkApiCallAllowed(request);
 
@@ -418,6 +449,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_HEIGHT, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String orphan(String targetHeightString) {
 		Security.checkApiCallAllowed(request);
 
@@ -435,8 +467,6 @@ public class AdminResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		} catch (NumberFormatException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_HEIGHT);
-		} catch (ApiException e) {
-			throw e;
 		}
 	}
 
@@ -461,6 +491,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_DATA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String forceSync(String targetPeerAddress) {
 		Security.checkApiCallAllowed(request);
 
@@ -492,8 +523,6 @@ public class AdminResource {
 			return syncResult.name();
 		} catch (IllegalArgumentException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-		} catch (ApiException e) {
-			throw e;
 		} catch (UnknownHostException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
 		} catch (InterruptedException e) {
@@ -501,4 +530,151 @@ public class AdminResource {
 		}
 	}
 
+	@GET
+	@Path("/repository/data")
+	@Operation(
+		summary = "Export sensitive/node-local data from repository.",
+		description = "Exports data to .script files on local machine"
+	)
+	@ApiErrors({ApiError.INVALID_DATA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String exportRepository() {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.exportNodeLocalData();
+				return "true";
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform export
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/repository/data")
+	@Operation(
+		summary = "Import data into repository.",
+		description = "Imports data from file on local machine. Filename is forced to 'import.script' if apiKey is not set.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string", example = "MintingAccounts.script"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "\"true\"",
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String importRepository(String filename) {
+		Security.checkApiCallAllowed(request);
+
+		// Hard-coded because it's too dangerous to allow user-supplied filenames in weaker security contexts
+		if (Settings.getInstance().getApiKey() == null)
+			filename = "import.script";
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.importDataFromFile(filename);
+				repository.saveChanges();
+
+				return "true";
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform import
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/repository/checkpoint")
+	@Operation(
+		summary = "Checkpoint data in repository.",
+		description = "Forces repository to checkpoint uncommitted writes.",
+		responses = {
+			@ApiResponse(
+				description = "\"true\"",
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String checkpointRepository() {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.checkpoint(true);
+				repository.saveChanges();
+
+				return "true";
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform checkpoint
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@DELETE
+	@Path("/repository")
+	@Operation(
+		summary = "Perform maintenance on repository.",
+		description = "Requires enough free space to rebuild repository. This will pause your node for a while."
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public void performRepositoryMaintenance() {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.performPeriodicMaintenance();
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// No big deal
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
 }

src/main/java/org/qortal/api/resource/ApiDefinition.java

@@ -1,11 +1,17 @@
 package org.qortal.api.resource;
 
 import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.annotations.enums.SecuritySchemeIn;
+import io.swagger.v3.oas.annotations.enums.SecuritySchemeType;
 import io.swagger.v3.oas.annotations.extensions.Extension;
 import io.swagger.v3.oas.annotations.extensions.ExtensionProperty;
 import io.swagger.v3.oas.annotations.info.Info;
+import io.swagger.v3.oas.annotations.security.SecurityScheme;
+import io.swagger.v3.oas.annotations.security.SecuritySchemes;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
+import org.qortal.api.Security;
+
 @OpenAPIDefinition(
 		info = @Info( title = "Qortal API", description = "NOTE: byte-arrays are encoded in Base58" ),
 		tags = {
@@ -30,5 +36,9 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 			})
 		}
 )
+@SecuritySchemes({
+	@SecurityScheme(name = "basicAuth", type = SecuritySchemeType.HTTP, scheme = "basic"),
+	@SecurityScheme(name = "apiKey", type = SecuritySchemeType.APIKEY, in = SecuritySchemeIn.HEADER, paramName = Security.API_KEY_HEADER)
+})
 public class ApiDefinition {
 }

src/main/java/org/qortal/api/resource/ChatResource.java

@@ -7,6 +7,7 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.parameters.RequestBody;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.util.List;
@@ -156,6 +157,7 @@ public class ChatResource {
 		}
 	)
 	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String buildChat(ChatTransactionData transactionData) {
 		Security.checkApiCallAllowed(request);
 
@@ -203,6 +205,7 @@ public class ChatResource {
 		}
 	)
 	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.INVALID_DATA, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String buildChat(String rawBytes58) {
 		Security.checkApiCallAllowed(request);
 

src/main/java/org/qortal/api/resource/CrossChainResource.java

@@ -7,6 +7,7 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.parameters.RequestBody;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.math.BigDecimal;
@@ -58,6 +59,7 @@ import org.qortal.controller.TradeBot;
 import org.qortal.crosschain.BTC;
 import org.qortal.crosschain.BTCACCT;
 import org.qortal.crosschain.BTCP2SH;
+import org.qortal.crosschain.BitcoinException;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.at.ATData;
 import org.qortal.data.at.ATStateData;
@@ -154,6 +156,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_DATA, ApiError.INVALID_REFERENCE, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String buildTrade(CrossChainBuildRequest tradeRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -249,6 +252,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String buildTradeMessage(CrossChainTradeRequest tradeRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -332,6 +336,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_DATA, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String buildRedeemMessage(CrossChainSecretRequest secretRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -403,6 +408,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String buildCancelMessage(CrossChainCancelRequest cancelRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -458,6 +464,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String deriveP2shA(CrossChainBitcoinTemplateRequest templateRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -484,6 +491,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String deriveP2shB(CrossChainBitcoinTemplateRequest templateRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -541,6 +549,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public CrossChainBitcoinP2SHStatus checkP2shA(CrossChainBitcoinTemplateRequest templateRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -567,6 +576,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public CrossChainBitcoinP2SHStatus checkP2shB(CrossChainBitcoinTemplateRequest templateRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -602,17 +612,12 @@ public class CrossChainResource {
 
 			Address p2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
 
-			Integer medianBlockTime = BTC.getInstance().getMedianBlockTime();
-			if (medianBlockTime == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
+			int medianBlockTime = BTC.getInstance().getMedianBlockTime();
 
 			long now = NTP.getTime();
 
 			// Check P2SH is funded
-
-			Long p2shBalance = BTC.getInstance().getBalance(p2shAddress.toString());
-			if (p2shBalance == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+			long p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
 
 			CrossChainBitcoinP2SHStatus p2shStatus = new CrossChainBitcoinP2SHStatus();
 			p2shStatus.bitcoinP2shAddress = p2shAddress.toString();
@@ -634,6 +639,8 @@ public class CrossChainResource {
 			return p2shStatus;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		} catch (BitcoinException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
 		}
 	}
 
@@ -658,6 +665,7 @@ public class CrossChainResource {
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN,
 		ApiError.BTC_TOO_SOON, ApiError.BTC_BALANCE_ISSUE, ApiError.BTC_NETWORK_ISSUE, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String refundP2shA(CrossChainBitcoinRefundRequest refundRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -685,6 +693,7 @@ public class CrossChainResource {
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN,
 		ApiError.BTC_TOO_SOON, ApiError.BTC_BALANCE_ISSUE, ApiError.BTC_NETWORK_ISSUE, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String refundP2shB(CrossChainBitcoinRefundRequest refundRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -719,6 +728,13 @@ public class CrossChainResource {
 		if (refundRequest.atAddress == null || !Crypto.isValidAtAddress(refundRequest.atAddress))
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
+		if (refundRequest.receivingAccountInfo == null)
+			refundRequest.receivingAccountInfo = refundKey.getPubKeyHash();
+
+		if (refundRequest.receivingAccountInfo.length != 20)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+
 		// Extract data from cross-chain trading AT
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			ATData atData = fetchAtDataWithChecking(repository, refundRequest.atAddress);
@@ -739,9 +755,7 @@ public class CrossChainResource {
 
 			// Check P2SH is funded
 
-			Long p2shBalance = BTC.getInstance().getBalance(p2shAddress.toString());
-			if (p2shBalance == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+			long p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
 
 			List<TransactionOutput> fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
 			if (fundingOutputs.isEmpty())
@@ -756,15 +770,15 @@ public class CrossChainResource {
 
 			Coin refundAmount = Coin.valueOf(p2shBalance - refundRequest.bitcoinMinerFee.unscaledValue().longValue());
 
-			org.bitcoinj.core.Transaction refundTransaction = BTCP2SH.buildRefundTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime);
-			boolean wasBroadcast = BTC.getInstance().broadcastTransaction(refundTransaction);
+			org.bitcoinj.core.Transaction refundTransaction = BTCP2SH.buildRefundTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundRequest.receivingAccountInfo);
+			BTC.getInstance().broadcastTransaction(refundTransaction);
 
-			if (!wasBroadcast)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
 
 			return refundTransaction.getTxId().toString();
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		} catch (BitcoinException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
 		}
 	}
 
@@ -790,6 +804,7 @@ public class CrossChainResource {
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN,
 		ApiError.BTC_TOO_SOON, ApiError.BTC_BALANCE_ISSUE, ApiError.BTC_NETWORK_ISSUE, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String redeemP2shA(CrossChainBitcoinRedeemRequest redeemRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -818,6 +833,7 @@ public class CrossChainResource {
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN,
 		ApiError.BTC_TOO_SOON, ApiError.BTC_BALANCE_ISSUE, ApiError.BTC_NETWORK_ISSUE, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String redeemP2shB(CrossChainBitcoinRedeemRequest redeemRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -877,16 +893,12 @@ public class CrossChainResource {
 
 			Address p2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
 
-			Integer medianBlockTime = BTC.getInstance().getMedianBlockTime();
-			if (medianBlockTime == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
+			int medianBlockTime = BTC.getInstance().getMedianBlockTime();
 
 			long now = NTP.getTime();
 
 			// Check P2SH is funded
-			Long p2shBalance = BTC.getInstance().getBalance(p2shAddress.toString());
-			if (p2shBalance == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+			long p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
 
 			if (p2shBalance < crossChainTradeData.expectedBitcoin)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_BALANCE_ISSUE);
@@ -902,14 +914,14 @@ public class CrossChainResource {
 			Coin redeemAmount = Coin.valueOf(p2shBalance - redeemRequest.bitcoinMinerFee.unscaledValue().longValue());
 
 			org.bitcoinj.core.Transaction redeemTransaction = BTCP2SH.buildRedeemTransaction(redeemAmount, redeemKey, fundingOutputs, redeemScriptBytes, redeemRequest.secret, redeemRequest.receivingAccountInfo);
-			boolean wasBroadcast = BTC.getInstance().broadcastTransaction(redeemTransaction);
 
-			if (!wasBroadcast)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
+			BTC.getInstance().broadcastTransaction(redeemTransaction);
 
 			return redeemTransaction.getTxId().toString();
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		} catch (BitcoinException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
 		}
 	}
 
@@ -936,6 +948,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PRIVATE_KEY})
+	@SecurityRequirement(name = "apiKey")
 	public String getBitcoinWalletBalance(String xprv58) {
 		Security.checkApiCallAllowed(request);
 
@@ -970,6 +983,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.BTC_BALANCE_ISSUE, ApiError.BTC_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String sendBitcoin(BitcoinSendRequest bitcoinSendRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -994,8 +1008,11 @@ public class CrossChainResource {
 		if (spendTransaction == null)
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_BALANCE_ISSUE);
 
-		if (!BTC.getInstance().broadcastTransaction(spendTransaction))
+		try {
+			BTC.getInstance().broadcastTransaction(spendTransaction);
+		} catch (BitcoinException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BTC_NETWORK_ISSUE);
+		}
 
 		return "true";
 	}
@@ -1017,6 +1034,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public List<TradeBotData> getTradeBotStates() {
 		Security.checkApiCallAllowed(request);
 
@@ -1047,6 +1065,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String tradeBotCreator(TradeBotCreateRequest tradeBotCreateRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -1102,6 +1121,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.BTC_BALANCE_ISSUE, ApiError.BTC_NETWORK_ISSUE, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String tradeBotResponder(TradeBotRespondRequest tradeBotRespondRequest) {
 		Security.checkApiCallAllowed(request);
 
@@ -1166,6 +1186,7 @@ public class CrossChainResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String tradeBotDelete(String tradePrivateKey58) {
 		Security.checkApiCallAllowed(request);
 

src/main/java/org/qortal/api/resource/PeersResource.java

@@ -6,8 +6,11 @@ import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.parameters.RequestBody;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
+import java.net.InetSocketAddress;
+import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -26,10 +29,17 @@ import org.qortal.api.ApiException;
 import org.qortal.api.ApiExceptionFactory;
 import org.qortal.api.Security;
 import org.qortal.api.model.ConnectedPeer;
+import org.qortal.controller.Controller;
+import org.qortal.controller.Synchronizer;
+import org.qortal.controller.Synchronizer.SynchronizationResult;
+import org.qortal.data.block.BlockSummaryData;
 import org.qortal.data.network.PeerData;
 import org.qortal.network.Network;
+import org.qortal.network.Peer;
 import org.qortal.network.PeerAddress;
 import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
 import org.qortal.utils.ExecuteProduceConsume;
 import org.qortal.utils.NTP;
 
@@ -122,6 +132,7 @@ public class PeersResource {
 			)
 		}
 	)
+	@SecurityRequirement(name = "apiKey")
 	public ExecuteProduceConsume.StatsSnapshot getEngineStats() {
 		Security.checkApiCallAllowed(request);
 
@@ -159,6 +170,7 @@ public class PeersResource {
 	@ApiErrors({
 		ApiError.INVALID_NETWORK_ADDRESS, ApiError.REPOSITORY_ISSUE
 	})
+	@SecurityRequirement(name = "apiKey")
 	public String addPeer(String address) {
 		Security.checkApiCallAllowed(request);
 
@@ -213,6 +225,7 @@ public class PeersResource {
 	@ApiErrors({
 		ApiError.INVALID_NETWORK_ADDRESS, ApiError.REPOSITORY_ISSUE
 	})
+	@SecurityRequirement(name = "apiKey")
 	public String removePeer(String address) {
 		Security.checkApiCallAllowed(request);
 
@@ -248,6 +261,7 @@ public class PeersResource {
 	@ApiErrors({
 		ApiError.REPOSITORY_ISSUE
 	})
+	@SecurityRequirement(name = "apiKey")
 	public String removeKnownPeers(String address) {
 		Security.checkApiCallAllowed(request);
 
@@ -260,4 +274,68 @@ public class PeersResource {
 		}
 	}
 
+	@POST
+	@Path("/commonblock")
+	@Operation(
+		summary = "Report common block with given peer.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string", example = "node2.qortal.org"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "the block",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = BlockSummaryData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_DATA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public List<BlockSummaryData> commonBlock(String targetPeerAddress) {
+		Security.checkApiCallAllowed(request);
+
+		try {
+			// Try to resolve passed address to make things easier
+			PeerAddress peerAddress = PeerAddress.fromString(targetPeerAddress);
+			InetSocketAddress resolvedAddress = peerAddress.toSocketAddress();
+
+			List<Peer> peers = Network.getInstance().getHandshakedPeers();
+			Peer targetPeer = peers.stream().filter(peer -> peer.getResolvedAddress().equals(resolvedAddress)).findFirst().orElse(null);
+
+			if (targetPeer == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int ourInitialHeight = Controller.getInstance().getChainHeight();
+				boolean force = true;
+				List<BlockSummaryData> peerBlockSummaries = new ArrayList<>();
+
+				SynchronizationResult findCommonBlockResult = Synchronizer.getInstance().fetchSummariesFromCommonBlock(repository, targetPeer, ourInitialHeight, force, peerBlockSummaries);
+				if (findCommonBlockResult != SynchronizationResult.OK)
+					return null;
+
+				return peerBlockSummaries;
+			}
+		} catch (IllegalArgumentException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+		} catch (UnknownHostException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		} catch (InterruptedException e) {
+			return null;
+		}
+	}
+
 }

src/main/java/org/qortal/api/websocket/ActiveChatsWebSocket.java

@@ -31,6 +31,7 @@ public class ActiveChatsWebSocket extends ApiWebSocket {
 	}
 
 	@OnWebSocketConnect
+	@Override
 	public void onWebSocketConnect(Session session) {
 		Map<String, String> pathParams = getPathParams(session, "/{address}");
 
@@ -49,16 +50,19 @@ public class ActiveChatsWebSocket extends ApiWebSocket {
 	}
 
 	@OnWebSocketClose
+	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
 		ChatNotifier.getInstance().deregister(session);
 	}
 
 	@OnWebSocketError
 	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
 	}
 
 	@OnWebSocketMessage
 	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
 	}
 
 	private void onNotify(Session session, ChatTransactionData chatTransactionData, String ourAddress, AtomicReference<String> previousOutput) {

src/main/java/org/qortal/api/websocket/AdminStatusWebSocket.java

@@ -13,59 +13,87 @@ import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
 import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
 import org.qortal.api.model.NodeStatus;
-import org.qortal.controller.StatusNotifier;
-import org.qortal.repository.DataException;
-import org.qortal.repository.Repository;
-import org.qortal.repository.RepositoryManager;
+import org.qortal.controller.Controller;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
 
 @WebSocket
 @SuppressWarnings("serial")
-public class AdminStatusWebSocket extends ApiWebSocket {
+public class AdminStatusWebSocket extends ApiWebSocket implements Listener {
+
+	private static final AtomicReference<String> previousOutput = new AtomicReference<>(null);
 
 	@Override
 	public void configure(WebSocketServletFactory factory) {
 		factory.register(AdminStatusWebSocket.class);
+
+		try {
+			previousOutput.set(buildStatusString());
+		} catch (IOException e) {
+			// How to fail properly?
+			return;
+		}
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.StatusChangeEvent))
+			return;
+
+		String newOutput;
+		try {
+			newOutput = buildStatusString();
+		} catch (IOException e) {
+			// Ignore this time?
+			return;
+		}
+
+		if (previousOutput.getAndUpdate(currentValue -> newOutput).equals(newOutput))
+			// Output hasn't changed, so don't send anything
+			return;
+
+		for (Session session : getSessions())
+			this.sendStatus(session, newOutput);
 	}
 
 	@OnWebSocketConnect
+	@Override
 	public void onWebSocketConnect(Session session) {
-		AtomicReference<String> previousOutput = new AtomicReference<>(null);
+		this.sendStatus(session, previousOutput.get());
 
-		StatusNotifier.Listener listener = timestamp -> onNotify(session, previousOutput);
-		StatusNotifier.getInstance().register(session, listener);
-
-		this.onNotify(session, previousOutput);
+		super.onWebSocketConnect(session);
 	}
 
 	@OnWebSocketClose
+	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
-		StatusNotifier.getInstance().deregister(session);
+		super.onWebSocketClose(session, statusCode, reason);
 	}
 
 	@OnWebSocketError
 	public void onWebSocketError(Session session, Throwable throwable) {
+		/* We ignore errors for now, but method here to silence log spam */
 	}
 
 	@OnWebSocketMessage
 	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
 	}
 
-	private void onNotify(Session session,AtomicReference<String> previousOutput) {
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			NodeStatus nodeStatus = new NodeStatus();
+	private static String buildStatusString() throws IOException {
+		NodeStatus nodeStatus = new NodeStatus();
+		StringWriter stringWriter = new StringWriter();
+		marshall(stringWriter, nodeStatus);
+		return stringWriter.toString();
+	}
 
-			StringWriter stringWriter = new StringWriter();
-
-			marshall(stringWriter, nodeStatus);
-
-			// Only output if something has changed
-			String output = stringWriter.toString();
-			if (output.equals(previousOutput.get()))
-				return;
-
-			previousOutput.set(output);
-			session.getRemote().sendStringByFuture(output);
-		} catch (DataException | IOException | WebSocketException e) {
+	private void sendStatus(Session session, String status) {
+		try {
+			session.getRemote().sendStringByFuture(status);
+		} catch (WebSocketException e) {
 			// No output this time?
 		}
 	}

src/main/java/org/qortal/api/websocket/BlocksWebSocket.java

@@ -14,7 +14,11 @@ import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
 import org.qortal.api.ApiError;
 import org.qortal.api.model.BlockInfo;
-import org.qortal.controller.BlockNotifier;
+import org.qortal.controller.Controller;
+import org.qortal.data.block.BlockData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
@@ -22,26 +26,42 @@ import org.qortal.utils.Base58;
 
 @WebSocket
 @SuppressWarnings("serial")
-public class BlocksWebSocket extends ApiWebSocket {
+public class BlocksWebSocket extends ApiWebSocket implements Listener {
 
 	@Override
 	public void configure(WebSocketServletFactory factory) {
 		factory.register(BlocksWebSocket.class);
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.NewBlockEvent))
+			return;
+
+		BlockData blockData = ((Controller.NewBlockEvent) event).getBlockData();
+		BlockInfo blockInfo = new BlockInfo(blockData);
+
+		for (Session session : getSessions())
+			sendBlockInfo(session, blockInfo);
 	}
 
 	@OnWebSocketConnect
+	@Override
 	public void onWebSocketConnect(Session session) {
-		BlockNotifier.Listener listener = blockInfo -> onNotify(session, blockInfo);
-		BlockNotifier.getInstance().register(session, listener);
+		super.onWebSocketConnect(session);
 	}
 
 	@OnWebSocketClose
+	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
-		BlockNotifier.getInstance().deregister(session);
+		super.onWebSocketClose(session, statusCode, reason);
 	}
 
 	@OnWebSocketError
 	public void onWebSocketError(Session session, Throwable throwable) {
+		/* We ignore errors for now, but method here to silence log spam */
 	}
 
 	@OnWebSocketMessage
@@ -71,7 +91,7 @@ public class BlocksWebSocket extends ApiWebSocket {
 					return;
 				}
 
-				onNotify(session, blockInfos.get(0));
+				sendBlockInfo(session, blockInfos.get(0));
 			} catch (DataException e) {
 				sendError(session, ApiError.REPOSITORY_ISSUE);
 			}
@@ -100,13 +120,13 @@ public class BlocksWebSocket extends ApiWebSocket {
 				return;
 			}
 
-			onNotify(session, blockInfos.get(0));
+			sendBlockInfo(session, blockInfos.get(0));
 		} catch (DataException e) {
 			sendError(session, ApiError.REPOSITORY_ISSUE);
 		}
 	}
 
-	private void onNotify(Session session, BlockInfo blockInfo) {
+	private void sendBlockInfo(Session session, BlockInfo blockInfo) {
 		StringWriter stringWriter = new StringWriter();
 
 		try {

src/main/java/org/qortal/api/websocket/ChatMessagesWebSocket.java

@@ -32,6 +32,7 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 	}
 
 	@OnWebSocketConnect
+	@Override
 	public void onWebSocketConnect(Session session) {
 		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
 
@@ -86,16 +87,19 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 	}
 
 	@OnWebSocketClose
+	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
 		ChatNotifier.getInstance().deregister(session);
 	}
 
 	@OnWebSocketError
 	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
 	}
 
 	@OnWebSocketMessage
 	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
 	}
 
 	private void onNotify(Session session, ChatTransactionData chatTransactionData, int txGroupId) {

src/main/java/org/qortal/api/websocket/TradeBotWebSocket.java

@@ -11,6 +11,7 @@ import java.util.stream.Collectors;
 import org.eclipse.jetty.websocket.api.Session;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
 import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
@@ -71,6 +72,7 @@ public class TradeBotWebSocket extends ApiWebSocket implements Listener {
 	}
 
 	@OnWebSocketConnect
+	@Override
 	public void onWebSocketConnect(Session session) {
 		// Send all known trade-bot entries
 		try (final Repository repository = RepositoryManager.getRepository()) {
@@ -92,10 +94,16 @@ public class TradeBotWebSocket extends ApiWebSocket implements Listener {
 	}
 
 	@OnWebSocketClose
+	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
 		super.onWebSocketClose(session, statusCode, reason);
 	}
 
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
 	@OnWebSocketMessage
 	public void onWebSocketMessage(Session session, String message) {
 		/* ignored */

src/main/java/org/qortal/api/websocket/TradeOffersWebSocket.java

@@ -6,20 +6,27 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.eclipse.jetty.websocket.api.Session;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
 import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
-import org.qortal.api.model.BlockInfo;
 import org.qortal.api.model.CrossChainOfferSummary;
-import org.qortal.controller.BlockNotifier;
+import org.qortal.controller.Controller;
 import org.qortal.crosschain.BTCACCT;
 import org.qortal.data.at.ATStateData;
+import org.qortal.data.block.BlockData;
 import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
@@ -27,120 +34,55 @@ import org.qortal.utils.NTP;
 
 @WebSocket
 @SuppressWarnings("serial")
-public class TradeOffersWebSocket extends ApiWebSocket {
+public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
+
+	private static final Logger LOGGER = LogManager.getLogger(TradeOffersWebSocket.class);
+
+	private static final Map<String, BTCACCT.Mode> previousAtModes = new HashMap<>();
+
+	// OFFERING
+	private static final Map<String, CrossChainOfferSummary> currentSummaries = new HashMap<>();
+	// REDEEMED/REFUNDED/CANCELLED
+	private static final Map<String, CrossChainOfferSummary> historicSummaries = new HashMap<>();
+
+	private static final Predicate<CrossChainOfferSummary> isHistoric = offerSummary
+			-> offerSummary.getMode() == BTCACCT.Mode.REDEEMED
+			|| offerSummary.getMode() == BTCACCT.Mode.REFUNDED
+			|| offerSummary.getMode() == BTCACCT.Mode.CANCELLED;
+
 
 	@Override
 	public void configure(WebSocketServletFactory factory) {
 		factory.register(TradeOffersWebSocket.class);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			populateCurrentSummaries(repository);
+
+			populateHistoricSummaries(repository);
+		} catch (DataException e) {
+			// How to fail properly?
+			return;
+		}
+
+		EventBus.INSTANCE.addListener(this::listen);
 	}
 
-	@OnWebSocketConnect
-	public void onWebSocketConnect(Session session) {
-		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.NewBlockEvent))
+			return;
 
-		final boolean includeHistoric = queryParams.get("includeHistoric") != null;
-		final Map<String, BTCACCT.Mode> previousAtModes = new HashMap<>();
+		BlockData blockData = ((Controller.NewBlockEvent) event).getBlockData();
+
+		// Process any new info
 		List<CrossChainOfferSummary> crossChainOfferSummaries;
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			List<ATStateData> initialAtStates;
-
-			// We want ALL OFFERING trades
-			Boolean isFinished = Boolean.FALSE;
-			Integer dataByteOffset = BTCACCT.MODE_BYTE_OFFSET;
-			Long expectedValue = (long) BTCACCT.Mode.OFFERING.value;
-			Integer minimumFinalHeight = null;
-
-			initialAtStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
-					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
-					null, null, null);
-
-			if (initialAtStates == null) {
-				session.close(4001, "repository issue fetching OFFERING trades");
-				return;
-			}
-
-			// Save initial AT modes
-			previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> BTCACCT.Mode.OFFERING)));
-
-			// Convert to offer summaries
-			crossChainOfferSummaries = produceSummaries(repository, initialAtStates, null);
-
-			if (includeHistoric) {
-				// We also want REDEEMED/REFUNDED/CANCELLED trades over the last 24 hours
-				long timestamp = NTP.getTime() - 24 * 60 * 60 * 1000L;
-				minimumFinalHeight = repository.getBlockRepository().getHeightFromTimestamp(timestamp);
-
-				if (minimumFinalHeight != 0) {
-					isFinished = Boolean.TRUE;
-					dataByteOffset = null;
-					expectedValue = null;
-					++minimumFinalHeight; // because height is just *before* timestamp
-
-					List<ATStateData> historicAtStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
-							isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
-							null, null, null);
-
-					if (historicAtStates == null) {
-						session.close(4002, "repository issue fetching historic trades");
-						return;
-					}
-
-					for (ATStateData historicAtState : historicAtStates) {
-						CrossChainOfferSummary historicOfferSummary = produceSummary(repository, historicAtState, null);
-
-						switch (historicOfferSummary.getMode()) {
-							case REDEEMED:
-							case REFUNDED:
-							case CANCELLED:
-								break;
-
-							default:
-								continue;
-						}
-
-						// Add summary to initial burst
-						crossChainOfferSummaries.add(historicOfferSummary);
-
-						// Save initial AT mode
-						previousAtModes.put(historicAtState.getATAddress(), historicOfferSummary.getMode());
-					}
-				}
-			}
-
-		} catch (DataException e) {
-			session.close(4003, "generic repository issue");
-			return;
-		}
-
-		if (!sendOfferSummaries(session, crossChainOfferSummaries)) {
-			session.close(4004, "websocket issue");
-			return;
-		}
-
-		BlockNotifier.Listener listener = blockInfo -> onNotify(session, blockInfo, previousAtModes);
-		BlockNotifier.getInstance().register(session, listener);
-	}
-
-	@OnWebSocketClose
-	public void onWebSocketClose(Session session, int statusCode, String reason) {
-		BlockNotifier.getInstance().deregister(session);
-	}
-
-	@OnWebSocketMessage
-	public void onWebSocketMessage(Session session, String message) {
-		/* ignored */
-	}
-
-	private void onNotify(Session session, BlockInfo blockInfo, final Map<String, BTCACCT.Mode> previousAtModes) {
-		List<CrossChainOfferSummary> crossChainOfferSummaries = null;
-
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			// Find any new trade ATs since this block
+			// Find any new/changed trade ATs since this block
 			final Boolean isFinished = null;
 			final Integer dataByteOffset = null;
 			final Long expectedValue = null;
-			final Integer minimumFinalHeight = blockInfo.getHeight();
+			final Integer minimumFinalHeight = blockData.getHeight();
 
 			List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
 					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
@@ -149,12 +91,13 @@ public class TradeOffersWebSocket extends ApiWebSocket {
 			if (atStates == null)
 				return;
 
-			crossChainOfferSummaries = produceSummaries(repository, atStates, blockInfo.getTimestamp());
+			crossChainOfferSummaries = produceSummaries(repository, atStates, blockData.getTimestamp());
 		} catch (DataException e) {
 			// No output this time
+			return;
 		}
 
-		synchronized (previousAtModes) { //NOSONAR squid:S2445 suppressed because previousAtModes is final and curried in lambda
+		synchronized (previousAtModes) {
 			// Remove any entries unchanged from last time
 			crossChainOfferSummaries.removeIf(offerSummary -> previousAtModes.get(offerSummary.getQortalAtAddress()) == offerSummary.getMode());
 
@@ -162,13 +105,78 @@ public class TradeOffersWebSocket extends ApiWebSocket {
 			if (crossChainOfferSummaries.isEmpty())
 				return;
 
-			final boolean wasSent = sendOfferSummaries(session, crossChainOfferSummaries);
+			// Update
+			for (CrossChainOfferSummary offerSummary : crossChainOfferSummaries) {
+				previousAtModes.put(offerSummary.qortalAtAddress, offerSummary.getMode());
+				LOGGER.trace(() -> String.format("Block height: %d, AT: %s, mode: %s", blockData.getHeight(), offerSummary.qortalAtAddress, offerSummary.getMode().name()));
 
-			if (!wasSent)
-				return;
+				switch (offerSummary.getMode()) {
+					case OFFERING:
+						currentSummaries.put(offerSummary.qortalAtAddress, offerSummary);
+						historicSummaries.remove(offerSummary.qortalAtAddress);
+						break;
 
-			previousAtModes.putAll(crossChainOfferSummaries.stream().collect(Collectors.toMap(CrossChainOfferSummary::getQortalAtAddress, CrossChainOfferSummary::getMode)));
+					case REDEEMED:
+					case REFUNDED:
+					case CANCELLED:
+						currentSummaries.remove(offerSummary.qortalAtAddress);
+						historicSummaries.put(offerSummary.qortalAtAddress, offerSummary);
+						break;
+
+					case TRADING:
+						currentSummaries.remove(offerSummary.qortalAtAddress);
+						historicSummaries.remove(offerSummary.qortalAtAddress);
+						break;
+				}
+			}
+
+			// Remove any historic offers that are over 24 hours old
+			final long tooOldTimestamp = NTP.getTime() - 24 * 60 * 60 * 1000L;
+			historicSummaries.values().removeIf(historicSummary -> historicSummary.getTimestamp() < tooOldTimestamp);
 		}
+
+		// Notify sessions
+		for (Session session : getSessions())
+			sendOfferSummaries(session, crossChainOfferSummaries);
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+		final boolean includeHistoric = queryParams.get("includeHistoric") != null;
+
+		List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
+
+		synchronized (previousAtModes) {
+			crossChainOfferSummaries.addAll(currentSummaries.values());
+
+			if (includeHistoric)
+				crossChainOfferSummaries.addAll(historicSummaries.values());
+		}
+
+		if (!sendOfferSummaries(session, crossChainOfferSummaries)) {
+			session.close(4002, "websocket issue");
+			return;
+		}
+
+		super.onWebSocketConnect(session);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		super.onWebSocketClose(session, statusCode, reason);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
 	}
 
 	private boolean sendOfferSummaries(Session session, List<CrossChainOfferSummary> crossChainOfferSummaries) {
@@ -186,6 +194,61 @@ public class TradeOffersWebSocket extends ApiWebSocket {
 		return true;
 	}
 
+	private static void populateCurrentSummaries(Repository repository) throws DataException {
+		// We want ALL OFFERING trades
+		Boolean isFinished = Boolean.FALSE;
+		Integer dataByteOffset = BTCACCT.MODE_BYTE_OFFSET;
+		Long expectedValue = (long) BTCACCT.Mode.OFFERING.value;
+		Integer minimumFinalHeight = null;
+
+		List<ATStateData> initialAtStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
+				isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+				null, null, null);
+
+		if (initialAtStates == null)
+			throw new DataException("Couldn't fetch current trades from repository");
+
+		// Save initial AT modes
+		previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> BTCACCT.Mode.OFFERING)));
+
+		// Convert to offer summaries
+		currentSummaries.putAll(produceSummaries(repository, initialAtStates, null).stream().collect(Collectors.toMap(CrossChainOfferSummary::getQortalAtAddress, offerSummary -> offerSummary)));
+	}
+
+	private static void populateHistoricSummaries(Repository repository) throws DataException {
+		// We want REDEEMED/REFUNDED/CANCELLED trades over the last 24 hours
+		long timestamp = System.currentTimeMillis() - 24 * 60 * 60 * 1000L;
+		int minimumFinalHeight = repository.getBlockRepository().getHeightFromTimestamp(timestamp);
+
+		if (minimumFinalHeight == 0)
+			throw new DataException("Couldn't fetch block timestamp from repository");
+
+		Boolean isFinished = Boolean.TRUE;
+		Integer dataByteOffset = null;
+		Long expectedValue = null;
+		++minimumFinalHeight; // because height is just *before* timestamp
+
+		List<ATStateData> historicAtStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
+				isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+				null, null, null);
+
+		if (historicAtStates == null)
+			throw new DataException("Couldn't fetch historic trades from repository");
+
+		for (ATStateData historicAtState : historicAtStates) {
+			CrossChainOfferSummary historicOfferSummary = produceSummary(repository, historicAtState, null);
+
+			if (!isHistoric.test(historicOfferSummary))
+				continue;
+
+			// Add summary to initial burst
+			historicSummaries.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary);
+
+			// Save initial AT mode
+			previousAtModes.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary.getMode());
+		}
+	}
+
 	private static CrossChainOfferSummary produceSummary(Repository repository, ATStateData atState, Long timestamp) throws DataException {
 		CrossChainTradeData crossChainTradeData = BTCACCT.populateTradeData(repository, atState);
 
@@ -193,7 +256,7 @@ public class TradeOffersWebSocket extends ApiWebSocket {
 
 		if (crossChainTradeData.mode == BTCACCT.Mode.OFFERING)
 			// We want when trade was created, not when it was last updated
-			atStateTimestamp = atState.getCreation();
+			atStateTimestamp = crossChainTradeData.creationTimestamp;
 		else
 			atStateTimestamp = timestamp != null ? timestamp : repository.getBlockRepository().getTimestampFromHeight(atState.getHeight());
 

src/main/java/org/qortal/at/AT.java

@@ -51,16 +51,17 @@ public class AT {
 
 		MachineState machineState = new MachineState(api, loggerFactory, deployATTransactionData.getCreationBytes());
 
-		byte[] codeHash = Crypto.digest(machineState.getCodeBytes());
+		byte[] codeBytes = machineState.getCodeBytes();
+		byte[] codeHash = Crypto.digest(codeBytes);
 
-		this.atData = new ATData(atAddress, creatorPublicKey, creation, machineState.version, assetId, machineState.getCodeBytes(), codeHash,
+		this.atData = new ATData(atAddress, creatorPublicKey, creation, machineState.version, assetId, codeBytes, codeHash,
 				machineState.isSleeping(), machineState.getSleepUntilHeight(), machineState.isFinished(), machineState.hadFatalError(),
 				machineState.isFrozen(), machineState.getFrozenBalance());
 
 		byte[] stateData = machineState.toBytes();
 		byte[] stateHash = Crypto.digest(stateData);
 
-		this.atStateData = new ATStateData(atAddress, height, creation, stateData, stateHash, 0L, true);
+		this.atStateData = new ATStateData(atAddress, height, stateData, stateHash, 0L, true);
 	}
 
 	// Getters / setters
@@ -106,12 +107,11 @@ public class AT {
 			throw new DataException(String.format("Uncaught exception while running AT '%s'", atAddress), e);
 		}
 
-		long creation = this.atData.getCreation();
 		byte[] stateData = state.toBytes();
 		byte[] stateHash = Crypto.digest(stateData);
 		long atFees = api.calcFinalFees(state);
 
-		this.atStateData = new ATStateData(atAddress, blockHeight, creation, stateData, stateHash, atFees, false);
+		this.atStateData = new ATStateData(atAddress, blockHeight, stateData, stateHash, atFees, false);
 
 		return api.getTransactions();
 	}

src/main/java/org/qortal/block/Block.java

@@ -6,6 +6,8 @@ import static java.util.stream.Collectors.toMap;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.math.RoundingMode;
+import java.text.DecimalFormat;
+import java.text.NumberFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -15,6 +17,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.account.Account;
@@ -29,6 +32,7 @@ import org.qortal.controller.Controller;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.account.AccountBalanceData;
 import org.qortal.data.account.AccountData;
+import org.qortal.data.account.EligibleQoraHolderData;
 import org.qortal.data.account.QortFromQoraData;
 import org.qortal.data.account.RewardShareData;
 import org.qortal.data.at.ATData;
@@ -53,7 +57,6 @@ import org.qortal.transform.transaction.TransactionTransformer;
 import org.qortal.utils.Amounts;
 import org.qortal.utils.Base58;
 import org.qortal.utils.NTP;
-import org.roaringbitmap.IntIterator;
 
 import com.google.common.primitives.Bytes;
 import com.google.common.primitives.Longs;
@@ -128,7 +131,7 @@ public class Block {
 
 	@FunctionalInterface
 	private interface BlockRewardDistributor {
-		long distribute(long amount, Map<Account, Long> balanceChanges) throws DataException;
+		long distribute(long amount, Map<String, Long> balanceChanges) throws DataException;
 	}
 
 	/** Lazy-instantiated expanded info on block's online accounts. */
@@ -144,8 +147,8 @@ public class Block {
 		private final Account recipientAccount;
 		private final AccountData recipientAccountData;
 
-		ExpandedAccount(Repository repository, int accountIndex) throws DataException {
-			this.rewardShareData = repository.getAccountRepository().getRewardShareByIndex(accountIndex);
+		ExpandedAccount(Repository repository, RewardShareData rewardShareData) throws DataException {
+			this.rewardShareData = rewardShareData;
 			this.sharePercent = this.rewardShareData.getSharePercent();
 
 			this.mintingAccount = new Account(repository, this.rewardShareData.getMinter());
@@ -188,12 +191,12 @@ public class Block {
 			return shareBinsByLevel[accountLevel];
 		}
 
-		public long distribute(long accountAmount, Map<Account, Long> balanceChanges) {
+		public long distribute(long accountAmount, Map<String, Long> balanceChanges) {
 			if (this.isRecipientAlsoMinter) {
 				// minter & recipient the same - simpler case
 				LOGGER.trace(() -> String.format("Minter/recipient account %s share: %s", this.mintingAccount.getAddress(), Amounts.prettyAmount(accountAmount)));
 				if (accountAmount != 0)
-					balanceChanges.merge(this.mintingAccount, accountAmount, Long::sum);
+					balanceChanges.merge(this.mintingAccount.getAddress(), accountAmount, Long::sum);
 			} else {
 				// minter & recipient different - extra work needed
 				long recipientAmount = (accountAmount * this.sharePercent) / 100L / 100L; // because scaled by 2dp and 'percent' means "per 100"
@@ -201,11 +204,11 @@ public class Block {
 
 				LOGGER.trace(() -> String.format("Minter account %s share: %s", this.mintingAccount.getAddress(), Amounts.prettyAmount(minterAmount)));
 				if (minterAmount != 0)
-					balanceChanges.merge(this.mintingAccount, minterAmount, Long::sum);
+					balanceChanges.merge(this.mintingAccount.getAddress(), minterAmount, Long::sum);
 
 				LOGGER.trace(() -> String.format("Recipient account %s share: %s", this.recipientAccount.getAddress(), Amounts.prettyAmount(recipientAmount)));
 				if (recipientAmount != 0)
-					balanceChanges.merge(this.recipientAccount, recipientAmount, Long::sum);
+					balanceChanges.merge(this.recipientAccount.getAddress(), recipientAmount, Long::sum);
 			}
 
 			// We always distribute all of the amount
@@ -217,6 +220,8 @@ public class Block {
 
 	/** Opportunistic cache of this block's valid online accounts. Only created by call to isValid(). */
 	private List<OnlineAccountData> cachedValidOnlineAccounts = null;
+	/** Opportunistic cache of this block's valid online reward-shares. Only created by call to isValid(). */
+	private List<RewardShareData> cachedOnlineRewardShares = null;
 
 	// Other useful constants
 
@@ -567,22 +572,28 @@ public class Block {
 	/**
 	 * Return expanded info on block's online accounts.
 	 * <p>
+	 * Typically called as part of Block.process() or Block.orphan()
+	 * so ideally after any calls to Block.isValid().
+	 * 
 	 * @throws DataException
 	 */
 	public List<ExpandedAccount> getExpandedAccounts() throws DataException {
 		if (this.cachedExpandedAccounts != null)
 			return this.cachedExpandedAccounts;
 
-		ConciseSet accountIndexes = BlockTransformer.decodeOnlineAccounts(this.blockData.getEncodedOnlineAccounts());
+		// We might already have a cache of online, reward-shares thanks to isValid()
+		if (this.cachedOnlineRewardShares == null) {
+			ConciseSet accountIndexes = BlockTransformer.decodeOnlineAccounts(this.blockData.getEncodedOnlineAccounts());
+			this.cachedOnlineRewardShares = repository.getAccountRepository().getRewardSharesByIndexes(accountIndexes.toArray());
+
+			if (this.cachedOnlineRewardShares == null)
+				throw new DataException("Online accounts invalid?");
+		}
+
 		List<ExpandedAccount> expandedAccounts = new ArrayList<>();
 
-		IntIterator iterator = accountIndexes.iterator();
-		while (iterator.hasNext()) {
-			int accountIndex = iterator.next();
-
-			ExpandedAccount accountInfo = new ExpandedAccount(repository, accountIndex);
-			expandedAccounts.add(accountInfo);
-		}
+		for (RewardShareData rewardShare : this.cachedOnlineRewardShares)
+			expandedAccounts.add(new ExpandedAccount(repository, rewardShare));
 
 		this.cachedExpandedAccounts = expandedAccounts;
 
@@ -783,15 +794,46 @@ public class Block {
 		return BigInteger.valueOf(blockSummaryData.getOnlineAccountsCount()).shiftLeft(ACCOUNTS_COUNT_SHIFT).add(keyDistance);
 	}
 
-	public static BigInteger calcChainWeight(int commonBlockHeight, byte[] commonBlockSignature, List<BlockSummaryData> blockSummaries) {
+	public static BigInteger calcChainWeight(int commonBlockHeight, byte[] commonBlockSignature, List<BlockSummaryData> blockSummaries, int maxHeight) {
 		BigInteger cumulativeWeight = BigInteger.ZERO;
 		int parentHeight = commonBlockHeight;
 		byte[] parentBlockSignature = commonBlockSignature;
+		NumberFormat formatter = new DecimalFormat("0.###E0");
+		boolean isLogging = LOGGER.getLevel().isLessSpecificThan(Level.TRACE);
 
 		for (BlockSummaryData blockSummaryData : blockSummaries) {
-			cumulativeWeight = cumulativeWeight.shiftLeft(CHAIN_WEIGHT_SHIFT).add(calcBlockWeight(parentHeight, parentBlockSignature, blockSummaryData));
+			StringBuilder stringBuilder = isLogging ? new StringBuilder(512) : null;
+
+			if (isLogging)
+				stringBuilder.append(formatter.format(cumulativeWeight)).append(" -> ");
+
+			cumulativeWeight = cumulativeWeight.shiftLeft(CHAIN_WEIGHT_SHIFT);
+			if (isLogging)
+				stringBuilder.append(formatter.format(cumulativeWeight)).append(" + ");
+
+			BigInteger blockWeight = calcBlockWeight(parentHeight, parentBlockSignature, blockSummaryData);
+			if (isLogging)
+				stringBuilder.append("(height: ")
+						.append(parentHeight + 1)
+						.append(", online: ")
+						.append(blockSummaryData.getOnlineAccountsCount())
+						.append(") ")
+						.append(formatter.format(blockWeight));
+
+			cumulativeWeight = cumulativeWeight.add(blockWeight);
+			if (isLogging)
+				stringBuilder.append(" -> ").append(formatter.format(cumulativeWeight));
+
+			if (isLogging && blockSummaries.size() > 1)
+				LOGGER.debug(() -> stringBuilder.toString()); //NOSONAR S1612 (false positive?)
+
 			parentHeight = blockSummaryData.getHeight();
 			parentBlockSignature = blockSummaryData.getSignature();
+
+			/* Potential future consensus change: only comparing the same number of blocks.
+			if (parentHeight >= maxHeight)
+				break;
+			*/
 		}
 
 		return cumulativeWeight;
@@ -917,19 +959,9 @@ public class Block {
 		if (accountIndexes.size() != this.blockData.getOnlineAccountsCount())
 			return ValidationResult.ONLINE_ACCOUNTS_INVALID;
 
-		List<RewardShareData> expandedAccounts = new ArrayList<>();
-
-		IntIterator iterator = accountIndexes.iterator();
-		while (iterator.hasNext()) {
-			int accountIndex = iterator.next();
-			RewardShareData rewardShareData = repository.getAccountRepository().getRewardShareByIndex(accountIndex);
-
-			// Check that claimed online account actually exists
-			if (rewardShareData == null)
-				return ValidationResult.ONLINE_ACCOUNT_UNKNOWN;
-
-			expandedAccounts.add(rewardShareData);
-		}
+		List<RewardShareData> onlineRewardShares = repository.getAccountRepository().getRewardSharesByIndexes(accountIndexes.toArray());
+		if (onlineRewardShares == null)
+			return ValidationResult.ONLINE_ACCOUNT_UNKNOWN;
 
 		// If block is past a certain age then we simply assume the signatures were correct
 		long signatureRequirementThreshold = NTP.getTime() - BlockChain.getInstance().getOnlineAccountSignaturesMinLifetime();
@@ -939,7 +971,7 @@ public class Block {
 		if (this.blockData.getOnlineAccountsSignatures() == null || this.blockData.getOnlineAccountsSignatures().length == 0)
 			return ValidationResult.ONLINE_ACCOUNT_SIGNATURES_MISSING;
 
-		if (this.blockData.getOnlineAccountsSignatures().length != expandedAccounts.size() * Transformer.SIGNATURE_LENGTH)
+		if (this.blockData.getOnlineAccountsSignatures().length != onlineRewardShares.size() * Transformer.SIGNATURE_LENGTH)
 			return ValidationResult.ONLINE_ACCOUNT_SIGNATURES_MALFORMED;
 
 		// Check signatures
@@ -961,7 +993,7 @@ public class Block {
 
 		for (int i = 0; i < onlineAccountsSignatures.size(); ++i) {
 			byte[] signature = onlineAccountsSignatures.get(i);
-			byte[] publicKey = expandedAccounts.get(i).getRewardSharePublicKey();
+			byte[] publicKey = onlineRewardShares.get(i).getRewardSharePublicKey();
 
 			OnlineAccountData onlineAccountData = new OnlineAccountData(onlineTimestamp, signature, publicKey);
 			ourOnlineAccounts.add(onlineAccountData);
@@ -982,6 +1014,7 @@ public class Block {
 
 		// All online accounts valid, so save our list of online accounts for potential later use
 		this.cachedValidOnlineAccounts = ourOnlineAccounts;
+		this.cachedOnlineRewardShares = onlineRewardShares;
 
 		return ValidationResult.OK;
 	}
@@ -1316,13 +1349,16 @@ public class Block {
 				allUniqueExpandedAccounts.add(expandedAccount.recipientAccountData);
 		}
 
-		// Decrease blocks minted count for all accounts
+		// Increase blocks minted count for all accounts
+
+		// Batch update in repository
+		repository.getAccountRepository().modifyMintedBlockCounts(allUniqueExpandedAccounts.stream().map(AccountData::getAddress).collect(Collectors.toList()), +1);
+
+		// Local changes and also checks for level bump
 		for (AccountData accountData : allUniqueExpandedAccounts) {
 			// Adjust count locally (in Java)
 			accountData.setBlocksMinted(accountData.getBlocksMinted() + 1);
-
-			int rowCount = repository.getAccountRepository().modifyMintedBlockCount(accountData.getAddress(), +1);
-			LOGGER.trace(() -> String.format("Block minter %s up to %d minted block%s (rowCount: %d)", accountData.getAddress(), accountData.getBlocksMinted(), (accountData.getBlocksMinted() != 1 ? "s" : ""), rowCount));
+			LOGGER.trace(() -> String.format("Block minter %s up to %d minted block%s", accountData.getAddress(), accountData.getBlocksMinted(), (accountData.getBlocksMinted() != 1 ? "s" : "")));
 
 			final int effectiveBlocksMinted = accountData.getBlocksMinted() + accountData.getBlocksMintedAdjustment();
 
@@ -1612,12 +1648,14 @@ public class Block {
 		}
 
 		// Decrease blocks minted count for all accounts
+
+		// Batch update in repository
+		repository.getAccountRepository().modifyMintedBlockCounts(allUniqueExpandedAccounts.stream().map(AccountData::getAddress).collect(Collectors.toList()), -1);
+
 		for (AccountData accountData : allUniqueExpandedAccounts) {
 			// Adjust count locally (in Java)
 			accountData.setBlocksMinted(accountData.getBlocksMinted() - 1);
-
-			int rowCount = repository.getAccountRepository().modifyMintedBlockCount(accountData.getAddress(), -1);
-			LOGGER.trace(() -> String.format("Block minter %s down to %d minted block%s (rowCount: %d)", accountData.getAddress(), accountData.getBlocksMinted(), (accountData.getBlocksMinted() != 1 ? "s" : ""), rowCount));
+			LOGGER.trace(() -> String.format("Block minter %s down to %d minted block%s", accountData.getAddress(), accountData.getBlocksMinted(), (accountData.getBlocksMinted() != 1 ? "s" : "")));
 
 			final int effectiveBlocksMinted = accountData.getBlocksMinted() + accountData.getBlocksMintedAdjustment();
 
@@ -1646,7 +1684,7 @@ public class Block {
 			this.distributionMethod = distributionMethod;
 		}
 
-		public long distribute(long distibutionAmount, Map<Account, Long> balanceChanges) throws DataException {
+		public long distribute(long distibutionAmount, Map<String, Long> balanceChanges) throws DataException {
 			return this.distributionMethod.distribute(distibutionAmount, balanceChanges);
 		}
 	}
@@ -1663,7 +1701,7 @@ public class Block {
 		// Now distribute to candidates
 
 		// Collate all balance changes and then apply in one final step
-		Map<Account, Long> balanceChanges = new HashMap<>();
+		Map<String, Long> balanceChanges = new HashMap<>();
 
 		long remainingAmount = totalAmount;
 		for (int r = 0; r < rewardCandidates.size(); ++r) {
@@ -1688,8 +1726,10 @@ public class Block {
 		}
 
 		// Apply balance changes
-		for (Map.Entry<Account, Long> balanceChange : balanceChanges.entrySet())
-			balanceChange.getKey().modifyAssetBalance(Asset.QORT, balanceChange.getValue());
+		List<AccountBalanceData> accountBalanceDeltas = balanceChanges.entrySet().stream()
+				.map(entry -> new AccountBalanceData(entry.getKey(), Asset.QORT, entry.getValue()))
+				.collect(Collectors.toList());
+		this.repository.getAccountRepository().modifyAssetBalances(accountBalanceDeltas);
 	}
 
 	protected List<BlockRewardCandidate> determineBlockRewardCandidates(boolean isProcessingNotOrphaning) throws DataException {
@@ -1759,7 +1799,7 @@ public class Block {
 		}
 
 		// Fetch list of legacy QORA holders who haven't reached their cap of QORT reward.
-		List<AccountBalanceData> qoraHolders = this.repository.getAccountRepository().getEligibleLegacyQoraHolders(isProcessingNotOrphaning ? null : this.blockData.getHeight());
+		List<EligibleQoraHolderData> qoraHolders = this.repository.getAccountRepository().getEligibleLegacyQoraHolders(isProcessingNotOrphaning ? null : this.blockData.getHeight());
 		final boolean haveQoraHolders = !qoraHolders.isEmpty();
 		final long qoraHoldersShare = BlockChain.getInstance().getQoraHoldersShare();
 
@@ -1812,7 +1852,7 @@ public class Block {
 		return rewardCandidates;
 	}
 
-	private static long distributeBlockRewardShare(long distributionAmount, List<ExpandedAccount> accounts, Map<Account, Long> balanceChanges) {
+	private static long distributeBlockRewardShare(long distributionAmount, List<ExpandedAccount> accounts, Map<String, Long> balanceChanges) {
 		// Collate all expanded accounts by minting account
 		Map<String, List<ExpandedAccount>> accountsByMinter = new HashMap<>();
 
@@ -1841,7 +1881,7 @@ public class Block {
 		return sharedAmount;
 	}
 
-	private static long distributeBlockRewardToQoraHolders(long qoraHoldersAmount, List<AccountBalanceData> qoraHolders, Map<Account, Long> balanceChanges, Block block) throws DataException {
+	private static long distributeBlockRewardToQoraHolders(long qoraHoldersAmount, List<EligibleQoraHolderData> qoraHolders, Map<String, Long> balanceChanges, Block block) throws DataException {
 		final boolean isProcessingNotOrphaning = qoraHoldersAmount >= 0;
 
 		long qoraPerQortReward = BlockChain.getInstance().getQoraPerQortReward();
@@ -1849,7 +1889,7 @@ public class Block {
 
 		long totalQoraHeld = 0;
 		for (int i = 0; i < qoraHolders.size(); ++i)
-			totalQoraHeld += qoraHolders.get(i).getBalance();
+			totalQoraHeld += qoraHolders.get(i).getQoraBalance();
 
 		long finalTotalQoraHeld = totalQoraHeld;
 		LOGGER.trace(() -> String.format("Total legacy QORA held: %s", Amounts.prettyAmount(finalTotalQoraHeld)));
@@ -1862,9 +1902,13 @@ public class Block {
 		BigInteger totalQoraHeldBI = BigInteger.valueOf(totalQoraHeld);
 
 		long sharedAmount = 0;
+		// For batched update of QORT_FROM_QORA balances
+		List<AccountBalanceData> newQortFromQoraBalances = new ArrayList<>();
+
 		for (int h = 0; h < qoraHolders.size(); ++h) {
-			AccountBalanceData qoraHolder = qoraHolders.get(h);
-			BigInteger qoraHolderBalanceBI = BigInteger.valueOf(qoraHolder.getBalance());
+			EligibleQoraHolderData qoraHolder = qoraHolders.get(h);
+			BigInteger qoraHolderBalanceBI = BigInteger.valueOf(qoraHolder.getQoraBalance());
+			String qoraHolderAddress = qoraHolder.getAddress();
 
 			// This is where a 128bit integer library could help:
 			// long holderReward = (qoraHoldersAmount * qoraHolder.getBalance()) / totalQoraHeld;
@@ -1872,15 +1916,13 @@ public class Block {
 
 			final long holderRewardForLogging = holderReward;
 			LOGGER.trace(() -> String.format("QORA holder %s has %s / %s QORA so share: %s",
-					qoraHolder.getAddress(), Amounts.prettyAmount(qoraHolder.getBalance()), finalTotalQoraHeld, Amounts.prettyAmount(holderRewardForLogging)));
+					qoraHolderAddress, Amounts.prettyAmount(qoraHolder.getQoraBalance()), finalTotalQoraHeld, Amounts.prettyAmount(holderRewardForLogging)));
 
 			// Too small to register this time?
 			if (holderReward == 0)
 				continue;
 
-			Account qoraHolderAccount = new Account(block.repository, qoraHolder.getAddress());
-
-			long newQortFromQoraBalance = qoraHolderAccount.getConfirmedBalance(Asset.QORT_FROM_QORA) + holderReward;
+			long newQortFromQoraBalance = qoraHolder.getQortFromQoraBalance() + holderReward;
 
 			// If processing, make sure we don't overpay
 			if (isProcessingNotOrphaning) {
@@ -1894,44 +1936,43 @@ public class Block {
 					newQortFromQoraBalance -= adjustment;
 
 					// This is also the QORA holder's final QORT-from-QORA block
-					QortFromQoraData qortFromQoraData = new QortFromQoraData(qoraHolder.getAddress(), holderReward, block.blockData.getHeight());
+					QortFromQoraData qortFromQoraData = new QortFromQoraData(qoraHolderAddress, holderReward, block.blockData.getHeight());
 					block.repository.getAccountRepository().save(qortFromQoraData);
 
 					long finalAdjustedHolderReward = holderReward;
 					LOGGER.trace(() -> String.format("QORA holder %s final share %s at height %d",
-							qoraHolder.getAddress(), Amounts.prettyAmount(finalAdjustedHolderReward), block.blockData.getHeight()));
+							qoraHolderAddress, Amounts.prettyAmount(finalAdjustedHolderReward), block.blockData.getHeight()));
 				}
 			} else {
 				// Orphaning
-				QortFromQoraData qortFromQoraData = block.repository.getAccountRepository().getQortFromQoraInfo(qoraHolder.getAddress());
-				if (qortFromQoraData != null) {
+				if (qoraHolder.getFinalBlockHeight() != null) {
 					// Final QORT-from-QORA amount from repository was stored during processing, and hence positive.
 					// So we use + here as qortFromQora is negative during orphaning.
 					// More efficient than "holderReward - (0 - final-qort-from-qora)"
-					long adjustment = holderReward + qortFromQoraData.getFinalQortFromQora();
+					long adjustment = holderReward + qoraHolder.getFinalQortFromQora();
 
 					holderReward -= adjustment;
 					newQortFromQoraBalance -= adjustment;
 
-					block.repository.getAccountRepository().deleteQortFromQoraInfo(qoraHolder.getAddress());
+					block.repository.getAccountRepository().deleteQortFromQoraInfo(qoraHolderAddress);
 
 					long finalAdjustedHolderReward = holderReward;
 					LOGGER.trace(() -> String.format("QORA holder %s final share %s was at height %d",
-							qoraHolder.getAddress(), Amounts.prettyAmount(finalAdjustedHolderReward), block.blockData.getHeight()));
+							qoraHolderAddress, Amounts.prettyAmount(finalAdjustedHolderReward), block.blockData.getHeight()));
 				}
 			}
 
-			balanceChanges.merge(qoraHolderAccount, holderReward, Long::sum);
+			balanceChanges.merge(qoraHolderAddress, holderReward, Long::sum);
 
-			if (newQortFromQoraBalance > 0)
-				qoraHolderAccount.setConfirmedBalance(Asset.QORT_FROM_QORA, newQortFromQoraBalance);
-			else
-				// Remove QORT_FROM_QORA balance as it's zero
-				qoraHolderAccount.deleteBalance(Asset.QORT_FROM_QORA);
+			// Add to batched QORT_FROM_QORA balance update list
+			newQortFromQoraBalances.add(new AccountBalanceData(qoraHolderAddress, Asset.QORT_FROM_QORA, newQortFromQoraBalance));
 
 			sharedAmount += holderReward;
 		}
 
+		// Perform batched update of QORT_FROM_QORA balances
+		block.repository.getAccountRepository().setAssetBalances(newQortFromQoraBalances);
+
 		return sharedAmount;
 	}
 

src/main/java/org/qortal/block/BlockChain.java

@@ -32,7 +32,6 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
-import org.qortal.utils.NTP;
 import org.qortal.utils.StringLongMapXmlAdapter;
 
 /**
@@ -532,7 +531,8 @@ public class BlockChain {
 
 	private static void rebuildBlockchain() throws DataException {
 		// (Re)build repository
-		RepositoryManager.rebuild();
+		if (!RepositoryManager.wasPristineAtOpen())
+			RepositoryManager.rebuild();
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			GenesisBlock genesisBlock = GenesisBlock.getInstance(repository);
@@ -554,17 +554,23 @@ public class BlockChain {
 
 		try {
 			try (final Repository repository = RepositoryManager.getRepository()) {
-				for (int height = repository.getBlockRepository().getBlockchainHeight(); height > targetHeight; --height) {
+				int height = repository.getBlockRepository().getBlockchainHeight();
+				BlockData orphanBlockData = repository.getBlockRepository().fromHeight(height);
+
+				while (height > targetHeight) {
 					LOGGER.info(String.format("Forcably orphaning block %d", height));
 
-					BlockData blockData = repository.getBlockRepository().fromHeight(height);
-					Block block = new Block(repository, blockData);
+					Block block = new Block(repository, orphanBlockData);
 					block.orphan();
-					repository.saveChanges();
-				}
 
-				BlockData lastBlockData = repository.getBlockRepository().getLastBlock();
-				Controller.getInstance().setChainTip(lastBlockData);
+					repository.saveChanges();
+
+					--height;
+					orphanBlockData = repository.getBlockRepository().fromHeight(height);
+
+					repository.discardChanges(); // clear transaction status to prevent deadlocks
+					Controller.getInstance().onOrphanedBlock(orphanBlockData);
+				}
 
 				return true;
 			}
@@ -573,33 +579,4 @@ public class BlockChain {
 		}
 	}
 
-	public static void trimOldOnlineAccountsSignatures() {
-		final Long now = NTP.getTime();
-		if (now == null)
-			return;
-
-		ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
-		if (!blockchainLock.tryLock())
-			// Too busy to trim right now, try again later
-			return;
-
-		try {
-			try (final Repository repository = RepositoryManager.tryRepository()) {
-				if (repository == null)
-					return;
-
-				int numBlocksTrimmed = repository.getBlockRepository().trimOldOnlineAccountsSignatures(now - BlockChain.getInstance().getOnlineAccountSignaturesMaxLifetime());
-
-				if (numBlocksTrimmed > 0)
-					LOGGER.debug(String.format("Trimmed old online accounts signatures from %d block%s", numBlocksTrimmed, (numBlocksTrimmed != 1 ? "s" : "")));
-
-				repository.saveChanges();
-			} catch (DataException e) {
-				LOGGER.warn(String.format("Repository issue trying to trim old online accounts signatures: %s", e.getMessage()));
-			}
-		} finally {
-			blockchainLock.unlock();
-		}
-	}
-
 }

src/main/java/org/qortal/controller/AtStatesTrimmer.java

@@ -0,0 +1,77 @@
+package org.qortal.controller;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.data.block.BlockData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.utils.NTP;
+
+public class AtStatesTrimmer implements Runnable {
+
+	private static final Logger LOGGER = LogManager.getLogger(AtStatesTrimmer.class);
+
+	@Override
+	public void run() {
+		Thread.currentThread().setName("AT States trimmer");
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			repository.getATRepository().prepareForAtStateTrimming();
+			repository.saveChanges();
+
+			while (!Controller.isStopping()) {
+				repository.discardChanges();
+
+				Thread.sleep(Settings.getInstance().getAtStatesTrimInterval());
+
+				BlockData chainTip = Controller.getInstance().getChainTip();
+				if (chainTip == null || NTP.getTime() == null)
+					continue;
+
+				// Don't even attempt if we're mid-sync as our repository requests will be delayed for ages
+				if (Controller.getInstance().isSynchronizing())
+					continue;
+
+				long currentTrimmableTimestamp = NTP.getTime() - Settings.getInstance().getAtStatesMaxLifetime();
+				// We want to keep AT states near the tip of our copy of blockchain so we can process/orphan nearby blocks
+				long chainTrimmableTimestamp = chainTip.getTimestamp() - Settings.getInstance().getAtStatesMaxLifetime();
+
+				long upperTrimmableTimestamp = Math.min(currentTrimmableTimestamp, chainTrimmableTimestamp);
+				int upperTrimmableHeight = repository.getBlockRepository().getHeightFromTimestamp(upperTrimmableTimestamp);
+
+				int trimStartHeight = repository.getATRepository().getAtTrimHeight();
+
+				int upperBatchHeight = trimStartHeight + Settings.getInstance().getAtStatesTrimBatchSize();
+				int upperTrimHeight = Math.min(upperBatchHeight, upperTrimmableHeight);
+
+				if (trimStartHeight >= upperTrimHeight)
+					continue;
+
+				int numAtStatesTrimmed = repository.getATRepository().trimAtStates(trimStartHeight, upperTrimHeight, Settings.getInstance().getAtStatesTrimLimit());
+				repository.saveChanges();
+
+				if (numAtStatesTrimmed > 0) {
+					LOGGER.debug(() -> String.format("Trimmed %d AT state%s between blocks %d and %d",
+							numAtStatesTrimmed, (numAtStatesTrimmed != 1 ? "s" : ""),
+							trimStartHeight, upperTrimHeight));
+				} else {
+					// Can we move onto next batch?
+					if (upperTrimmableHeight > upperBatchHeight) {
+						repository.getATRepository().setAtTrimHeight(upperBatchHeight);
+						repository.getATRepository().prepareForAtStateTrimming();
+						repository.saveChanges();
+
+						LOGGER.debug(() -> String.format("Bumping AT state trim height to %d", upperBatchHeight));
+					}
+				}
+			}
+		} catch (DataException e) {
+			LOGGER.warn(String.format("Repository issue trying to trim AT states: %s", e.getMessage()));
+		} catch (InterruptedException e) {
+			// Time to exit
+		}
+	}
+
+}

src/main/java/org/qortal/controller/BlockMinter.java

@@ -1,4 +1,4 @@
-package org.qortal.block;
+package org.qortal.controller;
 
 import java.math.BigInteger;
 import java.util.ArrayList;
@@ -13,8 +13,9 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
+import org.qortal.block.Block;
 import org.qortal.block.Block.ValidationResult;
-import org.qortal.controller.Controller;
+import org.qortal.block.BlockChain;
 import org.qortal.data.account.MintingAccountData;
 import org.qortal.data.account.RewardShareData;
 import org.qortal.data.block.BlockData;
@@ -60,7 +61,7 @@ public class BlockMinter extends Thread {
 				List<TransactionData> unconfirmedTransactions = repository.getTransactionRepository().getUnconfirmedTransactions();
 
 				for (TransactionData transactionData : unconfirmedTransactions) {
-					LOGGER.trace(String.format("Deleting unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
+					LOGGER.trace(() -> String.format("Deleting unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
 					repository.getTransactionRepository().delete(transactionData);
 				}
 
@@ -69,7 +70,7 @@ public class BlockMinter extends Thread {
 
 			// Going to need this a lot...
 			BlockRepository blockRepository = repository.getBlockRepository();
-			Block previousBlock = null;
+			BlockData previousBlockData = null;
 
 			List<Block> newBlocks = new ArrayList<>();
 
@@ -115,7 +116,7 @@ public class BlockMinter extends Thread {
 
 					RewardShareData rewardShareData = repository.getAccountRepository().getRewardShare(mintingAccountData.getPublicKey());
 					if (rewardShareData == null) {
-						// Reward-share doesn't even exist - probably not a good sign
+						// Reward-share doesn't exist - probably cancelled but not yet removed from node's list of minting accounts
 						madi.remove();
 						continue;
 					}
@@ -150,8 +151,8 @@ public class BlockMinter extends Thread {
 				isMintingPossible = true;
 
 				// Check blockchain hasn't changed
-				if (previousBlock == null || !Arrays.equals(previousBlock.getSignature(), lastBlockData.getSignature())) {
-					previousBlock = new Block(repository, lastBlockData);
+				if (previousBlockData == null || !Arrays.equals(previousBlockData.getSignature(), lastBlockData.getSignature())) {
+					previousBlockData = lastBlockData;
 					newBlocks.clear();
 
 					// Reduce log timeout
@@ -162,12 +163,12 @@ public class BlockMinter extends Thread {
 				mintingAccountsData.removeIf(mintingAccountData -> newBlocks.stream().anyMatch(newBlock -> Arrays.equals(newBlock.getBlockData().getMinterPublicKey(), mintingAccountData.getPublicKey())));
 
 				// Do we need to build any potential new blocks?
-				List<PrivateKeyAccount> mintingAccounts = mintingAccountsData.stream().map(accountData -> new PrivateKeyAccount(repository, accountData.getPrivateKey())).collect(Collectors.toList());
+				List<PrivateKeyAccount> newBlocksMintingAccounts = mintingAccountsData.stream().map(accountData -> new PrivateKeyAccount(repository, accountData.getPrivateKey())).collect(Collectors.toList());
 
-				for (PrivateKeyAccount mintingAccount : mintingAccounts) {
+				for (PrivateKeyAccount mintingAccount : newBlocksMintingAccounts) {
 					// First block does the AT heavy-lifting
 					if (newBlocks.isEmpty()) {
-						Block newBlock = Block.mint(repository, previousBlock.getBlockData(), mintingAccount);
+						Block newBlock = Block.mint(repository, previousBlockData, mintingAccount);
 						if (newBlock == null) {
 							// For some reason we can't mint right now
 							moderatedLog(() -> LOGGER.error("Couldn't build a to-be-minted block"));
@@ -195,7 +196,7 @@ public class BlockMinter extends Thread {
 				// Make sure we're the only thread modifying the blockchain
 				ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
 				if (!blockchainLock.tryLock(30, TimeUnit.SECONDS)) {
-					LOGGER.warn("Couldn't acquire blockchain lock even after waiting 30 seconds");
+					LOGGER.debug("Couldn't acquire blockchain lock even after waiting 30 seconds");
 					continue;
 				}
 
@@ -233,8 +234,8 @@ public class BlockMinter extends Thread {
 						continue;
 
 					// Pick best block
-					final int parentHeight = previousBlock.getBlockData().getHeight();
-					final byte[] parentBlockSignature = previousBlock.getSignature();
+					final int parentHeight = previousBlockData.getHeight();
+					final byte[] parentBlockSignature = previousBlockData.getSignature();
 
 					BigInteger bestWeight = null;
 
@@ -274,9 +275,10 @@ public class BlockMinter extends Thread {
 					try {
 						newBlock.process();
 
-						LOGGER.info(String.format("Minted new block: %d", newBlock.getBlockData().getHeight()));
 						repository.saveChanges();
 
+						LOGGER.info(String.format("Minted new block: %d", newBlock.getBlockData().getHeight()));
+
 						RewardShareData rewardShareData = repository.getAccountRepository().getRewardShare(newBlock.getBlockData().getMinterPublicKey());
 
 						if (rewardShareData != null) {
@@ -292,9 +294,7 @@ public class BlockMinter extends Thread {
 									newBlock.getMinter().getAddress()));
 						}
 
-						repository.saveChanges();
-
-						// Notify controller
+						// Notify controller after we're released blockchain lock
 						newBlockMinted = true;
 					} catch (DataException e) {
 						// Unable to process block - report and discard
@@ -305,8 +305,16 @@ public class BlockMinter extends Thread {
 					blockchainLock.unlock();
 				}
 
-				if (newBlockMinted)
-					Controller.getInstance().onNewBlock(newBlock.getBlockData());
+				if (newBlockMinted) {
+					// Notify Controller and broadcast our new chain to network
+					BlockData newBlockData = newBlock.getBlockData();
+
+					repository.discardChanges(); // clear transaction status to prevent deadlocks
+					Controller.getInstance().onNewBlock(newBlockData);
+
+					Network network = Network.getInstance();
+					network.broadcast(broadcastPeer -> network.buildHeightMessage(broadcastPeer, newBlockData));
+				}
 			}
 		} catch (DataException e) {
 			LOGGER.warn("Repository issue while running block minter", e);

src/main/java/org/qortal/controller/BlockNotifier.java

@@ -1,61 +0,0 @@
-package org.qortal.controller;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.eclipse.jetty.websocket.api.Session;
-import org.qortal.api.model.BlockInfo;
-import org.qortal.data.block.BlockData;
-
-public class BlockNotifier {
-
-	private static BlockNotifier instance;
-
-	@FunctionalInterface
-	public interface Listener {
-		void notify(BlockInfo blockInfo);
-	}
-
-	private Map<Session, Listener> listenersBySession = new HashMap<>();
-
-	private BlockNotifier() {
-	}
-
-	public static synchronized BlockNotifier getInstance() {
-		if (instance == null)
-			instance = new BlockNotifier();
-
-		return instance;
-	}
-
-	public void register(Session session, Listener listener) {
-		synchronized (this.listenersBySession) {
-			this.listenersBySession.put(session, listener);
-		}
-	}
-
-	public void deregister(Session session) {
-		synchronized (this.listenersBySession) {
-			this.listenersBySession.remove(session);
-		}
-	}
-
-	public void onNewBlock(BlockData blockData) {
-		// Convert BlockData to BlockInfo
-		BlockInfo blockInfo = new BlockInfo(blockData);
-
-		for (Listener listener : getAllListeners())
-			listener.notify(blockInfo);
-	}
-
-	private Collection<Listener> getAllListeners() {
-		// Make a copy of listeners to both avoid concurrent modification
-		// and reduce synchronization time
-		synchronized (this.listenersBySession) {
-			return new ArrayList<>(this.listenersBySession.values());
-		}
-	}
-
-}

src/main/java/org/qortal/controller/Controller.java

@@ -16,16 +16,24 @@ import java.util.Collections;
 import java.util.Deque;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Random;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
@@ -36,7 +44,6 @@ import org.qortal.account.PublicKeyAccount;
 import org.qortal.api.ApiService;
 import org.qortal.block.Block;
 import org.qortal.block.BlockChain;
-import org.qortal.block.BlockMinter;
 import org.qortal.block.BlockChain.BlockTimingByHeight;
 import org.qortal.controller.Synchronizer.SynchronizationResult;
 import org.qortal.crypto.Crypto;
@@ -50,6 +57,8 @@ import org.qortal.data.network.PeerData;
 import org.qortal.data.transaction.ArbitraryTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.data.transaction.ArbitraryTransactionData.DataType;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
 import org.qortal.data.transaction.ChatTransactionData;
 import org.qortal.globalization.Translator;
 import org.qortal.gui.Gui;
@@ -85,6 +94,7 @@ import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.transaction.Transaction.ValidationResult;
 import org.qortal.utils.Base58;
 import org.qortal.utils.ByteArray;
+import org.qortal.utils.DaemonThreadFactory;
 import org.qortal.utils.NTP;
 import org.qortal.utils.Triple;
 
@@ -132,16 +142,31 @@ public class Controller extends Thread {
 	private ExecutorService callbackExecutor = Executors.newFixedThreadPool(3);
 	private volatile boolean notifyGroupMembershipChange = false;
 
-	private volatile BlockData chainTip = null;
+	private static final int BLOCK_CACHE_SIZE = 10; // To cover typical Synchronizer request + a few spare
+	/** Latest blocks on our chain. Note: tail/last is the latest block. */
+	private final Deque<BlockData> latestBlocks = new LinkedList<>();
+
+	/** Cache of BlockMessages, indexed by block signature */
+	@SuppressWarnings("serial")
+	private final LinkedHashMap<ByteArray, BlockMessage> blockMessageCache = new LinkedHashMap<>() {
+		@Override
+		protected boolean removeEldestEntry(Map.Entry<ByteArray, BlockMessage> eldest) {
+			return this.size() > BLOCK_CACHE_SIZE;
+		}
+	};
 
 	private long repositoryBackupTimestamp = startTime; // ms
+	private long repositoryCheckpointTimestamp = startTime; // ms
 	private long ntpCheckTimestamp = startTime; // ms
 	private long deleteExpiredTimestamp = startTime + DELETE_EXPIRED_INTERVAL; // ms
+
 	private long onlineAccountsTasksTimestamp = startTime + ONLINE_ACCOUNTS_TASKS_INTERVAL; // ms
 
 	/** Whether we can mint new blocks, as reported by BlockMinter. */
 	private volatile boolean isMintingPossible = false;
 
+	/** Synchronization object for sync variables below */
+	private final Object syncLock = new Object();
 	/** Whether we are attempting to synchronize. */
 	private volatile boolean isSynchronizing = false;
 	/** Temporary estimate of synchronization progress for SysTray use. */
@@ -177,6 +202,47 @@ public class Controller extends Thread {
 	/** Cache of latest blocks' online accounts */
 	Deque<List<OnlineAccountData>> latestBlocksOnlineAccounts = new ArrayDeque<>(MAX_BLOCKS_CACHED_ONLINE_ACCOUNTS);
 
+	// Stats
+	@XmlAccessorType(XmlAccessType.FIELD)
+	public static class StatsSnapshot {
+		public static class GetBlockMessageStats {
+			public AtomicLong requests = new AtomicLong();
+			public AtomicLong cacheHits = new AtomicLong();
+			public AtomicLong unknownBlocks = new AtomicLong();
+			public AtomicLong cacheFills = new AtomicLong();
+
+			public GetBlockMessageStats() {
+			}
+		}
+		public GetBlockMessageStats getBlockMessageStats = new GetBlockMessageStats();
+
+		public static class GetBlockSummariesStats {
+			public AtomicLong requests = new AtomicLong();
+			public AtomicLong cacheHits = new AtomicLong();
+			public AtomicLong fullyFromCache = new AtomicLong();
+
+			public GetBlockSummariesStats() {
+			}
+		}
+		public GetBlockSummariesStats getBlockSummariesStats = new GetBlockSummariesStats();
+
+		public static class GetBlockSignaturesV2Stats {
+			public AtomicLong requests = new AtomicLong();
+			public AtomicLong cacheHits = new AtomicLong();
+			public AtomicLong fullyFromCache = new AtomicLong();
+
+			public GetBlockSignaturesV2Stats() {
+			}
+		}
+		public GetBlockSignaturesV2Stats getBlockSignaturesV2Stats = new GetBlockSignaturesV2Stats();
+
+		public AtomicLong latestBlocksCacheRefills = new AtomicLong();
+
+		public StatsSnapshot() {
+		}
+	}
+	private final StatsSnapshot stats = new StatsSnapshot();
+
 	// Constructors
 
 	private Controller(String[] args) {
@@ -232,21 +298,36 @@ public class Controller extends Thread {
 
 	/** Returns current blockchain height, or 0 if it's not available. */
 	public int getChainHeight() {
-		BlockData blockData = this.chainTip;
-		if (blockData == null)
-			return 0;
+		synchronized (this.latestBlocks) {
+			BlockData blockData = this.latestBlocks.peekLast();
+			if (blockData == null)
+				return 0;
 
-		return blockData.getHeight();
+			return blockData.getHeight();
+		}
 	}
 
 	/** Returns highest block, or null if it's not available. */
 	public BlockData getChainTip() {
-		return this.chainTip;
+		synchronized (this.latestBlocks) {
+			return this.latestBlocks.peekLast();
+		}
 	}
 
-	/** Cache new blockchain tip. */
-	public void setChainTip(BlockData blockData) {
-		this.chainTip = blockData;
+	public void refillLatestBlocksCache() throws DataException {
+		// Set initial chain height/tip
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			BlockData blockData = repository.getBlockRepository().getLastBlock();
+
+			synchronized (this.latestBlocks) {
+				this.latestBlocks.clear();
+
+				for (int i = 0; i < BLOCK_CACHE_SIZE && blockData != null; ++i) {
+					this.latestBlocks.addFirst(blockData);
+					blockData = repository.getBlockRepository().fromHeight(blockData.getHeight() - 1);
+				}
+			}
+		}
 	}
 
 	public ReentrantLock getBlockchainLock() {
@@ -271,7 +352,9 @@ public class Controller extends Thread {
 	}
 
 	public Integer getSyncPercent() {
-		return this.isSynchronizing ? this.syncPercent : null;
+		synchronized (this.syncLock) {
+			return this.isSynchronizing ? this.syncPercent : null;
+		}
 	}
 
 	// Entry point
@@ -326,13 +409,8 @@ public class Controller extends Thread {
 		try {
 			BlockChain.validate();
 
-			// Set initial chain height/tip
-			try (final Repository repository = RepositoryManager.getRepository()) {
-				BlockData blockData = repository.getBlockRepository().getLastBlock();
-
-				Controller.getInstance().setChainTip(blockData);
-				LOGGER.info(String.format("Our chain height at start-up: %d", blockData.getHeight()));
-			}
+			Controller.getInstance().refillLatestBlocksCache();
+			LOGGER.info(String.format("Our chain height at start-up: %d", Controller.getInstance().getChainHeight()));
 		} catch (DataException e) {
 			LOGGER.error("Couldn't validate blockchain", e);
 			Gui.getInstance().fatalError("Blockchain validation issue", e);
@@ -366,6 +444,9 @@ public class Controller extends Thread {
 		blockMinter = new BlockMinter();
 		blockMinter.start();
 
+		LOGGER.info("Starting trade-bot");
+		TradeBot.getInstance();
+
 		// Arbitrary transaction data manager
 		// LOGGER.info("Starting arbitrary-transaction data manager");
 		// ArbitraryDataManager.getInstance().start();
@@ -404,6 +485,11 @@ public class Controller extends Thread {
 		Thread.currentThread().setName("Controller");
 
 		final long repositoryBackupInterval = Settings.getInstance().getRepositoryBackupInterval();
+		final long repositoryCheckpointInterval = Settings.getInstance().getRepositoryCheckpointInterval();
+
+		ExecutorService trimExecutor = Executors.newCachedThreadPool(new DaemonThreadFactory());
+		trimExecutor.execute(new AtStatesTrimmer());
+		trimExecutor.execute(new OnlineAccountsSignaturesTrimmer());
 
 		try {
 			while (!isStopping) {
@@ -445,6 +531,18 @@ public class Controller extends Thread {
 				final long requestMinimumTimestamp = now - ARBITRARY_REQUEST_TIMEOUT;
 				arbitraryDataRequests.entrySet().removeIf(entry -> entry.getValue().getC() < requestMinimumTimestamp);
 
+				// Time to 'checkpoint' uncommitted repository writes?
+				if (now >= repositoryCheckpointTimestamp + repositoryCheckpointInterval) {
+					repositoryCheckpointTimestamp = now + repositoryCheckpointInterval;
+
+					if (Settings.getInstance().getShowCheckpointNotification())
+						SysTray.getInstance().showMessage(Translator.INSTANCE.translate("SysTray", "DB_CHECKPOINT"),
+								Translator.INSTANCE.translate("SysTray", "PERFORMING_DB_CHECKPOINT"),
+								MessageType.INFO);
+
+					RepositoryManager.checkpoint(true);
+				}
+
 				// Give repository a chance to backup (if enabled)
 				if (repositoryBackupInterval > 0 && now >= repositoryBackupTimestamp + repositoryBackupInterval) {
 					repositoryBackupTimestamp = now + repositoryBackupInterval;
@@ -477,7 +575,17 @@ public class Controller extends Thread {
 				}
 			}
 		} catch (InterruptedException e) {
+			// Clear interrupted flag so we can shutdown trim threads
+			Thread.interrupted();
 			// Fall-through to exit
+		} finally {
+			trimExecutor.shutdownNow();
+
+			try {
+				trimExecutor.awaitTermination(2L, TimeUnit.SECONDS);
+			} catch (InterruptedException e) {
+				// We tried...
+			}
 		}
 	}
 
@@ -510,6 +618,10 @@ public class Controller extends Thread {
 	};
 
 	private void potentiallySynchronize() throws InterruptedException {
+		// Already synchronizing via another thread?
+		if (this.isSynchronizing)
+			return;
+
 		List<Peer> peers = Network.getInstance().getHandshakedPeers();
 
 		// Disregard peers that have "misbehaved" recently
@@ -542,14 +654,21 @@ public class Controller extends Thread {
 	}
 
 	public SynchronizationResult actuallySynchronize(Peer peer, boolean force) throws InterruptedException {
-		syncPercent = (this.chainTip.getHeight() * 100) / peer.getChainTipData().getLastHeight();
-		// Only update SysTray if we're potentially changing height
-		if (syncPercent < 100) {
-			isSynchronizing = true;
-			updateSysTray();
+		boolean hasStatusChanged = false;
+		BlockData priorChainTip = this.getChainTip();
+
+		synchronized (this.syncLock) {
+			this.syncPercent = (priorChainTip.getHeight() * 100) / peer.getChainTipData().getLastHeight();
+
+			// Only update SysTray if we're potentially changing height
+			if (this.syncPercent < 100) {
+				this.isSynchronizing = true;
+				hasStatusChanged = true;
+			}
 		}
 
-		BlockData priorChainTip = this.chainTip;
+		if (hasStatusChanged)
+			updateSysTray();
 
 		try {
 			SynchronizationResult syncResult = Synchronizer.getInstance().synchronize(peer, force);
@@ -619,8 +738,8 @@ public class Controller extends Thread {
 				// Reset our cache of inferior chains
 				inferiorChainSignatures.clear();
 
-				// Update chain-tip, systray, notify peers, websockets, etc.
-				this.onNewBlock(newChainTip);
+				Network network = Network.getInstance();
+				network.broadcast(broadcastPeer -> network.buildHeightMessage(broadcastPeer, newChainTip));
 			}
 
 			return syncResult;
@@ -629,6 +748,11 @@ public class Controller extends Thread {
 		}
 	}
 
+	public static class StatusChangeEvent implements Event {
+		public StatusChangeEvent() {
+		}
+	}
+
 	private void updateSysTray() {
 		if (NTP.getTime() == null) {
 			SysTray.getInstance().setToolTipText(Translator.INSTANCE.translate("SysTray", "SYNCHRONIZING_CLOCK"));
@@ -643,20 +767,23 @@ public class Controller extends Thread {
 		String heightText = Translator.INSTANCE.translate("SysTray", "BLOCK_HEIGHT");
 
 		String actionText;
-		if (isMintingPossible)
-			actionText = Translator.INSTANCE.translate("SysTray", "MINTING_ENABLED");
-		else if (isSynchronizing)
-			actionText = String.format("%s - %d%%", Translator.INSTANCE.translate("SysTray", "SYNCHRONIZING_BLOCKCHAIN"), syncPercent);
-		else if (numberOfPeers < Settings.getInstance().getMinBlockchainPeers())
-			actionText = Translator.INSTANCE.translate("SysTray", "CONNECTING");
-		else
-			actionText = Translator.INSTANCE.translate("SysTray", "MINTING_DISABLED");
+
+		synchronized (this.syncLock) {
+			if (this.isMintingPossible)
+				actionText = Translator.INSTANCE.translate("SysTray", "MINTING_ENABLED");
+			else if (this.isSynchronizing)
+				actionText = String.format("%s - %d%%", Translator.INSTANCE.translate("SysTray", "SYNCHRONIZING_BLOCKCHAIN"), this.syncPercent);
+			else if (numberOfPeers < Settings.getInstance().getMinBlockchainPeers())
+				actionText = Translator.INSTANCE.translate("SysTray", "CONNECTING");
+			else
+				actionText = Translator.INSTANCE.translate("SysTray", "MINTING_DISABLED");
+		}
 
 		String tooltip = String.format("%s - %d %s - %s %d", actionText, numberOfPeers, connectionsText, heightText, height);
 		SysTray.getInstance().setToolTipText(tooltip);
 
 		this.callbackExecutor.execute(() -> {
-			StatusNotifier.getInstance().onStatusChange(NTP.getTime());
+			EventBus.INSTANCE.notify(new StatusChangeEvent());
 		});
 	}
 
@@ -783,25 +910,126 @@ public class Controller extends Thread {
 		requestSysTrayUpdate = true;
 	}
 
+	public static class NewBlockEvent implements Event {
+		private final BlockData blockData;
+
+		public NewBlockEvent(BlockData blockData) {
+			this.blockData = blockData;
+		}
+
+		public BlockData getBlockData() {
+			return this.blockData;
+		}
+	}
+
+	/**
+	 * Callback for when we've received a new block.
+	 * <p>
+	 * See <b>WARNING</b> for {@link EventBus#notify(Event)}
+	 * to prevent deadlocks.
+	 */
 	public void onNewBlock(BlockData latestBlockData) {
-		this.setChainTip(latestBlockData);
-		requestSysTrayUpdate = true;
+		// Protective copy
+		BlockData blockDataCopy = new BlockData(latestBlockData);
 
-		// Broadcast our new height info and notify websocket listeners
-		this.callbackExecutor.execute(() -> {
-			Network network = Network.getInstance();
-			network.broadcast(peer -> network.buildHeightMessage(peer, latestBlockData));
+		synchronized (this.latestBlocks) {
+			BlockData cachedChainTip = this.latestBlocks.peekLast();
 
-			BlockNotifier.getInstance().onNewBlock(latestBlockData);
+			if (cachedChainTip != null && Arrays.equals(cachedChainTip.getSignature(), blockDataCopy.getReference())) {
+				// Chain tip is parent for new latest block, so we can safely add new latest block
+				this.latestBlocks.addLast(latestBlockData);
 
-			if (this.notifyGroupMembershipChange) {
-				this.notifyGroupMembershipChange = false;
-				ChatNotifier.getInstance().onGroupMembershipChange();
+				// Trim if necessary
+				if (this.latestBlocks.size() >= BLOCK_CACHE_SIZE)
+					this.latestBlocks.pollFirst();
+			} else {
+				if (cachedChainTip != null)
+					// Chain tip didn't match - potentially abnormal behaviour?
+					LOGGER.debug(() -> String.format("Cached chain tip %.8s not parent for new latest block %.8s (reference %.8s)",
+							Base58.encode(cachedChainTip.getSignature()),
+							Base58.encode(blockDataCopy.getSignature()),
+							Base58.encode(blockDataCopy.getReference())));
+
+				// Defensively rebuild cache
+				try {
+					this.stats.latestBlocksCacheRefills.incrementAndGet();
+
+					this.refillLatestBlocksCache();
+				} catch (DataException e) {
+					LOGGER.warn(() -> "Couldn't refill latest blocks cache?", e);
+				}
+			}
+		}
+
+		this.onNewOrOrphanedBlock(blockDataCopy, NewBlockEvent::new);
+	}
+
+	public static class OrphanedBlockEvent implements Event {
+		private final BlockData blockData;
+
+		public OrphanedBlockEvent(BlockData blockData) {
+			this.blockData = blockData;
+		}
+
+		public BlockData getBlockData() {
+			return this.blockData;
+		}
+	}
+
+	/**
+	 * Callback for when we've orphaned a block.
+	 * <p>
+	 * See <b>WARNING</b> for {@link EventBus#notify(Event)}
+	 * to prevent deadlocks.
+	 */
+	public void onOrphanedBlock(BlockData latestBlockData) {
+		// Protective copy
+		BlockData blockDataCopy = new BlockData(latestBlockData);
+
+		synchronized (this.latestBlocks) {
+			BlockData cachedChainTip = this.latestBlocks.pollLast();
+			boolean refillNeeded = false;
+
+			if (cachedChainTip != null && Arrays.equals(cachedChainTip.getReference(), blockDataCopy.getSignature())) {
+				// Chain tip was parent for new latest block that has been orphaned, so we're good
+
+				// However, if we've emptied the cache then we will need to refill it
+				refillNeeded = this.latestBlocks.isEmpty();
+			} else {
+				if (cachedChainTip != null)
+					// Chain tip didn't match - potentially abnormal behaviour?
+					LOGGER.debug(() -> String.format("Cached chain tip %.8s (reference %.8s) was not parent for new latest block %.8s",
+							Base58.encode(cachedChainTip.getSignature()),
+							Base58.encode(cachedChainTip.getReference()),
+							Base58.encode(blockDataCopy.getSignature())));
+
+				// Defensively rebuild cache
+				refillNeeded = true;
 			}
 
-			// Trade-bot might want to perform some actions too
-			TradeBot.getInstance().onChainTipChange();
-		});
+			if (refillNeeded)
+				try {
+					this.stats.latestBlocksCacheRefills.incrementAndGet();
+
+					this.refillLatestBlocksCache();
+				} catch (DataException e) {
+					LOGGER.warn(() -> "Couldn't refill latest blocks cache?", e);
+				}
+		}
+
+		this.onNewOrOrphanedBlock(blockDataCopy, OrphanedBlockEvent::new);
+	}
+
+	private void onNewOrOrphanedBlock(BlockData blockDataCopy, Function<BlockData, Event> eventConstructor) {
+		requestSysTrayUpdate = true;
+
+		// Notify listeners, trade-bot, etc.
+		EventBus.INSTANCE.notify(eventConstructor.apply(blockDataCopy));
+
+		if (this.notifyGroupMembershipChange) {
+			this.notifyGroupMembershipChange = false;
+			ChatNotifier.getInstance().onGroupMembershipChange();
+		}
 	}
 
 	/** Callback for when we've received a new transaction via API or peer. */
@@ -896,11 +1124,31 @@ public class Controller extends Thread {
 	private void onNetworkGetBlockMessage(Peer peer, Message message) {
 		GetBlockMessage getBlockMessage = (GetBlockMessage) message;
 		byte[] signature = getBlockMessage.getSignature();
+		this.stats.getBlockMessageStats.requests.incrementAndGet();
+
+		ByteArray signatureAsByteArray = new ByteArray(signature);
+
+		BlockMessage cachedBlockMessage = this.blockMessageCache.get(signatureAsByteArray);
+
+		// Check cached latest block message
+		if (cachedBlockMessage != null) {
+			this.stats.getBlockMessageStats.cacheHits.incrementAndGet();
+
+			// We need to duplicate it to prevent multiple threads setting ID on the same message
+			BlockMessage clonedBlockMessage = cachedBlockMessage.cloneWithNewId(message.getId());
+
+			if (!peer.sendMessage(clonedBlockMessage))
+				peer.disconnect("failed to send block");
+
+			return;
+		}
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			BlockData blockData = repository.getBlockRepository().fromSignature(signature);
+
 			if (blockData == null) {
 				// We don't have this block
+				this.stats.getBlockMessageStats.unknownBlocks.getAndIncrement();
 
 				// Send valid, yet unexpected message type in response, so peer's synchronizer doesn't have to wait for timeout
 				LOGGER.debug(() -> String.format("Sending 'block unknown' response to peer %s for GET_BLOCK request for unknown block %s", peer, Base58.encode(signature)));
@@ -915,10 +1163,19 @@ public class Controller extends Thread {
 
 			Block block = new Block(repository, blockData);
 
-			Message blockMessage = new BlockMessage(block);
+			BlockMessage blockMessage = new BlockMessage(block);
 			blockMessage.setId(message.getId());
+
+			// This call also causes the other needed data to be pulled in from repository
 			if (!peer.sendMessage(blockMessage))
 				peer.disconnect("failed to send block");
+
+			// If request is for a recent block, cache it
+			if (getChainHeight() - blockData.getHeight() <= BLOCK_CACHE_SIZE) {
+				this.stats.getBlockMessageStats.cacheFills.incrementAndGet();
+
+				this.blockMessageCache.put(new ByteArray(blockData.getSignature()), blockMessage);
+			}
 		} catch (DataException e) {
 			LOGGER.error(String.format("Repository issue while send block %s to peer %s", Base58.encode(signature), peer), e);
 		}
@@ -965,59 +1222,110 @@ public class Controller extends Thread {
 
 	private void onNetworkGetBlockSummariesMessage(Peer peer, Message message) {
 		GetBlockSummariesMessage getBlockSummariesMessage = (GetBlockSummariesMessage) message;
-		byte[] parentSignature = getBlockSummariesMessage.getParentSignature();
+		final byte[] parentSignature = getBlockSummariesMessage.getParentSignature();
+		this.stats.getBlockSummariesStats.requests.incrementAndGet();
 
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			List<BlockSummaryData> blockSummaries = new ArrayList<>();
-
-			int numberRequested = Math.min(Network.MAX_BLOCK_SUMMARIES_PER_REPLY, getBlockSummariesMessage.getNumberRequested());
-
-			do {
-				BlockData blockData = repository.getBlockRepository().fromReference(parentSignature);
-
-				if (blockData == null)
-					// No more blocks to send to peer
-					break;
-
-				BlockSummaryData blockSummary = new BlockSummaryData(blockData);
-				blockSummaries.add(blockSummary);
-				parentSignature = blockData.getSignature();
-			} while (blockSummaries.size() < numberRequested);
-
-			Message blockSummariesMessage = new BlockSummariesMessage(blockSummaries);
+		// If peer's parent signature matches our latest block signature
+		// then we can short-circuit with an empty response
+		BlockData chainTip = getChainTip();
+		if (chainTip != null && Arrays.equals(parentSignature, chainTip.getSignature())) {
+			Message blockSummariesMessage = new BlockSummariesMessage(Collections.emptyList());
 			blockSummariesMessage.setId(message.getId());
 			if (!peer.sendMessage(blockSummariesMessage))
 				peer.disconnect("failed to send block summaries");
-		} catch (DataException e) {
-			LOGGER.error(String.format("Repository issue while sending block summaries after %s to peer %s", Base58.encode(parentSignature), peer), e);
+
+			return;
 		}
+
+		List<BlockSummaryData> blockSummaries = new ArrayList<>();
+
+		// Attempt to serve from our cache of latest blocks
+		synchronized (this.latestBlocks) {
+			blockSummaries = this.latestBlocks.stream()
+					.dropWhile(cachedBlockData -> !Arrays.equals(cachedBlockData.getReference(), parentSignature))
+					.map(BlockSummaryData::new)
+					.collect(Collectors.toList());
+		}
+
+		if (blockSummaries.isEmpty()) {
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int numberRequested = Math.min(Network.MAX_BLOCK_SUMMARIES_PER_REPLY, getBlockSummariesMessage.getNumberRequested());
+
+				BlockData blockData = repository.getBlockRepository().fromReference(parentSignature);
+
+				while (blockData != null && blockSummaries.size() < numberRequested) {
+					BlockSummaryData blockSummary = new BlockSummaryData(blockData);
+					blockSummaries.add(blockSummary);
+
+					blockData = repository.getBlockRepository().fromReference(blockData.getSignature());
+				}
+			} catch (DataException e) {
+				LOGGER.error(String.format("Repository issue while sending block summaries after %s to peer %s", Base58.encode(parentSignature), peer), e);
+			}
+		} else {
+			this.stats.getBlockSummariesStats.cacheHits.incrementAndGet();
+
+			if (blockSummaries.size() >= getBlockSummariesMessage.getNumberRequested())
+				this.stats.getBlockSummariesStats.fullyFromCache.incrementAndGet();
+		}
+
+		Message blockSummariesMessage = new BlockSummariesMessage(blockSummaries);
+		blockSummariesMessage.setId(message.getId());
+		if (!peer.sendMessage(blockSummariesMessage))
+			peer.disconnect("failed to send block summaries");
 	}
 
 	private void onNetworkGetSignaturesV2Message(Peer peer, Message message) {
 		GetSignaturesV2Message getSignaturesMessage = (GetSignaturesV2Message) message;
-		byte[] parentSignature = getSignaturesMessage.getParentSignature();
+		final byte[] parentSignature = getSignaturesMessage.getParentSignature();
+		this.stats.getBlockSignaturesV2Stats.requests.incrementAndGet();
 
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			List<byte[]> signatures = new ArrayList<>();
-
-			do {
-				BlockData blockData = repository.getBlockRepository().fromReference(parentSignature);
-
-				if (blockData == null)
-					// No more signatures to send to peer
-					break;
-
-				parentSignature = blockData.getSignature();
-				signatures.add(parentSignature);
-			} while (signatures.size() < getSignaturesMessage.getNumberRequested());
-
-			Message signaturesMessage = new SignaturesMessage(signatures);
+		// If peer's parent signature matches our latest block signature
+		// then we can short-circuit with an empty response
+		BlockData chainTip = getChainTip();
+		if (chainTip != null && Arrays.equals(parentSignature, chainTip.getSignature())) {
+			Message signaturesMessage = new SignaturesMessage(Collections.emptyList());
 			signaturesMessage.setId(message.getId());
 			if (!peer.sendMessage(signaturesMessage))
 				peer.disconnect("failed to send signatures (v2)");
-		} catch (DataException e) {
-			LOGGER.error(String.format("Repository issue while sending V2 signatures after %s to peer %s", Base58.encode(parentSignature), peer), e);
+
+			return;
 		}
+
+		List<byte[]> signatures = new ArrayList<>();
+
+		// Attempt to serve from our cache of latest blocks
+		synchronized (this.latestBlocks) {
+			signatures = this.latestBlocks.stream()
+					.dropWhile(cachedBlockData -> !Arrays.equals(cachedBlockData.getReference(), parentSignature))
+					.map(BlockData::getSignature)
+					.collect(Collectors.toList());
+		}
+
+		if (signatures.isEmpty()) {
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int numberRequested = getSignaturesMessage.getNumberRequested();
+				BlockData blockData = repository.getBlockRepository().fromReference(parentSignature);
+
+				while (blockData != null && signatures.size() < numberRequested) {
+					signatures.add(blockData.getSignature());
+
+					blockData = repository.getBlockRepository().fromReference(blockData.getSignature());
+				}
+			} catch (DataException e) {
+				LOGGER.error(String.format("Repository issue while sending V2 signatures after %s to peer %s", Base58.encode(parentSignature), peer), e);
+			}
+		} else {
+			this.stats.getBlockSignaturesV2Stats.cacheHits.incrementAndGet();
+
+			if (signatures.size() >= getSignaturesMessage.getNumberRequested())
+				this.stats.getBlockSignaturesV2Stats.fullyFromCache.incrementAndGet();
+		}
+
+		Message signaturesMessage = new SignaturesMessage(signatures);
+		signaturesMessage.setId(message.getId());
+		if (!peer.sendMessage(signaturesMessage))
+			peer.disconnect("failed to send signatures (v2)");
 	}
 
 	private void onNetworkHeightV2Message(Peer peer, Message message) {
@@ -1367,9 +1675,6 @@ public class Controller extends Thread {
 
 		// Refresh our online accounts signatures?
 		sendOurOnlineAccountsInfo();
-
-		// Trim blockchain by removing 'old' online accounts signatures
-		BlockChain.trimOldOnlineAccountsSignatures();
 	}
 
 	private void sendOurOnlineAccountsInfo() {
@@ -1631,4 +1936,8 @@ public class Controller extends Thread {
 		return now - offset;
 	}
 
+	public StatsSnapshot getStatsSnapshot() {
+		return this.stats;
+	}
+
 }

src/main/java/org/qortal/controller/OnlineAccountsSignaturesTrimmer.java

@@ -0,0 +1,75 @@
+package org.qortal.controller;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.block.BlockChain;
+import org.qortal.data.block.BlockData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.utils.NTP;
+
+public class OnlineAccountsSignaturesTrimmer implements Runnable {
+
+	private static final Logger LOGGER = LogManager.getLogger(OnlineAccountsSignaturesTrimmer.class);
+
+	private static final long INITIAL_SLEEP_PERIOD = 5 * 60 * 1000L + 1234L; // ms
+
+	public void run() {
+		Thread.currentThread().setName("Online Accounts trimmer");
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			// Don't even start trimming until initial rush has ended
+			Thread.sleep(INITIAL_SLEEP_PERIOD);
+
+			while (!Controller.isStopping()) {
+				repository.discardChanges();
+
+				Thread.sleep(Settings.getInstance().getOnlineSignaturesTrimInterval());
+
+				BlockData chainTip = Controller.getInstance().getChainTip();
+				if (chainTip == null || NTP.getTime() == null)
+					continue;
+
+				// Don't even attempt if we're mid-sync as our repository requests will be delayed for ages
+				if (Controller.getInstance().isSynchronizing())
+					continue;
+
+				// Trim blockchain by removing 'old' online accounts signatures
+				long upperTrimmableTimestamp = NTP.getTime() - BlockChain.getInstance().getOnlineAccountSignaturesMaxLifetime();
+				int upperTrimmableHeight = repository.getBlockRepository().getHeightFromTimestamp(upperTrimmableTimestamp);
+
+				int trimStartHeight = repository.getBlockRepository().getOnlineAccountsSignaturesTrimHeight();
+
+				int upperBatchHeight = trimStartHeight + Settings.getInstance().getOnlineSignaturesTrimBatchSize();
+				int upperTrimHeight = Math.min(upperBatchHeight, upperTrimmableHeight);
+
+				if (trimStartHeight >= upperTrimHeight)
+					continue;
+
+				int numSigsTrimmed = repository.getBlockRepository().trimOldOnlineAccountsSignatures(trimStartHeight, upperTrimHeight);
+				repository.saveChanges();
+
+				if (numSigsTrimmed > 0) {
+					LOGGER.debug(() -> String.format("Trimmed %d online accounts signature%s between blocks %d and %d",
+							numSigsTrimmed, (numSigsTrimmed != 1 ? "s" : ""),
+							trimStartHeight, upperTrimHeight));
+				} else {
+					// Can we move onto next batch?
+					if (upperTrimmableHeight > upperBatchHeight) {
+						repository.getBlockRepository().setOnlineAccountsSignaturesTrimHeight(upperBatchHeight);
+						repository.saveChanges();
+
+						LOGGER.debug(() -> String.format("Bumping online accounts signatures trim height to %d", upperBatchHeight));
+					}
+				}
+			}
+		} catch (DataException e) {
+			LOGGER.warn(String.format("Repository issue trying to trim online accounts signatures: %s", e.getMessage()));
+		} catch (InterruptedException e) {
+			// Time to exit
+		}
+	}
+
+}

src/main/java/org/qortal/controller/StatusNotifier.java

@@ -1,56 +0,0 @@
-package org.qortal.controller;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.eclipse.jetty.websocket.api.Session;
-
-public class StatusNotifier {
-
-	private static StatusNotifier instance;
-
-	@FunctionalInterface
-	public interface Listener {
-		void notify(long timestamp);
-	}
-
-	private Map<Session, Listener> listenersBySession = new HashMap<>();
-
-	private StatusNotifier() {
-	}
-
-	public static synchronized StatusNotifier getInstance() {
-		if (instance == null)
-			instance = new StatusNotifier();
-
-		return instance;
-	}
-
-	public void register(Session session, Listener listener) {
-		synchronized (this.listenersBySession) {
-			this.listenersBySession.put(session, listener);
-		}
-	}
-
-	public void deregister(Session session) {
-		synchronized (this.listenersBySession) {
-			this.listenersBySession.remove(session);
-		}
-	}
-
-	public void onStatusChange(long now) {
-		for (Listener listener : getAllListeners())
-			listener.notify(now);
-	}
-
-	private Collection<Listener> getAllListeners() {
-		// Make a copy of listeners to both avoid concurrent modification
-		// and reduce synchronization time
-		synchronized (this.listenersBySession) {
-			return new ArrayList<>(this.listenersBySession.values());
-		}
-	}
-
-}

src/main/java/org/qortal/controller/Synchronizer.java

@@ -4,6 +4,7 @@ import java.math.BigInteger;
 import java.text.DecimalFormat;
 import java.text.NumberFormat;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.stream.Collectors;
@@ -11,11 +12,13 @@ import java.util.stream.Collectors;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.account.Account;
+import org.qortal.account.PublicKeyAccount;
 import org.qortal.block.Block;
 import org.qortal.block.Block.ValidationResult;
 import org.qortal.data.block.BlockData;
 import org.qortal.data.block.BlockSummaryData;
 import org.qortal.data.network.PeerChainTipData;
+import org.qortal.data.transaction.RewardShareTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.network.Peer;
 import org.qortal.network.message.BlockMessage;
@@ -172,7 +175,7 @@ public class Synchronizer {
 	 * @throws DataException
 	 * @throws InterruptedException
 	 */
-	private SynchronizationResult fetchSummariesFromCommonBlock(Repository repository, Peer peer, int ourHeight, boolean force, List<BlockSummaryData> blockSummariesFromCommon) throws DataException, InterruptedException {
+	public SynchronizationResult fetchSummariesFromCommonBlock(Repository repository, Peer peer, int ourHeight, boolean force, List<BlockSummaryData> blockSummariesFromCommon) throws DataException, InterruptedException {
 		// Start by asking for a few recent block hashes as this will cover a majority of reorgs
 		// Failing that, back off exponentially
 		int step = INITIAL_BLOCK_STEP;
@@ -238,15 +241,15 @@ public class Synchronizer {
 		blockSummariesFromCommon.addAll(blockSummariesBatch);
 
 		// Trim summaries so that first summary is common block.
-		// Currently we work back from the end until we hit a block we also have.
+		// Currently we work forward from common block until we hit a block we don't have
 		// TODO: rewrite as modified binary search!
-		for (int i = blockSummariesFromCommon.size() - 1; i > 0; --i) {
-			if (repository.getBlockRepository().exists(blockSummariesFromCommon.get(i).getSignature())) {
-				// Note: index i isn't cleared: List.subList is fromIndex inclusive to toIndex exclusive
-				blockSummariesFromCommon.subList(0, i).clear();
+		int i;
+		for (i = 1; i < blockSummariesFromCommon.size(); ++i)
+			if (!repository.getBlockRepository().exists(blockSummariesFromCommon.get(i).getSignature()))
 				break;
-			}
-		}
+
+		// Note: index i - 1 isn't cleared: List.subList is fromIndex inclusive to toIndex exclusive
+		blockSummariesFromCommon.subList(0, i - 1).clear();
 
 		return SynchronizationResult.OK;
 	}
@@ -310,18 +313,21 @@ public class Synchronizer {
 			List<BlockSummaryData> ourBlockSummaries = repository.getBlockRepository().getBlockSummaries(commonBlockHeight + 1, ourLatestBlockData.getHeight());
 
 			// Populate minter account levels for both lists of block summaries
-			populateBlockSummariesMinterLevels(repository, peerBlockSummaries);
 			populateBlockSummariesMinterLevels(repository, ourBlockSummaries);
+			populateBlockSummariesMinterLevels(repository, peerBlockSummaries);
+
+			final int mutualHeight = commonBlockHeight - 1 + Math.min(ourBlockSummaries.size(), peerBlockSummaries.size());
 
 			// Calculate cumulative chain weights of both blockchain subsets, from common block to highest mutual block.
-			BigInteger ourChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, ourBlockSummaries);
-			BigInteger peerChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, peerBlockSummaries);
+			BigInteger ourChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, ourBlockSummaries, mutualHeight);
+			BigInteger peerChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockSig, peerBlockSummaries, mutualHeight);
+
+			NumberFormat formatter = new DecimalFormat("0.###E0");
+			LOGGER.debug(String.format("Our chain weight: %s, peer's chain weight: %s (higher is better)", formatter.format(ourChainWeight), formatter.format(peerChainWeight)));
 
 			// If our blockchain has greater weight then don't synchronize with peer
 			if (ourChainWeight.compareTo(peerChainWeight) >= 0) {
 				LOGGER.debug(String.format("Not synchronizing with peer %s as we have better blockchain", peer));
-				NumberFormat formatter = new DecimalFormat("0.###E0");
-				LOGGER.debug(String.format("Our chain weight: %s, peer's chain weight: %s (higher is better)", formatter.format(ourChainWeight), formatter.format(peerChainWeight)));
 				return SynchronizationResult.INFERIOR_CHAIN;
 			}
 		}
@@ -394,15 +400,23 @@ public class Synchronizer {
 		// Unwind to common block (unless common block is our latest block)
 		LOGGER.debug(String.format("Orphaning blocks back to common block height %d, sig %.8s", commonBlockHeight, commonBlockSig58));
 
+		BlockData orphanBlockData = repository.getBlockRepository().fromHeight(ourHeight);
 		while (ourHeight > commonBlockHeight) {
 			if (Controller.isStopping())
 				return SynchronizationResult.SHUTTING_DOWN;
 
-			BlockData blockData = repository.getBlockRepository().fromHeight(ourHeight);
-			Block block = new Block(repository, blockData);
+			Block block = new Block(repository, orphanBlockData);
 			block.orphan();
 
+			LOGGER.trace(String.format("Orphaned block height %d, sig %.8s", ourHeight, Base58.encode(orphanBlockData.getSignature())));
+
+			repository.saveChanges();
+
 			--ourHeight;
+			orphanBlockData = repository.getBlockRepository().fromHeight(ourHeight);
+
+			repository.discardChanges(); // clear transaction status to prevent deadlocks
+			Controller.getInstance().onOrphanedBlock(orphanBlockData);
 		}
 
 		LOGGER.debug(String.format("Orphaned blocks back to height %d, sig %.8s - applying new blocks from peer %s", commonBlockHeight, commonBlockSig58, peer));
@@ -423,9 +437,11 @@ public class Synchronizer {
 
 			newBlock.process();
 
-			// If we've grown our blockchain then at least save progress so far
-			if (ourHeight > ourInitialHeight)
-				repository.saveChanges();
+			LOGGER.trace(String.format("Processed block height %d, sig %.8s", newBlock.getBlockData().getHeight(), Base58.encode(newBlock.getBlockData().getSignature())));
+
+			repository.saveChanges();
+
+			Controller.getInstance().onNewBlock(newBlock.getBlockData());
 		}
 
 		return SynchronizationResult.OK;
@@ -505,9 +521,11 @@ public class Synchronizer {
 
 			newBlock.process();
 
-			// If we've grown our blockchain then at least save progress so far
-			if (ourHeight > ourInitialHeight)
-				repository.saveChanges();
+			LOGGER.trace(String.format("Processed block height %d, sig %.8s", newBlock.getBlockData().getHeight(), Base58.encode(newBlock.getBlockData().getSignature())));
+
+			repository.saveChanges();
+
+			Controller.getInstance().onNewBlock(newBlock.getBlockData());
 		}
 
 		return SynchronizationResult.OK;
@@ -550,16 +568,34 @@ public class Synchronizer {
 	}
 
 	private void populateBlockSummariesMinterLevels(Repository repository, List<BlockSummaryData> blockSummaries) throws DataException {
+		final int firstBlockHeight = blockSummaries.get(0).getHeight();
+
 		for (int i = 0; i < blockSummaries.size(); ++i) {
 			BlockSummaryData blockSummary = blockSummaries.get(i);
 
 			// Qortal: minter is always a reward-share, so find actual minter and get their effective minting level
 			int minterLevel = Account.getRewardShareEffectiveMintingLevel(repository, blockSummary.getMinterPublicKey());
 			if (minterLevel == 0) {
-				// We don't want to throw, or use zero, as this will kill Controller thread and make client unstable.
-				// So we log this but use 1 instead
-				LOGGER.warn(String.format("Unexpected zero effective minter level for reward-share %s - using 1 instead!", Base58.encode(blockSummary.getMinterPublicKey())));
-				minterLevel = 1;
+				// It looks like this block's minter's reward-share has been cancelled.
+				// So search for REWARD_SHARE transactions since common block to find missing minter info
+				List<byte[]> transactionSignatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(Transaction.TransactionType.REWARD_SHARE, null, firstBlockHeight, null);
+
+				for (byte[] transactionSignature : transactionSignatures) {
+					RewardShareTransactionData transactionData = (RewardShareTransactionData) repository.getTransactionRepository().fromSignature(transactionSignature);
+
+					if (transactionData != null && Arrays.equals(transactionData.getRewardSharePublicKey(), blockSummary.getMinterPublicKey())) {
+						Account rewardShareMinter = new PublicKeyAccount(repository, transactionData.getMinterPublicKey());
+						minterLevel = rewardShareMinter.getEffectiveMintingLevel();
+						break;
+					}
+				}
+
+				if (minterLevel == 0) {
+					// We don't want to throw, or use zero, as this will kill Controller thread and make client unstable.
+					// So we log this but use 1 instead
+					LOGGER.debug(() -> String.format("Unexpected zero effective minter level for reward-share %s - using 1 instead!", Base58.encode(blockSummary.getMinterPublicKey())));
+					minterLevel = 1;
+				}
 			}
 
 			blockSummary.setMinterLevel(minterLevel);

src/main/java/org/qortal/crosschain/BTC.java

@@ -10,6 +10,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.bitcoinj.core.Address;
 import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.Context;
 import org.bitcoinj.core.ECKey;
 import org.bitcoinj.core.InsufficientMoneyException;
 import org.bitcoinj.core.LegacyAddress;
@@ -20,6 +21,7 @@ import org.bitcoinj.core.TransactionOutput;
 import org.bitcoinj.core.UTXO;
 import org.bitcoinj.core.UTXOProvider;
 import org.bitcoinj.core.UTXOProviderException;
+import org.bitcoinj.crypto.ChildNumber;
 import org.bitcoinj.crypto.DeterministicHierarchy;
 import org.bitcoinj.crypto.DeterministicKey;
 import org.bitcoinj.params.MainNetParams;
@@ -31,7 +33,6 @@ import org.bitcoinj.utils.MonetaryFormat;
 import org.bitcoinj.wallet.DeterministicKeyChain;
 import org.bitcoinj.wallet.SendRequest;
 import org.bitcoinj.wallet.Wallet;
-import org.qortal.crosschain.ElectrumX.UnspentOutput;
 import org.qortal.crypto.Crypto;
 import org.qortal.settings.Settings;
 import org.qortal.utils.BitTwiddling;
@@ -44,8 +45,17 @@ public class BTC {
 	public static final long LOCKTIME_NO_RBF_SEQUENCE = NO_LOCKTIME_NO_RBF_SEQUENCE - 1;
 	public static final int HASH160_LENGTH = 20;
 
+	public static final boolean INCLUDE_UNCONFIRMED = true;
+	public static final boolean EXCLUDE_UNCONFIRMED = false;
+
 	protected static final Logger LOGGER = LogManager.getLogger(BTC.class);
 
+	// Temporary values until a dynamic fee system is written.
+	private static final long OLD_FEE_AMOUNT = 4_000L; // Not 5000 so that existing P2SH-B can output 1000, avoiding dust issue, leaving 4000 for fees.
+	private static final long NEW_FEE_TIMESTAMP = 1598280000000L; // milliseconds since epoch
+	private static final long NEW_FEE_AMOUNT = 10_000L;
+	private static final long NON_MAINNET_FEE = 1000L; // enough for TESTNET3 and should be OK for REGTEST
+
 	private static final int TIMESTAMP_OFFSET = 4 + 32 + 32;
 	private static final MonetaryFormat FORMAT = new MonetaryFormat().minDecimals(8).postfixCode();
 
@@ -75,6 +85,7 @@ public class BTC {
 	private static BTC instance;
 	private final NetworkParameters params;
 	private final ElectrumX electrumX;
+	private final Context bitcoinjContext;
 
 	// Let ECKey.equals() do the hard work
 	private final Set<ECKey> spentKeys = new HashSet<>();
@@ -88,6 +99,7 @@ public class BTC {
 		LOGGER.info(() -> String.format("Starting Bitcoin support using %s", bitcoinNet.name()));
 
 		this.electrumX = ElectrumX.getInstance(bitcoinNet.name());
+		this.bitcoinjContext = new Context(this.params);
 	}
 
 	public static synchronized BTC getInstance() {
@@ -119,6 +131,7 @@ public class BTC {
 
 	public boolean isValidXprv(String xprv58) {
 		try {
+			Context.propagate(bitcoinjContext);
 			DeterministicKey.deserializeB58(null, xprv58, this.params);
 			return true;
 		} catch (IllegalArgumentException e) {
@@ -128,25 +141,29 @@ public class BTC {
 
 	/** Returns P2PKH Bitcoin address using passed public key hash. */
 	public String pkhToAddress(byte[] publicKeyHash) {
+		Context.propagate(bitcoinjContext);
 		return LegacyAddress.fromPubKeyHash(this.params, publicKeyHash).toString();
 	}
 
 	public String deriveP2shAddress(byte[] redeemScriptBytes) {
 		byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
+		Context.propagate(bitcoinjContext);
 		Address p2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
 		return p2shAddress.toString();
 	}
 
-	/** Returns median timestamp from latest 11 blocks, in seconds. */
-	public Integer getMedianBlockTime() {
-		Integer height = this.electrumX.getCurrentHeight();
-		if (height == null)
-			return null;
+	/**
+	 * Returns median timestamp from latest 11 blocks, in seconds.
+	 * <p>
+	 * @throws BitcoinException if error occurs
+	 */
+	public Integer getMedianBlockTime() throws BitcoinException {
+		int height = this.electrumX.getCurrentHeight();
 
 		// Grab latest 11 blocks
 		List<byte[]> blockHeaders = this.electrumX.getBlockHeaders(height - 11, 11);
-		if (blockHeaders == null || blockHeaders.size() < 11)
-			return null;
+		if (blockHeaders.size() < 11)
+			throw new BitcoinException("Not enough blocks to determine median block time");
 
 		List<Integer> blockTimestamps = blockHeaders.stream().map(blockHeader -> BitTwiddling.intFromLEBytes(blockHeader, TIMESTAMP_OFFSET)).collect(Collectors.toList());
 
@@ -157,20 +174,45 @@ public class BTC {
 		return blockTimestamps.get(5);
 	}
 
-	public Long getBalance(String base58Address) {
-		return this.electrumX.getBalance(addressToScript(base58Address));
+	/**
+	 * Returns estimated BTC fee, in sats per 1000bytes, optionally for historic timestamp.
+	 * 
+	 * @param timestamp optional milliseconds since epoch, or null for 'now'
+	 * @return sats per 1000bytes, or throws BitcoinException if something went wrong
+	 */
+	public long estimateFee(Long timestamp) throws BitcoinException {
+		if (!this.params.getId().equals(NetworkParameters.ID_MAINNET))
+			return NON_MAINNET_FEE;
+
+		// TODO: This will need to be replaced with something better in the near future!
+		if (timestamp != null && timestamp < NEW_FEE_TIMESTAMP)
+			return OLD_FEE_AMOUNT;
+
+		return NEW_FEE_AMOUNT;
 	}
 
-	public List<TransactionOutput> getUnspentOutputs(String base58Address) {
-		List<UnspentOutput> unspentOutputs = this.electrumX.getUnspentOutputs(addressToScript(base58Address));
-		if (unspentOutputs == null)
-			return null;
+	/**
+	 * Returns confirmed balance, based on passed payment script.
+	 * <p>
+	 * @return confirmed balance, or zero if script unknown
+	 * @throws BitcoinException if there was an error
+	 */
+	public long getConfirmedBalance(String base58Address) throws BitcoinException {
+		return this.electrumX.getConfirmedBalance(addressToScript(base58Address));
+	}
+
+	/**
+	 * Returns list of unspent outputs pertaining to passed address.
+	 * <p>
+	 * @return list of unspent outputs, or empty list if address unknown
+	 * @throws BitcoinException if there was an error.
+	 */
+	public List<TransactionOutput> getUnspentOutputs(String base58Address) throws BitcoinException {
+		List<UnspentOutput> unspentOutputs = this.electrumX.getUnspentOutputs(addressToScript(base58Address), false);
 
 		List<TransactionOutput> unspentTransactionOutputs = new ArrayList<>();
 		for (UnspentOutput unspentOutput : unspentOutputs) {
-			List<TransactionOutput> transactionOutputs = getOutputs(unspentOutput.hash);
-			if (transactionOutputs == null)
-				return null;
+			List<TransactionOutput> transactionOutputs = this.getOutputs(unspentOutput.hash);
 
 			unspentTransactionOutputs.add(transactionOutputs.get(unspentOutput.index));
 		}
@@ -178,22 +220,65 @@ public class BTC {
 		return unspentTransactionOutputs;
 	}
 
-	public List<TransactionOutput> getOutputs(byte[] txHash) {
+	/**
+	 * Returns list of outputs pertaining to passed transaction hash.
+	 * <p>
+	 * @return list of outputs, or empty list if transaction unknown
+	 * @throws BitcoinException if there was an error.
+	 */
+	public List<TransactionOutput> getOutputs(byte[] txHash) throws BitcoinException {
 		byte[] rawTransactionBytes = this.electrumX.getRawTransaction(txHash);
-		if (rawTransactionBytes == null)
-			return null;
 
+		// XXX bitcoinj: replace with getTransaction() below
+		Context.propagate(bitcoinjContext);
 		Transaction transaction = new Transaction(this.params, rawTransactionBytes);
 		return transaction.getOutputs();
 	}
 
-	/** Returns list of raw transactions spending passed address. */
-	public List<byte[]> getAddressTransactions(String base58Address) {
-		return this.electrumX.getAddressTransactions(addressToScript(base58Address));
+	/**
+	 * Returns list of transaction hashes pertaining to passed address.
+	 * <p>
+	 * @return list of unspent outputs, or empty list if script unknown
+	 * @throws BitcoinException if there was an error.
+	 */
+	public List<TransactionHash> getAddressTransactions(String base58Address, boolean includeUnconfirmed) throws BitcoinException {
+		return this.electrumX.getAddressTransactions(addressToScript(base58Address), includeUnconfirmed);
 	}
 
-	public boolean broadcastTransaction(Transaction transaction) {
-		return this.electrumX.broadcastTransaction(transaction.bitcoinSerialize());
+	/**
+	 * Returns list of raw, confirmed transactions involving given address.
+	 * <p>
+	 * @throws BitcoinException if there was an error
+	 */
+	public List<byte[]> getAddressTransactions(String base58Address) throws BitcoinException {
+		List<TransactionHash> transactionHashes = this.electrumX.getAddressTransactions(addressToScript(base58Address), false);
+
+		List<byte[]> rawTransactions = new ArrayList<>();
+		for (TransactionHash transactionInfo : transactionHashes) {
+			byte[] rawTransaction = this.electrumX.getRawTransaction(HashCode.fromString(transactionInfo.txHash).asBytes());
+			rawTransactions.add(rawTransaction);
+		}
+
+		return rawTransactions;
+	}
+
+	/**
+	 * Returns transaction info for passed transaction hash.
+	 * <p>
+	 * @throws BitcoinException.NotFoundException if transaction unknown
+	 * @throws BitcoinException if error occurs
+	 */
+	public BitcoinTransaction getTransaction(String txHash) throws BitcoinException {
+		return this.electrumX.getTransaction(txHash);
+	}
+
+	/**
+	 * Broadcasts raw transaction to Bitcoin network.
+	 * <p>
+	 * @throws BitcoinException if error occurs
+	 */
+	public void broadcastTransaction(Transaction transaction) throws BitcoinException {
+		this.electrumX.broadcastTransaction(transaction.bitcoinSerialize());
 	}
 
 	/**
@@ -205,8 +290,9 @@ public class BTC {
 	 * @return transaction, or null if insufficient funds
 	 */
 	public Transaction buildSpend(String xprv58, String recipient, long amount) {
+		Context.propagate(bitcoinjContext);
 		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
-		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet, WalletAwareUTXOProvider.KeySearchMode.REQUEST_MORE_IF_ALL_SPENT));
+		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet, WalletAwareUTXOProvider.KeySearchMode.REQUEST_MORE_IF_ANY_SPENT));
 
 		Address destination = Address.fromString(this.params, recipient);
 		SendRequest sendRequest = SendRequest.to(destination, Coin.valueOf(amount));
@@ -230,6 +316,7 @@ public class BTC {
 	 * @return unspent BTC balance, or null if unable to determine balance
 	 */
 	public Long getWalletBalance(String xprv58) {
+		Context.propagate(bitcoinjContext);
 		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
 		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet, WalletAwareUTXOProvider.KeySearchMode.REQUEST_MORE_IF_ANY_SPENT));
 
@@ -240,6 +327,87 @@ public class BTC {
 		return balance.value;
 	}
 
+	/**
+	 * Returns first unused receive address given 'm' BIP32 key.
+	 *
+	 * @param xprv58 BIP32 extended Bitcoin private key
+	 * @return Bitcoin P2PKH address
+	 * @throws BitcoinException if something went wrong
+	 */
+	public String getUnusedReceiveAddress(String xprv58) throws BitcoinException {
+		Context.propagate(bitcoinjContext);
+		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
+		DeterministicKeyChain keyChain = wallet.getActiveKeyChain();
+
+		keyChain.setLookaheadSize(WalletAwareUTXOProvider.LOOKAHEAD_INCREMENT);
+		keyChain.maybeLookAhead();
+
+		final int keyChainPathSize = keyChain.getAccountPath().size();
+		List<DeterministicKey> keys = new ArrayList<>(keyChain.getLeafKeys());
+
+		int ki = 0;
+		do {
+			for (; ki < keys.size(); ++ki) {
+				DeterministicKey dKey = keys.get(ki);
+				List<ChildNumber> dKeyPath = dKey.getPath();
+
+				// If keyChain is based on 'm', then make sure dKey is m/0/ki
+				if (dKeyPath.size() != keyChainPathSize + 2 || dKeyPath.get(dKeyPath.size() - 2) != ChildNumber.ZERO)
+					continue;
+
+				// Check unspent
+				Address address = Address.fromKey(this.params, dKey, ScriptType.P2PKH);
+				byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
+
+				List<UnspentOutput> unspentOutputs = this.electrumX.getUnspentOutputs(script, false);
+
+				/*
+				 * If there are no unspent outputs then either:
+				 * a) all the outputs have been spent
+				 * b) address has never been used
+				 * 
+				 * For case (a) we want to remember not to check this address (key) again.
+				 */
+
+				if (unspentOutputs.isEmpty()) {
+					// If this is a known key that has been spent before, then we can skip asking for transaction history
+					if (this.spentKeys.contains(dKey)) {
+						wallet.getActiveKeyChain().markKeyAsUsed((DeterministicKey) dKey);
+						continue;
+					}
+
+					// Ask for transaction history - if it's empty then key has never been used
+					List<TransactionHash> historicTransactionHashes = this.electrumX.getAddressTransactions(script, false);
+
+					if (!historicTransactionHashes.isEmpty()) {
+						// Fully spent key - case (a)
+						this.spentKeys.add(dKey);
+						wallet.getActiveKeyChain().markKeyAsUsed(dKey);
+					} else {
+						// Key never been used - case (b)
+						return address.toString();
+					}
+				}
+
+				// Key has unspent outputs, hence used, so no good to us
+				this.spentKeys.remove(dKey);
+			}
+
+			// Generate some more keys
+			keyChain.setLookaheadSize(keyChain.getLookaheadSize() + WalletAwareUTXOProvider.LOOKAHEAD_INCREMENT);
+			keyChain.maybeLookAhead();
+
+			// This returns all keys, including those already in 'keys'
+			List<DeterministicKey> allLeafKeys = keyChain.getLeafKeys();
+			// Add only new keys onto our list of keys to search
+			List<DeterministicKey> newKeys = allLeafKeys.subList(ki, allLeafKeys.size());
+			keys.addAll(newKeys);
+			// Fall-through to checking more keys as now 'ki' is smaller than 'keys.size()' again
+
+			// Process new keys
+		} while (true);
+	}
+
 	// UTXOProvider support
 
 	static class WalletAwareUTXOProvider implements UTXOProvider {
@@ -280,9 +448,12 @@ public class BTC {
 					Address address = Address.fromKey(btc.params, key, ScriptType.P2PKH);
 					byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
 
-					List<UnspentOutput> unspentOutputs = btc.electrumX.getUnspentOutputs(script);
-					if (unspentOutputs == null)
+					List<UnspentOutput> unspentOutputs;
+					try {
+						unspentOutputs = btc.electrumX.getUnspentOutputs(script, false);
+					} catch (BitcoinException e) {
 						throw new UTXOProviderException(String.format("Unable to fetch unspent outputs for %s", address));
+					}
 
 					/*
 					 * If there are no unspent outputs then either:
@@ -301,10 +472,12 @@ public class BTC {
 						}
 
 						// Ask for transaction history - if it's empty then key has never been used
-						List<byte[]> historicTransactionHashes = btc.electrumX.getAddressTransactions(script);
-						if (historicTransactionHashes == null)
-							throw new UTXOProviderException(
-									String.format("Unable to fetch transaction history for %s", address));
+						List<TransactionHash> historicTransactionHashes;
+						try {
+							historicTransactionHashes = btc.electrumX.getAddressTransactions(script, false);
+						} catch (BitcoinException e) {
+							throw new UTXOProviderException(String.format("Unable to fetch transaction history for %s", address));
+						}
 
 						if (!historicTransactionHashes.isEmpty()) {
 							// Fully spent key - case (a)
@@ -320,13 +493,17 @@ public class BTC {
 					}
 
 					// If we reach here, then there's definitely at least one unspent key
+					btc.spentKeys.remove(key);
 					areAllKeysSpent = false;
 
 					for (UnspentOutput unspentOutput : unspentOutputs) {
-						List<TransactionOutput> transactionOutputs = btc.getOutputs(unspentOutput.hash);
-						if (transactionOutputs == null)
+						List<TransactionOutput> transactionOutputs;
+						try {
+							transactionOutputs = btc.getOutputs(unspentOutput.hash);
+						} catch (BitcoinException e) {
 							throw new UTXOProviderException(String.format("Unable to fetch outputs for TX %s",
 									HashCode.fromBytes(unspentOutput.hash)));
+						}
 
 						TransactionOutput transactionOutput = transactionOutputs.get(unspentOutput.index);
 
@@ -359,11 +536,11 @@ public class BTC {
 		}
 
 		public int getChainHeadHeight() throws UTXOProviderException {
-			Integer height = btc.electrumX.getCurrentHeight();
-			if (height == null)
+			try {
+				return btc.electrumX.getCurrentHeight();
+			} catch (BitcoinException e) {
 				throw new UTXOProviderException("Unable to determine Bitcoin chain height");
-
-			return height.intValue();
+			}
 		}
 
 		public NetworkParameters getParams() {
@@ -374,6 +551,7 @@ public class BTC {
 	// Utility methods for us
 
 	private byte[] addressToScript(String base58Address) {
+		Context.propagate(bitcoinjContext);
 		Address address = Address.fromString(this.params, base58Address);
 		return ScriptBuilder.createOutputScript(address).getProgram();
 	}

src/main/java/org/qortal/crosschain/BTCACCT.java

@@ -611,7 +611,7 @@ public class BTCACCT {
 	 */
 	public static CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
 		ATStateData atStateData = repository.getATRepository().getLatestATState(atData.getATAddress());
-		return populateTradeData(repository, atData.getCreatorPublicKey(), atStateData);
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
 	}
 
 	/**
@@ -622,8 +622,8 @@ public class BTCACCT {
 	 * @throws DataException
 	 */
 	public static CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException {
-		byte[] creatorPublicKey = repository.getATRepository().getCreatorPublicKey(atStateData.getATAddress());
-		return populateTradeData(repository, creatorPublicKey, atStateData);
+		ATData atData = repository.getATRepository().fromATAddress(atStateData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
 	}
 
 	/**
@@ -633,7 +633,7 @@ public class BTCACCT {
 	 * @param atAddress
 	 * @throws DataException
 	 */
-	public static CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, ATStateData atStateData) throws DataException {
+	public static CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, long creationTimestamp, ATStateData atStateData) throws DataException {
 		byte[] addressBytes = new byte[25]; // for general use
 		String atAddress = atStateData.getATAddress();
 
@@ -641,7 +641,7 @@ public class BTCACCT {
 
 		tradeData.qortalAtAddress = atAddress;
 		tradeData.qortalCreator = Crypto.toAddress(creatorPublicKey);
-		tradeData.creationTimestamp = atStateData.getCreation();
+		tradeData.creationTimestamp = creationTimestamp;
 
 		Account atAccount = new Account(repository, atAddress);
 		tradeData.qortBalance = atAccount.getConfirmedBalance(Asset.QORT);
@@ -874,7 +874,8 @@ public class BTCACCT {
 		String atAddress = crossChainTradeData.qortalAtAddress;
 		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
 
-		List<MessageTransactionData> messageTransactionsData = repository.getTransactionRepository().getMessagesByRecipient(atAddress, null, null, null);
+		// We don't have partner's public key so we check every message to AT
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, atAddress, null, null, null);
 		if (messageTransactionsData == null)
 			return null;
 

src/main/java/org/qortal/crosschain/BTCP2SH.java

@@ -1,9 +1,15 @@
 package org.qortal.crosschain;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Function;
 
 import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Base58;
 import org.bitcoinj.core.Coin;
 import org.bitcoinj.core.ECKey;
 import org.bitcoinj.core.LegacyAddress;
@@ -25,6 +31,10 @@ import com.google.common.primitives.Bytes;
 
 public class BTCP2SH {
 
+	public enum Status {
+		UNFUNDED, FUNDING_IN_PROGRESS, FUNDED, REDEEM_IN_PROGRESS, REDEEMED, REFUND_IN_PROGRESS, REFUNDED
+	}
+
 	public static final int SECRET_LENGTH = 32;
 	public static final int MIN_LOCKTIME = 1500000000;
 
@@ -131,9 +141,10 @@ public class BTCP2SH {
 	 * @param fundingOutput output from transaction that funded P2SH address
 	 * @param redeemScriptBytes the redeemScript itself, in byte[] form
 	 * @param lockTime transaction nLockTime - must be at least locktime used in redeemScript
+	 * @param receivingAccountInfo Bitcoin PKH used for output
 	 * @return Signed Bitcoin transaction for refunding P2SH
 	 */
-	public static Transaction buildRefundTransaction(Coin refundAmount, ECKey refundKey, List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes, long lockTime) {
+	public static Transaction buildRefundTransaction(Coin refundAmount, ECKey refundKey, List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes, long lockTime, byte[] receivingAccountInfo) {
 		Function<byte[], Script> refundSigScriptBuilder = (txSigBytes) -> {
 			// Build scriptSig with...
 			ScriptBuilder scriptBuilder = new ScriptBuilder();
@@ -152,7 +163,7 @@ public class BTCP2SH {
 		};
 
 		// Send funds back to funding address
-		return buildP2shTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundSigScriptBuilder, refundKey.getPubKeyHash());
+		return buildP2shTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundSigScriptBuilder, receivingAccountInfo);
 	}
 
 	/**
@@ -233,4 +244,129 @@ public class BTCP2SH {
 		return null;
 	}
 
+	/** Returns P2SH status, given P2SH address and expected redeem/refund amount, or throws BitcoinException if error occurs. */
+	public static Status determineP2shStatus(String p2shAddress, long minimumAmount) throws BitcoinException {
+		final BTC btc = BTC.getInstance();
+
+		List<TransactionHash> transactionHashes = btc.getAddressTransactions(p2shAddress, BTC.INCLUDE_UNCONFIRMED);
+
+		// Sort by confirmed first, followed by ascending height
+		transactionHashes.sort(TransactionHash.CONFIRMED_FIRST.thenComparing(TransactionHash::getHeight));
+
+		// Transaction cache
+		Map<String, BitcoinTransaction> transactionsByHash = new HashMap<>();
+		// HASH160(redeem script) for this p2shAddress
+		byte[] ourRedeemScriptHash = addressToRedeemScriptHash(p2shAddress);
+
+		// Check for spends first, caching full transaction info as we progress just in case we don't return in this loop
+		for (TransactionHash transactionInfo : transactionHashes) {
+			BitcoinTransaction bitcoinTransaction = btc.getTransaction(transactionInfo.txHash);
+
+			// Cache for possible later reuse
+			transactionsByHash.put(transactionInfo.txHash, bitcoinTransaction);
+
+			// Acceptable funding is one transaction output, so we're expecting only one input
+			if (bitcoinTransaction.inputs.size() != 1)
+				// Wrong number of inputs
+				continue;
+
+			String scriptSig = bitcoinTransaction.inputs.get(0).scriptSig;
+
+			List<byte[]> scriptSigChunks = extractScriptSigChunks(HashCode.fromString(scriptSig).asBytes());
+			if (scriptSigChunks.size() < 3 || scriptSigChunks.size() > 4)
+				// Not spending one of these P2SH
+				continue;
+
+			// Last chunk is redeem script
+			byte[] redeemScriptBytes = scriptSigChunks.get(scriptSigChunks.size() - 1);
+			byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
+			if (!Arrays.equals(redeemScriptHash, ourRedeemScriptHash))
+				// Not spending our specific P2SH
+				continue;
+
+			// If we have 4 chunks, then secret is present
+			return scriptSigChunks.size() == 4
+					? (transactionInfo.height == 0 ? Status.REDEEM_IN_PROGRESS : Status.REDEEMED)
+					: (transactionInfo.height == 0 ? Status.REFUND_IN_PROGRESS : Status.REFUNDED);
+		}
+
+		String ourScriptPubKey = HashCode.fromBytes(addressToScriptPubKey(p2shAddress)).toString();
+
+		// Check for funding
+		for (TransactionHash transactionInfo : transactionHashes) {
+			BitcoinTransaction bitcoinTransaction = transactionsByHash.get(transactionInfo.txHash);
+			if (bitcoinTransaction == null)
+				// Should be present in map!
+				throw new BitcoinException("Cached Bitcoin transaction now missing?");
+
+			// Check outputs for our specific P2SH
+			for (BitcoinTransaction.Output output : bitcoinTransaction.outputs) {
+				// Check amount
+				if (output.value < minimumAmount)
+					// Output amount too small (not taking fees into account)
+					continue;
+
+				String scriptPubKey = output.scriptPubKey;
+				if (!scriptPubKey.equals(ourScriptPubKey))
+					// Not funding our specific P2SH
+					continue;
+
+				return transactionInfo.height == 0 ? Status.FUNDING_IN_PROGRESS : Status.FUNDED;
+			}
+		}
+
+		return Status.UNFUNDED;
+	}
+
+	private static List<byte[]> extractScriptSigChunks(byte[] scriptSigBytes) {
+		List<byte[]> chunks = new ArrayList<>();
+
+		int offset = 0;
+		int previousOffset = 0;
+		while (offset < scriptSigBytes.length) {
+			byte pushOp = scriptSigBytes[offset++];
+
+			if (pushOp < 0 || pushOp > 0x4c)
+				// Unacceptable OP
+				return Collections.emptyList();
+
+			// Special treatment for OP_PUSHDATA1
+			if (pushOp == 0x4c) {
+				if (offset >= scriptSigBytes.length)
+					// Run out of scriptSig bytes?
+					return Collections.emptyList();
+
+				pushOp = scriptSigBytes[offset++];
+			}
+
+			previousOffset = offset;
+			offset += Byte.toUnsignedInt(pushOp);
+
+			byte[] chunk = Arrays.copyOfRange(scriptSigBytes, previousOffset, offset);
+			chunks.add(chunk);
+		}
+
+		return chunks;
+	}
+
+	private static byte[] addressToScriptPubKey(String p2shAddress) {
+		// We want the HASH160 part of the P2SH address
+		byte[] p2shAddressBytes = Base58.decode(p2shAddress);
+
+		byte[] scriptPubKey = new byte[1 + 1 + 20 + 1];
+		scriptPubKey[0x00] = (byte) 0xa9; /* OP_HASH160 */
+		scriptPubKey[0x01] = (byte) 0x14; /* PUSH 0x14 bytes */
+		System.arraycopy(p2shAddressBytes, 1, scriptPubKey, 2, 0x14);
+		scriptPubKey[0x16] = (byte) 0x87; /* OP_EQUAL */
+
+		return scriptPubKey;
+	}
+
+	private static byte[] addressToRedeemScriptHash(String p2shAddress) {
+		// We want the HASH160 part of the P2SH address
+		byte[] p2shAddressBytes = Base58.decode(p2shAddress);
+
+		return Arrays.copyOfRange(p2shAddressBytes, 1, 1 + 20);
+	}
+
 }

src/main/java/org/qortal/crosschain/BitcoinException.java

@@ -0,0 +1,57 @@
+package org.qortal.crosschain;
+
+@SuppressWarnings("serial")
+public class BitcoinException extends Exception {
+
+	public BitcoinException() {
+		super();
+	}
+
+	public BitcoinException(String message) {
+		super(message);
+	}
+
+	public static class NetworkException extends BitcoinException {
+		private final Integer daemonErrorCode;
+
+		public NetworkException() {
+			super();
+			this.daemonErrorCode = null;
+		}
+
+		public NetworkException(String message) {
+			super(message);
+			this.daemonErrorCode = null;
+		}
+
+		public NetworkException(int errorCode, String message) {
+			super(message);
+			this.daemonErrorCode = errorCode;
+		}
+
+		public Integer getDaemonErrorCode() {
+			return this.daemonErrorCode;
+		}
+	}
+
+	public static class NotFoundException extends BitcoinException {
+		public NotFoundException() {
+			super();
+		}
+
+		public NotFoundException(String message) {
+			super(message);
+		}
+	}
+
+	public static class InsufficientFundsException extends BitcoinException {
+		public InsufficientFundsException() {
+			super();
+		}
+
+		public InsufficientFundsException(String message) {
+			super(message);
+		}
+	}
+
+}

src/main/java/org/qortal/crosschain/BitcoinNetworkProvider.java

@@ -0,0 +1,31 @@
+package org.qortal.crosschain;
+
+import java.util.List;
+
+interface BitcoinNetworkProvider {
+
+	/** Returns current blockchain height. */
+	int getCurrentHeight() throws BitcoinException;
+
+	/** Returns a list of raw block headers, starting at <tt>startHeight</tt> (inclusive), up to <tt>count</tt> max. */
+	List<byte[]> getRawBlockHeaders(int startHeight, int count) throws BitcoinException;
+
+	/** Returns balance of address represented by <tt>scriptPubKey</tt>. */
+	long getConfirmedBalance(byte[] scriptPubKey) throws BitcoinException;
+
+	/** Returns raw, serialized, transaction bytes given <tt>txHash</tt>. */
+	byte[] getRawTransaction(String txHash) throws BitcoinException;
+
+	/** Returns unpacked transaction given <tt>txHash</tt>. */
+	BitcoinTransaction getTransaction(String txHash) throws BitcoinException;
+
+	/** Returns list of transaction hashes (and heights) for address represented by <tt>scriptPubKey</tt>, optionally including unconfirmed transactions. */
+	List<TransactionHash> getAddressTransactions(byte[] scriptPubKey, boolean includeUnconfirmed) throws BitcoinException;
+
+	/** Returns list of unspent transaction outputs for address represented by <tt>scriptPubKey</tt>, optionally including unconfirmed transactions. */
+	List<UnspentOutput> getUnspentOutputs(byte[] scriptPubKey, boolean includeUnconfirmed) throws BitcoinException;
+
+	/** Broadcasts raw, serialized, transaction bytes to network, returning success/failure. */
+	boolean broadcastTransaction(byte[] rawTransaction) throws BitcoinException;
+
+}

src/main/java/org/qortal/crosschain/BitcoinTransaction.java

@@ -0,0 +1,70 @@
+package org.qortal.crosschain;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class BitcoinTransaction {
+
+	public final String txHash;
+	public final int size;
+	public final int locktime;
+	// Not present if transaction is unconfirmed
+	public final Integer timestamp;
+
+	public static class Input {
+		public final String scriptSig;
+		public final int sequence;
+		public final String outputTxHash;
+		public final int outputVout;
+
+		public Input(String scriptSig, int sequence, String outputTxHash, int outputVout) {
+			this.scriptSig = scriptSig;
+			this.sequence = sequence;
+			this.outputTxHash = outputTxHash;
+			this.outputVout = outputVout;
+		}
+
+		public String toString() {
+			return String.format("{output %s:%d, sequence %d, scriptSig %s}",
+					this.outputTxHash, this.outputVout, this.sequence, this.scriptSig);
+		}
+	}
+	public final List<Input> inputs;
+
+	public static class Output {
+		public final String scriptPubKey;
+		public final long value;
+
+		public Output(String scriptPubKey, long value) {
+			this.scriptPubKey = scriptPubKey;
+			this.value = value;
+		}
+
+		public String toString() {
+			return String.format("{value %d, scriptPubKey %s}", this.value, this.scriptPubKey);
+		}
+	}
+	public final List<Output> outputs;
+
+	public BitcoinTransaction(String txHash, int size, int locktime, Integer timestamp,
+			List<Input> inputs, List<Output> outputs) {
+		this.txHash = txHash;
+		this.size = size;
+		this.locktime = locktime;
+		this.timestamp = timestamp;
+		this.inputs = inputs;
+		this.outputs = outputs;
+	}
+
+	public String toString() {
+		return String.format("txHash %s, size %d, locktime %d, timestamp %d\n"
+				+ "\tinputs: [%s]\n"
+				+ "\toutputs: [%s]\n",
+				this.txHash,
+				this.size,
+				this.locktime,
+				this.timestamp,
+				this.inputs.stream().map(Input::toString).collect(Collectors.joining(",\n\t\t")),
+				this.outputs.stream().map(Output::toString).collect(Collectors.joining(",\n\t\t")));
+	}
+}

src/main/java/org/qortal/crosschain/ElectrumX.java

@@ -14,8 +14,9 @@ import java.util.NoSuchElementException;
 import java.util.Random;
 import java.util.Scanner;
 import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
-import javax.net.ssl.SSLSocket;
 import javax.net.ssl.SSLSocketFactory;
 
 import org.apache.logging.log4j.LogManager;
@@ -35,17 +36,27 @@ public class ElectrumX {
 	private static final Logger LOGGER = LogManager.getLogger(ElectrumX.class);
 	private static final Random RANDOM = new Random();
 
+	private static final double MIN_PROTOCOL_VERSION = 1.2;
+
 	private static final int DEFAULT_TCP_PORT = 50001;
 	private static final int DEFAULT_SSL_PORT = 50002;
 
 	private static final int BLOCK_HEADER_LENGTH = 80;
 
+	private static final String MAIN_GENESIS_HASH = "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f";
+	private static final String TEST3_GENESIS_HASH = "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943";
+	// We won't know REGTEST (i.e. local) genesis block hash
+
+	// "message": "daemon error: DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})"
+	private static final Pattern DAEMON_ERROR_REGEX = Pattern.compile("DaemonError\\(\\{.*'code': ?(-?[0-9]+).*\\}\\)\\z"); // Capture 'code' inside curly-brace content
+
+	// Key: Bitcoin network (e.g. "MAIN", "TEST3", "REGTEST"), value: ElectrumX instance
 	private static final Map<String, ElectrumX> instances = new HashMap<>();
 
-	static class Server {
+	private static class Server {
 		String hostname;
 
-		enum ConnectionType { TCP, SSL };
+		enum ConnectionType { TCP, SSL }
 		ConnectionType connectionType;
 
 		int port;
@@ -82,7 +93,9 @@ public class ElectrumX {
 		}
 	}
 	private Set<Server> servers = new HashSet<>();
+	private List<Server> remainingServers = new ArrayList<>();
 
+	private String expectedGenesisHash;
 	private Server currentServer;
 	private Socket socket;
 	private Scanner scanner;
@@ -93,34 +106,59 @@ public class ElectrumX {
 	private ElectrumX(String bitcoinNetwork) {
 		switch (bitcoinNetwork) {
 			case "MAIN":
-				servers.addAll(Arrays.asList(
+				this.expectedGenesisHash = MAIN_GENESIS_HASH;
+
+				this.servers.addAll(Arrays.asList(
 						// Servers chosen on NO BASIS WHATSOEVER from various sources!
-						new Server("tardis.bauerj.eu", Server.ConnectionType.SSL, 50002),
-						new Server("rbx.curalle.ovh", Server.ConnectionType.SSL, 50002),
-						new Server("quick.electumx.live", Server.ConnectionType.SSL, 50002),
 						new Server("enode.duckdns.org", Server.ConnectionType.SSL, 50002),
-						new Server("electrumx.ddns.net", Server.ConnectionType.SSL, 50002),
 						new Server("electrumx.ml", Server.ConnectionType.SSL, 50002),
-						new Server("electrum.eff.ro", Server.ConnectionType.SSL, 50002),
 						new Server("electrum.bitkoins.nl", Server.ConnectionType.SSL, 50512),
-						new Server("E-X.not.fyi", Server.ConnectionType.SSL, 50002),
 						new Server("btc.electroncash.dk", Server.ConnectionType.SSL, 60002),
-						new Server("electrum.blockstream.info", Server.ConnectionType.TCP, 50001),
-						new Server("electrum.blockstream.info", Server.ConnectionType.SSL, 50002),
+						new Server("electrumx.electricnewyear.net", Server.ConnectionType.SSL, 50002),
+						new Server("dxm.no-ip.biz", Server.ConnectionType.TCP, 50001),
+						new Server("kirsche.emzy.de", Server.ConnectionType.TCP, 50001),
+						new Server("2AZZARITA.hopto.org", Server.ConnectionType.TCP, 50001),
+						new Server("xtrum.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.srvmin.network", Server.ConnectionType.TCP, 50001),
+						new Server("electrumx.alexridevski.net", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.lukechilds.co", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.poiuty.com", Server.ConnectionType.TCP, 50001),
+						new Server("horsey.cryptocowboys.net", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.emzy.de", Server.ConnectionType.TCP, 50001),
+						new Server("electrum-server.ninja", Server.ConnectionType.TCP, 50081),
+						new Server("bitcoin.electrumx.multicoin.co", Server.ConnectionType.TCP, 50001),
+						new Server("esx.geekhosters.com", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.grey.pw", Server.ConnectionType.TCP, 50003),
+						new Server("exs.ignorelist.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.coinext.com.br", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.aranguren.org", Server.ConnectionType.TCP, 50001),
+						new Server("skbxmit.coinjoined.com", Server.ConnectionType.TCP, 50001),
+						new Server("alviss.coinjoined.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum2.privateservers.network", Server.ConnectionType.TCP, 50001),
+						new Server("electrumx.schulzemic.net", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoins.sk", Server.ConnectionType.TCP, 56001),
+						new Server("node.mendonca.xyz", Server.ConnectionType.TCP, 50001),
 						new Server("bitcoin.aranguren.org", Server.ConnectionType.TCP, 50001)));
 				break;
 
 			case "TEST3":
-				servers.addAll(Arrays.asList(
-						new Server("tn.not.fyi", Server.ConnectionType.TCP, 55001),
-						new Server("tn.not.fyi", Server.ConnectionType.SSL, 55002),
+				this.expectedGenesisHash = TEST3_GENESIS_HASH;
+
+				this.servers.addAll(Arrays.asList(
+						new Server("electrum.blockstream.info", Server.ConnectionType.TCP, 60001),
+						new Server("electrum.blockstream.info", Server.ConnectionType.SSL, 60002),
+						new Server("electrumx-test.1209k.com", Server.ConnectionType.SSL, 50002),
+						new Server("testnet.qtornado.com", Server.ConnectionType.TCP, 51001),
+						new Server("testnet.qtornado.com", Server.ConnectionType.SSL, 51002),
 						new Server("testnet.aranguren.org", Server.ConnectionType.TCP, 51001),
 						new Server("testnet.aranguren.org", Server.ConnectionType.SSL, 51002),
 						new Server("testnet.hsmiths.com", Server.ConnectionType.SSL, 53012)));
 				break;
 
 			case "REGTEST":
-				servers.addAll(Arrays.asList(
+				this.expectedGenesisHash = null;
+
+				this.servers.addAll(Arrays.asList(
 						new Server("localhost", Server.ConnectionType.TCP, DEFAULT_TCP_PORT),
 						new Server("localhost", Server.ConnectionType.SSL, DEFAULT_SSL_PORT)));
 				break;
@@ -130,7 +168,6 @@ public class ElectrumX {
 		}
 
 		LOGGER.debug(() -> String.format("Starting ElectrumX support for %s Bitcoin network", bitcoinNetwork));
-		rpc("server.banner");
 	}
 
 	/** Returns ElectrumX instance linked to passed Bitcoin network, one of "MAIN", "TEST3" or "REGTEST". */
@@ -143,35 +180,50 @@ public class ElectrumX {
 
 	// Methods for use by other classes
 
-	public Integer getCurrentHeight() {
+	/**
+	 * Returns current blockchain height.
+	 * <p>
+	 * @throws BitcoinException if error occurs
+	 */
+	public int getCurrentHeight() throws BitcoinException {
 		Object blockObj = this.rpc("blockchain.headers.subscribe");
 		if (!(blockObj instanceof JSONObject))
-			return null;
+			throw new BitcoinException.NetworkException("Unexpected output from ElectrumX blockchain.headers.subscribe RPC");
 
 		JSONObject blockJson = (JSONObject) blockObj;
 
-		if (!blockJson.containsKey("height"))
-			return null;
+		Object heightObj = blockJson.get("height");
 
-		return ((Long) blockJson.get("height")).intValue();
+		if (!(heightObj instanceof Long))
+			throw new BitcoinException.NetworkException("Missing/invalid 'height' in JSON from ElectrumX blockchain.headers.subscribe RPC");
+
+		return ((Long) heightObj).intValue();
 	}
 
-	public List<byte[]> getBlockHeaders(int startHeight, long count) {
+	/**
+	 * Returns list of raw block headers, starting from <tt>startHeight</tt> inclusive.
+	 * <p>
+	 * @throws BitcoinException if error occurs
+	 */
+	public List<byte[]> getBlockHeaders(int startHeight, long count) throws BitcoinException {
 		Object blockObj = this.rpc("blockchain.block.headers", startHeight, count);
 		if (!(blockObj instanceof JSONObject))
-			return null;
+			throw new BitcoinException.NetworkException("Unexpected output from ElectrumX blockchain.block.headers RPC");
 
 		JSONObject blockJson = (JSONObject) blockObj;
 
-		if (!blockJson.containsKey("count") || !blockJson.containsKey("hex"))
-			return null;
+		Object countObj = blockJson.get("count");
+		Object hexObj = blockJson.get("hex");
 
-		Long returnedCount = (Long) blockJson.get("count");
-		String hex = (String) blockJson.get("hex");
+		if (!(countObj instanceof Long) || !(hexObj instanceof String))
+			throw new BitcoinException.NetworkException("Missing/invalid 'count' or 'hex' entries in JSON from ElectrumX blockchain.block.headers RPC");
+
+		Long returnedCount = (Long) countObj;
+		String hex = (String) hexObj;
 
 		byte[] raw = HashCode.fromString(hex).asBytes();
 		if (raw.length != returnedCount * BLOCK_HEADER_LENGTH)
-			return null;
+			throw new BitcoinException.NetworkException("Unexpected raw header length in JSON from ElectrumX blockchain.block.headers RPC");
 
 		List<byte[]> rawBlockHeaders = new ArrayList<>(returnedCount.intValue());
 		for (int i = 0; i < returnedCount; ++i)
@@ -180,46 +232,43 @@ public class ElectrumX {
 		return rawBlockHeaders;
 	}
 
-	/** Returns confirmed balance, based on passed payment script, or null if there was an error or no known balance. */
-	public Long getBalance(byte[] script) {
+	/**
+	 * Returns confirmed balance, based on passed payment script.
+	 * <p>
+	 * @return confirmed balance, or zero if script unknown
+	 * @throws BitcoinException if there was an error
+	 */
+	public long getConfirmedBalance(byte[] script) throws BitcoinException {
 		byte[] scriptHash = Crypto.digest(script);
 		Bytes.reverse(scriptHash);
 
 		Object balanceObj = this.rpc("blockchain.scripthash.get_balance", HashCode.fromBytes(scriptHash).toString());
 		if (!(balanceObj instanceof JSONObject))
-			return null;
+			throw new BitcoinException.NetworkException("Unexpected output from ElectrumX blockchain.scripthash.get_balance RPC");
 
 		JSONObject balanceJson = (JSONObject) balanceObj;
 
-		if (!balanceJson.containsKey("confirmed"))
-			return null;
+		Object confirmedBalanceObj = balanceJson.get("confirmed");
+
+		if (!(confirmedBalanceObj instanceof Long))
+			throw new BitcoinException.NetworkException("Missing confirmed balance from ElectrumX blockchain.scripthash.get_balance RPC");
 
 		return (Long) balanceJson.get("confirmed");
 	}
 
-	/** Unspent output info as returned by ElectrumX network. */
-	public static class UnspentOutput {
-		public final byte[] hash;
-		public final int index;
-		public final int height;
-		public final long value;
-
-		public UnspentOutput(byte[] hash, int index, int height, long value) {
-			this.hash = hash;
-			this.index = index;
-			this.height = height;
-			this.value = value;
-		}
-	}
-
-	/** Returns list of unspent outputs pertaining to passed payment script, or null if there was an error. */
-	public List<UnspentOutput> getUnspentOutputs(byte[] script) {
+	/**
+	 * Returns list of unspent outputs pertaining to passed payment script.
+	 * <p>
+	 * @return list of unspent outputs, or empty list if script unknown
+	 * @throws BitcoinException if there was an error.
+	 */
+	public List<UnspentOutput> getUnspentOutputs(byte[] script, boolean includeUnconfirmed) throws BitcoinException {
 		byte[] scriptHash = Crypto.digest(script);
 		Bytes.reverse(scriptHash);
 
 		Object unspentJson = this.rpc("blockchain.scripthash.listunspent", HashCode.fromBytes(scriptHash).toString());
 		if (!(unspentJson instanceof JSONArray))
-			return null;
+			throw new BitcoinException("Expected array output from ElectrumX blockchain.scripthash.listunspent RPC");
 
 		List<UnspentOutput> unspentOutputs = new ArrayList<>();
 		for (Object rawUnspent : (JSONArray) unspentJson) {
@@ -227,7 +276,7 @@ public class ElectrumX {
 
 			int height = ((Long) unspent.get("height")).intValue();
 			// We only want unspent outputs from confirmed transactions (and definitely not mempool duplicates with height 0)
-			if (height <= 0)
+			if (!includeUnconfirmed && height <= 0)
 				continue;
 
 			byte[] txHash = HashCode.fromString((String) unspent.get("tx_hash")).asBytes();
@@ -240,68 +289,163 @@ public class ElectrumX {
 		return unspentOutputs;
 	}
 
-	/** Returns raw transaction for passed transaction hash, or null if not found. */
-	public byte[] getRawTransaction(byte[] txHash) {
-		Object rawTransactionHex = this.rpc("blockchain.transaction.get", HashCode.fromBytes(txHash).toString());
+	/**
+	 * Returns raw transaction for passed transaction hash.
+	 * <p>
+	 * @throws BitcoinException.NotFoundException if transaction not found
+	 * @throws BitcoinException if error occurs
+	 */
+	public byte[] getRawTransaction(byte[] txHash) throws BitcoinException {
+		Object rawTransactionHex;
+		try {
+			rawTransactionHex = this.rpc("blockchain.transaction.get", HashCode.fromBytes(txHash).toString());
+		} catch (BitcoinException.NetworkException e) {
+			// DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})
+			if (Integer.valueOf(-5).equals(e.getDaemonErrorCode()))
+				throw new BitcoinException.NotFoundException(e.getMessage());
+
+			throw e;
+		}
+
 		if (!(rawTransactionHex instanceof String))
-			return null;
+			throw new BitcoinException.NetworkException("Expected hex string as raw transaction from ElectrumX blockchain.transaction.get RPC");
 
 		return HashCode.fromString((String) rawTransactionHex).asBytes();
 	}
 
-	/** Returns list of raw transactions, relating to passed payment script, if null if there's an error. */
-	public List<byte[]> getAddressTransactions(byte[] script) {
+	/**
+	 * Returns transaction info for passed transaction hash.
+	 * <p>
+	 * @throws BitcoinException.NotFoundException if transaction not found
+	 * @throws BitcoinException if error occurs
+	 */
+	public BitcoinTransaction getTransaction(String txHash) throws BitcoinException {
+		Object transactionObj;
+		try {
+			transactionObj = this.rpc("blockchain.transaction.get", txHash, true);
+		} catch (BitcoinException.NetworkException e) {
+			// DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})
+			if (Integer.valueOf(-5).equals(e.getDaemonErrorCode()))
+				throw new BitcoinException.NotFoundException(e.getMessage());
+
+			throw e;
+		}
+
+		if (!(transactionObj instanceof JSONObject))
+			throw new BitcoinException.NetworkException("Expected JSONObject as response from ElectrumX blockchain.transaction.get RPC");
+
+		JSONObject transactionJson = (JSONObject) transactionObj;
+
+		Object inputsObj = transactionJson.get("vin");
+		if (!(inputsObj instanceof JSONArray))
+			throw new BitcoinException.NetworkException("Expected JSONArray for 'vin' from ElectrumX blockchain.transaction.get RPC");
+
+		Object outputsObj = transactionJson.get("vout");
+		if (!(outputsObj instanceof JSONArray))
+			throw new BitcoinException.NetworkException("Expected JSONArray for 'vout' from ElectrumX blockchain.transaction.get RPC");
+
+		try {
+			int size = ((Long) transactionJson.get("size")).intValue();
+			int locktime = ((Long) transactionJson.get("locktime")).intValue();
+
+			// Timestamp might not be present, e.g. for unconfirmed transaction
+			Object timeObj = transactionJson.get("time");
+			Integer timestamp = timeObj != null
+					? ((Long) timeObj).intValue()
+					: null;
+
+			List<BitcoinTransaction.Input> inputs = new ArrayList<>();
+			for (Object inputObj : (JSONArray) inputsObj) {
+				JSONObject inputJson = (JSONObject) inputObj;
+
+				String scriptSig = (String) ((JSONObject) inputJson.get("scriptSig")).get("hex");
+				int sequence = ((Long) inputJson.get("sequence")).intValue();
+				String outputTxHash = (String) inputJson.get("txid");
+				int outputVout = ((Long) inputJson.get("vout")).intValue();
+
+				inputs.add(new BitcoinTransaction.Input(scriptSig, sequence, outputTxHash, outputVout));
+			}
+
+			List<BitcoinTransaction.Output> outputs = new ArrayList<>();
+			for (Object outputObj : (JSONArray) outputsObj) {
+				JSONObject outputJson = (JSONObject) outputObj;
+
+				String scriptPubKey = (String) ((JSONObject) outputJson.get("scriptPubKey")).get("hex");
+				long value = (long) (((Double) outputJson.get("value")) * 1e8);
+
+				outputs.add(new BitcoinTransaction.Output(scriptPubKey, value));
+			}
+
+			return new BitcoinTransaction(txHash, size, locktime, timestamp, inputs, outputs);
+		} catch (NullPointerException | ClassCastException e) {
+			// Unexpected / invalid response from ElectrumX server
+		}
+
+		throw new BitcoinException.NetworkException("Unexpected JSON format from ElectrumX blockchain.transaction.get RPC");
+	}
+
+	/**
+	 * Returns list of transactions, relating to passed payment script.
+	 * <p>
+	 * @return list of related transactions, or empty list if script unknown
+	 * @throws BitcoinException if error occurs
+	 */
+	public List<TransactionHash> getAddressTransactions(byte[] script, boolean includeUnconfirmed) throws BitcoinException {
 		byte[] scriptHash = Crypto.digest(script);
 		Bytes.reverse(scriptHash);
 
 		Object transactionsJson = this.rpc("blockchain.scripthash.get_history", HashCode.fromBytes(scriptHash).toString());
 		if (!(transactionsJson instanceof JSONArray))
-			return null;
+			throw new BitcoinException.NetworkException("Expected array output from ElectrumX blockchain.scripthash.get_history RPC");
 
-		List<byte[]> rawTransactions = new ArrayList<>();
+		List<TransactionHash> transactionHashes = new ArrayList<>();
 
 		for (Object rawTransactionInfo : (JSONArray) transactionsJson) {
 			JSONObject transactionInfo = (JSONObject) rawTransactionInfo;
 
-			// We only want confirmed transactions
-			if (!transactionInfo.containsKey("height"))
+			Long height = (Long) transactionInfo.get("height");
+			if (!includeUnconfirmed && (height == null || height == 0))
+				// We only want confirmed transactions
 				continue;
 
 			String txHash = (String) transactionInfo.get("tx_hash");
-			String rawTransactionHex = (String) this.rpc("blockchain.transaction.get", txHash);
-			if (rawTransactionHex == null)
-				return null;
 
-			rawTransactions.add(HashCode.fromString(rawTransactionHex).asBytes());
+			transactionHashes.add(new TransactionHash(height.intValue(), txHash));
 		}
 
-		return rawTransactions;
+		return transactionHashes;
 	}
 
-	/** Returns true if raw transaction successfully broadcast. */
-	public boolean broadcastTransaction(byte[] transactionBytes) {
+	/**
+	 * Broadcasts raw transaction to Bitcoin network.
+	 * <p>
+	 * @throws BitcoinException if error occurs
+	 */
+	public void broadcastTransaction(byte[] transactionBytes) throws BitcoinException {
 		Object rawBroadcastResult = this.rpc("blockchain.transaction.broadcast", HashCode.fromBytes(transactionBytes).toString());
-		if (rawBroadcastResult == null)
-			return false;
 
-		// If result is a String, then it is simply transaction hash.
-		// Otherwise result is JSON and probably contains error info instead.
-		return rawBroadcastResult instanceof String;
+		// We're expecting a simple string that is the transaction hash
+		if (!(rawBroadcastResult instanceof String))
+			throw new BitcoinException.NetworkException("Unexpected response from ElectrumX blockchain.transaction.broadcast RPC");
 	}
 
 	// Class-private utility methods
 
-	/** Query current server for its list of peer servers, and return those we can parse. */
-	private Set<Server> serverPeersSubscribe() {
+	/**
+	 * Query current server for its list of peer servers, and return those we can parse.
+	 * <p>
+	 * @throws BitcoinException
+	 * @throws ClassCastException to be handled by caller
+	 */
+	private Set<Server> serverPeersSubscribe() throws BitcoinException {
 		Set<Server> newServers = new HashSet<>();
 
 		Object peers = this.connectedRpc("server.peers.subscribe");
-		if (!(peers instanceof JSONArray))
-			return newServers;
 
 		for (Object rawPeer : (JSONArray) peers) {
 			JSONArray peer = (JSONArray) rawPeer;
 			if (peer.size() < 3)
+				// We're expecting at least 3 fields for each peer entry: IP, hostname, features
 				continue;
 
 			String hostname = (String) peer.get(1);
@@ -322,9 +466,14 @@ public class ElectrumX {
 						connectionType = Server.ConnectionType.TCP;
 						port = DEFAULT_TCP_PORT;
 						break;
+
+					default:
+						// e.g. could be 'v' for protocol version, or 'p' for pruning limit
+						break;
 				}
 
 				if (connectionType == null)
+					// We couldn't extract any peer connection info?
 					continue;
 
 				// Possible non-default port?
@@ -344,8 +493,16 @@ public class ElectrumX {
 		return newServers;
 	}
 
-	/** Return output from RPC call, with automatic reconnection to different server if needed. */
-	private synchronized Object rpc(String method, Object...params) {
+	/**
+	 * Performs RPC call, with automatic reconnection to different server if needed.
+	 * <p>
+	 * @return "result" object from within JSON output
+	 * @throws BitcoinException if server returns error or something goes wrong
+	 */
+	private synchronized Object rpc(String method, Object...params) throws BitcoinException {
+		if (this.remainingServers.isEmpty())
+			this.remainingServers.addAll(this.servers);
+
 		while (haveConnection()) {
 			Object response = connectedRpc(method, params);
 			if (response != null)
@@ -360,18 +517,17 @@ public class ElectrumX {
 			this.scanner = null;
 		}
 
-		return null;
+		// Failed to perform RPC - maybe lack of servers?
+		throw new BitcoinException.NetworkException("Failed to perform Bitcoin RPC");
 	}
 
 	/** Returns true if we have, or create, a connection to an ElectrumX server. */
-	private boolean haveConnection() {
+	private boolean haveConnection() throws BitcoinException {
 		if (this.currentServer != null)
 			return true;
 
-		List<Server> remainingServers = new ArrayList<>(this.servers);
-
-		while (!remainingServers.isEmpty()) {
-			Server server = remainingServers.remove(RANDOM.nextInt(remainingServers.size()));
+		while (!this.remainingServers.isEmpty()) {
+			Server server = this.remainingServers.remove(RANDOM.nextInt(this.remainingServers.size()));
 			LOGGER.trace(() -> String.format("Connecting to %s", server));
 
 			try {
@@ -384,23 +540,41 @@ public class ElectrumX {
 
 				if (server.connectionType == Server.ConnectionType.SSL) {
 					SSLSocketFactory factory = TrustlessSSLSocketFactory.getSocketFactory();
-					this.socket = (SSLSocket) factory.createSocket(this.socket, server.hostname, server.port, true);
+					this.socket = factory.createSocket(this.socket, server.hostname, server.port, true);
 				}
 
 				this.scanner = new Scanner(this.socket.getInputStream());
 				this.scanner.useDelimiter("\n");
 
-				// Check connection works by asking for more servers
+				// Check connection is suitable by asking for server features, including genesis block hash
+				JSONObject featuresJson = (JSONObject) this.connectedRpc("server.features");
+
+				if (featuresJson == null || Double.valueOf((String) featuresJson.get("protocol_min")) < MIN_PROTOCOL_VERSION)
+					continue;
+
+				if (this.expectedGenesisHash != null && !((String) featuresJson.get("genesis_hash")).equals(this.expectedGenesisHash))
+					continue;
+
+				// Ask for more servers
 				Set<Server> moreServers = serverPeersSubscribe();
+				// Discard duplicate servers we already know
 				moreServers.removeAll(this.servers);
-				remainingServers.addAll(moreServers);
+				// Add to both lists
+				this.remainingServers.addAll(moreServers);
 				this.servers.addAll(moreServers);
 
 				LOGGER.debug(() -> String.format("Connected to %s", server));
 				this.currentServer = server;
 				return true;
-			} catch (IOException e) {
+			} catch (IOException | BitcoinException | ClassCastException | NullPointerException e) {
 				// Try another server...
+				if (this.socket != null && !this.socket.isClosed())
+					try {
+						this.socket.close();
+					} catch (IOException e1) {
+						// We did try...
+					}
+
 				this.socket = null;
 				this.scanner = null;
 			}
@@ -409,11 +583,20 @@ public class ElectrumX {
 		return false;
 	}
 
+	/**
+	 * Perform RPC using currently connected server.
+	 * <p>
+	 * @param method
+	 * @param params
+	 * @return response Object, or null if server fails to respond
+	 * @throws BitcoinException if server returns error
+	 */
 	@SuppressWarnings("unchecked")
-	private Object connectedRpc(String method, Object...params) {
+	private Object connectedRpc(String method, Object...params) throws BitcoinException {
 		JSONObject requestJson = new JSONObject();
 		requestJson.put("id", this.nextId++);
 		requestJson.put("method", method);
+		requestJson.put("jsonrpc", "2.0");
 
 		JSONArray requestParams = new JSONArray();
 		requestParams.addAll(Arrays.asList(params));
@@ -428,20 +611,52 @@ public class ElectrumX {
 			this.socket.getOutputStream().write(request.getBytes());
 			response = scanner.next();
 		} catch (IOException | NoSuchElementException e) {
+			// Unable to send, or receive -- try another server?
 			return null;
 		}
 
 		LOGGER.trace(() -> String.format("Response: %s", response));
 
 		if (response.isEmpty())
+			// Empty response - try another server?
 			return null;
 
 		Object responseObj = JSONValue.parse(response);
 		if (!(responseObj instanceof JSONObject))
+			// Unexpected response - try another server?
 			return null;
 
 		JSONObject responseJson = (JSONObject) responseObj;
 
+		Object errorObj = responseJson.get("error");
+		if (errorObj != null) {
+			if (!(errorObj instanceof JSONObject))
+				throw new BitcoinException.NetworkException(String.format("Unexpected error response from ElectrumX RPC %s", method));
+
+			JSONObject errorJson = (JSONObject) errorObj;
+
+			Object messageObj = errorJson.get("message");
+
+			if (!(messageObj instanceof String))
+				throw new BitcoinException.NetworkException(String.format("Missing/invalid message in error response from ElectrumX RPC %s", method));
+
+			String message = (String) messageObj;
+
+			// Some error 'messages' are actually wrapped upstream bitcoind errors:
+			// "message": "daemon error: DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})"
+			// We want to detect these and extract the upstream error code for caller's use
+			Matcher messageMatcher = DAEMON_ERROR_REGEX.matcher(message);
+			if (messageMatcher.find())
+				try {
+					int daemonErrorCode = Integer.parseInt(messageMatcher.group(1));
+					throw new BitcoinException.NetworkException(daemonErrorCode, message);
+				} catch (NumberFormatException e) {
+					// We couldn't parse the error code integer? Fall-through to generic exception...
+				}
+
+			throw new BitcoinException.NetworkException(message);
+		}
+
 		return responseJson.get("result");
 	}
 

src/main/java/org/qortal/crosschain/TransactionHash.java

@@ -0,0 +1,31 @@
+package org.qortal.crosschain;
+
+import java.util.Comparator;
+
+public class TransactionHash {
+
+	public static final Comparator<TransactionHash> CONFIRMED_FIRST = (a, b) -> Boolean.compare(a.height != 0, b.height != 0);
+
+	public final int height;
+	public final String txHash;
+
+	public TransactionHash(int height, String txHash) {
+		this.height = height;
+		this.txHash = txHash;
+	}
+
+	public int getHeight() {
+		return this.height;
+	}
+
+	public String getTxHash() {
+		return this.txHash;
+	}
+
+	public String toString() {
+		return this.height == 0
+				? String.format("txHash %s (unconfirmed)", this.txHash)
+				: String.format("txHash %s (height %d)", this.txHash, this.height);
+	}
+
+}

src/main/java/org/qortal/crosschain/UnspentOutput.java

@@ -0,0 +1,16 @@
+package org.qortal.crosschain;
+
+/** Unspent output info as returned by ElectrumX network. */
+public class UnspentOutput {
+	public final byte[] hash;
+	public final int index;
+	public final int height;
+	public final long value;
+
+	public UnspentOutput(byte[] hash, int index, int height, long value) {
+		this.hash = hash;
+		this.index = index;
+		this.height = height;
+		this.value = value;
+	}
+}

src/main/java/org/qortal/crypto/Crypto.java

@@ -1,5 +1,6 @@
 package org.qortal.crypto;
 
+import java.nio.ByteBuffer;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Arrays;
@@ -42,6 +43,27 @@ public abstract class Crypto {
 		}
 	}
 
+	/**
+	 * Returns 32-byte SHA-256 digest of message passed in input.
+	 * 
+	 * @param input
+	 *            variable-length byte[] message
+	 * @return byte[32] digest, or null if SHA-256 algorithm can't be accessed
+	 */
+	public static byte[] digest(ByteBuffer input) {
+		if (input == null)
+			return null;
+
+		try {
+			// SHA2-256
+			MessageDigest sha256 = MessageDigest.getInstance("SHA-256");
+			sha256.update(input);
+			return sha256.digest();
+		} catch (NoSuchAlgorithmException e) {
+			throw new RuntimeException("SHA-256 message digest not available");
+		}
+	}
+
 	/**
 	 * Returns 32-byte digest of two rounds of SHA-256 on message passed in input.
 	 * 

src/main/java/org/qortal/crypto/MemoryPoW.java

@@ -29,6 +29,10 @@ public class MemoryPoW {
 		do {
 			++nonce;
 
+			// If we've been interrupted, exit fast with invalid value
+			if (Thread.currentThread().isInterrupted())
+				return -1;
+
 			seed *= seedMultiplier; // per nonce
 
 			state[0] = longHash[0] ^ seed;

src/main/java/org/qortal/data/account/EligibleQoraHolderData.java

@@ -0,0 +1,48 @@
+package org.qortal.data.account;
+
+public class EligibleQoraHolderData {
+
+	// Properties
+
+	private String address;
+
+	private long qoraBalance;
+	private long qortFromQoraBalance;
+
+	private Long finalQortFromQora;
+	private Integer finalBlockHeight;
+
+	// Constructors
+
+	public EligibleQoraHolderData(String address, long qoraBalance, long qortFromQoraBalance, Long finalQortFromQora,
+			Integer finalBlockHeight) {
+		this.address = address;
+		this.qoraBalance = qoraBalance;
+		this.qortFromQoraBalance = qortFromQoraBalance;
+		this.finalQortFromQora = finalQortFromQora;
+		this.finalBlockHeight = finalBlockHeight;
+	}
+
+	// Getters/Setters
+
+	public String getAddress() {
+		return this.address;
+	}
+
+	public long getQoraBalance() {
+		return this.qoraBalance;
+	}
+
+	public long getQortFromQoraBalance() {
+		return this.qortFromQoraBalance;
+	}
+
+	public Long getFinalQortFromQora() {
+		return this.finalQortFromQora;
+	}
+
+	public Integer getFinalBlockHeight() {
+		return this.finalBlockHeight;
+	}
+
+}

src/main/java/org/qortal/data/at/ATStateData.java

@@ -5,7 +5,6 @@ public class ATStateData {
 	// Properties
 	private String ATAddress;
 	private Integer height;
-	private Long creation;
 	private byte[] stateData;
 	private byte[] stateHash;
 	private Long fees;
@@ -14,10 +13,9 @@ public class ATStateData {
 	// Constructors
 
 	/** Create new ATStateData */
-	public ATStateData(String ATAddress, Integer height, Long creation, byte[] stateData, byte[] stateHash, Long fees, boolean isInitial) {
+	public ATStateData(String ATAddress, Integer height, byte[] stateData, byte[] stateHash, Long fees, boolean isInitial) {
 		this.ATAddress = ATAddress;
 		this.height = height;
-		this.creation = creation;
 		this.stateData = stateData;
 		this.stateHash = stateHash;
 		this.fees = fees;
@@ -26,21 +24,21 @@ public class ATStateData {
 
 	/** For recreating per-block ATStateData from repository where not all info is needed */
 	public ATStateData(String ATAddress, int height, byte[] stateHash, Long fees, boolean isInitial) {
-		this(ATAddress, height, null, null, stateHash, fees, isInitial);
+		this(ATAddress, height, null, stateHash, fees, isInitial);
 	}
 
 	/** For creating ATStateData from serialized bytes when we don't have all the info */
 	public ATStateData(String ATAddress, byte[] stateHash) {
 		// This won't ever be initial AT state from deployment as that's never serialized over the network,
 		// but generated when the DeployAtTransaction is processed locally.
-		this(ATAddress, null, null, null, stateHash, null, false);
+		this(ATAddress, null, null, stateHash, null, false);
 	}
 
 	/** For creating ATStateData from serialized bytes when we don't have all the info */
 	public ATStateData(String ATAddress, byte[] stateHash, Long fees) {
 		// This won't ever be initial AT state from deployment as that's never serialized over the network,
 		// but generated when the DeployAtTransaction is processed locally.
-		this(ATAddress, null, null, null, stateHash, fees, false);
+		this(ATAddress, null, null, stateHash, fees, false);
 	}
 
 	// Getters / setters
@@ -58,10 +56,6 @@ public class ATStateData {
 		this.height = height;
 	}
 
-	public Long getCreation() {
-		return this.creation;
-	}
-
 	public byte[] getStateData() {
 		return this.stateData;
 	}

src/main/java/org/qortal/data/block/BlockData.java

@@ -79,6 +79,25 @@ public class BlockData implements Serializable {
 				null, 0, null, null);
 	}
 
+	public BlockData(BlockData other) {
+		this.version = other.version;
+		this.reference = other.reference;
+		this.transactionCount = other.transactionCount;
+		this.totalFees = other.totalFees;
+		this.transactionsSignature = other.transactionsSignature;
+		this.height = other.height;
+		this.timestamp = other.timestamp;
+		this.minterPublicKey = other.minterPublicKey;
+		this.minterSignature = other.minterSignature;
+		this.atCount = other.atCount;
+		this.atFees = other.atFees;
+		this.encodedOnlineAccounts = other.encodedOnlineAccounts;
+		this.onlineAccountsCount = other.onlineAccountsCount;
+		this.onlineAccountsTimestamp = other.onlineAccountsTimestamp;
+		this.onlineAccountsSignatures = other.onlineAccountsSignatures;
+		this.signature = other.signature;
+	}
+
 	// Getters/setters
 
 	public byte[] getSignature() {

src/main/java/org/qortal/data/crosschain/TradeBotData.java

@@ -190,4 +190,9 @@ public class TradeBotData {
 		return this.receivingAccountInfo;
 	}
 
+	// Mostly for debugging
+	public String toString() {
+		return String.format("%s: %s", this.atAddress, this.tradeState.name());
+	}
+
 }

src/main/java/org/qortal/event/EventBus.java

@@ -20,6 +20,21 @@ public enum EventBus {
 		}
 	}
 
+	/**
+	 * <b>WARNING:</b> before calling this method,
+	 * make sure repository holds no locks, e.g. by calling
+	 * <tt>repository.discardChanges()</tt>.
+	 * <p>
+	 * This is because event listeners might open a new
+	 * repository session which will deadlock HSQLDB
+	 * if it tries to CHECKPOINT.
+	 * <p>
+	 * The HSQLDB deadlock occurs because the caller's
+	 * repository session blocks the CHECKPOINT until
+	 * their transaction is closed, yet event listeners
+	 * new sessions are blocked until CHECKPOINT is
+	 * completed, hence deadlock.
+	 */
 	public void notify(Event event) {
 		List<Listener> clonedListeners;
 

src/main/java/org/qortal/globalization/Translator.java

@@ -10,12 +10,12 @@ import java.util.Set;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.qortal.settings.Settings;
 
 public enum Translator {
 	INSTANCE;
 
 	private static final Logger LOGGER = LogManager.getLogger(Translator.class);
-	private static final String DEFAULT_LANG = Locale.getDefault().getLanguage();
 
 	private static final Map<String, ResourceBundle> resourceBundles = new HashMap<>();
 
@@ -34,7 +34,7 @@ public enum Translator {
 	}
 
 	public String translate(String className, String key) {
-		return this.translate(className, DEFAULT_LANG, key);
+		return this.translate(className, Settings.getInstance().getLocaleLang(), key);
 	}
 
 	public Set<String> keySet(String className, String lang) {

src/main/java/org/qortal/network/Network.java

@@ -96,22 +96,24 @@ public class Network {
 	private final String ourNodeId = Crypto.toNodeAddress(edPublicKeyParams.getEncoded());
 
 	private final int maxMessageSize;
+	private final int minOutboundPeers;
+	private final int maxPeers;
 
 	private final List<PeerData> allKnownPeers = new ArrayList<>();
 	private final List<Peer> connectedPeers = new ArrayList<>();
 	private final List<PeerAddress> selfPeers = new ArrayList<>();
 
-	private ExecuteProduceConsume networkEPC;
+	private final ExecuteProduceConsume networkEPC;
 	private Selector channelSelector;
 	private ServerSocketChannel serverChannel;
 	private Iterator<SelectionKey> channelIterator = null;
 
-	private int minOutboundPeers;
-	private int maxPeers;
-	private long nextConnectTaskTimestamp = 0L; // ms - try first connect once NTP syncs
+	// volatile because value is updated inside any one of the EPC threads
+	private volatile long nextConnectTaskTimestamp = 0L; // ms - try first connect once NTP syncs
 
 	private ExecutorService broadcastExecutor = Executors.newCachedThreadPool();
-	private long nextBroadcastTimestamp = 0L; // ms - try first broadcast once NTP syncs
+	// volatile because value is updated inside any one of the EPC threads
+	private volatile long nextBroadcastTimestamp = 0L; // ms - try first broadcast once NTP syncs
 
 	private final Lock mergePeersLock = new ReentrantLock();
 
@@ -429,35 +431,38 @@ public class Network {
 		private Task maybeProduceChannelTask(boolean canBlock) throws InterruptedException {
 			final SelectionKey nextSelectionKey;
 
-			// anything to do?
-			if (channelIterator == null) {
-				try {
-					if (canBlock)
-						channelSelector.select(1000L);
-					else
-						channelSelector.selectNow();
-				} catch (IOException e) {
-					LOGGER.warn(String.format("Channel selection threw IOException: %s", e.getMessage()));
-					return null;
+			// Synchronization here to enforce thread-safety on channelIterator
+			synchronized (channelSelector) {
+				// anything to do?
+				if (channelIterator == null) {
+					try {
+						if (canBlock)
+							channelSelector.select(1000L);
+						else
+							channelSelector.selectNow();
+					} catch (IOException e) {
+						LOGGER.warn(String.format("Channel selection threw IOException: %s", e.getMessage()));
+						return null;
+					}
+
+					if (Thread.currentThread().isInterrupted())
+						throw new InterruptedException();
+
+					channelIterator = channelSelector.selectedKeys().iterator();
 				}
 
-				if (Thread.currentThread().isInterrupted())
-					throw new InterruptedException();
+				if (channelIterator.hasNext()) {
+					nextSelectionKey = channelIterator.next();
+					channelIterator.remove();
+				} else {
+					nextSelectionKey = null;
+					channelIterator = null; // Nothing to do so reset iterator to cause new select
+				}
 
-				channelIterator = channelSelector.selectedKeys().iterator();
+				LOGGER.trace(() -> String.format("Thread %d, nextSelectionKey %s, channelIterator now %s",
+						Thread.currentThread().getId(), nextSelectionKey, channelIterator));
 			}
 
-			if (channelIterator.hasNext()) {
-				nextSelectionKey = channelIterator.next();
-				channelIterator.remove();
-			} else {
-				nextSelectionKey = null;
-				channelIterator = null; // Nothing to do so reset iterator to cause new select
-			}
-
-			LOGGER.trace(() -> String.format("Thread %d, nextSelectionKey %s, channelIterator now %s",
-					Thread.currentThread().getId(), nextSelectionKey, channelIterator));
-
 			if (nextSelectionKey == null)
 				return null;
 

src/main/java/org/qortal/network/Peer.java

@@ -33,6 +33,7 @@ import org.qortal.settings.Settings;
 import org.qortal.utils.ExecuteProduceConsume;
 import org.qortal.utils.NTP;
 
+import com.google.common.hash.HashCode;
 import com.google.common.net.HostAndPort;
 import com.google.common.net.InetAddresses;
 
@@ -348,21 +349,37 @@ public class Peer {
 				if (this.byteBuffer == null)
 					this.byteBuffer = ByteBuffer.allocate(Network.getInstance().getMaxMessageSize());
 
+				final int priorPosition = this.byteBuffer.position();
 				final int bytesRead = this.socketChannel.read(this.byteBuffer);
 				if (bytesRead == -1) {
 					this.disconnect("EOF");
 					return;
 				}
 
-				LOGGER.trace(() -> String.format("Received %d bytes from peer %s", bytesRead, this));
+				LOGGER.trace(() -> {
+					if (bytesRead > 0) {
+						byte[] leadingBytes = new byte[Math.min(bytesRead, 8)];
+						this.byteBuffer.asReadOnlyBuffer().position(priorPosition).get(leadingBytes);
+						String leadingHex = HashCode.fromBytes(leadingBytes).toString();
+
+						return String.format("Received %d bytes, starting %s, into byteBuffer[%d] from peer %s",
+								bytesRead,
+								leadingHex,
+								priorPosition,
+								this);
+					} else {
+						return String.format("Received %d bytes into byteBuffer[%d] from peer %s", bytesRead, priorPosition, this);
+					}
+				});
 				final boolean wasByteBufferFull = !this.byteBuffer.hasRemaining();
 
 				while (true) {
 					final Message message;
 
 					// Can we build a message from buffer now?
+					ByteBuffer readOnlyBuffer = this.byteBuffer.asReadOnlyBuffer().flip();
 					try {
-						message = Message.fromByteBuffer(this.byteBuffer);
+						message = Message.fromByteBuffer(readOnlyBuffer);
 					} catch (MessageException e) {
 						LOGGER.debug(String.format("%s, from peer %s", e.getMessage(), this));
 						this.disconnect(e.getMessage());
@@ -387,6 +404,13 @@ public class Peer {
 
 					LOGGER.trace(() -> String.format("Received %s message with ID %d from peer %s", message.getType().name(), message.getId(), this));
 
+					// Tidy up buffers:
+					this.byteBuffer.flip();
+					// Read-only, flipped buffer's position will be after end of message, so copy that
+					this.byteBuffer.position(readOnlyBuffer.position());
+					// Copy bytes after read message to front of buffer, adjusting position accordingly, reset limit to capacity
+					this.byteBuffer.compact();
+
 					BlockingQueue<Message> queue = this.replyQueues.get(message.getId());
 					if (queue != null) {
 						// Adding message to queue will unblock thread waiting for response
@@ -399,7 +423,7 @@ public class Peer {
 
 					// Add message to pending queue
 					if (!this.pendingMessages.offer(message)) {
-						LOGGER.info(String.format("No room to queue message from peer %s - discarding", this));
+						LOGGER.info(() -> String.format("No room to queue message from peer %s - discarding", this));
 						return;
 					}
 
@@ -454,10 +478,24 @@ public class Peer {
 				while (outputBuffer.hasRemaining()) {
 					int bytesWritten = this.socketChannel.write(outputBuffer);
 
+					LOGGER.trace(() -> String.format("Sent %d bytes of %s message with ID %d to peer %s",
+							bytesWritten,
+							message.getType().name(),
+							message.getId(),
+							this));
+
 					if (bytesWritten == 0)
 						// Underlying socket's internal buffer probably full,
 						// so wait a short while for bytes to actually be transmitted over the wire
-						this.socketChannel.wait(1L);
+
+						/*
+						 * NOSONAR squid:S2276 - we don't want to use this.socketChannel.wait()
+						 * as this releases the lock held by synchronized() above
+						 * and would allow another thread to send another message,
+						 * potentially interleaving them on-the-wire, causing checksum failures
+						 * and connection loss.
+						 */
+						Thread.sleep(1L); //NOSONAR squid:S2276
 				}
 			}
 		} catch (MessageException e) {

src/main/java/org/qortal/network/message/BlockMessage.java

@@ -34,6 +34,7 @@ public class BlockMessage extends Message {
 		super(MessageType.BLOCK);
 
 		this.block = block;
+		this.blockData = block.getBlockData();
 		this.height = block.getBlockData().getHeight();
 	}
 
@@ -93,4 +94,10 @@ public class BlockMessage extends Message {
 		}
 	}
 
+	public BlockMessage cloneWithNewId(int newId) {
+		BlockMessage clone = new BlockMessage(this.block);
+		clone.setId(newId);
+		return clone;
+	}
+
 }

src/main/java/org/qortal/network/message/Message.java

@@ -160,80 +160,72 @@ public abstract class Message {
 	/**
 	 * Attempt to read a message from byte buffer.
 	 * 
-	 * @param byteBuffer
+	 * @param readOnlyBuffer
 	 * @return null if no complete message can be read
 	 * @throws MessageException
 	 */
-	public static Message fromByteBuffer(ByteBuffer byteBuffer) throws MessageException {
+	public static Message fromByteBuffer(ByteBuffer readOnlyBuffer) throws MessageException {
 		try {
-			byteBuffer.flip();
-
-			ByteBuffer readBuffer = byteBuffer.asReadOnlyBuffer();
-
 			// Read only enough bytes to cover Message "magic" preamble
 			byte[] messageMagic = new byte[MAGIC_LENGTH];
-			readBuffer.get(messageMagic);
+			readOnlyBuffer.get(messageMagic);
 
 			if (!Arrays.equals(messageMagic, Network.getInstance().getMessageMagic()))
 				// Didn't receive correct Message "magic"
 				throw new MessageException("Received incorrect message 'magic'");
 
 			// Find supporting object
-			int typeValue = readBuffer.getInt();
+			int typeValue = readOnlyBuffer.getInt();
 			MessageType messageType = MessageType.valueOf(typeValue);
 			if (messageType == null)
 				// Unrecognised message type
 				throw new MessageException(String.format("Received unknown message type [%d]", typeValue));
 
 			// Optional message ID
-			byte hasId = readBuffer.get();
+			byte hasId = readOnlyBuffer.get();
 			int id = -1;
 			if (hasId != 0) {
-				id = readBuffer.getInt();
+				id = readOnlyBuffer.getInt();
 
 				if (id <= 0)
 					// Invalid ID
 					throw new MessageException("Invalid negative ID");
 			}
 
-			int dataSize = readBuffer.getInt();
+			int dataSize = readOnlyBuffer.getInt();
 
 			if (dataSize > MAX_DATA_SIZE)
 				// Too large
 				throw new MessageException(String.format("Declared data length %d larger than max allowed %d", dataSize, MAX_DATA_SIZE));
 
+			// Don't have all the data yet?
+			if (dataSize > 0 && dataSize + CHECKSUM_LENGTH > readOnlyBuffer.remaining())
+				return null;
+
 			ByteBuffer dataSlice = null;
 			if (dataSize > 0) {
 				byte[] expectedChecksum = new byte[CHECKSUM_LENGTH];
-				readBuffer.get(expectedChecksum);
+				readOnlyBuffer.get(expectedChecksum);
 
-				// Remember this position in readBuffer so we can pass to Message subclass
-				dataSlice = readBuffer.slice();
-
-				// Consume data from buffer
-				byte[] data = new byte[dataSize];
-				readBuffer.get(data);
-
-				// We successfully read all the data bytes, so we can set limit on dataSlice
+				// Slice data in readBuffer so we can pass to Message subclass
+				dataSlice = readOnlyBuffer.slice();
 				dataSlice.limit(dataSize);
 
 				// Test checksum
-				byte[] actualChecksum = generateChecksum(data);
+				byte[] actualChecksum = generateChecksum(dataSlice);
 				if (!Arrays.equals(expectedChecksum, actualChecksum))
 					throw new MessageException("Message checksum incorrect");
+
+				// Reset position after being consumed by generateChecksum
+				dataSlice.position(0);
+				// Update position in readOnlyBuffer
+				readOnlyBuffer.position(readOnlyBuffer.position() + dataSize);
 			}
 
-			Message message = messageType.fromByteBuffer(id, dataSlice);
-
-			// We successfully read a message, so bump byteBuffer's position to reflect this
-			byteBuffer.position(readBuffer.position());
-
-			return message;
+			return messageType.fromByteBuffer(id, dataSlice);
 		} catch (BufferUnderflowException e) {
 			// Not enough bytes to fully decode message...
 			return null;
-		} finally {
-			byteBuffer.compact();
 		}
 	}
 
@@ -241,6 +233,10 @@ public abstract class Message {
 		return Arrays.copyOfRange(Crypto.digest(data), 0, CHECKSUM_LENGTH);
 	}
 
+	protected static byte[] generateChecksum(ByteBuffer dataBuffer) {
+		return Arrays.copyOfRange(Crypto.digest(dataBuffer), 0, CHECKSUM_LENGTH);
+	}
+
 	public byte[] toBytes() throws MessageException {
 		try {
 			ByteArrayOutputStream bytes = new ByteArrayOutputStream(256);

src/main/java/org/qortal/repository/ATRepository.java

@@ -87,6 +87,21 @@ public interface ATRepository {
 	 */
 	public List<ATStateData> getBlockATStatesAtHeight(int height) throws DataException;
 
+	/** Returns height of first trimmable AT state. */
+	public int getAtTrimHeight() throws DataException;
+
+	/** Sets new base height for AT state trimming.
+	 * <p>
+	 * NOTE: performs implicit <tt>repository.saveChanges()</tt>.
+	 */
+	public void setAtTrimHeight(int trimHeight) throws DataException;
+
+	/** Hook to allow repository to prepare/cache info for AT state trimming. */
+	public void prepareForAtStateTrimming() throws DataException;
+
+	/** Trims full AT state data between passed heights. Returns number of trimmed rows. */
+	public int trimAtStates(int minHeight, int maxHeight, int limit) throws DataException;
+
 	/**
 	 * Save ATStateData into repository.
 	 * <p>

src/main/java/org/qortal/repository/AccountRepository.java

@@ -4,6 +4,7 @@ import java.util.List;
 
 import org.qortal.data.account.AccountBalanceData;
 import org.qortal.data.account.AccountData;
+import org.qortal.data.account.EligibleQoraHolderData;
 import org.qortal.data.account.MintingAccountData;
 import org.qortal.data.account.QortFromQoraData;
 import org.qortal.data.account.RewardShareData;
@@ -89,6 +90,13 @@ public interface AccountRepository {
 	 */
 	public int modifyMintedBlockCount(String address, int delta) throws DataException;
 
+	/**
+	 * Modifies batch of accounts' minted block count only.
+	 * <p>
+	 * This is a one-shot, batch version of modifyMintedBlockCount(String, int) above.
+	 */
+	public void modifyMintedBlockCounts(List<String> addresses, int delta) throws DataException;
+
 	/** Delete account from repository. */
 	public void delete(String address) throws DataException;
 
@@ -106,6 +114,9 @@ public interface AccountRepository {
 	 */
 	public AccountBalanceData getBalance(String address, long assetId) throws DataException;
 
+	/** Returns all account balances for given assetID, optionally excluding zero balances. */
+	public List<AccountBalanceData> getAssetBalances(long assetId, Boolean excludeZero) throws DataException;
+
 	/** How to order results when fetching asset balances. */
 	public enum BalanceOrdering {
 		/** assetID first, then balance, then account address */
@@ -116,15 +127,18 @@ public interface AccountRepository {
 		ASSET_ACCOUNT
 	}
 
-	/** Returns all account balances for given assetID, optionally excluding zero balances. */
-	public List<AccountBalanceData> getAssetBalances(long assetId, Boolean excludeZero) throws DataException;
-
 	/** Returns account balances for matching addresses / assetIDs, optionally excluding zero balances, with pagination, used by API. */
 	public List<AccountBalanceData> getAssetBalances(List<String> addresses, List<Long> assetIds, BalanceOrdering balanceOrdering, Boolean excludeZero, Integer limit, Integer offset, Boolean reverse) throws DataException;
 
 	/** Modifies account's asset balance by <tt>deltaBalance</tt>. */
 	public void modifyAssetBalance(String address, long assetId, long deltaBalance) throws DataException;
 
+	/** Modifies a batch of account asset balances, treating AccountBalanceData.balance as <tt>deltaBalance</tt>. */
+	public void modifyAssetBalances(List<AccountBalanceData> accountBalanceDeltas) throws DataException;
+
+	/** Batch update of account asset balances. */
+	public void setAssetBalances(List<AccountBalanceData> accountBalances) throws DataException;
+
 	public void save(AccountBalanceData accountBalanceData) throws DataException;
 
 	public void delete(String address, long assetId) throws DataException;
@@ -156,6 +170,16 @@ public interface AccountRepository {
 	 */
 	public RewardShareData getRewardShareByIndex(int index) throws DataException;
 
+	/**
+	 * Returns list of reward-share data using array of indexes into list of reward-shares (sorted by reward-share public key).
+	 * <p>
+	 * This is a one-shot, batch form of the above <tt>getRewardShareByIndex(int)</tt> call.
+	 * 
+	 * @return list of reward-share data, or null if one (or more) index is invalid
+	 * @throws DataException
+	 */
+	public List<RewardShareData> getRewardSharesByIndexes(int[] indexes) throws DataException;
+
 	public boolean rewardShareExists(byte[] rewardSharePublicKey) throws DataException;
 
 	public void save(RewardShareData rewardShareData) throws DataException;
@@ -175,7 +199,7 @@ public interface AccountRepository {
 	// Managing QORT from legacy QORA
 
 	/**
-	 * Returns balance data for accounts with legacy QORA asset that are eligible
+	 * Returns full info for accounts with legacy QORA asset that are eligible
 	 * for more block reward (block processing) or for block reward removal (block orphaning).
 	 * <p>
 	 * For block processing, accounts that have already received their final QORT reward for owning
@@ -187,7 +211,7 @@ public interface AccountRepository {
 	 * @param blockHeight QORT reward must have be present at this height (for orphaning only)
 	 * @throws DataException
 	 */
-	public List<AccountBalanceData> getEligibleLegacyQoraHolders(Integer blockHeight) throws DataException;
+	public List<EligibleQoraHolderData> getEligibleLegacyQoraHolders(Integer blockHeight) throws DataException;
 
 	public QortFromQoraData getQortFromQoraInfo(String address) throws DataException;
 

src/main/java/org/qortal/repository/BlockRepository.java

@@ -143,13 +143,21 @@ public interface BlockRepository {
 	 */
 	public List<BlockInfo> getBlockInfos(Integer startHeight, Integer endHeight, Integer count) throws DataException;
 
+	/** Returns height of first trimmable online accounts signatures. */
+	public int getOnlineAccountsSignaturesTrimHeight() throws DataException;
+
+	/** Sets new base height for trimming online accounts signatures.
+	 * <p>
+	 * NOTE: performs implicit <tt>repository.saveChanges()</tt>.
+	 */
+	public void setOnlineAccountsSignaturesTrimHeight(int trimHeight) throws DataException;
+
 	/**
-	 * Trim online accounts signatures from blocks older than passed timestamp.
+	 * Trim online accounts signatures from blocks between passed heights.
 	 * 
-	 * @param timestamp
 	 * @return number of blocks trimmed
 	 */
-	public int trimOldOnlineAccountsSignatures(long timestamp) throws DataException;
+	public int trimOldOnlineAccountsSignatures(int minHeight, int maxHeight) throws DataException;
 
 	/**
 	 * Returns first (lowest height) block that doesn't link back to specified block.

src/main/java/org/qortal/repository/MessageRepository.java

@@ -0,0 +1,31 @@
+package org.qortal.repository;
+
+import java.util.List;
+
+import org.qortal.data.transaction.MessageTransactionData;
+
+public interface MessageRepository {
+
+	/**
+	 * Returns list of confirmed MESSAGE transaction data matching (some) participants.
+	 * <p>
+	 * At least one of <tt>senderPublicKey</tt> or <tt>recipient</tt> must be specified.
+	 * <p>
+	 * @throws DataException
+	 */
+	public List<MessageTransactionData> getMessagesByParticipants(byte[] senderPublicKey,
+			String recipient, Integer limit, Integer offset, Boolean reverse) throws DataException;
+
+	/**
+	 * Does a MESSAGE exist with matching sender (pubkey), recipient and message payload?
+	 * <p>
+	 * Includes both confirmed and unconfirmed transactions!
+	 * <p>
+	 * @param senderPublicKey
+	 * @param recipient
+	 * @param messageData
+	 * @return true if a message exists, false otherwise
+	 */
+	public boolean exists(byte[] senderPublicKey, String recipient, byte[] messageData) throws DataException;
+
+}

src/main/java/org/qortal/repository/Repository.java

@@ -18,6 +18,8 @@ public interface Repository extends AutoCloseable {
 
 	public GroupRepository getGroupRepository();
 
+	public MessageRepository getMessageRepository();
+
 	public NameRepository getNameRepository();
 
 	public NetworkRepository getNetworkRepository();
@@ -45,4 +47,12 @@ public interface Repository extends AutoCloseable {
 
 	public void backup(boolean quick) throws DataException;
 
+	public void checkpoint(boolean quick) throws DataException;
+
+	public void performPeriodicMaintenance() throws DataException;
+
+	public void exportNodeLocalData() throws DataException;
+
+	public void importDataFromFile(String filename) throws DataException;
+
 }

src/main/java/org/qortal/repository/RepositoryFactory.java

@@ -2,6 +2,8 @@ package org.qortal.repository;
 
 public interface RepositoryFactory {
 
+	public boolean wasPristineAtOpen();
+
 	public RepositoryFactory reopen() throws DataException;
 
 	public Repository getRepository() throws DataException;

src/main/java/org/qortal/repository/RepositoryManager.java

@@ -8,6 +8,13 @@ public abstract class RepositoryManager {
 		repositoryFactory = newRepositoryFactory;
 	}
 
+	public static boolean wasPristineAtOpen() throws DataException {
+		if (repositoryFactory == null)
+			throw new DataException("No repository available");
+
+		return repositoryFactory.wasPristineAtOpen();
+	}
+
 	public static Repository getRepository() throws DataException {
 		if (repositoryFactory == null)
 			throw new DataException("No repository available");
@@ -35,6 +42,14 @@ public abstract class RepositoryManager {
 		}
 	}
 
+	public static void checkpoint(boolean quick) {
+		try (final Repository repository = getRepository()) {
+			repository.checkpoint(quick);
+		} catch (DataException e) {
+			// Checkpoint is best-effort so don't complain
+		}
+	}
+
 	public static void rebuild() throws DataException {
 		RepositoryFactory oldRepositoryFactory = repositoryFactory;
 

src/main/java/org/qortal/repository/TransactionRepository.java

@@ -6,7 +6,6 @@ import java.util.Map;
 import org.qortal.api.resource.TransactionsResource.ConfirmationStatus;
 import org.qortal.data.group.GroupApprovalData;
 import org.qortal.data.transaction.GroupApprovalTransactionData;
-import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.data.transaction.TransferAssetTransactionData;
 import org.qortal.transaction.Transaction.TransactionType;
@@ -91,6 +90,22 @@ public interface TransactionRepository {
 	public List<byte[]> getSignaturesMatchingCriteria(TransactionType txType, byte[] publicKey,
 			ConfirmationStatus confirmationStatus, Integer limit, Integer offset, Boolean reverse) throws DataException;
 
+	/**
+	 * Returns signatures for transactions that match search criteria.
+	 * <p>
+	 * Simpler version that only checks accepts one (optional) transaction type,
+	 * and one (optional) public key, within an block height range.
+	 * 
+	 * @param txType
+	 * @param publicKey
+	 * @param minBlockHeight
+	 * @param maxBlockHeight
+	 * @return
+	 * @throws DataException
+	 */
+	public List<byte[]> getSignaturesMatchingCriteria(TransactionType txType, byte[] publicKey,
+			Integer minBlockHeight, Integer maxBlockHeight) throws DataException;
+
 	/**
 	 * Returns signature for latest auto-update transaction.
 	 * <p>
@@ -108,18 +123,6 @@ public interface TransactionRepository {
 	 */
 	public byte[] getLatestAutoUpdateTransaction(TransactionType txType, int txGroupId, Integer service) throws DataException;
 
-	/**
-	 * Returns list of MESSAGE transaction data matching recipient.
-	 * @param recipient
-	 * @param limit
-	 * @param offset
-	 * @param reverse
-	 * @return
-	 * @throws DataException
-	 */
-	public List<MessageTransactionData> getMessagesByRecipient(String recipient,
-			Integer limit, Integer offset, Boolean reverse) throws DataException;
-
 	/**
 	 * Returns list of transactions relating to specific asset ID.
 	 * 

src/main/java/org/qortal/repository/hsqldb/HSQLDBATRepository.java

@@ -10,6 +10,8 @@ import org.qortal.data.at.ATStateData;
 import org.qortal.repository.ATRepository;
 import org.qortal.repository.DataException;
 
+import com.google.common.primitives.Longs;
+
 public class HSQLDBATRepository implements ATRepository {
 
 	protected HSQLDBRepository repository;
@@ -48,7 +50,7 @@ public class HSQLDBATRepository implements ATRepository {
 			boolean hadFatalError = resultSet.getBoolean(10);
 			boolean isFrozen = resultSet.getBoolean(11);
 
-			Long frozenBalance = resultSet.getLong(11);
+			Long frozenBalance = resultSet.getLong(12);
 			if (frozenBalance == 0 && resultSet.wasNull())
 				frozenBalance = null;
 
@@ -116,7 +118,7 @@ public class HSQLDBATRepository implements ATRepository {
 				boolean hadFatalError = resultSet.getBoolean(10);
 				boolean isFrozen = resultSet.getBoolean(11);
 
-				Long frozenBalance = resultSet.getLong(11);
+				Long frozenBalance = resultSet.getLong(12);
 				if (frozenBalance == 0 && resultSet.wasNull())
 					frozenBalance = null;
 
@@ -135,16 +137,21 @@ public class HSQLDBATRepository implements ATRepository {
 	@Override
 	public List<ATData> getATsByFunctionality(byte[] codeHash, Boolean isExecutable, Integer limit, Integer offset, Boolean reverse) throws DataException {
 		StringBuilder sql = new StringBuilder(512);
+		List<Object> bindParams = new ArrayList<>();
+
 		sql.append("SELECT AT_address, creator, created_when, version, asset_id, code_bytes, ")
 				.append("is_sleeping, sleep_until_height, is_finished, had_fatal_error, ")
 				.append("is_frozen, frozen_balance ")
 				.append("FROM ATs ")
 				.append("WHERE code_hash = ? ");
+		bindParams.add(codeHash);
 
-		if (isExecutable != null)
-			sql.append("AND is_finished = ").append(isExecutable ? "false" : "true");
+		if (isExecutable != null) {
+			sql.append("AND is_finished != ? ");
+			bindParams.add(isExecutable);
+		}
 
-		sql.append(" ORDER BY created_when ");
+		sql.append("ORDER BY created_when ");
 		if (reverse != null && reverse)
 			sql.append("DESC");
 
@@ -152,7 +159,7 @@ public class HSQLDBATRepository implements ATRepository {
 
 		List<ATData> matchingATs = new ArrayList<>();
 
-		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), codeHash)) {
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
 			if (resultSet == null)
 				return matchingATs;
 
@@ -241,22 +248,22 @@ public class HSQLDBATRepository implements ATRepository {
 
 	@Override
 	public ATStateData getATStateAtHeight(String atAddress, int height) throws DataException {
-		String sql = "SELECT created_when, state_data, state_hash, fees, is_initial "
+		String sql = "SELECT state_data, state_hash, fees, is_initial "
 				+ "FROM ATStates "
-				+ "WHERE AT_address = ? AND height = ? "
+				+ "LEFT OUTER JOIN ATStatesData USING (AT_address, height) "
+				+ "WHERE ATStates.AT_address = ? AND ATStates.height = ? "
 				+ "LIMIT 1";
 
 		try (ResultSet resultSet = this.repository.checkedExecute(sql, atAddress, height)) {
 			if (resultSet == null)
 				return null;
 
-			long created = resultSet.getLong(1);
-			byte[] stateData = resultSet.getBytes(2); // Actually BLOB
-			byte[] stateHash = resultSet.getBytes(3);
-			long fees = resultSet.getLong(4);
-			boolean isInitial = resultSet.getBoolean(5);
+			byte[] stateData = resultSet.getBytes(1); // Actually BLOB
+			byte[] stateHash = resultSet.getBytes(2);
+			long fees = resultSet.getLong(3);
+			boolean isInitial = resultSet.getBoolean(4);
 
-			return new ATStateData(atAddress, height, created, stateData, stateHash, fees, isInitial);
+			return new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch AT state from repository", e);
 		}
@@ -264,25 +271,26 @@ public class HSQLDBATRepository implements ATRepository {
 
 	@Override
 	public ATStateData getLatestATState(String atAddress) throws DataException {
-		String sql = "SELECT height, created_when, state_data, state_hash, fees, is_initial "
+		String sql = "SELECT height, state_data, state_hash, fees, is_initial "
 				+ "FROM ATStates "
-				+ "WHERE AT_address = ? "
-				+ "ORDER BY height DESC "
-				+ "LIMIT 1 "
-				+ "USING INDEX";
+				+ "JOIN ATStatesData USING (AT_address, height) "
+				+ "WHERE ATStates.AT_address = ? "
+				// Order by AT_address and height to use compound primary key as index
+				// Both must be the same direction (DESC) also
+				+ "ORDER BY ATStates.AT_address DESC, ATStates.height DESC "
+				+ "LIMIT 1 ";
 
 		try (ResultSet resultSet = this.repository.checkedExecute(sql, atAddress)) {
 			if (resultSet == null)
 				return null;
 
 			int height = resultSet.getInt(1);
-			long created = resultSet.getLong(2);
-			byte[] stateData = resultSet.getBytes(3); // Actually BLOB
-			byte[] stateHash = resultSet.getBytes(4);
-			long fees = resultSet.getLong(5);
-			boolean isInitial = resultSet.getBoolean(6);
+			byte[] stateData = resultSet.getBytes(2); // Actually BLOB
+			byte[] stateHash = resultSet.getBytes(3);
+			long fees = resultSet.getLong(4);
+			boolean isInitial = resultSet.getBoolean(5);
 
-			return new ATStateData(atAddress, height, created, stateData, stateHash, fees, isInitial);
+			return new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch latest AT state from repository", e);
 		}
@@ -293,18 +301,27 @@ public class HSQLDBATRepository implements ATRepository {
 			Integer dataByteOffset, Long expectedValue, Integer minimumFinalHeight,
 			Integer limit, Integer offset, Boolean reverse) throws DataException {
 		StringBuilder sql = new StringBuilder(1024);
-		sql.append("SELECT AT_address, height, created_when, state_data, state_hash, fees, is_initial "
+		List<Object> bindParams = new ArrayList<>();
+
+		sql.append("SELECT AT_address, height, state_data, state_hash, fees, is_initial "
 				+ "FROM ATs "
 				+ "CROSS JOIN LATERAL("
-					+ "SELECT height, created_when, state_data, state_hash, fees, is_initial "
+					+ "SELECT height, state_data, state_hash, fees, is_initial "
 					+ "FROM ATStates "
-					+ "WHERE ATStates.AT_address = ATs.AT_address "
-					+ "ORDER BY height DESC "
+					+ "JOIN ATStatesData USING (AT_address, height) "
+					+ "WHERE ATStates.AT_address = ATs.AT_address ");
+
+		if (minimumFinalHeight != null) {
+			sql.append("AND ATStates.height >= ? ");
+			bindParams.add(minimumFinalHeight);
+		}
+
+		// Order by AT_address and height to use compound primary key as index
+		// Both must be the same direction (DESC) also
+		sql.append("ORDER BY ATStates.AT_address DESC, ATStates.height DESC "
 					+ "LIMIT 1 "
 				+ ") AS FinalATStates "
 				+ "WHERE code_hash = ? ");
-
-		List<Object> bindParams = new ArrayList<>();
 		bindParams.add(codeHash);
 
 		if (isFinished != null) {
@@ -313,22 +330,17 @@ public class HSQLDBATRepository implements ATRepository {
 		}
 
 		if (dataByteOffset != null && expectedValue != null) {
-			sql.append("AND RAWTOHEX(SUBSTRING(state_data FROM ? FOR 8)) = ? ");
+			sql.append("AND SUBSTRING(state_data FROM ? FOR 8) = ? ");
 
-			// We convert our long to hex Java-side to control endian
-			String expectedHexValue = String.format("%016x", expectedValue); // left-zero-padding and conversion
+			// We convert our long on Java-side to control endian
+			byte[] rawExpectedValue = Longs.toByteArray(expectedValue);
 
 			// SQL binary data offsets start at 1
 			bindParams.add(dataByteOffset + 1);
-			bindParams.add(expectedHexValue);
+			bindParams.add(rawExpectedValue);
 		}
 
-		if (minimumFinalHeight != null) {
-			sql.append("AND height >= ");
-			sql.append(minimumFinalHeight);
-		}
-
-		sql.append(" ORDER BY height ");
+		sql.append(" ORDER BY FinalATStates.height ");
 		if (reverse != null && reverse)
 			sql.append("DESC");
 
@@ -343,13 +355,12 @@ public class HSQLDBATRepository implements ATRepository {
 			do {
 				String atAddress = resultSet.getString(1);
 				int height = resultSet.getInt(2);
-				long created = resultSet.getLong(3);
-				byte[] stateData = resultSet.getBytes(4); // Actually BLOB
-				byte[] stateHash = resultSet.getBytes(5);
-				long fees = resultSet.getLong(6);
-				boolean isInitial = resultSet.getBoolean(7);
+				byte[] stateData = resultSet.getBytes(3); // Actually BLOB
+				byte[] stateHash = resultSet.getBytes(4);
+				long fees = resultSet.getLong(5);
+				boolean isInitial = resultSet.getBoolean(6);
 
-				ATStateData atStateData = new ATStateData(atAddress, height, created, stateData, stateHash, fees, isInitial);
+				ATStateData atStateData = new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
 
 				atStates.add(atStateData);
 			} while (resultSet.next());
@@ -363,8 +374,10 @@ public class HSQLDBATRepository implements ATRepository {
 	@Override
 	public List<ATStateData> getBlockATStatesAtHeight(int height) throws DataException {
 		String sql = "SELECT AT_address, state_hash, fees, is_initial "
-				+ "FROM ATStates "
-				+ "WHERE height = ? "
+				+ "FROM ATs "
+				+ "LEFT OUTER JOIN ATStates "
+				+ "ON ATStates.AT_address = ATs.AT_address AND height = ? "
+				+ "WHERE ATStates.AT_address IS NOT NULL "
 				+ "ORDER BY created_when ASC";
 
 		List<ATStateData> atStates = new ArrayList<>();
@@ -391,29 +404,131 @@ public class HSQLDBATRepository implements ATRepository {
 	}
 
 	@Override
-	public void save(ATStateData atStateData) throws DataException {
-		// We shouldn't ever save partial ATStateData
-		if (atStateData.getCreation() == null || atStateData.getStateHash() == null || atStateData.getHeight() == null)
-			throw new IllegalArgumentException("Refusing to save partial AT state into repository!");
+	public int getAtTrimHeight() throws DataException {
+		String sql = "SELECT AT_trim_height FROM DatabaseInfo";
 
-		HSQLDBSaver saveHelper = new HSQLDBSaver("ATStates");
+		try (ResultSet resultSet = this.repository.checkedExecute(sql)) {
+			if (resultSet == null)
+				return 0;
 
-		saveHelper.bind("AT_address", atStateData.getATAddress()).bind("height", atStateData.getHeight())
-				.bind("created_when", atStateData.getCreation()).bind("state_data", atStateData.getStateData())
-				.bind("state_hash", atStateData.getStateHash()).bind("fees", atStateData.getFees())
-				.bind("is_initial", atStateData.isInitial());
+			return resultSet.getInt(1);
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch AT state trim height from repository", e);
+		}
+	}
+
+	@Override
+	public void setAtTrimHeight(int trimHeight) throws DataException {
+		// trimHeightsLock is to prevent concurrent update on DatabaseInfo
+		// that could result in "transaction rollback: serialization failure"
+		synchronized (this.repository.trimHeightsLock) {
+			String updateSql = "UPDATE DatabaseInfo SET AT_trim_height = ?";
+
+			try {
+				this.repository.executeCheckedUpdate(updateSql, trimHeight);
+				this.repository.saveChanges();
+			} catch (SQLException e) {
+				repository.examineException(e);
+				throw new DataException("Unable to set AT state trim height in repository", e);
+			}
+		}
+	}
+
+	@Override
+	public void prepareForAtStateTrimming() throws DataException {
+		// Rebuild cache of latest AT states that we can't trim
+		String deleteSql = "DELETE FROM LatestATStates";
+		try {
+			this.repository.executeCheckedUpdate(deleteSql);
+		} catch (SQLException e) {
+			repository.examineException(e);
+			throw new DataException("Unable to delete temporary latest AT states cache from repository", e);
+		}
+
+		String insertSql = "INSERT INTO LatestATStates ("
+				+ "SELECT AT_address, height FROM ATs "
+				+ "CROSS JOIN LATERAL("
+					+ "SELECT height FROM ATStates "
+					+ "WHERE ATStates.AT_address = ATs.AT_address "
+					+ "ORDER BY AT_address DESC, height DESC LIMIT 1"
+				+ ") "
+			+ ")";
+		try {
+			this.repository.executeCheckedUpdate(insertSql);
+		} catch (SQLException e) {
+			repository.examineException(e);
+			throw new DataException("Unable to populate temporary latest AT states cache in repository", e);
+		}
+	}
+
+	@Override
+	public int trimAtStates(int minHeight, int maxHeight, int limit) throws DataException {
+		if (minHeight >= maxHeight)
+			return 0;
+
+		// We're often called so no need to trim all states in one go.
+		// Limit updates to reduce CPU and memory load.
+		String sql = "DELETE FROM ATStatesData "
+				+ "WHERE height BETWEEN ? AND ? "
+				+ "AND NOT EXISTS("
+					+ "SELECT TRUE FROM LatestATStates "
+					+ "WHERE LatestATStates.AT_address = ATStatesData.AT_address "
+					+ "AND LatestATStates.height = ATStatesData.height"
+				+ ") "
+				+ "LIMIT ?";
 
 		try {
-			saveHelper.execute(this.repository);
+			return this.repository.executeCheckedUpdate(sql, minHeight, maxHeight, limit);
+		} catch (SQLException e) {
+			repository.examineException(e);
+			throw new DataException("Unable to trim AT states in repository", e);
+		}
+	}
+
+	@Override
+	public void save(ATStateData atStateData) throws DataException {
+		// We shouldn't ever save partial ATStateData
+		if (atStateData.getStateHash() == null || atStateData.getHeight() == null)
+			throw new IllegalArgumentException("Refusing to save partial AT state into repository!");
+
+		HSQLDBSaver atStatesSaver = new HSQLDBSaver("ATStates");
+
+		atStatesSaver.bind("AT_address", atStateData.getATAddress()).bind("height", atStateData.getHeight())
+				.bind("state_hash", atStateData.getStateHash())
+				.bind("fees", atStateData.getFees()).bind("is_initial", atStateData.isInitial());
+
+		try {
+			atStatesSaver.execute(this.repository);
 		} catch (SQLException e) {
 			throw new DataException("Unable to save AT state into repository", e);
 		}
+
+		if (atStateData.getStateData() != null) {
+			HSQLDBSaver atStatesDataSaver = new HSQLDBSaver("ATStatesData");
+
+			atStatesDataSaver.bind("AT_address", atStateData.getATAddress()).bind("height", atStateData.getHeight())
+					.bind("state_data", atStateData.getStateData());
+
+			try {
+				atStatesDataSaver.execute(this.repository);
+			} catch (SQLException e) {
+				throw new DataException("Unable to save AT state data into repository", e);
+			}
+		} else {
+			try {
+				this.repository.delete("ATStatesData", "AT_address = ? AND height = ?",
+						atStateData.getATAddress(), atStateData.getHeight());
+			} catch (SQLException e) {
+				throw new DataException("Unable to delete AT state data from repository", e);
+			}
+		}
 	}
 
 	@Override
 	public void delete(String atAddress, int height) throws DataException {
 		try {
 			this.repository.delete("ATStates", "AT_address = ? AND height = ?", atAddress, height);
+			this.repository.delete("ATStatesData", "AT_address = ? AND height = ?", atAddress, height);
 		} catch (SQLException e) {
 			throw new DataException("Unable to delete AT state from repository", e);
 		}
@@ -423,6 +538,7 @@ public class HSQLDBATRepository implements ATRepository {
 	public void deleteATStates(int height) throws DataException {
 		try {
 			this.repository.delete("ATStates", "height = ?", height);
+			this.repository.delete("ATStatesData", "height = ?", height);
 		} catch (SQLException e) {
 			throw new DataException("Unable to delete AT states from repository", e);
 		}

src/main/java/org/qortal/repository/hsqldb/HSQLDBAccountRepository.java

@@ -1,13 +1,17 @@
 package org.qortal.repository.hsqldb;
 
+import static org.qortal.utils.Amounts.prettyAmount;
+
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.qortal.asset.Asset;
 import org.qortal.data.account.AccountBalanceData;
 import org.qortal.data.account.AccountData;
+import org.qortal.data.account.EligibleQoraHolderData;
 import org.qortal.data.account.MintingAccountData;
 import org.qortal.data.account.QortFromQoraData;
 import org.qortal.data.account.RewardShareData;
@@ -145,7 +149,7 @@ public class HSQLDBAccountRepository implements AccountRepository {
 	public void ensureAccount(AccountData accountData) throws DataException {
 		String sql = "INSERT IGNORE INTO Accounts (account, public_key) VALUES (?, ?)"; // MySQL syntax
 		try {
-			this.repository.checkedExecuteUpdateCount(sql, accountData.getAddress(), accountData.getPublicKey());
+			this.repository.executeCheckedUpdate(sql, accountData.getAddress(), accountData.getPublicKey());
 		} catch (SQLException e) {
 			throw new DataException("Unable to ensure minimal account in repository", e);
 		}
@@ -260,12 +264,26 @@ public class HSQLDBAccountRepository implements AccountRepository {
 			"ON DUPLICATE KEY UPDATE blocks_minted = blocks_minted + ?";
 
 		try {
-			return this.repository.checkedExecuteUpdateCount(sql, address, delta, delta);
+			return this.repository.executeCheckedUpdate(sql, address, delta, delta);
 		} catch (SQLException e) {
 			throw new DataException("Unable to modify account's minted block count in repository", e);
 		}
 	}
 
+	@Override
+	public void modifyMintedBlockCounts(List<String> addresses, int delta) throws DataException {
+		String sql = "INSERT INTO Accounts (account, blocks_minted) VALUES (?, ?) " +
+				"ON DUPLICATE KEY UPDATE blocks_minted = blocks_minted + ?";
+
+		List<Object[]> bindParamRows = addresses.stream().map(address -> new Object[] { address, delta, delta }).collect(Collectors.toList());
+
+		try {
+			this.repository.executeCheckedBatchUpdate(sql, bindParamRows);
+		} catch (SQLException e) {
+			throw new DataException("Unable to modify many account minted block counts in repository", e);
+		}
+	}
+
 	@Override
 	public void delete(String address) throws DataException {
 		// NOTE: Account balances are deleted automatically by the database thanks to "ON DELETE CASCADE" in AccountBalances' FOREIGN KEY
@@ -447,7 +465,7 @@ public class HSQLDBAccountRepository implements AccountRepository {
 			// Perform actual balance change
 			String sql = "UPDATE AccountBalances set balance = balance + ? WHERE account = ? AND asset_id = ?";
 			try {
-				this.repository.checkedExecuteUpdateCount(sql, deltaBalance, address, assetId);
+				this.repository.executeCheckedUpdate(sql, deltaBalance, address, assetId);
 			} catch (SQLException e) {
 				throw new DataException("Unable to reduce account balance in repository", e);
 			}
@@ -455,7 +473,7 @@ public class HSQLDBAccountRepository implements AccountRepository {
 			// We have to ensure parent row exists to satisfy foreign key constraint
 			try {
 				String sql = "INSERT IGNORE INTO Accounts (account) VALUES (?)"; // MySQL syntax
-				this.repository.checkedExecuteUpdateCount(sql, address);
+				this.repository.executeCheckedUpdate(sql, address);
 			} catch (SQLException e) {
 				throw new DataException("Unable to ensure minimal account in repository", e);
 			}
@@ -464,13 +482,95 @@ public class HSQLDBAccountRepository implements AccountRepository {
 			String sql = "INSERT INTO AccountBalances (account, asset_id, balance) VALUES (?, ?, ?) " +
 				"ON DUPLICATE KEY UPDATE balance = balance + ?";
 			try {
-				this.repository.checkedExecuteUpdateCount(sql, address, assetId, deltaBalance, deltaBalance);
+				this.repository.executeCheckedUpdate(sql, address, assetId, deltaBalance, deltaBalance);
 			} catch (SQLException e) {
 				throw new DataException("Unable to increase account balance in repository", e);
 			}
 		}
 	}
 
+	public void modifyAssetBalances(List<AccountBalanceData> accountBalanceDeltas) throws DataException {
+		// Nothing to do?
+		if (accountBalanceDeltas == null || accountBalanceDeltas.isEmpty())
+			return;
+
+		// Map balance changes into SQL bind params, filtering out no-op changes
+		List<Object[]> modifyBalanceParams = accountBalanceDeltas.stream()
+				.filter(accountBalance -> accountBalance.getBalance() != 0L)
+				.map(accountBalance -> new Object[] { accountBalance.getAddress(), accountBalance.getAssetId(), accountBalance.getBalance(), accountBalance.getBalance() })
+				.collect(Collectors.toList());
+
+		// Before we modify balances, ensure parent accounts exist
+		String ensureSql = "INSERT IGNORE INTO Accounts (account) VALUES (?)"; // MySQL syntax
+		try {
+			this.repository.executeCheckedBatchUpdate(ensureSql, modifyBalanceParams.stream().map(objects -> new Object[] { objects[0] }).collect(Collectors.toList()));
+		} catch (SQLException e) {
+			throw new DataException("Unable to ensure minimal accounts in repository", e);
+		}
+
+		// Perform actual balance changes
+		String sql = "INSERT INTO AccountBalances (account, asset_id, balance) VALUES (?, ?, ?) " +
+			"ON DUPLICATE KEY UPDATE balance = balance + ?";
+		try {
+			this.repository.executeCheckedBatchUpdate(sql, modifyBalanceParams);
+		} catch (SQLException e) {
+			throw new DataException("Unable to modify account balances in repository", e);
+		}
+	}
+
+
+	@Override
+	public void setAssetBalances(List<AccountBalanceData> accountBalances) throws DataException {
+		// Nothing to do?
+		if (accountBalances == null || accountBalances.isEmpty())
+			return;
+
+		/*
+		 * Split workload into zero and non-zero balances,
+		 * checking for negative balances as we progress.
+		 */
+
+		List<Object[]> zeroAccountBalanceParams = new ArrayList<>();
+		List<Object[]> nonZeroAccountBalanceParams = new ArrayList<>();
+
+		for (AccountBalanceData accountBalanceData : accountBalances) {
+			final long balance = accountBalanceData.getBalance();
+
+			if (balance < 0)
+				throw new DataException(String.format("Refusing to set negative balance %s [assetId %d] for %s",
+						prettyAmount(balance), accountBalanceData.getAssetId(), accountBalanceData.getAddress()));
+
+			if (balance == 0)
+				zeroAccountBalanceParams.add(new Object[] { accountBalanceData.getAddress(), accountBalanceData.getAssetId() });
+			else
+				nonZeroAccountBalanceParams.add(new Object[] { accountBalanceData.getAddress(), accountBalanceData.getAssetId(), balance, balance });
+		}
+
+		// Batch update (actually delete) of zero balances
+		try {
+			this.repository.deleteBatch("AccountBalances", "account = ? AND asset_id = ?", zeroAccountBalanceParams);
+		} catch (SQLException e) {
+			throw new DataException("Unable to delete account balances from repository", e);
+		}
+
+		// Before we set new balances, ensure parent accounts exist
+		String ensureSql = "INSERT IGNORE INTO Accounts (account) VALUES (?)"; // MySQL syntax
+		try {
+			this.repository.executeCheckedBatchUpdate(ensureSql, nonZeroAccountBalanceParams.stream().map(objects -> new Object[] { objects[0] }).collect(Collectors.toList()));
+		} catch (SQLException e) {
+			throw new DataException("Unable to ensure minimal accounts in repository", e);
+		}
+
+		// Now set all balances in one go
+		String setSql = "INSERT INTO AccountBalances (account, asset_id, balance) VALUES (?, ?, ?) " +
+				"ON DUPLICATE KEY UPDATE balance = ?";
+		try {
+			this.repository.executeCheckedBatchUpdate(setSql, nonZeroAccountBalanceParams);
+		} catch (SQLException e) {
+			throw new DataException("Unable to set account balances in repository", e);
+		}
+	}
+
 	@Override
 	public void save(AccountBalanceData accountBalanceData) throws DataException {
 		HSQLDBSaver saveHelper = new HSQLDBSaver("AccountBalances");
@@ -699,7 +799,52 @@ public class HSQLDBAccountRepository implements AccountRepository {
 
 			return new RewardShareData(minterPublicKey, minter, recipient, rewardSharePublicKey, sharePercent);
 		} catch (SQLException e) {
-			throw new DataException("Unable to fetch reward-share info from repository", e);
+			throw new DataException("Unable to fetch indexed reward-share from repository", e);
+		}
+	}
+
+	@Override
+	public List<RewardShareData> getRewardSharesByIndexes(int[] indexes) throws DataException {
+		String sql = "SELECT minter_public_key, minter, recipient, share_percent, reward_share_public_key FROM RewardShares "
+				+ "ORDER BY reward_share_public_key ASC";
+
+		if (indexes == null)
+			return null;
+
+		List<RewardShareData> rewardShares = new ArrayList<>();
+		if (indexes.length == 0)
+			return rewardShares;
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql)) {
+			if (resultSet == null)
+				return null;
+
+			int rowNum = 1;
+			for (int i = 0; i < indexes.length; ++i) {
+				final int index = indexes[i];
+
+				while (rowNum < index + 1) { // +1 because in JDBC, first row is row 1
+					if (!resultSet.next())
+						// Index is out of bounds
+						return null;
+
+					++rowNum;
+				}
+
+				byte[] minterPublicKey = resultSet.getBytes(1);
+				String minter = resultSet.getString(2);
+				String recipient = resultSet.getString(3);
+				int sharePercent = resultSet.getInt(4);
+				byte[] rewardSharePublicKey = resultSet.getBytes(5);
+
+				RewardShareData rewardShareData = new RewardShareData(minterPublicKey, minter, recipient, rewardSharePublicKey, sharePercent);
+
+				rewardShares.add(rewardShareData);
+			}
+
+			return rewardShares;
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch indexed reward-shares from repository", e);
 		}
 	}
 
@@ -785,35 +930,49 @@ public class HSQLDBAccountRepository implements AccountRepository {
 	// Managing QORT from legacy QORA
 
 	@Override
-	public List<AccountBalanceData> getEligibleLegacyQoraHolders(Integer blockHeight) throws DataException {
+	public List<EligibleQoraHolderData> getEligibleLegacyQoraHolders(Integer blockHeight) throws DataException {
 		StringBuilder sql = new StringBuilder(1024);
-		sql.append("SELECT account, balance from AccountBalances ");
+		List<Object> bindParams = new ArrayList<>();
+
+		sql.append("SELECT account, Qora.balance, QortFromQora.balance, final_qort_from_qora, final_block_height ");
+		sql.append("FROM AccountBalances AS Qora ");
 		sql.append("LEFT OUTER JOIN AccountQortFromQoraInfo USING (account) ");
-		sql.append("WHERE asset_id = ");
+		sql.append("LEFT OUTER JOIN AccountBalances AS QortFromQora ON QortFromQora.account = Qora.account AND QortFromQora.asset_id = ");
+		sql.append(Asset.QORT_FROM_QORA); // int is safe to use literally
+		sql.append(" WHERE Qora.asset_id = ");
 		sql.append(Asset.LEGACY_QORA); // int is safe to use literally
 		sql.append(" AND (final_block_height IS NULL");
 
 		if (blockHeight != null) {
-			sql.append(" OR final_block_height >= ");
-			sql.append(blockHeight);
+			sql.append(" OR final_block_height >= ?");
+			bindParams.add(blockHeight);
 		}
 
 		sql.append(")");
 
-		List<AccountBalanceData> accountBalances = new ArrayList<>();
+		List<EligibleQoraHolderData> eligibleLegacyQoraHolders = new ArrayList<>();
 
-		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString())) {
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
 			if (resultSet == null)
-				return accountBalances;
+				return eligibleLegacyQoraHolders;
 
 			do {
 				String address = resultSet.getString(1);
-				long balance = resultSet.getLong(2);
+				long qoraBalance = resultSet.getLong(2);
+				long qortFromQoraBalance = resultSet.getLong(3);
 
-				accountBalances.add(new AccountBalanceData(address, Asset.LEGACY_QORA, balance));
+				Long finalQortFromQora = resultSet.getLong(4);
+				if (finalQortFromQora == 0 && resultSet.wasNull())
+					finalQortFromQora = null;
+
+				Integer finalBlockHeight = resultSet.getInt(5);
+				if (finalBlockHeight == 0 && resultSet.wasNull())
+					finalBlockHeight = null;
+
+				eligibleLegacyQoraHolders.add(new EligibleQoraHolderData(address, qoraBalance, qortFromQoraBalance, finalQortFromQora, finalBlockHeight));
 			} while (resultSet.next());
 
-			return accountBalances;
+			return eligibleLegacyQoraHolders;
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch eligible legacy QORA holders from repository", e);
 		}

src/main/java/org/qortal/repository/hsqldb/HSQLDBBlockRepository.java

@@ -120,7 +120,7 @@ public class HSQLDBBlockRepository implements BlockRepository {
 	@Override
 	public int getHeightFromTimestamp(long timestamp) throws DataException {
 		// Uses (minted_when, height) index
-		String sql = "SELECT height FROM Blocks WHERE minted_when <= ? ORDER BY minted_when DESC LIMIT 1";
+		String sql = "SELECT height FROM Blocks WHERE minted_when <= ? ORDER BY minted_when DESC, height DESC LIMIT 1";
 
 		try (ResultSet resultSet = this.repository.checkedExecute(sql, timestamp)) {
 			if (resultSet == null)
@@ -175,7 +175,11 @@ public class HSQLDBBlockRepository implements BlockRepository {
 	public List<TransactionData> getTransactionsFromSignature(byte[] signature, Integer limit, Integer offset, Boolean reverse) throws DataException {
 		StringBuilder sql = new StringBuilder(256);
 
-		sql.append("SELECT transaction_signature FROM BlockTransactions WHERE block_signature = ? ORDER BY sequence");
+		sql.append("SELECT transaction_signature FROM BlockTransactions WHERE block_signature = ? ORDER BY block_signature");
+		if (reverse != null && reverse)
+			sql.append(" DESC");
+
+		sql.append(", sequence");
 		if (reverse != null && reverse)
 			sql.append(" DESC");
 
@@ -378,6 +382,8 @@ public class HSQLDBBlockRepository implements BlockRepository {
 	@Override
 	public List<BlockInfo> getBlockInfos(Integer startHeight, Integer endHeight, Integer count) throws DataException {
 		StringBuilder sql = new StringBuilder(512);
+		List<Object> bindParams = new ArrayList<>();
+
 		sql.append("SELECT signature, height, minted_when, transaction_count, RewardShares.minter ");
 
 		/*
@@ -396,10 +402,9 @@ public class HSQLDBBlockRepository implements BlockRepository {
 		if (startHeight != null && endHeight != null) {
 			sql.append("FROM Blocks ");
 			sql.append("JOIN RewardShares ON RewardShares.reward_share_public_key = Blocks.minter ");
-			sql.append("WHERE height BETWEEN ");
-			sql.append(startHeight);
-			sql.append(" AND ");
-			sql.append(endHeight - 1);
+			sql.append("WHERE height BETWEEN ? AND ?");
+			bindParams.add(startHeight);
+			bindParams.add(Integer.valueOf(endHeight - 1));
 		} else if (endHeight != null || (startHeight == null && count != null)) {
 			// we are going to return blocks from the end of the chain
 			if (count == null)
@@ -407,17 +412,15 @@ public class HSQLDBBlockRepository implements BlockRepository {
 
 			if (endHeight == null) {
 				sql.append("FROM (SELECT height FROM Blocks ORDER BY height DESC LIMIT 1) AS MaxHeights (max_height) ");
-				sql.append("JOIN Blocks ON height BETWEEN (max_height - ");
-				sql.append(count);
-				sql.append(" + 1) AND max_height ");
+				sql.append("JOIN Blocks ON height BETWEEN (max_height - ? + 1) AND max_height ");
 				sql.append("JOIN RewardShares ON RewardShares.reward_share_public_key = Blocks.minter");
+				bindParams.add(count);
 			} else {
 				sql.append("FROM Blocks ");
 				sql.append("JOIN RewardShares ON RewardShares.reward_share_public_key = Blocks.minter ");
-				sql.append("WHERE height BETWEEN ");
-				sql.append(endHeight - count);
-				sql.append(" AND ");
-				sql.append(endHeight - 1);
+				sql.append("WHERE height BETWEEN ? AND ?");
+				bindParams.add(Integer.valueOf(endHeight - count));
+				bindParams.add(Integer.valueOf(endHeight - 1));
 			}
 
 		} else {
@@ -430,15 +433,14 @@ public class HSQLDBBlockRepository implements BlockRepository {
 
 			sql.append("FROM Blocks ");
 			sql.append("JOIN RewardShares ON RewardShares.reward_share_public_key = Blocks.minter ");
-			sql.append("WHERE height BETWEEN ");
-			sql.append(startHeight);
-			sql.append(" AND ");
-			sql.append(startHeight + count - 1);
+			sql.append("WHERE height BETWEEN ? AND ?");
+			bindParams.add(startHeight);
+			bindParams.add(Integer.valueOf(startHeight + count - 1));
 		}
 
 		List<BlockInfo> blockInfos = new ArrayList<>();
 
-		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString())) {
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
 			if (resultSet == null)
 				return blockInfos;
 
@@ -460,12 +462,48 @@ public class HSQLDBBlockRepository implements BlockRepository {
 	}
 
 	@Override
-	public int trimOldOnlineAccountsSignatures(long timestamp) throws DataException {
-		String sql = "UPDATE Blocks set online_accounts_signatures = NULL WHERE minted_when < ? AND online_accounts_signatures IS NOT NULL";
+	public int getOnlineAccountsSignaturesTrimHeight() throws DataException {
+		String sql = "SELECT online_signatures_trim_height FROM DatabaseInfo";
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql)) {
+			if (resultSet == null)
+				return 0;
+
+			return resultSet.getInt(1);
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch online accounts signatures trim height from repository", e);
+		}
+	}
+
+	@Override
+	public void setOnlineAccountsSignaturesTrimHeight(int trimHeight) throws DataException {
+		// trimHeightsLock is to prevent concurrent update on DatabaseInfo
+		// that could result in "transaction rollback: serialization failure"
+		synchronized (this.repository.trimHeightsLock) {
+			String updateSql = "UPDATE DatabaseInfo SET online_signatures_trim_height = ?";
+
+			try {
+				this.repository.executeCheckedUpdate(updateSql, trimHeight);
+				this.repository.saveChanges();
+			} catch (SQLException e) {
+				repository.examineException(e);
+				throw new DataException("Unable to set online accounts signatures trim height in repository", e);
+			}
+		}
+	}
+
+	@Override
+	public int trimOldOnlineAccountsSignatures(int minHeight, int maxHeight) throws DataException {
+		// We're often called so no need to trim all blocks in one go.
+		// Limit updates to reduce CPU and memory load.
+		String sql = "UPDATE Blocks SET online_accounts_signatures = NULL "
+				+ "WHERE online_accounts_signatures IS NOT NULL "
+				+ "AND height BETWEEN ? AND ?";
 
 		try {
-			return this.repository.checkedExecuteUpdateCount(sql, timestamp);
+			return this.repository.executeCheckedUpdate(sql, minHeight, maxHeight);
 		} catch (SQLException e) {
+			repository.examineException(e);
 			throw new DataException("Unable to trim old online accounts signatures in repository", e);
 		}
 	}

src/main/java/org/qortal/repository/hsqldb/HSQLDBDatabaseUpdates.java

@@ -18,11 +18,16 @@ public class HSQLDBDatabaseUpdates {
 	/**
 	 * Apply any incremental changes to database schema.
 	 * 
+	 * @return true if database was non-existent/empty, false otherwise
 	 * @throws SQLException
 	 */
-	public static void updateDatabase(Connection connection) throws SQLException {
-		while (databaseUpdating(connection))
+	public static boolean updateDatabase(Connection connection) throws SQLException {
+		final boolean wasPristine = fetchDatabaseVersion(connection) == 0;
+
+		while (databaseUpdating(connection, wasPristine))
 			incrementDatabaseVersion(connection);
+
+		return wasPristine;
 	}
 
 	/**
@@ -40,23 +45,21 @@ public class HSQLDBDatabaseUpdates {
 	/**
 	 * Fetch current version of database schema.
 	 * 
-	 * @return int, 0 if no schema yet
+	 * @return database version, or 0 if no schema yet
 	 * @throws SQLException
 	 */
 	private static int fetchDatabaseVersion(Connection connection) throws SQLException {
-		int databaseVersion = 0;
-
 		try (Statement stmt = connection.createStatement()) {
 			if (stmt.execute("SELECT version FROM DatabaseInfo"))
 				try (ResultSet resultSet = stmt.getResultSet()) {
 					if (resultSet.next())
-						databaseVersion = resultSet.getInt(1);
+						return resultSet.getInt(1);
 				}
 		} catch (SQLException e) {
 			// empty database
 		}
 
-		return databaseVersion;
+		return 0;
 	}
 
 	/**
@@ -65,7 +68,7 @@ public class HSQLDBDatabaseUpdates {
 	 * @return true - if a schema update happened, false otherwise
 	 * @throws SQLException
 	 */
-	private static boolean databaseUpdating(Connection connection) throws SQLException {
+	private static boolean databaseUpdating(Connection connection, boolean wasPristine) throws SQLException {
 		int databaseVersion = fetchDatabaseVersion(connection);
 
 		try (Statement stmt = connection.createStatement()) {
@@ -141,7 +144,7 @@ public class HSQLDBDatabaseUpdates {
 							+ "transaction_count INTEGER NOT NULL, total_fees QortalAmount NOT NULL, transactions_signature Signature NOT NULL, "
 							+ "height INTEGER NOT NULL, minted_when EpochMillis NOT NULL, "
 							+ "minter QortalPublicKey NOT NULL, minter_signature Signature NOT NULL, AT_count INTEGER NOT NULL, AT_fees QortalAmount NOT NULL, "
-							+ "online_accounts VARBINARY(1204), online_accounts_count INTEGER NOT NULL, online_accounts_timestamp EpochMillis, online_accounts_signatures VARBINARY(1M), "
+							+ "online_accounts VARBINARY(1024), online_accounts_count INTEGER NOT NULL, online_accounts_timestamp EpochMillis, online_accounts_signatures VARBINARY(1M), "
 							+ "PRIMARY KEY (signature))");
 					// For finding blocks by height.
 					stmt.execute("CREATE INDEX BlockHeightIndex ON Blocks (height)");
@@ -153,16 +156,6 @@ public class HSQLDBDatabaseUpdates {
 					stmt.execute("CREATE INDEX BlockTimestampHeightIndex ON Blocks (minted_when, height)");
 					// Use a separate table space as this table will be very large.
 					stmt.execute("SET TABLE Blocks NEW SPACE");
-
-					// Table to hold next block height.
-					stmt.execute("CREATE TABLE NextBlockHeight (height INT NOT NULL)");
-					// Initial value - should work for empty DB or populated DB.
-					stmt.execute("INSERT INTO NextBlockHeight VALUES (SELECT IFNULL(MAX(height), 0) + 1 FROM Blocks)");
-					// We use triggers on Blocks to update a simple "next block height" table
-					String blockUpdateSql = "UPDATE NextBlockHeight SET height = (SELECT height + 1 FROM Blocks ORDER BY height DESC LIMIT 1)";
-					stmt.execute("CREATE TRIGGER Next_block_height_insert_trigger AFTER INSERT ON Blocks " + blockUpdateSql);
-					stmt.execute("CREATE TRIGGER Next_block_height_update_trigger AFTER UPDATE ON Blocks " + blockUpdateSql);
-					stmt.execute("CREATE TRIGGER Next_block_height_delete_trigger AFTER DELETE ON Blocks " + blockUpdateSql);
 					break;
 
 				case 2:
@@ -222,6 +215,8 @@ public class HSQLDBDatabaseUpdates {
 							+ "PRIMARY KEY (account))");
 					// For looking up an account by public key
 					stmt.execute("CREATE INDEX AccountPublicKeyIndex on Accounts (public_key)");
+					// Use a separate table space as this table will be very large.
+					stmt.execute("SET TABLE Accounts NEW SPACE");
 
 					// Account balances
 					stmt.execute("CREATE TABLE AccountBalances (account QortalAddress, asset_id AssetID, balance QortalAmount NOT NULL, "
@@ -230,6 +225,8 @@ public class HSQLDBDatabaseUpdates {
 					stmt.execute("CREATE INDEX AccountBalancesAssetBalanceIndex ON AccountBalances (asset_id, balance)");
 					// Add CHECK constraint to account balances
 					stmt.execute("ALTER TABLE AccountBalances ADD CONSTRAINT CheckBalanceNotNegative CHECK (balance >= 0)");
+					// Use a separate table space as this table will be very large.
+					stmt.execute("SET TABLE AccountBalances NEW SPACE");
 
 					// Keeping track of QORT gained from holding legacy QORA
 					stmt.execute("CREATE TABLE AccountQortFromQoraInfo (account QortalAddress, final_qort_from_qora QortalAmount, final_block_height INT, "
@@ -427,6 +424,8 @@ public class HSQLDBDatabaseUpdates {
 							+ "PRIMARY KEY (AT_address, height), FOREIGN KEY (AT_address) REFERENCES ATs (AT_address) ON DELETE CASCADE)");
 					// For finding per-block AT states, ordered by creation timestamp
 					stmt.execute("CREATE INDEX BlockATStateIndex on ATStates (height, created_when)");
+					// Use a separate table space as this table will be very large.
+					stmt.execute("SET TABLE ATStates NEW SPACE");
 
 					// Deploy CIYAM AT Transactions
 					stmt.execute("CREATE TABLE DeployATTransactions (signature Signature, creator QortalPublicKey NOT NULL, AT_name ATName NOT NULL, "
@@ -650,6 +649,128 @@ public class HSQLDBDatabaseUpdates {
 					stmt.execute("CHECKPOINT");
 					break;
 
+				case 23:
+					// MESSAGE transactions index
+					stmt.execute("CREATE INDEX IF NOT EXISTS MessageTransactionsRecipientIndex ON MessageTransactions (recipient, sender)");
+					break;
+
+				case 24:
+					// Remove unused NextBlockHeight table and corresponding triggers
+					stmt.execute("DROP TRIGGER IF EXISTS Next_block_height_insert_trigger");
+					stmt.execute("DROP TRIGGER IF EXISTS Next_block_height_update_trigger");
+					stmt.execute("DROP TRIGGER IF EXISTS Next_block_height_delete_trigger");
+					stmt.execute("DROP TABLE IF EXISTS NextBlockHeight");
+					break;
+
+				case 25:
+					// DISABLED: improved version in case 30!
+					// Remove excess created_when from ATStates
+					// stmt.execute("ALTER TABLE ATStates DROP created_when");
+					// stmt.execute("CREATE INDEX ATStateHeightIndex on ATStates (height)");
+					break;
+
+				case 26:
+					// Support for trimming
+					stmt.execute("ALTER TABLE DatabaseInfo ADD AT_trim_height INT NOT NULL DEFAULT 0");
+					stmt.execute("ALTER TABLE DatabaseInfo ADD online_signatures_trim_height INT NOT NULL DEFAULT 0");
+					break;
+
+				case 27:
+					// More indexes
+					stmt.execute("CREATE INDEX IF NOT EXISTS PaymentTransactionsRecipientIndex ON PaymentTransactions (recipient)");
+					stmt.execute("CREATE INDEX IF NOT EXISTS ATTransactionsRecipientIndex ON ATTransactions (recipient)");
+					break;
+
+				case 28:
+					// Latest AT state cache
+					stmt.execute("CREATE TEMPORARY TABLE IF NOT EXISTS LatestATStates ("
+								+ "AT_address QortalAddress NOT NULL, "
+								+ "height INT NOT NULL"
+							+ ")");
+					break;
+
+				case 29:
+					// Turn off HSQLDB redo-log "blockchain.log" and periodically call "CHECKPOINT" ourselves
+					stmt.execute("SET FILES LOG FALSE");
+					stmt.execute("CHECKPOINT");
+					break;
+
+				case 30:
+					// Split AT state data off to new table for better performance/management.
+
+					if (!wasPristine && !"mem".equals(HSQLDBRepository.getDbPathname(connection.getMetaData().getURL()))) {
+						// First, backup node-local data in case user wants to avoid long reshape and use bootstrap instead
+						try (ResultSet resultSet = stmt.executeQuery("SELECT COUNT(*) FROM MintingAccounts")) {
+							int rowCount = resultSet.next() ? resultSet.getInt(1) : 0;
+							if (rowCount > 0) {
+								stmt.execute("PERFORM EXPORT SCRIPT FOR TABLE MintingAccounts DATA TO 'MintingAccounts.script'");
+								LOGGER.info("Exported sensitive/node-local minting keys into MintingAccounts.script");
+							}
+						}
+
+						try (ResultSet resultSet = stmt.executeQuery("SELECT COUNT(*) FROM TradeBotStates")) {
+							int rowCount = resultSet.next() ? resultSet.getInt(1) : 0;
+							if (rowCount > 0) {
+								stmt.execute("PERFORM EXPORT SCRIPT FOR TABLE TradeBotStates DATA TO 'TradeBotStates.script'");
+								LOGGER.info("Exported sensitive/node-local trade-bot states into TradeBotStates.script");
+							}
+						}
+
+						LOGGER.info("If following reshape takes too long, use bootstrap and import node-local data using API's POST /admin/repository/data");
+					}
+
+					// Create new AT-states table without full state data
+					stmt.execute("CREATE TABLE ATStatesNew ("
+							+ "AT_address QortalAddress, height INTEGER NOT NULL, state_hash ATStateHash NOT NULL, "
+							+ "fees QortalAmount NOT NULL, is_initial BOOLEAN NOT NULL, "
+							+ "PRIMARY KEY (AT_address, height), "
+							+ "FOREIGN KEY (AT_address) REFERENCES ATs (AT_address) ON DELETE CASCADE)");
+					stmt.execute("SET TABLE ATStatesNew NEW SPACE");
+					stmt.execute("CHECKPOINT");
+
+					ResultSet resultSet = stmt.executeQuery("SELECT height FROM Blocks ORDER BY height DESC LIMIT 1");
+					final int blockchainHeight = resultSet.next() ? resultSet.getInt(1) : 0;
+					final int heightStep = 100;
+
+					LOGGER.info("Rebuilding AT state summaries in repository - this might take a while... (approx. 2 mins on high-spec)");
+					for (int minHeight = 1; minHeight < blockchainHeight; minHeight += heightStep) {
+						stmt.execute("INSERT INTO ATStatesNew ("
+								+ "SELECT AT_address, height, state_hash, fees, is_initial "
+								+ "FROM ATStates "
+								+ "WHERE height BETWEEN " + minHeight + " AND " + (minHeight + heightStep - 1)
+								+ ")");
+						stmt.execute("COMMIT");
+					}
+					stmt.execute("CHECKPOINT");
+
+					LOGGER.info("Rebuilding AT states height index in repository - this might take about 3x longer...");
+					stmt.execute("CREATE INDEX ATStatesHeightIndex ON ATStatesNew (height)");
+					stmt.execute("CHECKPOINT");
+
+					stmt.execute("CREATE TABLE ATStatesData ("
+							+ "AT_address QortalAddress, height INTEGER NOT NULL, state_data ATState NOT NULL, "
+							+ "PRIMARY KEY (height, AT_address), "
+							+ "FOREIGN KEY (AT_address) REFERENCES ATs (AT_address) ON DELETE CASCADE)");
+					stmt.execute("SET TABLE ATStatesData NEW SPACE");
+					stmt.execute("CHECKPOINT");
+
+					LOGGER.info("Rebuilding AT state data in repository - this might take a while... (approx. 2 mins on high-spec)");
+					for (int minHeight = 1; minHeight < blockchainHeight; minHeight += heightStep) {
+						stmt.execute("INSERT INTO ATStatesData ("
+								+ "SELECT AT_address, height, state_data "
+								+ "FROM ATstates "
+								+ "WHERE state_data IS NOT NULL "
+								+ "AND height BETWEEN " + minHeight + " AND " + (minHeight + heightStep - 1)
+								+ ")");
+						stmt.execute("COMMIT");
+					}
+					stmt.execute("CHECKPOINT");
+
+					stmt.execute("DROP TABLE ATStates");
+					stmt.execute("ALTER TABLE ATStatesNew RENAME TO ATStates");
+					stmt.execute("CHECKPOINT");
+					break;
+
 				default:
 					// nothing to do
 					return false;

src/main/java/org/qortal/repository/hsqldb/HSQLDBMessageRepository.java

@@ -0,0 +1,85 @@
+package org.qortal.repository.hsqldb;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.MessageRepository;
+import org.qortal.transaction.Transaction.TransactionType;
+
+public class HSQLDBMessageRepository implements MessageRepository {
+
+	protected HSQLDBRepository repository;
+
+	public HSQLDBMessageRepository(HSQLDBRepository repository) {
+		this.repository = repository;
+	}
+
+	@Override
+	public List<MessageTransactionData> getMessagesByParticipants(byte[] senderPublicKey,
+			String recipient, Integer limit, Integer offset, Boolean reverse) throws DataException {
+		if (senderPublicKey == null && recipient == null)
+			throw new DataException("At least one of senderPublicKey or recipient required to fetch matching messages");
+
+		StringBuilder sql = new StringBuilder(1024);
+		sql.append("SELECT signature from MessageTransactions "
+				+ "JOIN Transactions USING (signature) "
+				+ "JOIN BlockTransactions ON transaction_signature = signature "
+				+ "WHERE ");
+
+		List<String> whereClauses = new ArrayList<>();
+		List<Object> bindParams = new ArrayList<>();
+
+		if (senderPublicKey != null) {
+			whereClauses.add("sender = ?");
+			bindParams.add(senderPublicKey);
+		}
+
+		if (recipient != null) {
+			whereClauses.add("recipient = ?");
+			bindParams.add(recipient);
+		}
+
+		sql.append(String.join(" AND ", whereClauses));
+
+		sql.append("ORDER BY Transactions.created_when");
+		sql.append((reverse == null || !reverse) ? " ASC" : " DESC");
+
+		HSQLDBRepository.limitOffsetSql(sql, limit, offset);
+
+		List<MessageTransactionData> messageTransactionsData = new ArrayList<>();
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
+			if (resultSet == null)
+				return messageTransactionsData;
+
+			do {
+				byte[] signature = resultSet.getBytes(1);
+
+				TransactionData transactionData = this.repository.getTransactionRepository().fromSignature(signature);
+				if (transactionData == null || transactionData.getType() != TransactionType.MESSAGE)
+					throw new DataException("Inconsistent data from repository when fetching message");
+
+				messageTransactionsData.add((MessageTransactionData) transactionData);
+			} while (resultSet.next());
+
+			return messageTransactionsData;
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch matching messages from repository", e);
+		}
+	}
+
+	@Override
+	public boolean exists(byte[] senderPublicKey, String recipient, byte[] messageData) throws DataException {
+		try {
+			return this.repository.exists("MessageTransactions", "sender = ? AND recipient = ? AND data = ?", senderPublicKey, recipient, messageData);
+		} catch (SQLException e) {
+			throw new DataException("Unable to check for existing message in repository", e);
+		}
+	}
+
+}

src/main/java/org/qortal/repository/hsqldb/HSQLDBRepository.java

@@ -16,11 +16,15 @@ import java.sql.Savepoint;
 import java.sql.Statement;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.Deque;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Stream;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -35,6 +39,7 @@ import org.qortal.repository.ChatRepository;
 import org.qortal.repository.CrossChainRepository;
 import org.qortal.repository.DataException;
 import org.qortal.repository.GroupRepository;
+import org.qortal.repository.MessageRepository;
 import org.qortal.repository.NameRepository;
 import org.qortal.repository.NetworkRepository;
 import org.qortal.repository.Repository;
@@ -49,18 +54,33 @@ public class HSQLDBRepository implements Repository {
 	private static final Logger LOGGER = LogManager.getLogger(HSQLDBRepository.class);
 
 	protected Connection connection;
-	protected Deque<Savepoint> savepoints;
+	protected final Deque<Savepoint> savepoints = new ArrayDeque<>(3);
 	protected boolean debugState = false;
 	protected Long slowQueryThreshold = null;
 	protected List<String> sqlStatements;
 	protected long sessionId;
+	protected final Map<String, PreparedStatement> preparedStatementCache = new HashMap<>();
+	protected final Object trimHeightsLock = new Object();
+
+	private final ATRepository atRepository = new HSQLDBATRepository(this);
+	private final AccountRepository accountRepository = new HSQLDBAccountRepository(this);
+	private final ArbitraryRepository arbitraryRepository = new HSQLDBArbitraryRepository(this);
+	private final AssetRepository assetRepository = new HSQLDBAssetRepository(this);
+	private final BlockRepository blockRepository = new HSQLDBBlockRepository(this);
+	private final ChatRepository chatRepository = new HSQLDBChatRepository(this);
+	private final CrossChainRepository crossChainRepository = new HSQLDBCrossChainRepository(this);
+	private final GroupRepository groupRepository = new HSQLDBGroupRepository(this);
+	private final MessageRepository messageRepository = new HSQLDBMessageRepository(this);
+	private final NameRepository nameRepository = new HSQLDBNameRepository(this);
+	private final NetworkRepository networkRepository = new HSQLDBNetworkRepository(this);
+	private final TransactionRepository transactionRepository = new HSQLDBTransactionRepository(this);
+	private final VotingRepository votingRepository = new HSQLDBVotingRepository(this);
 
 	// Constructors
 
 	// NB: no visibility modifier so only callable from within same package
 	/* package */ HSQLDBRepository(Connection connection) throws DataException {
 		this.connection = connection;
-		this.savepoints = new ArrayDeque<>(3);
 
 		this.slowQueryThreshold = Settings.getInstance().getSlowQueryThreshold();
 		if (this.slowQueryThreshold != null)
@@ -88,62 +108,67 @@ public class HSQLDBRepository implements Repository {
 
 	@Override
 	public ATRepository getATRepository() {
-		return new HSQLDBATRepository(this);
+		return this.atRepository;
 	}
 
 	@Override
 	public AccountRepository getAccountRepository() {
-		return new HSQLDBAccountRepository(this);
+		return this.accountRepository;
 	}
 
 	@Override
 	public ArbitraryRepository getArbitraryRepository() {
-		return new HSQLDBArbitraryRepository(this);
+		return this.arbitraryRepository;
 	}
 
 	@Override
 	public AssetRepository getAssetRepository() {
-		return new HSQLDBAssetRepository(this);
+		return this.assetRepository;
 	}
 
 	@Override
 	public BlockRepository getBlockRepository() {
-		return new HSQLDBBlockRepository(this);
+		return this.blockRepository;
 	}
 
 	@Override
 	public ChatRepository getChatRepository() {
-		return new HSQLDBChatRepository(this);
+		return this.chatRepository;
 	}
 
 	@Override
 	public CrossChainRepository getCrossChainRepository() {
-		return new HSQLDBCrossChainRepository(this);
+		return this.crossChainRepository;
 	}
 
 	@Override
 	public GroupRepository getGroupRepository() {
-		return new HSQLDBGroupRepository(this);
+		return this.groupRepository;
+	}
+
+	@Override
+	public MessageRepository getMessageRepository() {
+		return this.messageRepository;
 	}
 
 	@Override
 	public NameRepository getNameRepository() {
-		return new HSQLDBNameRepository(this);
+		return this.nameRepository;
 	}
 
 	@Override
 	public NetworkRepository getNetworkRepository() {
-		return new HSQLDBNetworkRepository(this);
+		return this.networkRepository;
 	}
 
 	@Override
 	public TransactionRepository getTransactionRepository() {
-		return new HSQLDBTransactionRepository(this);
+		return this.transactionRepository;
 	}
 
 	@Override
 	public VotingRepository getVotingRepository() {
-		return new HSQLDBVotingRepository(this);
+		return this.votingRepository;
 	}
 
 	@Override
@@ -160,8 +185,20 @@ public class HSQLDBRepository implements Repository {
 
 	@Override
 	public void saveChanges() throws DataException {
+		long beforeQuery = this.slowQueryThreshold == null ? 0 : System.currentTimeMillis();
+
 		try {
 			this.connection.commit();
+
+			if (this.slowQueryThreshold != null) {
+				long queryTime = System.currentTimeMillis() - beforeQuery;
+
+				if (queryTime > this.slowQueryThreshold) {
+					LOGGER.info(() -> String.format("[Session %d] HSQLDB COMMIT took %d ms", this.sessionId, queryTime), new SQLException("slow commit"));
+
+					logStatements();
+				}
+			}
 		} catch (SQLException e) {
 			throw new DataException("commit error", e);
 		} finally {
@@ -185,7 +222,7 @@ public class HSQLDBRepository implements Repository {
 			this.savepoints.clear();
 
 			// Before clearing statements so we can log what led to assertion error
-			assertEmptyTransaction("transaction commit");
+			assertEmptyTransaction("transaction rollback");
 
 			if (this.sqlStatements != null)
 				this.sqlStatements.clear();
@@ -240,7 +277,12 @@ public class HSQLDBRepository implements Repository {
 		try (Statement stmt = this.connection.createStatement()) {
 			assertEmptyTransaction("connection close");
 
-			// give connection back to the pool
+			// Assume we are not going to be GC'd for a while
+			this.preparedStatementCache.clear();
+			this.sqlStatements = null;
+			this.savepoints.clear();
+
+			// Give connection back to the pool
 			this.connection.close();
 			this.connection = null;
 		} catch (SQLException e) {
@@ -270,11 +312,12 @@ public class HSQLDBRepository implements Repository {
 				Path oldRepoDirPath = Paths.get(dbPathname).getParent();
 
 				// Delete old repository files
-				Files.walk(oldRepoDirPath)
-						.sorted(Comparator.reverseOrder())
+				try (Stream<Path> paths = Files.walk(oldRepoDirPath)) {
+					paths.sorted(Comparator.reverseOrder())
 						.map(Path::toFile)
 						.filter(file -> file.getPath().startsWith(dbPathname))
 						.forEach(File::delete);
+				}
 			}
 		} catch (NoSuchFileException e) {
 			// Nothing to remove
@@ -314,11 +357,12 @@ public class HSQLDBRepository implements Repository {
 			Path backupDirPath = Paths.get(backupPathname).getParent();
 			String backupDirPathname = backupDirPath.toString();
 
-			Files.walk(backupDirPath)
-					.sorted(Comparator.reverseOrder())
+			try (Stream<Path> paths = Files.walk(backupDirPath)) {
+				paths.sorted(Comparator.reverseOrder())
 					.map(Path::toFile)
 					.filter(file -> file.getPath().startsWith(backupDirPathname))
 					.forEach(File::delete);
+			}
 		} catch (NoSuchFileException e) {
 			// Nothing to remove
 		} catch (SQLException | IOException e) {
@@ -333,8 +377,56 @@ public class HSQLDBRepository implements Repository {
 		}
 	}
 
+	@Override
+	public void checkpoint(boolean quick) throws DataException {
+		try (Statement stmt = this.connection.createStatement()) {
+			stmt.execute(quick ? "CHECKPOINT" : "CHECKPOINT DEFRAG");
+		} catch (SQLException e) {
+			throw new DataException("Unable to perform repository checkpoint");
+		}
+	}
+
+	@Override
+	public void performPeriodicMaintenance() throws DataException {
+		// Defrag DB - takes a while!
+		try (Statement stmt = this.connection.createStatement()) {
+			LOGGER.info("performing maintenance - this will take a while");
+			stmt.execute("CHECKPOINT");
+			stmt.execute("CHECKPOINT DEFRAG");
+			LOGGER.info("maintenance completed");
+		} catch (SQLException e) {
+			throw new DataException("Unable to defrag repository");
+		}
+	}
+
+	@Override
+	public void exportNodeLocalData() throws DataException {
+		try (Statement stmt = this.connection.createStatement()) {
+			stmt.execute("PERFORM EXPORT SCRIPT FOR TABLE MintingAccounts DATA TO 'MintingAccounts.script'");
+			stmt.execute("PERFORM EXPORT SCRIPT FOR TABLE TradeBotStates DATA TO 'TradeBotStates.script'");
+			LOGGER.info("Exported sensitive/node-local data: minting keys and trade bot states");
+		} catch (SQLException e) {
+			throw new DataException("Unable to export sensitive/node-local data from repository");
+		}
+	}
+
+	@Override
+	public void importDataFromFile(String filename) throws DataException {
+		try (Statement stmt = this.connection.createStatement()) {
+			LOGGER.info(() -> String.format("Importing data into repository from %s", filename));
+
+			String escapedFilename = stmt.enquoteLiteral(filename);
+			stmt.execute("PERFORM IMPORT SCRIPT DATA FROM " + escapedFilename + " STOP ON ERROR");
+
+			LOGGER.info(() -> String.format("Imported data into repository from %s", filename));
+		} catch (SQLException e) {
+			LOGGER.info(() -> String.format("Failed to import data into repository from %s: %s", filename, e.getMessage()));
+			throw new DataException("Unable to export sensitive/node-local data from repository: " + e.getMessage());
+		}
+	}
+
 	/** Returns DB pathname from passed connection URL. If memory DB, returns "mem". */
-	private static String getDbPathname(String connectionUrl) {
+	/*package*/ static String getDbPathname(String connectionUrl) {
 		Pattern pattern = Pattern.compile("hsqldb:(mem|file):(.*?)(;|$)");
 		Matcher matcher = pattern.matcher(connectionUrl);
 
@@ -370,11 +462,12 @@ public class HSQLDBRepository implements Repository {
 			LOGGER.info("Attempting repository recovery using backup");
 
 			// Move old repository files out the way
-			Files.walk(oldRepoDirPath)
-					.sorted(Comparator.reverseOrder())
+			try (Stream<Path> paths = Files.walk(oldRepoDirPath)) {
+				paths.sorted(Comparator.reverseOrder())
 					.map(Path::toFile)
 					.filter(file -> file.getPath().startsWith(dbPathname))
 					.forEach(File::delete);
+			}
 
 			try (Statement stmt = connection.createStatement()) {
 				// Now "backup" the backup back to original repository location (the parent).
@@ -414,7 +507,33 @@ public class HSQLDBRepository implements Repository {
 		if (this.sqlStatements != null)
 			this.sqlStatements.add(sql);
 
-		return this.connection.prepareStatement(sql);
+		return cachePreparedStatement(sql);
+	}
+
+	private PreparedStatement cachePreparedStatement(String sql) throws SQLException {
+		/*
+		 * We cache a duplicate PreparedStatement for this SQL string,
+		 * which we never close, which means HSQLDB also caches a parsed,
+		 * prepared statement that can be reused for subsequent
+		 * calls to HSQLDB.prepareStatement(sql).
+		 * 
+		 * See org.hsqldb.StatementManager for more details.
+		 */
+		PreparedStatement preparedStatement = this.preparedStatementCache.get(sql);
+		if (preparedStatement == null || preparedStatement.isClosed()) {
+			if (preparedStatement != null)
+				// This shouldn't occur, so log, but recompile
+				LOGGER.debug(() -> String.format("Recompiling closed PreparedStatement: %s", sql));
+
+			preparedStatement =  this.connection.prepareStatement(sql);
+			this.preparedStatementCache.put(sql, preparedStatement);
+		} else {
+			// Clean up ready for reuse
+			preparedStatement.clearBatch();
+			preparedStatement.clearParameters();
+		}
+
+		return preparedStatement;
 	}
 
 	/**
@@ -430,9 +549,8 @@ public class HSQLDBRepository implements Repository {
 	public ResultSet checkedExecute(String sql, Object... objects) throws SQLException {
 		PreparedStatement preparedStatement = this.prepareStatement(sql);
 
-		// Close the PreparedStatement when the ResultSet is closed otherwise there's a potential resource leak.
-		// We can't use try-with-resources here as closing the PreparedStatement on return would also prematurely close the ResultSet.
-		preparedStatement.closeOnCompletion();
+		// We don't close the PreparedStatement when the ResultSet is closed because we cached PreparedStatements now.
+		// They are cleaned up when connection/session is closed.
 
 		long beforeQuery = this.slowQueryThreshold == null ? 0 : System.currentTimeMillis();
 
@@ -442,7 +560,7 @@ public class HSQLDBRepository implements Repository {
 			long queryTime = System.currentTimeMillis() - beforeQuery;
 
 			if (queryTime > this.slowQueryThreshold) {
-				LOGGER.info(() -> String.format("HSQLDB query took %d ms: %s", queryTime, sql), new SQLException("slow query"));
+				LOGGER.info(() -> String.format("[Session %d] HSQLDB query took %d ms: %s", this.sessionId, queryTime, sql), new SQLException("slow query"));
 
 				logStatements();
 			}
@@ -460,7 +578,7 @@ public class HSQLDBRepository implements Repository {
 	 * @param objects
 	 * @throws SQLException
 	 */
-	private void prepareExecute(PreparedStatement preparedStatement, Object... objects) throws SQLException {
+	private void bindStatementParams(PreparedStatement preparedStatement, Object... objects) throws SQLException {
 		for (int i = 0; i < objects.length; ++i)
 			// Special treatment for BigDecimals so that they retain their "scale",
 			// which would otherwise be assumed as 0.
@@ -481,7 +599,7 @@ public class HSQLDBRepository implements Repository {
 	 * @throws SQLException
 	 */
 	private ResultSet checkedExecuteResultSet(PreparedStatement preparedStatement, Object... objects) throws SQLException {
-		prepareExecute(preparedStatement, objects);
+		bindStatementParams(preparedStatement, objects);
 
 		if (!preparedStatement.execute())
 			throw new SQLException("Fetching from database produced no results");
@@ -504,31 +622,52 @@ public class HSQLDBRepository implements Repository {
 	 * @return number of changed rows
 	 * @throws SQLException
 	 */
-	/* package */ int checkedExecuteUpdateCount(String sql, Object... objects) throws SQLException {
-		try (PreparedStatement preparedStatement = this.prepareStatement(sql)) {
-			prepareExecute(preparedStatement, objects);
+	/* package */ int executeCheckedUpdate(String sql, Object... objects) throws SQLException {
+		return this.executeCheckedBatchUpdate(sql, Collections.singletonList(objects));
+	}
 
-			long beforeQuery = this.slowQueryThreshold == null ? 0 : System.currentTimeMillis();
+	/**
+	 * Execute batched PreparedStatement
+	 * 
+	 * @param preparedStatement
+	 * @param objects
+	 * @return number of changed rows
+	 * @throws SQLException
+	 */
+	/* package */ int executeCheckedBatchUpdate(String sql, List<Object[]> batchedObjects) throws SQLException {
+		// Nothing to do?
+		if (batchedObjects == null || batchedObjects.isEmpty())
+			return 0;
 
-			if (preparedStatement.execute())
-				throw new SQLException("Database produced results, not row count");
+		PreparedStatement preparedStatement = this.prepareStatement(sql);
+		for (Object[] objects : batchedObjects) {
+			this.bindStatementParams(preparedStatement, objects);
+			preparedStatement.addBatch();
+		}
 
-			if (this.slowQueryThreshold != null) {
-				long queryTime = System.currentTimeMillis() - beforeQuery;
+		long beforeQuery = this.slowQueryThreshold == null ? 0 : System.currentTimeMillis();
 
-				if (queryTime > this.slowQueryThreshold) {
-					LOGGER.info(() -> String.format("HSQLDB query took %d ms: %s", queryTime, sql), new SQLException("slow query"));
+		int[] updateCounts = preparedStatement.executeBatch();
 
-					logStatements();
-				}
+		if (this.slowQueryThreshold != null) {
+			long queryTime = System.currentTimeMillis() - beforeQuery;
+
+			if (queryTime > this.slowQueryThreshold) {
+				LOGGER.info(() -> String.format("[Session %d] HSQLDB query took %d ms: %s", this.sessionId, queryTime, sql), new SQLException("slow query"));
+
+				logStatements();
 			}
+		}
 
-			int rowCount = preparedStatement.getUpdateCount();
-			if (rowCount == -1)
+		int totalCount = 0;
+		for (int i = 0; i < updateCounts.length; ++i) {
+			if (updateCounts[i] < 0)
 				throw new SQLException("Database returned invalid row count");
 
-			return rowCount;
+			totalCount += updateCounts[i];
 		}
+
+		return totalCount;
 	}
 
 	/**
@@ -598,7 +737,25 @@ public class HSQLDBRepository implements Repository {
 		sql.append(" WHERE ");
 		sql.append(whereClause);
 
-		return this.checkedExecuteUpdateCount(sql.toString(), objects);
+		return this.executeCheckedUpdate(sql.toString(), objects);
+	}
+
+	/**
+	 * Delete rows from database table.
+	 * 
+	 * @param tableName
+	 * @param whereClause
+	 * @param objects
+	 * @throws SQLException
+	 */
+	public int deleteBatch(String tableName, String whereClause, List<Object[]> batchedObjects) throws SQLException {
+		StringBuilder sql = new StringBuilder(256);
+		sql.append("DELETE FROM ");
+		sql.append(tableName);
+		sql.append(" WHERE ");
+		sql.append(whereClause);
+
+		return this.executeCheckedBatchUpdate(sql.toString(), batchedObjects);
 	}
 
 	/**
@@ -612,7 +769,7 @@ public class HSQLDBRepository implements Repository {
 		sql.append("DELETE FROM ");
 		sql.append(tableName);
 
-		return this.checkedExecuteUpdateCount(sql.toString());
+		return this.executeCheckedUpdate(sql.toString());
 	}
 
 	/**
@@ -690,15 +847,15 @@ public class HSQLDBRepository implements Repository {
 		if (this.sqlStatements == null)
 			return;
 
-		LOGGER.info(() -> String.format("HSQLDB SQL statements (session %d) leading up to this were:", this.sessionId));
+		LOGGER.info(() -> String.format("[Session %d] HSQLDB SQL statements leading up to this were:", this.sessionId));
 
 		for (String sql : this.sqlStatements)
-			LOGGER.info(sql);
+			LOGGER.info(() -> String.format("[Session %d] %s", this.sessionId, sql));
 	}
 
-	/** Logs other HSQLDB sessions then re-throws passed exception */
-	public SQLException examineException(SQLException e) throws SQLException {
-		LOGGER.error(String.format("HSQLDB error (session %d): %s", this.sessionId, e.getMessage()), e);
+	/** Logs other HSQLDB sessions then returns passed exception */
+	public SQLException examineException(SQLException e) {
+		LOGGER.error(() -> String.format("[Session %d] HSQLDB error: %s", this.sessionId, e.getMessage()), e);
 
 		logStatements();
 
@@ -716,7 +873,11 @@ public class HSQLDBRepository implements Repository {
 				String thisWaitingFor = resultSet.getString(5);
 				String currentStatement = resultSet.getString(6);
 
-				LOGGER.error(String.format("Session %d, %s transaction (size %d), waiting for this '%s', this waiting for '%s', current statement: %s",
+				// Skip logging idle sessions
+				if (transactionSize == 0 && waitingForThis.isEmpty() && thisWaitingFor.isEmpty() && currentStatement.isEmpty())
+					continue;
+
+				LOGGER.error(() -> String.format("Session %d, %s transaction (size %d), waiting for this '%s', this waiting for '%s', current statement: %s",
 						systemSessionId, (inTransaction ? "in" : "not in"), transactionSize, waitingForThis, thisWaitingFor, currentStatement));
 			} while (resultSet.next());
 		} catch (SQLException de) {
@@ -728,14 +889,19 @@ public class HSQLDBRepository implements Repository {
 	}
 
 	private void assertEmptyTransaction(String context) throws DataException {
-		try (Statement stmt = this.connection.createStatement()) {
+		String sql = "SELECT transaction, transaction_size FROM information_schema.system_sessions WHERE session_id = ?";
+
+		try {
+			PreparedStatement stmt = this.cachePreparedStatement(sql);
+			stmt.setLong(1, this.sessionId);
+
 			// Diagnostic check for uncommitted changes
-			if (!stmt.execute("SELECT transaction, transaction_size FROM information_schema.system_sessions WHERE session_id = " + this.sessionId)) // TRANSACTION_SIZE() broken?
+			if (!stmt.execute()) // TRANSACTION_SIZE() broken?
 				throw new DataException("Unable to check repository status after " + context);
 
 			try (ResultSet resultSet = stmt.getResultSet()) {
 				if (resultSet == null || !resultSet.next()) {
-					LOGGER.warn(String.format("Unable to check repository status after %s", context));
+					LOGGER.warn(() -> String.format("Unable to check repository status after %s", context));
 					return;
 				}
 
@@ -743,7 +909,11 @@ public class HSQLDBRepository implements Repository {
 				int transactionCount = resultSet.getInt(2);
 
 				if (inTransaction && transactionCount != 0) {
-					LOGGER.warn(String.format("Uncommitted changes (%d) after %s, session [%d]", transactionCount, context, this.sessionId), new Exception("Uncommitted repository changes"));
+					LOGGER.warn(() -> String.format("Uncommitted changes (%d) after %s, session [%d]",
+							transactionCount,
+							context,
+							this.sessionId),
+							new Exception("Uncommitted repository changes"));
 					logStatements();
 				}
 			}

src/main/java/org/qortal/repository/hsqldb/HSQLDBRepositoryFactory.java

@@ -25,6 +25,7 @@ public class HSQLDBRepositoryFactory implements RepositoryFactory {
 
 	private String connectionUrl;
 	private HSQLDBPool connectionPool;
+	private final boolean wasPristine;
 
 	/**
 	 * Constructs new RepositoryFactory using passed <tt>connectionUrl</tt>.
@@ -65,12 +66,17 @@ public class HSQLDBRepositoryFactory implements RepositoryFactory {
 
 		// Perform DB updates?
 		try (final Connection connection = this.connectionPool.getConnection()) {
-			HSQLDBDatabaseUpdates.updateDatabase(connection);
+			this.wasPristine = HSQLDBDatabaseUpdates.updateDatabase(connection);
 		} catch (SQLException e) {
 			throw new DataException("Repository initialization error", e);
 		}
 	}
 
+	@Override
+	public boolean wasPristineAtOpen() {
+		return this.wasPristine;
+	}
+
 	@Override
 	public RepositoryFactory reopen() throws DataException {
 		return new HSQLDBRepositoryFactory(this.connectionUrl);

src/main/java/org/qortal/repository/hsqldb/HSQLDBSaver.java

@@ -60,7 +60,9 @@ public class HSQLDBSaver {
 	 */
 	public boolean execute(HSQLDBRepository repository) throws SQLException {
 		String sql = this.formatInsertWithPlaceholders();
-		try (PreparedStatement preparedStatement = repository.prepareStatement(sql)) {
+
+		try {
+			PreparedStatement preparedStatement = repository.prepareStatement(sql);
 			this.bindValues(preparedStatement);
 
 			return preparedStatement.execute();

src/main/java/org/qortal/repository/hsqldb/transaction/HSQLDBTransactionRepository.java

@@ -19,7 +19,6 @@ import org.qortal.data.PaymentData;
 import org.qortal.data.group.GroupApprovalData;
 import org.qortal.data.transaction.BaseTransactionData;
 import org.qortal.data.transaction.GroupApprovalTransactionData;
-import org.qortal.data.transaction.MessageTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.data.transaction.TransferAssetTransactionData;
 import org.qortal.repository.DataException;
@@ -586,6 +585,69 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 		}
 	}
 
+	@Override
+	public List<byte[]> getSignaturesMatchingCriteria(TransactionType txType, byte[] publicKey,
+			Integer minBlockHeight, Integer maxBlockHeight) throws DataException {
+		List<byte[]> signatures = new ArrayList<>();
+
+		StringBuilder sql = new StringBuilder(1024);
+		sql.append("SELECT signature FROM Transactions ");
+
+		List<String> whereClauses = new ArrayList<>();
+		List<Object> bindParams = new ArrayList<>();
+
+		if (txType != null) {
+			whereClauses.add("type = ?");
+			bindParams.add(txType.value);
+		}
+
+		if (publicKey != null) {
+			whereClauses.add("creator = ?");
+			bindParams.add(publicKey);
+		}
+
+		if (minBlockHeight != null) {
+			whereClauses.add("Transactions.block_height >= ?");
+			bindParams.add(minBlockHeight);
+		}
+
+		if (maxBlockHeight != null) {
+			whereClauses.add("Transactions.block_height <= ?");
+			bindParams.add(maxBlockHeight);
+		}
+
+		if (!whereClauses.isEmpty()) {
+			sql.append(" WHERE ");
+
+			final int whereClausesSize = whereClauses.size();
+			for (int wci = 0; wci < whereClausesSize; ++wci) {
+				if (wci != 0)
+					sql.append(" AND ");
+
+				sql.append(whereClauses.get(wci));
+			}
+		}
+
+		sql.append(" ORDER BY Transactions.created_when");
+
+		LOGGER.trace(() -> String.format("Transaction search SQL: %s", sql));
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
+			if (resultSet == null)
+				return signatures;
+
+			do {
+				byte[] signature = resultSet.getBytes(1);
+
+				signatures.add(signature);
+			} while (resultSet.next());
+
+			return signatures;
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch matching transaction signatures from repository", e);
+		}
+	}
+
 	@Override
 	public byte[] getLatestAutoUpdateTransaction(TransactionType txType, int txGroupId, Integer service) throws DataException {
 		StringBuilder sql = new StringBuilder(1024);
@@ -631,43 +693,6 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 		}
 	}
 
-	@Override
-	public List<MessageTransactionData> getMessagesByRecipient(String recipient,
-			Integer limit, Integer offset, Boolean reverse) throws DataException {
-		StringBuilder sql = new StringBuilder(1024);
-		sql.append("SELECT signature from MessageTransactions "
-				+ "JOIN Transactions USING (signature) "
-				+ "JOIN BlockTransactions ON transaction_signature = signature "
-				+ "WHERE recipient = ?");
-
-		sql.append("ORDER BY Transactions.created_when");
-		sql.append((reverse == null || !reverse) ? " ASC" : " DESC");
-
-		HSQLDBRepository.limitOffsetSql(sql, limit, offset);
-
-		List<MessageTransactionData> messageTransactionsData = new ArrayList<>();
-
-		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), recipient)) {
-			if (resultSet == null)
-				return messageTransactionsData;
-
-			do {
-				byte[] signature = resultSet.getBytes(1);
-
-				TransactionData transactionData = this.fromSignature(signature);
-				if (transactionData == null || transactionData.getType() != TransactionType.MESSAGE)
-					return null;
-
-				messageTransactionsData.add((MessageTransactionData) transactionData);
-			} while (resultSet.next());
-
-			return messageTransactionsData;
-		} catch (SQLException e) {
-			throw new DataException("Unable to fetch trade-bot messages from repository", e);
-		}
-	}
-
-
 	@Override
 	public List<TransactionData> getAssetTransactions(long assetId, ConfirmationStatus confirmationStatus, Integer limit, Integer offset, Boolean reverse)
 			throws DataException {

src/main/java/org/qortal/settings/Settings.java

@@ -5,6 +5,7 @@ import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.util.Locale;
 
 import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBException;
@@ -41,6 +42,9 @@ public class Settings {
 	// Settings, and other config files
 	private String userPath;
 
+	// General
+	private String localeLang = Locale.getDefault().getLanguage();
+
 	// Common to all networking (API/P2P)
 	private String bindAddress = "::"; // Use IPv6 wildcard to listen on all local addresses
 
@@ -61,6 +65,7 @@ public class Settings {
 		"::1", "127.0.0.1"
 	};
 	private Boolean apiRestricted;
+	private String apiKey = null;
 	private boolean apiLoggingEnabled = false;
 	private boolean apiDocumentationEnabled = false;
 	// Both of these need to be set for API to use SSL
@@ -79,6 +84,26 @@ public class Settings {
 	private long repositoryBackupInterval = 0; // ms
 	/** Whether to show a notification when we backup repository. */
 	private boolean showBackupNotification = false;
+	/** How long between repository checkpoints (ms). */
+	private long repositoryCheckpointInterval = 60 * 60 * 1000L; // 1 hour (ms) default
+	/** Whether to show a notification when we perform repository 'checkpoint'. */
+	private boolean showCheckpointNotification = false;
+
+	/** How long to keep old, full, AT state data (ms). */
+	private long atStatesMaxLifetime = 2 * 7 * 24 * 60 * 60 * 1000L; // milliseconds
+	/** How often to attempt AT state trimming (ms). */
+	private long atStatesTrimInterval = 5678L; // milliseconds
+	/** Block height range to scan for trimmable AT states.<br>
+	 * This has a significant effect on execution time. */
+	private int atStatesTrimBatchSize = 100; // blocks
+	/** Max number of AT states to trim in one go. */
+	private int atStatesTrimLimit = 4000; // records
+
+	/** How often to attempt online accounts signatures trimming (ms). */
+	private long onlineSignaturesTrimInterval = 9876L; // milliseconds
+	/** Block height range to scan for trimmable online accounts signatures.<br>
+	 * This has a significant effect on execution time. */
+	private int onlineSignaturesTrimBatchSize = 100; // blocks
 
 	// Peer-to-peer related
 	private boolean isTestNet = false;
@@ -98,6 +123,9 @@ public class Settings {
 	// Which blockchains this node is running
 	private String blockchainConfig = null; // use default from resources
 	private BitcoinNet bitcoinNet = BitcoinNet.MAIN;
+	// Also crosschain-related:
+	/** Whether to show SysTray pop-up notifications when trade-bot entries change state */
+	private boolean tradebotSystrayEnabled = false;
 
 	// Repository related
 	/** Queries that take longer than this are logged. (milliseconds) */
@@ -248,6 +276,9 @@ public class Settings {
 		// Validation goes here
 		if (this.minBlockchainPeers < 1)
 			throwValidationError("minBlockchainPeers must be at least 1");
+
+		if (this.apiKey != null && this.apiKey.trim().length() < 8)
+			throwValidationError("apiKey must be at least 8 characters");
 	}
 
 	// Getters / setters
@@ -256,6 +287,10 @@ public class Settings {
 		return this.userPath;
 	}
 
+	public String getLocaleLang() {
+		return this.localeLang;
+	}
+
 	public int getUiServerPort() {
 		return this.uiPort;
 	}
@@ -292,6 +327,10 @@ public class Settings {
 		return !BlockChain.getInstance().isTestChain();
 	}
 
+	public String getApiKey() {
+		return this.apiKey;
+	}
+
 	public boolean isApiLoggingEnabled() {
 		return this.apiLoggingEnabled;
 	}
@@ -367,6 +406,10 @@ public class Settings {
 		return this.bitcoinNet;
 	}
 
+	public boolean isTradebotSystrayEnabled() {
+		return this.tradebotSystrayEnabled;
+	}
+
 	public Long getSlowQueryThreshold() {
 		return this.slowQueryThreshold;
 	}
@@ -399,4 +442,36 @@ public class Settings {
 		return this.showBackupNotification;
 	}
 
+	public long getRepositoryCheckpointInterval() {
+		return this.repositoryCheckpointInterval;
+	}
+
+	public boolean getShowCheckpointNotification() {
+		return this.showCheckpointNotification;
+	}
+
+	public long getAtStatesMaxLifetime() {
+		return this.atStatesMaxLifetime;
+	}
+
+	public long getAtStatesTrimInterval() {
+		return this.atStatesTrimInterval;
+	}
+
+	public int getAtStatesTrimBatchSize() {
+		return this.atStatesTrimBatchSize;
+	}
+
+	public int getAtStatesTrimLimit() {
+		return this.atStatesTrimLimit;
+	}
+
+	public long getOnlineSignaturesTrimInterval() {
+		return this.onlineSignaturesTrimInterval;
+	}
+
+	public int getOnlineSignaturesTrimBatchSize() {
+		return this.onlineSignaturesTrimBatchSize;
+	}
+
 }

src/main/java/org/qortal/utils/NTP.java

@@ -28,7 +28,8 @@ public class NTP implements Runnable {
 	private static volatile boolean isStopping = false;
 	private static ExecutorService instanceExecutor;
 	private static NTP instance;
-	private static volatile Long offset = null;
+	private static volatile boolean isOffsetSet = false;
+	private static volatile long offset = 0;
 
 	static class NTPServer {
 		private static final int MIN_POLL = 64;
@@ -136,6 +137,7 @@ public class NTP implements Runnable {
 	public static synchronized void setFixedOffset(Long offset) {
 		// Fix offset, e.g. for testing
 		NTP.offset = offset;
+		isOffsetSet = true;
 	}
 
 	/**
@@ -144,7 +146,7 @@ public class NTP implements Runnable {
 	 * @return internet time (ms), or null if unsynchronized.
 	 */
 	public static Long getTime() {
-		if (NTP.offset == null)
+		if (!isOffsetSet)
 			return null;
 
 		return System.currentTimeMillis() + NTP.offset;
@@ -248,6 +250,7 @@ public class NTP implements Runnable {
 						thresholdStddev, filteredMean, filteredStddev, numberValues, ntpServers.size()));
 
 				NTP.offset = (long) filteredMean;
+				isOffsetSet = true;
 				LOGGER.debug(() -> String.format("New NTP offset: %d", NTP.offset));
 			}
 		}

src/main/resources/i18n/ApiError_en.properties

@@ -8,6 +8,12 @@ BLOCKCHAIN_NEEDS_SYNC = blockchain needs to synchronize first
 # Blocks
 BLOCK_UNKNOWN = block unknown
 
+BTC_BALANCE_ISSUE = insufficient Bitcoin balance
+
+BTC_NETWORK_ISSUE = Bitcoin/ElectrumX network issue
+
+BTC_TOO_SOON = too soon to broadcast Bitcoin transaction (lockTime/median block time)
+
 CANNOT_MINT = account cannot mint
 
 GROUP_UNKNOWN = group unknown
@@ -15,7 +21,7 @@ GROUP_UNKNOWN = group unknown
 INVALID_ADDRESS = invalid address
 
 # Assets
-INVALID_ASSET_ID = invalid asset id
+INVALID_ASSET_ID = invalid asset ID
 
 INVALID_CRITERIA = invalid search criteria
 
@@ -36,18 +42,21 @@ INVALID_REFERENCE = invalid reference
 # Validation
 INVALID_SIGNATURE = invalid signature
 
-JSON = failed to parse json message
+JSON = failed to parse JSON message
 
 NAME_UNKNOWN = name unknown
 
 NON_PRODUCTION = this API call is not permitted for production systems
 
+NO_TIME_SYNC = no clock synchronization yet
+
 ORDER_UNKNOWN = unknown asset order ID
 
 PUBLIC_KEY_NOT_FOUND = public key not found
 
 REPOSITORY_ISSUE = repository error
 
+# This one is special in that caller expected to pass two additional strings, hence the two %s
 TRANSACTION_INVALID = transaction invalid: %s (%s)
 
 TRANSACTION_UNKNOWN = transaction unknown

src/main/resources/i18n/ApiError_ru.properties

@@ -0,0 +1,53 @@
+#Generated by ResourceBundle Editor (http://essiembre.github.io/eclipse-rbe/)
+# Keys are from api.ApiError enum
+
+ADDRESS_UNKNOWN = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D1\u0083\u00D1\u0087\u00D0\u00B5\u00D1\u0082\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u00B7\u00D0\u00B0\u00D0\u00BF\u00D0\u00B8\u00D1\u0081\u00D1\u008C
+
+# Blocks
+BLOCK_UNKNOWN = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B1\u00D0\u00BB\u00D0\u00BE\u00D0\u00BA
+
+CANNOT_MINT = \u00D0\u00B0\u00D0\u00BA\u00D0\u00BA\u00D0\u00B0\u00D1\u0083\u00D0\u00BD\u00D1\u0082 \u00D0\u00BD\u00D0\u00B5 \u00D0\u00BC\u00D0\u00BE\u00D0\u00B6\u00D0\u00B5\u00D1\u0082 \u00D1\u0087\u00D0\u00B5\u00D0\u00BA\u00D0\u00B0\u00D0\u00BD\u00D0\u00B8\u00D1\u0082\u00D1\u008C
+
+GROUP_UNKNOWN = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D0\u00B0
+
+INVALID_ADDRESS = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B0\u00D0\u00B4\u00D1\u0080\u00D0\u00B5\u00D1\u0081
+
+# Assets
+INVALID_ASSET_ID = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B8\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D1\u0082\u00D0\u00B8\u00D1\u0084\u00D0\u00B8\u00D0\u00BA\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2\u00D0\u00B0
+
+INVALID_CRITERIA = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B5 \u00D0\u00BA\u00D1\u0080\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D1\u0080\u00D0\u00B8\u00D0\u00B8 \u00D0\u00BF\u00D0\u00BE\u00D0\u00B8\u00D1\u0081\u00D0\u00BA\u00D0\u00B0
+
+INVALID_DATA = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B5 \u00D0\u00B4\u00D0\u00B0\u00D0\u00BD\u00D0\u00BD\u00D1\u008B\u00D0\u00B5
+
+INVALID_HEIGHT = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00B0\u00D1\u008F \u00D0\u00B2\u00D1\u008B\u00D1\u0081\u00D0\u00BE\u00D1\u0082\u00D0\u00B0 \u00D0\u00B1\u00D0\u00BB\u00D0\u00BE\u00D0\u00BA\u00D0\u00B0
+
+INVALID_NETWORK_ADDRESS = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D1\u0081\u00D0\u00B5\u00D1\u0082\u00D0\u00B5\u00D0\u00B2\u00D0\u00BE\u00D0\u00B9 \u00D0\u00B0\u00D0\u00B4\u00D1\u0080\u00D0\u00B5\u00D1\u0081
+
+INVALID_ORDER_ID = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B8\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D1\u0082\u00D0\u00B8\u00D1\u0084\u00D0\u00B8\u00D0\u00BA\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D0\u00B0\u00D0\u00B7\u00D0\u00B0 \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2\u00D0\u00B0
+
+INVALID_PRIVATE_KEY = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BF\u00D1\u0080\u00D0\u00B8\u00D0\u00B2\u00D0\u00B0\u00D1\u0082\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087
+
+INVALID_PUBLIC_KEY = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BE\u00D1\u0082\u00D0\u00BA\u00D1\u0080\u00D1\u008B\u00D1\u0082\u00D1\u008B\u00D0\u00B9 \u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087
+
+INVALID_REFERENCE = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D1\u0081\u00D1\u0081\u00D1\u008B\u00D0\u00BB\u00D0\u00BA\u00D0\u00B0
+
+# Validation
+INVALID_SIGNATURE = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u00BF\u00D0\u00BE\u00D0\u00B4\u00D0\u00BF\u00D0\u00B8\u00D1\u0081\u00D1\u008C
+
+JSON = \u00D0\u00BD\u00D0\u00B5 \u00D1\u0083\u00D0\u00B4\u00D0\u00B0\u00D0\u00BB\u00D0\u00BE\u00D1\u0081\u00D1\u008C \u00D1\u0080\u00D0\u00B0\u00D0\u00B7\u00D0\u00BE\u00D0\u00B1\u00D1\u0080\u00D0\u00B0\u00D1\u0082\u00D1\u008C \u00D1\u0081\u00D0\u00BE\u00D0\u00BE\u00D0\u00B1\u00D1\u0089\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5 json
+
+NAME_UNKNOWN = \u00D0\u00B8\u00D0\u00BC\u00D1\u008F \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D0\u00BE
+
+ORDER_UNKNOWN = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B8\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D1\u0082\u00D0\u00B8\u00D1\u0084\u00D0\u00B8\u00D0\u00BA\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D0\u00B0\u00D0\u00B7\u00D0\u00B0 \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2\u00D0\u00B0
+
+PUBLIC_KEY_NOT_FOUND = \u00D0\u00BE\u00D1\u0082\u00D0\u00BA\u00D1\u0080\u00D1\u008B\u00D1\u0082\u00D1\u008B\u00D0\u00B9 \u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087 \u00D0\u00BD\u00D0\u00B5 \u00D0\u00BD\u00D0\u00B0\u00D0\u00B9\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD
+
+REPOSITORY_ISSUE = \u00D0\u00BE\u00D1\u0088\u00D0\u00B8\u00D0\u00B1\u00D0\u00BA\u00D0\u00B0 \u00D1\u0080\u00D0\u00B5\u00D0\u00BF\u00D0\u00BE\u00D0\u00B7\u00D0\u00B8\u00D1\u0082\u00D0\u00BE\u00D1\u0080\u00D0\u00B8\u00D1\u008F
+
+TRANSACTION_INVALID = \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008F \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D0\u00B0: %s (%s)
+
+TRANSACTION_UNKNOWN = \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008F \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D0\u00B0
+
+TRANSFORMATION_ERROR = \u00D0\u00BD\u00D0\u00B5 \u00D1\u0083\u00D0\u00B4\u00D0\u00B0\u00D0\u00BB\u00D0\u00BE\u00D1\u0081\u00D1\u008C \u00D0\u00BF\u00D1\u0080\u00D0\u00B5\u00D0\u00BE\u00D0\u00B1\u00D1\u0080\u00D0\u00B0\u00D0\u00B7\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D1\u0082\u00D1\u008C JSON \u00D0\u00B2 \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008E
+
+UNAUTHORIZED = \u00D0\u00B2\u00D1\u008B\u00D0\u00B7\u00D0\u00BE\u00D0\u00B2 API \u00D0\u00BD\u00D0\u00B5 \u00D0\u00B0\u00D0\u00B2\u00D1\u0082\u00D0\u00BE\u00D1\u0080\u00D0\u00B8\u00D0\u00B7\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D0\u00BD

src/main/resources/i18n/SysTray_en.properties

@@ -19,6 +19,8 @@ CREATING_BACKUP_OF_DB_FILES = Creating backup of database files...
 
 DB_BACKUP = Database Backup
 
+DB_CHECKPOINT = Database Checkpoint
+
 EXIT = Exit
 
 MINTING_DISABLED = NOT minting
@@ -34,6 +36,8 @@ NTP_NAG_TEXT_WINDOWS = Select "Synchronize clock" from menu to fix.
 
 OPEN_UI = Open UI
 
+PERFORMING_DB_CHECKPOINT = Saving uncommitted database changes...
+
 SYNCHRONIZE_CLOCK = Synchronize clock
 
 SYNCHRONIZING_BLOCKCHAIN = Synchronizing

src/main/resources/i18n/SysTray_ru.properties

@@ -0,0 +1,29 @@
+#Generated by ResourceBundle Editor (http://essiembre.github.io/eclipse-rbe/)
+# SysTray pop-up menu
+
+APPLYING_UPDATE_AND_RESTARTING = \u00D0\u009F\u00D1\u0080\u00D0\u00B8\u00D0\u00BC\u00D0\u00B5\u00D0\u00BD\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5 \u00D0\u00B0\u00D0\u00B2\u00D1\u0082\u00D0\u00BE\u00D0\u00BC\u00D0\u00B0\u00D1\u0082\u00D0\u00B8\u00D1\u0087\u00D0\u00B5\u00D1\u0081\u00D0\u00BA\u00D0\u00BE\u00D0\u00B3\u00D0\u00BE \u00D0\u00BE\u00D0\u00B1\u00D0\u00BD\u00D0\u00BE\u00D0\u00B2\u00D0\u00BB\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D1\u008F \u00D0\u00B8 \u00D0\u00BF\u00D0\u00B5\u00D1\u0080\u00D0\u00B5\u00D0\u00B7\u00D0\u00B0\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D0\u00BA\u00D0\u00B0...
+
+AUTO_UPDATE = \u00D0\u0090\u00D0\u00B2\u00D1\u0082\u00D0\u00BE\u00D0\u00BC\u00D0\u00B0\u00D1\u0082\u00D0\u00B8\u00D1\u0087\u00D0\u00B5\u00D1\u0081\u00D0\u00BA\u00D0\u00BE\u00D0\u00B5 \u00D0\u00BE\u00D0\u00B1\u00D0\u00BD\u00D0\u00BE\u00D0\u00B2\u00D0\u00BB\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5
+
+BLOCK_HEIGHT = \u00D0\u0092\u00D1\u008B\u00D1\u0081\u00D0\u00BE\u00D1\u0082\u00D0\u00B0 \u00D0\u00B1\u00D0\u00BB\u00D0\u00BE\u00D0\u00BA\u00D0\u00B0
+
+CHECK_TIME_ACCURACY = \u00D0\u009F\u00D1\u0080\u00D0\u00BE\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BA\u00D0\u00B0 \u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D0\u00BE\u00D0\u00B3\u00D0\u00BE \u00D0\u00B2\u00D1\u0080\u00D0\u00B5\u00D0\u00BC\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8
+
+CONNECTING = \u00D0\u009F\u00D0\u00BE\u00D0\u00B4\u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5
+
+CONNECTION = \u00D0\u00A1\u00D0\u00BE\u00D0\u00B5\u00D0\u00B4\u00D0\u00B8\u00D0\u00BD\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5
+
+CONNECTIONS = \u00D0\u00A1\u00D0\u00BE\u00D0\u00B5\u00D0\u00B4\u00D0\u00B8\u00D0\u00BD\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B9
+
+MINTING_DISABLED = \u00D0\u00A7\u00D0\u00B5\u00D0\u00BA\u00D0\u00B0\u00D0\u00BD\u00D0\u00BA\u00D0\u00B0 \u00D0\u00BE\u00D1\u0082\u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087\u00D0\u00B5\u00D0\u00BD\u00D0\u00B0
+
+MINTING_ENABLED = \u00D0\u00A7\u00D0\u00B5\u00D0\u00BA\u00D0\u00B0\u00D0\u00BD\u00D0\u00BA\u00D0\u00B0 \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2\u00D0\u00BD\u00D0\u00B0
+
+# Nagging about lack of NTP time sync
+NTP_NAG_CAPTION = \u00D0\u00A7\u00D0\u00B0\u00D1\u0081\u00D1\u008B \u00D0\u00BA\u00D0\u00BE\u00D0\u00BC\u00D0\u00BF\u00D1\u008C\u00D1\u008E\u00D1\u0082\u00D0\u00B5\u00D1\u0080\u00D0\u00B0 \u00D0\u00BD\u00D0\u00B5\u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D1\u008B!
+
+NTP_NAG_TEXT_UNIX = \u00D0\u00A3\u00D1\u0081\u00D1\u0082\u00D0\u00B0\u00D0\u00BD\u00D0\u00BE\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5 \u00D1\u0081\u00D0\u00BB\u00D1\u0083\u00D0\u00B6\u00D0\u00B1\u00D1\u0083 NTP, \u00D1\u0087\u00D1\u0082\u00D0\u00BE\u00D0\u00B1\u00D1\u008B \u00D0\u00BF\u00D0\u00BE\u00D0\u00BB\u00D1\u0083\u00D1\u0087\u00D0\u00B8\u00D1\u0082\u00D1\u008C \u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D0\u00BE\u00D0\u00B5 \u00D0\u00B2\u00D1\u0080\u00D0\u00B5\u00D0\u00BC\u00D1\u008F
+
+OPEN_UI = \u00D0\u009E\u00D1\u0082\u00D0\u00BA\u00D1\u0080\u00D1\u008B\u00D1\u0082\u00D1\u008C \u00D0\u00BF\u00D0\u00BE\u00D0\u00BB\u00D1\u008C\u00D0\u00B7\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D1\u0081\u00D0\u00BA\u00D0\u00B8\u00D0\u00B9 \u00D0\u00B8\u00D0\u00BD\u00D1\u0082\u00D0\u00B5\u00D1\u0080\u00D1\u0084\u00D0\u00B5\u00D0\u00B9\u00D1\u0081
+
+SYNCHRONIZING_CLOCK = \u00D0\u009F\u00D1\u0080\u00D0\u00BE\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BA\u00D0\u00B0 \u00D0\u00B2\u00D1\u0080\u00D0\u00B5\u00D0\u00BC\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8

src/main/resources/i18n/TransactionValidity_en.properties

@@ -11,166 +11,174 @@ ALREADY_VOTED_FOR_THAT_OPTION = already voted for that option
 
 ASSET_ALREADY_EXISTS = asset already exists
 
-ASSET_DOES_NOT_EXIST = ASSET_DOES_NOT_EXIST
+ASSET_DOES_NOT_EXIST = asset does not exist
 
-ASSET_DOES_NOT_MATCH_AT = ASSET_DOES_NOT_MATCH_AT
+ASSET_DOES_NOT_MATCH_AT = asset does not match AT's asset
 
-ASSET_NOT_SPENDABLE = ASSET_NOT_SPENDABLE
+ASSET_NOT_SPENDABLE = asset is not spendable
 
-AT_ALREADY_EXISTS = AT_ALREADY_EXISTS
+AT_ALREADY_EXISTS = AT already exists
 
-AT_IS_FINISHED = AT_IS_FINISHED
+AT_IS_FINISHED = AT has finished
 
-AT_UNKNOWN = AT_UNKNOWN
+AT_UNKNOWN = AT unknown
 
-BANNED_FROM_GROUP = BANNED_FROM_GROUP
+BANNED_FROM_GROUP = banned from group
 
-BAN_EXISTS = BAN_EXISTS
+BAN_EXISTS = ban already exists
 
-BAN_UNKNOWN = BAN_UNKNOWN
+BAN_UNKNOWN = ban unknown
 
-BUYER_ALREADY_OWNER = BUYER_ALREADY_OWNER
+BUYER_ALREADY_OWNER = buyer is already owner
 
-CLOCK_NOT_SYNCED = CLOCK_NOT_SYNCED
+CHAT = CHAT transactions are never valid for inclusion into blocks
 
-DUPLICATE_OPTION = DUPLICATE_OPTION
+CLOCK_NOT_SYNCED = clock not synchronized
 
-GROUP_ALREADY_EXISTS = GROUP_ALREADY_EXISTS
+DUPLICATE_OPTION = duplicate option
 
-GROUP_APPROVAL_DECIDED = GROUP_APPROVAL_DECIDED
+GROUP_ALREADY_EXISTS = group already exists
 
-GROUP_APPROVAL_NOT_REQUIRED = GROUP_APPROVAL_NOT_REQUIRED
+GROUP_APPROVAL_DECIDED = group-approval already decided
 
-GROUP_DOES_NOT_EXIST = GROUP_DOES_NOT_EXIST
+GROUP_APPROVAL_NOT_REQUIRED = group-approval not required
 
-GROUP_ID_MISMATCH = GROUP_ID_MISMATCH
+GROUP_DOES_NOT_EXIST = group does not exist
 
-GROUP_OWNER_CANNOT_LEAVE = GROUP_OWNER_CANNOT_LEAVE
+GROUP_ID_MISMATCH = group ID mismatch
 
-HAVE_EQUALS_WANT = HAVE_EQUALS_WANT
+GROUP_OWNER_CANNOT_LEAVE = group owner cannot leave group
 
-INSUFFICIENT_FEE = INSUFFICIENT_FEE
+HAVE_EQUALS_WANT = have-asset is the same as want-asset
 
-INVALID_ADDRESS = INVALID_ADDRESS
+INCORRECT_NONCE = incorrect PoW nonce
 
-INVALID_AMOUNT = INVALID_AMOUNT
+INSUFFICIENT_FEE = insufficient fee
 
-INVALID_ASSET_OWNER = INVALID_ASSET_OWNER
+INVALID_ADDRESS = invalid address
 
-INVALID_AT_TRANSACTION = INVALID_AT_TRANSACTION
+INVALID_AMOUNT = invalid amount
 
-INVALID_AT_TYPE_LENGTH = INVALID_AT_TYPE_LENGTH
+INVALID_ASSET_OWNER = invalid asset owner
 
-INVALID_CREATION_BYTES = INVALID_CREATION_BYTES
+INVALID_AT_TRANSACTION = invalid AT transaction
 
-INVALID_DATA_LENGTH = INVALID_DATA_LENGTH
+INVALID_AT_TYPE_LENGTH = invalid AT 'type' length
 
-INVALID_DESCRIPTION_LENGTH = INVALID_DESCRIPTION_LENGTH
+INVALID_CREATION_BYTES = invalid creation bytes
 
-INVALID_GROUP_APPROVAL_THRESHOLD = INVALID_GROUP_APPROVAL_THRESHOLD
+INVALID_DATA_LENGTH = invalid data length
 
-INVALID_GROUP_ID = INVALID_GROUP_ID
+INVALID_DESCRIPTION_LENGTH = invalid description length
 
-INVALID_GROUP_OWNER = INVALID_GROUP_OWNER
+INVALID_GROUP_APPROVAL_THRESHOLD = invalid group-approval threshold
 
-INVALID_LIFETIME = INVALID_LIFETIME
+INVALID_GROUP_BLOCK_DELAY = invalid group-approval block delay
 
-INVALID_NAME_LENGTH = INVALID_NAME_LENGTH
+INVALID_GROUP_ID = invalid group ID
 
-INVALID_NAME_OWNER = INVALID_NAME_OWNER
+INVALID_GROUP_OWNER = invalid group owner
 
-INVALID_OPTIONS_COUNT = INVALID_OPTIONS_COUNT
+INVALID_LIFETIME = invalid lifetime
 
-INVALID_OPTION_LENGTH = INVALID_OPTION_LENGTH
+INVALID_NAME_LENGTH = invalid name length
 
-INVALID_ORDER_CREATOR = INVALID_ORDER_CREATOR
+INVALID_NAME_OWNER = invalid name owner
 
-INVALID_PAYMENTS_COUNT = INVALID_PAYMENTS_COUNT
+INVALID_OPTIONS_COUNT = invalid options count
 
-INVALID_PUBLIC_KEY = INVALID_PUBLIC_KEY
+INVALID_OPTION_LENGTH = invalid options length
 
-INVALID_QUANTITY = INVALID_QUANTITY
+INVALID_ORDER_CREATOR = invalid order creator
 
-INVALID_REFERENCE = INVALID_REFERENCE
+INVALID_PAYMENTS_COUNT = invalid payments count
 
-INVALID_RETURN = INVALID_RETURN
+INVALID_PUBLIC_KEY = invalid public key
 
-INVALID_REWARD_SHARE_PERCENT = INVALID_REWARD_SHARE_PERCENT
+INVALID_QUANTITY = invalid quantity
 
-INVALID_SELLER = INVALID_SELLER
+INVALID_REFERENCE = invalid reference
 
-INVALID_TAGS_LENGTH = INVALID_TAGS_LENGTH
+INVALID_RETURN = invalid return
 
-INVALID_TX_GROUP_ID = INVALID_TX_GROUP_ID
+INVALID_REWARD_SHARE_PERCENT = invalid reward-share percent
 
-INVALID_VALUE_LENGTH = INVALID_VALUE_LENGTH
+INVALID_SELLER = invalid seller
 
-INVITE_UNKNOWN = INVITE_UNKNOWN
+INVALID_TAGS_LENGTH = invalid 'tags' length
 
-JOIN_REQUEST_EXISTS = JOIN_REQUEST_EXISTS
+INVALID_TX_GROUP_ID = invalid transaction group ID
 
-MAXIMUM_REWARD_SHARES = MAXIMUM_REWARD_SHARES
+INVALID_VALUE_LENGTH = invalid 'value' length
 
-MISSING_CREATOR = MISSING_CREATOR
+INVITE_UNKNOWN = group invite unknown
 
-MULTIPLE_NAMES_FORBIDDEN = MULTIPLE_NAMES_FORBIDDEN
+JOIN_REQUEST_EXISTS = group join request already exists
 
-NAME_ALREADY_FOR_SALE = NAME_ALREADY_FOR_SALE
+MAXIMUM_REWARD_SHARES = already at maximum number of reward-shares for this account
 
-NAME_ALREADY_REGISTERED = NAME_ALREADY_REGISTERED
+MISSING_CREATOR = missing creator
 
-NAME_DOES_NOT_EXIST = NAME_DOES_NOT_EXIST
+MULTIPLE_NAMES_FORBIDDEN = multiple registered names per account is forbidden
 
-NAME_NOT_FOR_SALE = NAME_NOT_FOR_SALE
+NAME_ALREADY_FOR_SALE = name already for sale
 
-NAME_NOT_LOWER_CASE = NAME_NOT_LOWER_CASE
+NAME_ALREADY_REGISTERED = name already registered
 
-NEGATIVE_AMOUNT = NEGATIVE_AMOUNT
+NAME_DOES_NOT_EXIST = name does not exist
 
-NEGATIVE_FEE = NEGATIVE_FEE
+NAME_NOT_FOR_SALE = name is not for sale
 
-NEGATIVE_PRICE = NEGATIVE_PRICE
+NAME_NOT_NORMALIZED = name not in Unicode 'normalized' form
 
-NOT_GROUP_ADMIN = NOT_GROUP_ADMIN
+NEGATIVE_AMOUNT = invalid/negative amount
 
-NOT_GROUP_MEMBER = NOT_GROUP_MEMBER
+NEGATIVE_FEE = invalid/negative fee
 
-NOT_MINTING_ACCOUNT = NOT_MINTING_ACCOUNT
+NEGATIVE_PRICE = invalid/negative price
 
-NOT_YET_RELEASED = NOT_YET_RELEASED
+NOT_GROUP_ADMIN = account is not a group admin
 
-NO_BALANCE = NO_BALANCE
+NOT_GROUP_MEMBER = account is not a group member
+
+NOT_MINTING_ACCOUNT = account cannot mint
+
+NOT_YET_RELEASED = feature not yet released
+
+NO_BALANCE = insufficient balance
 
 NO_BLOCKCHAIN_LOCK = node's blockchain currently busy
 
-NO_FLAG_PERMISSION = NO_FLAG_PERMISSION
+NO_FLAG_PERMISSION = account does not have that permission
 
 OK = OK
 
-ORDER_ALREADY_CLOSED = ORDER_ALREADY_CLOSED
+ORDER_ALREADY_CLOSED = asset trade order is already closed
 
-ORDER_DOES_NOT_EXIST = ORDER_DOES_NOT_EXIST
+ORDER_DOES_NOT_EXIST = asset trade order does not exist
 
-POLL_ALREADY_EXISTS = POLL_ALREADY_EXISTS
+POLL_ALREADY_EXISTS = poll already exists
 
-POLL_DOES_NOT_EXIST = POLL_DOES_NOT_EXIST
+POLL_DOES_NOT_EXIST = poll does not exist
 
-POLL_OPTION_DOES_NOT_EXIST = POLL_OPTION_DOES_NOT_EXIST
+POLL_OPTION_DOES_NOT_EXIST = poll option does not exist
 
-PUBLIC_KEY_UNKNOWN = PUBLIC_KEY_UNKNOWN
+PUBLIC_KEY_UNKNOWN = public key unknown
 
-SELF_SHARE_EXISTS = SELF_SHARE_EXISTS
+REWARD_SHARE_UNKNOWN = reward-share unknown
 
-TIMESTAMP_TOO_NEW = TIMESTAMP_TOO_NEW
+SELF_SHARE_EXISTS = self-share (reward-share) already exists
 
-TIMESTAMP_TOO_OLD = TIMESTAMP_TOO_OLD
+TIMESTAMP_TOO_NEW = timestamp too new
 
-TOO_MANY_UNCONFIRMED = TOO_MANY_UNCONFIRMED
+TIMESTAMP_TOO_OLD = timestamp too old
 
-TRANSACTION_ALREADY_CONFIRMED = TRANSACTION_ALREADY_CONFIRMED
+TOO_MANY_UNCONFIRMED = account has too many unconfirmed transactions pending
 
-TRANSACTION_ALREADY_EXISTS = TRANSACTION_ALREADY_EXISTS
+TRANSACTION_ALREADY_CONFIRMED = transaction has already confirmed
 
-TRANSACTION_UNKNOWN = TRANSACTION_UNKNOWN
+TRANSACTION_ALREADY_EXISTS = transaction already exists
 
-TX_GROUP_ID_MISMATCH = TX_GROUP_ID_MISMATCH
+TRANSACTION_UNKNOWN = transaction unknown
+
+TX_GROUP_ID_MISMATCH = transaction's group ID does not match

src/main/resources/i18n/TransactionValidity_ru.properties

@@ -0,0 +1,164 @@
+
+ACCOUNT_ALREADY_EXISTS = \u00D0\u00B0\u00D0\u00BA\u00D0\u00BA\u00D0\u00B0\u00D1\u0083\u00D0\u00BD\u00D1\u0082 \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+ACCOUNT_CANNOT_REWARD_SHARE = \u00D0\u00B0\u00D0\u00BA\u00D0\u00BA\u00D0\u00B0\u00D1\u0083\u00D0\u00BD\u00D1\u0082 \u00D0\u00BD\u00D0\u00B5 \u00D0\u00BC\u00D0\u00BE\u00D0\u00B6\u00D0\u00B5\u00D1\u0082 \u00D0\u00B4\u00D0\u00B5\u00D0\u00BB\u00D0\u00B8\u00D1\u0082\u00D1\u008C\u00D1\u0081\u00D1\u008F \u00D0\u00B2\u00D0\u00BE\u00D0\u00B7\u00D0\u00BD\u00D0\u00B0\u00D0\u00B3\u00D1\u0080\u00D0\u00B0\u00D0\u00B6\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5\u00D0\u00BC
+
+ALREADY_GROUP_ADMIN = \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D0\u00B0\u00D0\u00B4\u00D0\u00BC\u00D0\u00B8\u00D0\u00BD\u00D0\u00B8\u00D1\u0081\u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+ALREADY_GROUP_MEMBER = \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0087\u00D0\u00BB\u00D0\u00B5\u00D0\u00BD \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+ALREADY_VOTED_FOR_THAT_OPTION = \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D0\u00B3\u00D0\u00BE\u00D0\u00BB\u00D0\u00BE\u00D1\u0081\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D0\u00BB\u00D0\u00B8 \u00D0\u00B7\u00D0\u00B0 \u00D1\u008D\u00D1\u0082\u00D0\u00BE\u00D1\u0082 \u00D0\u00B2\u00D0\u00B0\u00D1\u0080\u00D0\u00B8\u00D0\u00B0\u00D0\u00BD\u00D1\u0082
+
+ASSET_ALREADY_EXISTS = \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2 \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+ASSET_DOES_NOT_EXIST = \u00D0\u0090\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+ASSET_DOES_NOT_MATCH_AT = \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D0\u00BE\u00D0\u00B2\u00D0\u00BF\u00D0\u00B0\u00D0\u00B4\u00D0\u00B0\u00D0\u00B5\u00D1\u0082 \u00D1\u0081 \u00D0\u0090\u00D0\u00A2
+
+AT_ALREADY_EXISTS = AT \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+AT_IS_FINISHED = AT \u00D0\u00B2 \u00D0\u00B7\u00D0\u00B0\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D1\u0088\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B8
+
+AT_UNKNOWN = \u00D0\u00BD\u00D0\u00B5 \u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u0090\u00D0\u00A2
+
+BANNED_FROM_GROUP = \u00D0\u00B8\u00D1\u0081\u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087\u00D0\u00B5\u00D0\u00BD \u00D0\u00B8\u00D0\u00B7 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+BAN_EXISTS = \u00D0\u0091\u00D0\u00B0\u00D0\u00BD
+
+BAN_UNKNOWN = \u00D0\u00BD\u00D0\u00B5 \u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B1\u00D0\u00B0\u00D0\u00BD
+
+BUYER_ALREADY_OWNER = \u00D0\u00BF\u00D0\u00BE\u00D0\u00BA\u00D1\u0083\u00D0\u00BF\u00D0\u00B0\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0081\u00D0\u00BE\u00D0\u00B1\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B5\u00D0\u00BD\u00D0\u00BD\u00D0\u00B8\u00D0\u00BA
+
+DUPLICATE_OPTION = \u00D0\u00B4\u00D1\u0083\u00D0\u00B1\u00D0\u00BB\u00D0\u00B8\u00D1\u0080\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D1\u0082\u00D1\u008C \u00D0\u00B2\u00D0\u00B0\u00D1\u0080\u00D0\u00B8\u00D0\u00B0\u00D0\u00BD\u00D1\u0082
+
+GROUP_ALREADY_EXISTS = \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D0\u00B0 \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+GROUP_APPROVAL_DECIDED = \u00D0\u00B3\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D0\u00B0 \u00D0\u00BE\u00D0\u00B4\u00D0\u00BE\u00D0\u00B1\u00D1\u0080\u00D0\u00B5\u00D0\u00BD\u00D0\u00B0
+
+GROUP_APPROVAL_NOT_REQUIRED = \u00D0\u00B3\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D0\u00BE\u00D0\u00B2\u00D0\u00BE\u00D0\u00B5 \u00D0\u00BE\u00D0\u00B4\u00D0\u00BE\u00D0\u00B1\u00D1\u0080\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0082\u00D1\u0080\u00D0\u00B5\u00D0\u00B1\u00D1\u0083\u00D0\u00B5\u00D1\u0082\u00D1\u0081\u00D1\u008F
+
+GROUP_DOES_NOT_EXIST = \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D0\u00B0 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+GROUP_ID_MISMATCH = \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D0\u00BE\u00D0\u00BE\u00D1\u0082\u00D0\u00B2\u00D0\u00B5\u00D1\u0082\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D0\u00B5 \u00D0\u00B8\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D1\u0082\u00D0\u00B8\u00D1\u0084\u00D0\u00B8\u00D0\u00BA\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080\u00D0\u00B0 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+GROUP_OWNER_CANNOT_LEAVE = \u00D0\u00B2\u00D0\u00BB\u00D0\u00B0\u00D0\u00B4\u00D0\u00B5\u00D0\u00BB\u00D0\u00B5\u00D1\u0086 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B \u00D0\u00BD\u00D0\u00B5 \u00D0\u00BC\u00D0\u00BE\u00D0\u00B6\u00D0\u00B5\u00D1\u0082 \u00D1\u0083\u00D0\u00B9\u00D1\u0082\u00D0\u00B8
+
+HAVE_EQUALS_WANT = \u00D0\u00B8\u00D0\u00BC\u00D0\u00BC\u00D0\u00B5\u00D1\u008E\u00D1\u0082\u00D1\u0081\u00D1\u008F \u00D1\u0080\u00D0\u00B0\u00D0\u00B2\u00D0\u00BD\u00D1\u008B\u00D0\u00B5 \u00D0\u00B6\u00D0\u00B5\u00D0\u00BB\u00D0\u00B0\u00D0\u00BD\u00D0\u00B8\u00D1\u008F
+
+INSUFFICIENT_FEE = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D1\u0081\u00D1\u0082\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u00BF\u00D0\u00BB\u00D0\u00B0\u00D1\u0082\u00D0\u00B0
+
+INVALID_ADDRESS = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B0\u00D0\u00B4\u00D1\u0080\u00D0\u00B5\u00D1\u0081
+
+INVALID_AMOUNT = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00B0\u00D1\u008F \u00D1\u0081\u00D1\u0083\u00D0\u00BC\u00D0\u00BC\u00D0\u00B0
+
+INVALID_ASSET_OWNER = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B2\u00D0\u00BB\u00D0\u00B0\u00D0\u00B4\u00D0\u00B5\u00D0\u00BB\u00D0\u00B5\u00D1\u0086 \u00D0\u00B0\u00D0\u00BA\u00D1\u0082\u00D0\u00B8\u00D0\u00B2\u00D0\u00B0
+
+INVALID_AT_TRANSACTION = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u0090\u00D0\u00A2 \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008F
+
+INVALID_AT_TYPE_LENGTH = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D0\u00BE \u00D0\u00B4\u00D0\u00BB\u00D1\u008F \u00D1\u0082\u00D0\u00B8\u00D0\u00BF\u00D0\u00B0 \u00D0\u00B4\u00D0\u00BB\u00D0\u00B8\u00D0\u00BD\u00D1\u008B AT
+
+INVALID_CREATION_BYTES = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D1\u008B\u00D0\u00B5 \u00D0\u00B1\u00D0\u00B0\u00D0\u00B9\u00D1\u0082\u00D1\u008B \u00D1\u0081\u00D0\u00BE\u00D0\u00B7\u00D0\u00B4\u00D0\u00B0\u00D0\u00BD\u00D0\u00B8\u00D1\u008F
+
+INVALID_DESCRIPTION_LENGTH = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00B0\u00D1\u008F \u00D0\u00B4\u00D0\u00BB\u00D0\u00B8\u00D0\u00BD\u00D0\u00B0 \u00D0\u00BE\u00D0\u00BF\u00D0\u00B8\u00D1\u0081\u00D0\u00B0\u00D0\u00BD\u00D0\u00B8\u00D1\u008F
+
+INVALID_GROUP_APPROVAL_THRESHOLD = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D1\u008B\u00D0\u00B9 \u00D0\u00BF\u00D0\u00BE\u00D1\u0080\u00D0\u00BE\u00D0\u00B3 \u00D1\u0083\u00D1\u0082\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00B6\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D1\u008F \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+INVALID_GROUP_ID = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D1\u008B\u00D0\u00B9 \u00D0\u00B8\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D1\u0082\u00D0\u00B8\u00D1\u0084\u00D0\u00B8\u00D0\u00BA\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+INVALID_GROUP_OWNER = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083 \u00D0\u00B2\u00D0\u00BB\u00D0\u00B0\u00D0\u00B4\u00D0\u00B5\u00D0\u00BB\u00D0\u00B5\u00D1\u0086 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+INVALID_LIFETIME = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083 \u00D1\u0081\u00D1\u0080\u00D0\u00BE\u00D0\u00BA \u00D1\u0081\u00D0\u00BB\u00D1\u0083\u00D0\u00B6\u00D0\u00B1\u00D1\u008B
+
+INVALID_NAME_LENGTH = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00B0\u00D1\u008F \u00D0\u00B4\u00D0\u00BB\u00D0\u00B8\u00D0\u00BD\u00D0\u00B0 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+INVALID_NAME_OWNER = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00BE\u00D0\u00B5 \u00D0\u00B8\u00D0\u00BC\u00D1\u008F \u00D0\u00B2\u00D0\u00BB\u00D0\u00B0\u00D0\u00B4\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D1\u0086\u00D0\u00B0
+
+INVALID_OPTIONS_COUNT = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D0\u00BE\u00D0\u00B5 \u00D0\u00BA\u00D0\u00BE\u00D0\u00BB\u00D0\u00B8\u00D1\u0087\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00BE \u00D0\u00BE\u00D0\u00BF\u00D1\u0086\u00D0\u00B8\u00D0\u00B9
+
+INVALID_OPTION_LENGTH = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00B0\u00D1\u008F \u00D0\u00B4\u00D0\u00BB\u00D0\u00B8\u00D0\u00BD\u00D0\u00B0 \u00D0\u00BE\u00D0\u00BF\u00D1\u0086\u00D0\u00B8\u00D0\u00B8
+
+INVALID_ORDER_CREATOR = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D1\u008B\u00D0\u00B9 \u00D1\u0081\u00D0\u00BE\u00D0\u00B7\u00D0\u00B4\u00D0\u00B0\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C \u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D0\u00B0\u00D0\u00B7\u00D0\u00B0
+
+INVALID_PAYMENTS_COUNT = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BF\u00D0\u00BE\u00D0\u00B4\u00D1\u0081\u00D1\u0087\u00D0\u00B5\u00D1\u0082 \u00D0\u00BF\u00D0\u00BB\u00D0\u00B0\u00D1\u0082\u00D0\u00B5\u00D0\u00B6\u00D0\u00B5\u00D0\u00B9
+
+INVALID_PUBLIC_KEY = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BE\u00D1\u0082\u00D0\u00BA\u00D1\u0080\u00D1\u008B\u00D1\u0082\u00D1\u008B\u00D0\u00B9 \u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087
+
+INVALID_QUANTITY = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00BE\u00D0\u00B5 \u00D0\u00BA\u00D0\u00BE\u00D0\u00BB\u00D0\u00B8\u00D1\u0087\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00BE
+
+INVALID_REFERENCE = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D1\u0081\u00D1\u0081\u00D1\u008B\u00D0\u00BB\u00D0\u00BA\u00D0\u00B0
+
+INVALID_RETURN = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D1\u008B\u00D0\u00B9 \u00D0\u00B2\u00D0\u00BE\u00D0\u00B7\u00D0\u00B2\u00D1\u0080\u00D0\u00B0\u00D1\u0082
+
+INVALID_REWARD_SHARE_PERCENT = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D1\u0086\u00D0\u00B5\u00D0\u00BD\u00D1\u0082 \u00D0\u00BD\u00D0\u00B0\u00D0\u00B3\u00D1\u0080\u00D0\u00B0\u00D0\u00B6\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D1\u008F
+
+INVALID_SELLER = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D0\u00B4\u00D0\u00B0\u00D0\u00B2\u00D0\u00B5\u00D1\u0086
+
+INVALID_TAGS_LENGTH = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u00B4\u00D0\u00BB\u00D0\u00B8\u00D0\u00BD\u00D0\u00B0 \u00D1\u0082\u00D1\u008D\u00D0\u00B3\u00D0\u00BE\u00D0\u00B2
+
+INVALID_TX_GROUP_ID = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00B5\u00D0\u00B9\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D0\u00B8\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D0\u00B8\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D1\u0082\u00D0\u00B8\u00D1\u0084\u00D0\u00B8\u00D0\u00BA\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B \u00D0\u00BF\u00D0\u00B5\u00D1\u0080\u00D0\u00B5\u00D0\u00B4\u00D0\u00B0\u00D1\u0087\u00D0\u00B8
+
+INVALID_VALUE_LENGTH = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D0\u00BF\u00D1\u0083\u00D1\u0081\u00D1\u0082\u00D0\u00B8\u00D0\u00BC\u00D0\u00BE\u00D0\u00B5 \u00D0\u00B7\u00D0\u00BD\u00D0\u00B0\u00D1\u0087\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5 \u00D0\u00B4\u00D0\u00BB\u00D0\u00B8\u00D0\u00BD\u00D1\u008B
+
+JOIN_REQUEST_EXISTS = \u00D0\u00B7\u00D0\u00B0\u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D1\u0081 \u00D0\u00BD\u00D0\u00B0 \u00D0\u00BF\u00D1\u0080\u00D0\u00B8\u00D1\u0081\u00D0\u00BE\u00D0\u00B5\u00D0\u00B4\u00D0\u00B8\u00D0\u00BD\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+MAXIMUM_REWARD_SHARES = \u00D0\u00BC\u00D0\u00B0\u00D0\u00BA\u00D1\u0081\u00D0\u00B8\u00D0\u00BC\u00D0\u00B0\u00D0\u00BB\u00D1\u008C\u00D0\u00BD\u00D0\u00BE\u00D0\u00B5 \u00D0\u00B2\u00D0\u00BE\u00D0\u00B7\u00D0\u00BD\u00D0\u00B0\u00D0\u00B3\u00D1\u0080\u00D0\u00B0\u00D0\u00B6\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D0\u00B5
+
+MISSING_CREATOR = \u00D0\u00BE\u00D1\u0082\u00D1\u0081\u00D1\u0083\u00D1\u0082\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D1\u008E\u00D1\u0089\u00D0\u00B8\u00D0\u00B9 \u00D1\u0081\u00D0\u00BE\u00D0\u00B7\u00D0\u00B4\u00D0\u00B0\u00D1\u0082\u00D0\u00B5\u00D0\u00BB\u00D1\u008C
+
+MULTIPLE_NAMES_FORBIDDEN = \u00D0\u00BD\u00D0\u00B5\u00D1\u0081\u00D0\u00BA\u00D0\u00BE\u00D0\u00BB\u00D1\u008C\u00D0\u00BA\u00D0\u00BE \u00D0\u00B8\u00D0\u00BC\u00D0\u00B5\u00D0\u00BD \u00D0\u00B7\u00D0\u00B0\u00D0\u00BF\u00D1\u0080\u00D0\u00B5\u00D1\u0089\u00D0\u00B5\u00D0\u00BD\u00D0\u00BE
+
+NAME_ALREADY_FOR_SALE = \u00D0\u00B8\u00D0\u00BC\u00D1\u008F \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D0\u00B2 \u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D0\u00B4\u00D0\u00B0\u00D0\u00B6\u00D0\u00B5
+
+NAME_ALREADY_REGISTERED = \u00D0\u00B8\u00D0\u00BC\u00D1\u008F \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D0\u00B7\u00D0\u00B0\u00D1\u0080\u00D0\u00B5\u00D0\u00B3\u00D0\u00B8\u00D1\u0081\u00D1\u0082\u00D1\u0080\u00D0\u00B8\u00D1\u0080\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D0\u00BD\u00D0\u00BE
+
+NAME_DOES_NOT_EXIST = \u00D0\u00B8\u00D0\u00BC\u00D1\u008F \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+NAME_NOT_FOR_SALE = \u00D0\u00B8\u00D0\u00BC\u00D1\u008F \u00D0\u00BD\u00D0\u00B5 \u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D0\u00B4\u00D0\u00B0\u00D0\u00B5\u00D1\u0082\u00D1\u0081\u00D1\u008F
+
+NAME_NOT_LOWER_CASE = \u00D0\u00B8\u00D0\u00BC\u00D0\u00BC\u00D1\u008F \u00D0\u00BD\u00D0\u00B5 \u00D0\u00B4\u00D0\u00BE\u00D0\u00BB\u00D0\u00B6\u00D0\u00BD\u00D0\u00BE \u00D1\u0081\u00D0\u00BE\u00D0\u00B4\u00D0\u00B5\u00D1\u0080\u00D0\u00B6\u00D0\u00B0\u00D1\u0082\u00D1\u008C \u00D1\u0081\u00D1\u0082\u00D1\u0080\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D1\u008B\u00D0\u00B9 \u00D1\u0080\u00D0\u00B5\u00D0\u00B3\u00D0\u00B8\u00D1\u0081\u00D1\u0082\u00D1\u0080
+
+NEGATIVE_AMOUNT = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D1\u0081\u00D1\u0082\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D1\u0081\u00D1\u0083\u00D0\u00BC\u00D0\u00BC\u00D0\u00B0
+
+NEGATIVE_FEE = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D1\u0081\u00D1\u0082\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D0\u00BA\u00D0\u00BE\u00D0\u00BC\u00D0\u00B8\u00D1\u0081\u00D1\u0081\u00D0\u00B8\u00D1\u008F
+
+NEGATIVE_PRICE = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B4\u00D0\u00BE\u00D1\u0081\u00D1\u0082\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0087\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D1\u0081\u00D1\u0082\u00D0\u00BE\u00D0\u00B8\u00D0\u00BC\u00D0\u00BE\u00D1\u0081\u00D1\u0082\u00D1\u008C
+
+NOT_GROUP_ADMIN = \u00D0\u00BD\u00D0\u00B5 \u00D0\u00B0\u00D0\u00B4\u00D0\u00BC\u00D0\u00B8\u00D0\u00BD\u00D0\u00B8\u00D1\u0081\u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D1\u0082\u00D0\u00BE\u00D1\u0080 \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+NOT_GROUP_MEMBER = \u00D0\u00BD\u00D0\u00B5 \u00D1\u0087\u00D0\u00BB\u00D0\u00B5\u00D0\u00BD \u00D0\u00B3\u00D1\u0080\u00D1\u0083\u00D0\u00BF\u00D0\u00BF\u00D1\u008B
+
+NOT_MINTING_ACCOUNT = \u00D1\u0081\u00D1\u0087\u00D0\u00B5\u00D1\u0082 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0087\u00D0\u00B5\u00D0\u00BA\u00D0\u00B0\u00D0\u00BD\u00D0\u00B8\u00D1\u0082
+
+NOT_YET_RELEASED = \u00D0\u00B5\u00D1\u0089\u00D0\u00B5 \u00D0\u00BD\u00D0\u00B5 \u00D0\u00B2\u00D1\u008B\u00D0\u00BF\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D0\u00BD\u00D0\u00BE
+
+NO_BALANCE = \u00D0\u00BD\u00D0\u00B5\u00D1\u0082 \u00D0\u00B1\u00D0\u00B0\u00D0\u00BB\u00D0\u00B0\u00D0\u00BD\u00D1\u0081\u00D0\u00B0
+
+NO_BLOCKCHAIN_LOCK = \u00D0\u00B1\u00D0\u00BB\u00D0\u00BE\u00D0\u00BA\u00D1\u0087\u00D0\u00B5\u00D0\u00B9\u00D0\u00BD \u00D1\u0083\u00D0\u00B7\u00D0\u00BB\u00D0\u00B0 \u00D0\u00B2 \u00D0\u00BD\u00D0\u00B0\u00D1\u0081\u00D1\u0082\u00D0\u00BE\u00D1\u008F\u00D1\u0089\u00D0\u00B5\u00D0\u00B5 \u00D0\u00B2\u00D1\u0080\u00D0\u00B5\u00D0\u00BC\u00D1\u008F \u00D0\u00B7\u00D0\u00B0\u00D0\u00BD\u00D1\u008F\u00D1\u0082
+
+NO_FLAG_PERMISSION = \u00D0\u00BD\u00D0\u00B5\u00D1\u0082 \u00D1\u0080\u00D0\u00B0\u00D0\u00B7\u00D1\u0080\u00D0\u00B5\u00D1\u0088\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8\u00D1\u008F \u00D0\u00BD\u00D0\u00B0 \u00D1\u0084\u00D0\u00BB\u00D0\u00B0\u00D0\u00B3
+
+OK = OK
+
+ORDER_ALREADY_CLOSED = \u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D0\u00B0\u00D0\u00B7 \u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0080\u00D1\u008B\u00D1\u0082
+
+ORDER_DOES_NOT_EXIST = \u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D0\u00B0\u00D0\u00B7\u00D0\u00B0 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+POLL_ALREADY_EXISTS = \u00D0\u00BE\u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D1\u0081 \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+POLL_DOES_NOT_EXIST = \u00D0\u00BE\u00D0\u00BF\u00D1\u0080\u00D0\u00BE\u00D1\u0081\u00D0\u00B0 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+POLL_OPTION_DOES_NOT_EXIST = \u00D0\u00B2\u00D0\u00B0\u00D1\u0080\u00D0\u00B8\u00D0\u00B0\u00D0\u00BD\u00D1\u0082\u00D0\u00BE\u00D0\u00B2 \u00D0\u00BE\u00D1\u0082\u00D0\u00B2\u00D0\u00B5\u00D1\u0082\u00D0\u00B0 \u00D0\u00BD\u00D0\u00B5 \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+PUBLIC_KEY_UNKNOWN = \u00D0\u00BE\u00D1\u0082\u00D0\u00BA\u00D1\u0080\u00D1\u008B\u00D1\u0082\u00D1\u008B\u00D0\u00B9 \u00D0\u00BA\u00D0\u00BB\u00D1\u008E\u00D1\u0087 \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B5\u00D0\u00BD
+
+SELF_SHARE_EXISTS = \u00D0\u00BF\u00D0\u00BE\u00D0\u00B4\u00D0\u00B5\u00D0\u00BB\u00D0\u00B8\u00D1\u0082\u00D1\u008C\u00D1\u0081\u00D1\u008F \u00D0\u00B4\u00D0\u00BE\u00D0\u00BB\u00D0\u00B5\u00D0\u00B9
+
+TIMESTAMP_TOO_NEW = \u00D0\u00BD\u00D0\u00BE\u00D0\u00B2\u00D0\u00B0\u00D1\u008F \u00D0\u00BC\u00D0\u00B5\u00D1\u0082\u00D0\u00BA\u00D0\u00B0 \u00D0\u00B2\u00D1\u0080\u00D0\u00B5\u00D0\u00BC\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8
+
+TIMESTAMP_TOO_OLD = \u00D1\u0081\u00D1\u0082\u00D0\u00B0\u00D1\u0080\u00D0\u00B0\u00D1\u008F \u00D0\u00BC\u00D0\u00B5\u00D1\u0082\u00D0\u00BA\u00D0\u00B0 \u00D0\u00B2\u00D1\u0080\u00D0\u00B5\u00D0\u00BC\u00D0\u00B5\u00D0\u00BD\u00D0\u00B8
+
+TRANSACTION_ALREADY_CONFIRMED = \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008F \u00D1\u0083\u00D0\u00B6\u00D0\u00B5 \u00D0\u00BF\u00D0\u00BE\u00D0\u00B4\u00D1\u0082\u00D0\u00B2\u00D0\u00B5\u00D1\u0080\u00D0\u00B6\u00D0\u00B4\u00D0\u00B5\u00D0\u00BD\u00D0\u00B0
+
+TRANSACTION_ALREADY_EXISTS = \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008F \u00D1\u0081\u00D1\u0083\u00D1\u0089\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00B2\u00D1\u0083\u00D0\u00B5\u00D1\u0082
+
+TRANSACTION_UNKNOWN = \u00D0\u00BD\u00D0\u00B5\u00D0\u00B8\u00D0\u00B7\u00D0\u00B2\u00D0\u00B5\u00D1\u0081\u00D1\u0082\u00D0\u00BD\u00D0\u00B0\u00D1\u008F \u00D1\u0082\u00D1\u0080\u00D0\u00B0\u00D0\u00BD\u00D0\u00B7\u00D0\u00B0\u00D0\u00BA\u00D1\u0086\u00D0\u00B8\u00D1\u008F

src/test/java/org/qortal/test/AccountBalanceTests.java

@@ -171,4 +171,84 @@ public class AccountBalanceTests extends Common {
 		Common.useDefaultSettings();
 	}
 
+	/** Test batch set/delete of account balances */
+	@Test
+	public void testBatchedBalanceChanges() throws DataException, SQLException {
+		Random random = new Random();
+		int ai;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			System.out.println("Creating random accounts...");
+
+			// Generate some random accounts
+			List<Account> accounts = new ArrayList<>();
+			for (ai = 0; ai < 2000; ++ai) {
+				byte[] publicKey = new byte[32];
+				random.nextBytes(publicKey);
+
+				PublicKeyAccount account = new PublicKeyAccount(repository, publicKey);
+				accounts.add(account);
+			}
+
+			List<AccountBalanceData> accountBalances = new ArrayList<>();
+
+			System.out.println("Setting random balances...");
+
+			// Fill with lots of random balances
+			for (ai = 0; ai < accounts.size(); ++ai) {
+				Account account = accounts.get(ai);
+				int assetId = random.nextInt(2);
+				// random zero, or non-zero, balance
+				long balance = random.nextBoolean() ? 0L : random.nextInt(100000);
+
+				accountBalances.add(new AccountBalanceData(account.getAddress(), assetId, balance));
+			}
+
+			repository.getAccountRepository().setAssetBalances(accountBalances);
+			repository.saveChanges();
+
+			System.out.println("Setting new random balances...");
+
+			// Now flip zero-ness for first half of balances
+			for (ai = 0; ai < accountBalances.size() / 2; ++ai) {
+				AccountBalanceData accountBalanceData = accountBalances.get(ai);
+
+				accountBalanceData.setBalance(accountBalanceData.getBalance() != 0 ? 0L : random.nextInt(100000));
+			}
+			// ...and randomize the rest
+			for (/*use ai from before*/; ai < accountBalances.size(); ++ai) {
+				AccountBalanceData accountBalanceData = accountBalances.get(ai);
+
+				accountBalanceData.setBalance(random.nextBoolean() ? 0L : random.nextInt(100000));
+			}
+
+			repository.getAccountRepository().setAssetBalances(accountBalances);
+			repository.saveChanges();
+
+			System.out.println("Modifying random balances...");
+
+			// Fill with lots of random balance changes
+			for (ai = 0; ai < accounts.size(); ++ai) {
+				Account account = accounts.get(ai);
+				int assetId = random.nextInt(2);
+				// random zero, or non-zero, balance
+				long balance = random.nextBoolean() ? 0L : random.nextInt(100000);
+
+				accountBalances.add(new AccountBalanceData(account.getAddress(), assetId, balance));
+			}
+
+			repository.getAccountRepository().modifyAssetBalances(accountBalances);
+			repository.saveChanges();
+
+			System.out.println("Deleting all balances...");
+
+			// Now simply delete all balances
+			for (ai = 0; ai < accountBalances.size(); ++ai)
+				accountBalances.get(ai).setBalance(0L);
+
+			repository.getAccountRepository().setAssetBalances(accountBalances);
+			repository.saveChanges();
+		}
+	}
+
 }

src/test/java/org/qortal/test/BlockTests.java

@@ -1,6 +1,10 @@
 package org.qortal.test;
 
+import java.util.Arrays;
+import java.util.Deque;
+import java.util.LinkedList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -133,4 +137,171 @@ public class BlockTests extends Common {
 		}
 	}
 
+	@Test
+	public void testLatestBlockCacheWithLatestBlock() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Deque<BlockData> latestBlockCache = buildLatestBlockCache(repository, 20);
+
+			BlockData latestBlock = repository.getBlockRepository().getLastBlock();
+			byte[] parentSignature = latestBlock.getSignature();
+
+			List<BlockData> childBlocks = findCachedChildBlocks(latestBlockCache, parentSignature);
+
+			assertEquals(true, childBlocks.isEmpty());
+		}
+	}
+
+	@Test
+	public void testLatestBlockCacheWithPenultimateBlock() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Deque<BlockData> latestBlockCache = buildLatestBlockCache(repository, 20);
+
+			BlockData latestBlock = repository.getBlockRepository().getLastBlock();
+			BlockData penultimateBlock = repository.getBlockRepository().fromHeight(latestBlock.getHeight() - 1);
+			byte[] parentSignature = penultimateBlock.getSignature();
+
+			List<BlockData> childBlocks = findCachedChildBlocks(latestBlockCache, parentSignature);
+
+			assertEquals(false, childBlocks.isEmpty());
+			assertEquals(1, childBlocks.size());
+
+			BlockData expectedBlock = latestBlock;
+			BlockData actualBlock = childBlocks.get(0);
+			assertArrayEquals(expectedBlock.getSignature(), actualBlock.getSignature());
+		}
+	}
+
+	@Test
+	public void testLatestBlockCacheWithMiddleBlock() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Deque<BlockData> latestBlockCache = buildLatestBlockCache(repository, 20);
+
+			int tipOffset = 5;
+
+			BlockData latestBlock = repository.getBlockRepository().getLastBlock();
+			BlockData parentBlock = repository.getBlockRepository().fromHeight(latestBlock.getHeight() - tipOffset);
+			byte[] parentSignature = parentBlock.getSignature();
+
+			List<BlockData> childBlocks = findCachedChildBlocks(latestBlockCache, parentSignature);
+
+			assertEquals(false, childBlocks.isEmpty());
+			assertEquals(tipOffset, childBlocks.size());
+
+			BlockData expectedFirstBlock = repository.getBlockRepository().fromHeight(parentBlock.getHeight() + 1);
+			BlockData actualFirstBlock = childBlocks.get(0);
+			assertArrayEquals(expectedFirstBlock.getSignature(), actualFirstBlock.getSignature());
+
+			BlockData expectedLastBlock = latestBlock;
+			BlockData actualLastBlock = childBlocks.get(childBlocks.size() - 1);
+			assertArrayEquals(expectedLastBlock.getSignature(), actualLastBlock.getSignature());
+		}
+	}
+
+	@Test
+	public void testLatestBlockCacheWithFirstBlock() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Deque<BlockData> latestBlockCache = buildLatestBlockCache(repository, 20);
+
+			int tipOffset = latestBlockCache.size();
+
+			BlockData latestBlock = repository.getBlockRepository().getLastBlock();
+			BlockData parentBlock = repository.getBlockRepository().fromHeight(latestBlock.getHeight() - tipOffset);
+			byte[] parentSignature = parentBlock.getSignature();
+
+			List<BlockData> childBlocks = findCachedChildBlocks(latestBlockCache, parentSignature);
+
+			assertEquals(false, childBlocks.isEmpty());
+			assertEquals(tipOffset, childBlocks.size());
+
+			BlockData expectedFirstBlock = repository.getBlockRepository().fromHeight(parentBlock.getHeight() + 1);
+			BlockData actualFirstBlock = childBlocks.get(0);
+			assertArrayEquals(expectedFirstBlock.getSignature(), actualFirstBlock.getSignature());
+
+			BlockData expectedLastBlock = latestBlock;
+			BlockData actualLastBlock = childBlocks.get(childBlocks.size() - 1);
+			assertArrayEquals(expectedLastBlock.getSignature(), actualLastBlock.getSignature());
+		}
+	}
+
+	@Test
+	public void testLatestBlockCacheWithNoncachedBlock() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Deque<BlockData> latestBlockCache = buildLatestBlockCache(repository, 20);
+
+			int tipOffset = latestBlockCache.size() + 1; // outside of cache
+
+			BlockData latestBlock = repository.getBlockRepository().getLastBlock();
+			BlockData parentBlock = repository.getBlockRepository().fromHeight(latestBlock.getHeight() - tipOffset);
+			byte[] parentSignature = parentBlock.getSignature();
+
+			List<BlockData> childBlocks = findCachedChildBlocks(latestBlockCache, parentSignature);
+
+			assertEquals(true, childBlocks.isEmpty());
+		}
+	}
+
+	private Deque<BlockData> buildLatestBlockCache(Repository repository, int count) throws DataException {
+		Deque<BlockData> latestBlockCache = new LinkedList<>();
+
+		// Mint some blocks
+		for (int h = 0; h < count; ++h)
+			latestBlockCache.addLast(BlockUtils.mintBlock(repository).getBlockData());
+
+		// Reduce cache down to latest 10 blocks
+		while (latestBlockCache.size() > 10)
+			latestBlockCache.removeFirst();
+
+		return latestBlockCache;
+	}
+
+	private List<BlockData> findCachedChildBlocks(Deque<BlockData> latestBlockCache, byte[] parentSignature) {
+		return latestBlockCache.stream()
+				.dropWhile(cachedBlockData -> !Arrays.equals(cachedBlockData.getReference(), parentSignature))
+				.collect(Collectors.toList());
+	}
+
+	@Test
+	public void testCommonBlockSearch() {
+		// Given a list of block summaries, trim all trailing summaries after common block
+
+		// We'll represent known block summaries as a list of booleans,
+		// where the boolean value indicates whether peer's block is also in our repository.
+
+		// Trivial case, single element array
+		assertCommonBlock(0, new boolean[] { true });
+
+		// Test odd and even array lengths
+		for (int arrayLength = 5; arrayLength <= 6; ++arrayLength) {
+			boolean[] testBlocks = new boolean[arrayLength];
+
+			// Test increasing amount of common blocks
+			for (int c = 1; c <= testBlocks.length; ++c) {
+				testBlocks[c - 1] = true;
+
+				assertCommonBlock(c - 1, testBlocks);
+			}
+		}
+	}
+
+	private void assertCommonBlock(int expectedIndex, boolean[] testBlocks) {
+		int commonBlockIndex = findCommonBlockIndex(testBlocks);
+		assertEquals(expectedIndex, commonBlockIndex);
+	}
+
+	private int findCommonBlockIndex(boolean[] testBlocks) {
+		int low = 1;
+		int high = testBlocks.length - 1;
+
+		while (low <= high) {
+			int mid = (low + high) >>> 1;
+
+			if (testBlocks[mid])
+				low = mid + 1;
+			else
+				high = mid - 1;
+		}
+
+		return low - 1;
+	}
+
 }

src/test/java/org/qortal/test/ChainWeightTests.java

@@ -103,8 +103,10 @@ public class ChainWeightTests extends Common {
 			populateBlockSummariesMinterLevels(repository, shorterChain);
 			populateBlockSummariesMinterLevels(repository, longerChain);
 
-			BigInteger shorterChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockGeneratorKey, shorterChain);
-			BigInteger longerChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockGeneratorKey, longerChain);
+			final int mutualHeight = commonBlockHeight - 1 + Math.min(shorterChain.size(), longerChain.size());
+
+			BigInteger shorterChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockGeneratorKey, shorterChain, mutualHeight);
+			BigInteger longerChainWeight = Block.calcChainWeight(commonBlockHeight, commonBlockGeneratorKey, longerChain, mutualHeight);
 
 			assertEquals("longer chain should have greater weight", 1, longerChainWeight.compareTo(shorterChainWeight));
 		}

src/test/java/org/qortal/test/RepositoryTests.java

@@ -4,6 +4,8 @@ import org.junit.Before;
 import org.junit.Test;
 import org.qortal.account.Account;
 import org.qortal.asset.Asset;
+import org.qortal.crosschain.BTCACCT;
+import org.qortal.crypto.Crypto;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
@@ -13,7 +15,11 @@ import org.qortal.test.common.Common;
 
 import static org.junit.Assert.*;
 
+import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -71,7 +77,7 @@ public class RepositoryTests extends Common {
 	}
 
 	@Test
-	public void testDeadlock() throws DataException {
+	public void testDeadlock() {
 		// Open connection 1
 		try (final Repository repository1 = RepositoryManager.getRepository()) {
 
@@ -92,18 +98,50 @@ public class RepositoryTests extends Common {
 			// Update account in 1
 			account1.setConfirmedBalance(Asset.QORT, 5678L);
 			repository1.saveChanges();
+		} catch (DataException e) {
+			fail("deadlock bug");
+		}
+	}
+
+	@Test
+	public void testUpdateReadDeadlock() {
+		// Open connection 1
+		try (final Repository repository1 = RepositoryManager.getRepository()) {
+			// Mint blocks so we have data (online account signatures) to work with
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository1);
+
+			// Perform database 'update', but don't commit at this stage
+			repository1.getBlockRepository().trimOldOnlineAccountsSignatures(1, 10);
+
+			// Open connection 2
+			try (final Repository repository2 = RepositoryManager.getRepository()) {
+				// Perform database read on same blocks - this should not deadlock
+				repository2.getBlockRepository().getTimestampFromHeight(5);
+			}
+
+			// Save updates - this should not deadlock
+			repository1.saveChanges();
+		} catch (DataException e) {
+			fail("deadlock bug");
 		}
 	}
 
 	/** Check that the <i>sub-query</i> used to fetch highest block height is optimized by HSQLDB. */
 	@Test
 	public void testBlockHeightSpeed() throws DataException, SQLException {
+		final int mintBlockCount = 30000;
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			// Mint some blocks
-			System.out.println("Minting test blocks - should take approx. 30 seconds...");
-			for (int i = 0; i < 30000; ++i)
+			System.out.println(String.format("Minting %d test blocks - should take approx. 30 seconds...", mintBlockCount));
+
+			long beforeBigMint = System.currentTimeMillis();
+			for (int i = 0; i < mintBlockCount; ++i)
 				BlockUtils.mintBlock(repository);
 
+			System.out.println(String.format("Minting %d blocks actually took %d seconds", mintBlockCount, (System.currentTimeMillis() - beforeBigMint) / 1000L));
+
 			final HSQLDBRepository hsqldb = (HSQLDBRepository) repository;
 
 			// Too slow:
@@ -158,6 +196,119 @@ public class RepositoryTests extends Common {
 		}
 	}
 
+	/**
+	 * Test HSQLDB bug-fix for INSERT INTO...ON DUPLICATE KEY UPDATE... bug
+	 * <p>
+	 * @see <A HREF="https://sourceforge.net/p/hsqldb/discussion/73674/thread/d8d35adb5d/">Behaviour of 'ON DUPLICATE KEY UPDATE'</A> SourceForge discussion
+	 */
+	@Test
+	public void testOnDuplicateKeyUpdateBugFix() throws SQLException, DataException {
+		ResultSet resultSet;
+
+		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
+			hsqldb.prepareStatement("DROP TABLE IF EXISTS bugtest").execute();
+			hsqldb.prepareStatement("CREATE TABLE bugtest (id INT NOT NULL, counter INT NOT NULL, PRIMARY KEY(id))").execute();
+
+			// No existing row, so new row's "counter" is set to value from VALUES clause, i.e. 1
+			hsqldb.prepareStatement("INSERT INTO bugtest (id, counter) VALUES (1, 1) ON DUPLICATE KEY UPDATE counter = counter + 1").execute();
+			resultSet = hsqldb.checkedExecute("SELECT counter FROM bugtest WHERE id = 1");
+			assertNotNull(resultSet);
+			assertEquals(1, resultSet.getInt(1));
+
+			// Prior to bug-fix, "counter = counter + 1" would always use the 100 from VALUES, instead of existing row's value, for "counter"
+			hsqldb.prepareStatement("INSERT INTO bugtest (id, counter) VALUES (1, 100) ON DUPLICATE KEY UPDATE counter = counter + 1").execute();
+			resultSet = hsqldb.checkedExecute("SELECT counter FROM bugtest WHERE id = 1");
+			assertNotNull(resultSet);
+			// Prior to bug-fix, this would be 100 + 1 = 101
+			assertEquals(2, resultSet.getInt(1));
+		}
+	}
+
+	/**
+	 * Test HSQLDB bug-fix for "General Error" in non-fully-qualified columns inside LATERAL()
+	 * <p>
+	 * @see <A HREF="https://sourceforge.net/p/hsqldb/bugs/1580/">#1580 General error with LATERAL and transitive join column</A> SourceForge ticket
+	 */
+	@Test
+	public void testOnLateralGeneralError() {
+		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
+			hsqldb.prepareStatement("DROP TABLE IF EXISTS tableA").execute();
+			hsqldb.prepareStatement("DROP TABLE IF EXISTS tableB").execute();
+			hsqldb.prepareStatement("DROP TABLE IF EXISTS tableC").execute();
+
+			hsqldb.prepareStatement("CREATE TABLE tableA (col1 INT)").execute();
+			hsqldb.prepareStatement("CREATE TABLE tableB (col1 INT)").execute();
+			hsqldb.prepareStatement("CREATE TABLE tableC (col2 INT, PRIMARY KEY (col2))").execute();
+
+			// Prior to bug-fix #1580 this would throw a General Error SQL Exception
+			hsqldb.prepareStatement("SELECT col3 FROM tableA JOIN tableB USING (col1) CROSS JOIN LATERAL(SELECT col2 FROM tableC WHERE col2 = col1) AS tableC (col3)").execute();
+		} catch (SQLException | DataException e) {
+			fail("HSQLDB bug #1580");
+		}
+	}
+
+	/** Specifically test LATERAL() usage in Asset repository */
+	@Test
+	public void testAssetLateral() {
+		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
+			List<Long> assetIds = Collections.emptyList();
+			List<Long> otherAssetIds = Collections.emptyList();
+			Integer limit = null;
+			Integer offset = null;
+			Boolean reverse = null;
+
+			hsqldb.getAssetRepository().getRecentTrades(assetIds, otherAssetIds, limit, offset, reverse);
+		} catch (DataException e) {
+			fail("HSQLDB bug #1580");
+		}
+	}
+
+	/** Specifically test LATERAL() usage in AT repository */
+	@Test
+	public void testAtLateral() {
+		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
+			byte[] codeHash = BTCACCT.CODE_BYTES_HASH;
+			Boolean isFinished = null;
+			Integer dataByteOffset = null;
+			Long expectedValue = null;
+			Integer minimumFinalHeight = 2;
+			Integer limit = null;
+			Integer offset = null;
+			Boolean reverse = null;
+
+			hsqldb.getATRepository().getMatchingFinalATStates(codeHash, isFinished, dataByteOffset, expectedValue, minimumFinalHeight, limit, offset, reverse);
+		} catch (DataException e) {
+			fail("HSQLDB bug #1580");
+		}
+	}
+
+	/** Specifically test LATERAL() usage in Chat repository */
+	@Test
+	public void testChatLateral() {
+		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
+			String address = Crypto.toAddress(new byte[32]);
+
+			hsqldb.getChatRepository().getActiveChats(address);
+		} catch (DataException e) {
+			fail("HSQLDB bug #1580");
+		}
+	}
+
+	/** Test batched DELETE */
+	@Test
+	public void testBatchedDelete() {
+		// Generate test data
+		List<Object[]> batchedObjects = new ArrayList<>();
+		for (int i = 0; i < 100; ++i)
+			batchedObjects.add(new Object[] { String.valueOf(i), 1L });
+
+		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
+			hsqldb.deleteBatch("AccountBalances", "account = ? AND asset_id = ?", batchedObjects);
+		} catch (DataException | SQLException e) {
+			fail("Batched delete failed: " + e.getMessage());
+		}
+	}
+
 	public static void hsqldbSleep(int millis) throws SQLException {
 		System.out.println(String.format("HSQLDB sleep() thread ID: %s", Thread.currentThread().getId()));
 

src/test/java/org/qortal/test/TransactionSearchTests.java

@@ -0,0 +1,76 @@
+package org.qortal.test;
+
+import static org.junit.Assert.*;
+
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.AccountUtils;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.transaction.Transaction.TransactionType;
+
+public class TransactionSearchTests extends Common {
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testFindingSpecificTransactionsWithinHeight() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount alice = Common.getTestAccount(repository, "alice");
+			PrivateKeyAccount chloe = Common.getTestAccount(repository, "chloe");
+
+			// Block 2
+			BlockUtils.mintBlock(repository);
+
+			// Block 3
+			AccountUtils.pay(repository, alice, chloe.getAddress(), 1234L);
+
+			// Block 4
+			AccountUtils.pay(repository, chloe, alice.getAddress(), 5678L);
+
+			// Block 5
+			BlockUtils.mintBlock(repository);
+
+			List<byte[]> signatures;
+
+			// No transactions with this type
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(TransactionType.GROUP_KICK, null, null, null);
+			assertEquals(0, signatures.size());
+
+			// 2 payments
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(TransactionType.PAYMENT, null, null, null);
+			assertEquals(2, signatures.size());
+
+			// 1 payment by Alice
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(TransactionType.PAYMENT, alice.getPublicKey(), null, null);
+			assertEquals(1, signatures.size());
+
+			// 1 transaction by Chloe
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(null, chloe.getPublicKey(), null, null);
+			assertEquals(1, signatures.size());
+
+			// 1 transaction from blocks 4 onwards
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(null, null, 4, null);
+			assertEquals(1, signatures.size());
+
+			// 1 transaction from blocks 2 to 3
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(null, null, 2, 3);
+			assertEquals(1, signatures.size());
+
+			// No transaction of this type from blocks 2 to 5
+			signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(TransactionType.ISSUE_ASSET, null, 2, 5);
+			assertEquals(0, signatures.size());
+		}
+
+	}
+
+}

src/test/java/org/qortal/test/TransferPrivsTests.java

@@ -7,7 +7,7 @@ import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
 import org.qortal.account.PublicKeyAccount;
 import org.qortal.block.BlockChain;
-import org.qortal.block.BlockMinter;
+import org.qortal.controller.BlockMinter;
 import org.qortal.data.account.AccountData;
 import org.qortal.data.transaction.BaseTransactionData;
 import org.qortal.data.transaction.PaymentTransactionData;

src/test/java/org/qortal/test/api/BlockApiTests.java

@@ -9,6 +9,7 @@ import java.util.List;
 import org.junit.Before;
 import org.junit.Test;
 import org.qortal.account.PrivateKeyAccount;
+import org.qortal.api.ApiError;
 import org.qortal.api.resource.BlocksResource;
 import org.qortal.block.GenesisBlock;
 import org.qortal.repository.DataException;
@@ -82,6 +83,19 @@ public class BlockApiTests extends ApiCommon {
 	@Test
 	public void testGetBlockRange() {
 		assertNotNull(this.blocksResource.getBlockRange(1, 1));
+
+		List<Integer> testValues = Arrays.asList(null, Integer.valueOf(1));
+
+		for (Integer startHeight : testValues)
+			for (Integer endHeight : testValues)
+				for (Integer count : testValues) {
+					if (startHeight != null && endHeight != null && count != null) {
+						assertApiError(ApiError.INVALID_CRITERIA, () -> this.blocksResource.getBlockRange(startHeight, endHeight, count));
+						continue;
+					}
+
+					assertNotNull(this.blocksResource.getBlockRange(startHeight, endHeight, count));
+				}
 	}
 
 	@Test

src/test/java/org/qortal/test/at/AtRepositoryTests.java

@@ -0,0 +1,426 @@
+package org.qortal.test.at;
+
+import static org.junit.Assert.*;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+import org.ciyam.at.CompilationException;
+import org.ciyam.at.MachineState;
+import org.ciyam.at.OpCode;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.transaction.DeployAtTransaction;
+
+public class AtRepositoryTests extends Common {
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testGetATStateAtHeightWithData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+
+			Integer testHeight = 8;
+			ATStateData atStateData = repository.getATRepository().getATStateAtHeight(atAddress, testHeight);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetATStateAtHeightWithoutData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+
+			int maxHeight = 8;
+			Integer testHeight = maxHeight - 2;
+
+			// Trim AT state data
+			repository.getATRepository().prepareForAtStateTrimming();
+			repository.getATRepository().trimAtStates(2, maxHeight, 1000);
+
+			ATStateData atStateData = repository.getATRepository().getATStateAtHeight(atAddress, testHeight);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetLatestATStateWithData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+			int blockchainHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			Integer testHeight = blockchainHeight;
+			ATStateData atStateData = repository.getATRepository().getLatestATState(atAddress);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetLatestATStatePostTrimming() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+			int blockchainHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			int maxHeight = blockchainHeight + 100; // more than latest block height
+			Integer testHeight = blockchainHeight;
+
+			// Trim AT state data
+			repository.getATRepository().prepareForAtStateTrimming();
+			repository.getATRepository().trimAtStates(2, maxHeight, 1000);
+
+			ATStateData atStateData = repository.getATRepository().getLatestATState(atAddress);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			// We should always have the latest AT state data available
+			assertNotNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetMatchingFinalATStatesWithoutDataValue() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+			int blockchainHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			Integer testHeight = blockchainHeight;
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+
+			byte[] codeHash = atData.getCodeHash();
+			Boolean isFinished = Boolean.FALSE;
+			Integer dataByteOffset = null;
+			Long expectedValue = null;
+			Integer minimumFinalHeight = null;
+			Integer limit = null;
+			Integer offset = null;
+			Boolean reverse = null;
+
+			List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(
+					codeHash,
+					isFinished,
+					dataByteOffset,
+					expectedValue,
+					minimumFinalHeight,
+					limit, offset, reverse);
+
+			assertEquals(false, atStates.isEmpty());
+			assertEquals(1, atStates.size());
+
+			ATStateData atStateData = atStates.get(0);
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetMatchingFinalATStatesWithDataValue() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+			int blockchainHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			Integer testHeight = blockchainHeight;
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+
+			byte[] codeHash = atData.getCodeHash();
+			Boolean isFinished = Boolean.FALSE;
+			Integer dataByteOffset = MachineState.HEADER_LENGTH + 0;
+			Long expectedValue = 0L;
+			Integer minimumFinalHeight = null;
+			Integer limit = null;
+			Integer offset = null;
+			Boolean reverse = null;
+
+			List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(
+					codeHash,
+					isFinished,
+					dataByteOffset,
+					expectedValue,
+					minimumFinalHeight,
+					limit, offset, reverse);
+
+			assertEquals(false, atStates.isEmpty());
+			assertEquals(1, atStates.size());
+
+			ATStateData atStateData = atStates.get(0);
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetBlockATStatesAtHeightWithData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			doDeploy(repository, deployer, creationBytes, fundingAmount);
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+
+			Integer testHeight = 8;
+			List<ATStateData> atStates = repository.getATRepository().getBlockATStatesAtHeight(testHeight);
+
+			assertEquals(false, atStates.isEmpty());
+			assertEquals(1, atStates.size());
+
+			ATStateData atStateData = atStates.get(0);
+			assertEquals(testHeight, atStateData.getHeight());
+			// getBlockATStatesAtHeight never returns actual AT state data anyway
+			assertNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testGetBlockATStatesAtHeightWithoutData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			doDeploy(repository, deployer, creationBytes, fundingAmount);
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+
+			int maxHeight = 8;
+			Integer testHeight = maxHeight - 2;
+
+			// Trim AT state data
+			repository.getATRepository().prepareForAtStateTrimming();
+			repository.getATRepository().trimAtStates(2, maxHeight, 1000);
+
+			List<ATStateData> atStates = repository.getATRepository().getBlockATStatesAtHeight(testHeight);
+
+			assertEquals(false, atStates.isEmpty());
+			assertEquals(1, atStates.size());
+
+			ATStateData atStateData = atStates.get(0);
+			assertEquals(testHeight, atStateData.getHeight());
+			// getBlockATStatesAtHeight never returns actual AT state data anyway
+			assertNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testSaveATStateWithData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+			int blockchainHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			Integer testHeight = blockchainHeight - 2;
+			ATStateData atStateData = repository.getATRepository().getATStateAtHeight(atAddress, testHeight);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+
+			repository.getATRepository().save(atStateData);
+
+			atStateData = repository.getATRepository().getATStateAtHeight(atAddress, testHeight);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+		}
+	}
+
+	@Test
+	public void testSaveATStateWithoutData() throws DataException {
+		byte[] creationBytes = buildSimpleAT();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "alice");
+
+			long fundingAmount = 1_00000000L;
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, creationBytes, fundingAmount);
+			String atAddress = deployAtTransaction.getATAccount().getAddress();
+
+			// Mint a few blocks
+			for (int i = 0; i < 10; ++i)
+				BlockUtils.mintBlock(repository);
+			int blockchainHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			Integer testHeight = blockchainHeight - 2;
+			ATStateData atStateData = repository.getATRepository().getATStateAtHeight(atAddress, testHeight);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNotNull(atStateData.getStateData());
+
+			// Clear data
+			ATStateData newAtStateData = new ATStateData(atStateData.getATAddress(),
+					atStateData.getHeight(),
+					/*StateData*/ null,
+					atStateData.getStateHash(),
+					atStateData.getFees(),
+					atStateData.isInitial());
+			repository.getATRepository().save(newAtStateData);
+
+			atStateData = repository.getATRepository().getATStateAtHeight(atAddress, testHeight);
+
+			assertEquals(testHeight, atStateData.getHeight());
+			assertNull(atStateData.getStateData());
+		}
+	}
+
+	private byte[] buildSimpleAT() {
+		// Pretend we use 4 values in data segment
+		int addrCounter = 4;
+
+		// Data segment
+		ByteBuffer dataByteBuffer = ByteBuffer.allocate(addrCounter * MachineState.VALUE_SIZE);
+
+		ByteBuffer codeByteBuffer = ByteBuffer.allocate(512);
+
+		// Two-pass version
+		for (int pass = 0; pass < 2; ++pass) {
+			codeByteBuffer.clear();
+
+			try {
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+			} catch (CompilationException e) {
+				throw new IllegalStateException("Unable to compile AT?", e);
+			}
+		}
+
+		codeByteBuffer.flip();
+
+		byte[] codeBytes = new byte[codeByteBuffer.limit()];
+		codeByteBuffer.get(codeBytes);
+
+		final short ciyamAtVersion = 2;
+		final short numCallStackPages = 0;
+		final short numUserStackPages = 0;
+		final long minActivationAmount = 0L;
+
+		return MachineState.toCreationBytes(ciyamAtVersion, codeBytes, dataByteBuffer.array(), numCallStackPages, numUserStackPages, minActivationAmount);
+	}
+
+	private DeployAtTransaction doDeploy(Repository repository, PrivateKeyAccount deployer, byte[] creationBytes, long fundingAmount) throws DataException {
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = deployer.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", deployer.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		String name = "Test AT";
+		String description = "Test AT";
+		String atType = "Test";
+		String tags = "TEST";
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, deployer.getPublicKey(), fee, null);
+		TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, fundingAmount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, deployAtTransactionData, deployer);
+
+		return deployAtTransaction;
+	}
+
+}

src/test/java/org/qortal/test/btcacct/BtcTests.java

@@ -12,6 +12,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.qortal.crosschain.BTC;
 import org.qortal.crosschain.BTCP2SH;
+import org.qortal.crosschain.BitcoinException;
 import org.qortal.repository.DataException;
 import org.qortal.test.common.Common;
 
@@ -28,7 +29,7 @@ public class BtcTests extends Common {
 	}
 
 	@Test
-	public void testGetMedianBlockTime() throws BlockStoreException {
+	public void testGetMedianBlockTime() throws BlockStoreException, BitcoinException {
 		System.out.println(String.format("Starting BTC instance..."));
 		BTC btc = BTC.getInstance();
 		System.out.println(String.format("BTC instance started"));
@@ -50,7 +51,7 @@ public class BtcTests extends Common {
 	}
 
 	@Test
-	public void testFindP2shSecret() {
+	public void testFindP2shSecret() throws BitcoinException {
 		// This actually exists on TEST3 but can take a while to fetch
 		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
 
@@ -104,4 +105,17 @@ public class BtcTests extends Common {
 		assertEquals(balance, repeatBalance);
 	}
 
+	@Test
+	public void testGetUnusedReceiveAddress() throws BitcoinException {
+		BTC btc = BTC.getInstance();
+
+		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
+
+		String address = btc.getUnusedReceiveAddress(xprv58);
+
+		assertNotNull(address);
+
+		System.out.println(address);
+	}
+
 }

src/test/java/org/qortal/test/btcacct/CheckP2SH.java

@@ -16,6 +16,7 @@ import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.qortal.controller.Controller;
 import org.qortal.crosschain.BTC;
 import org.qortal.crosschain.BTCP2SH;
+import org.qortal.crosschain.BitcoinException;
 import org.qortal.crypto.Crypto;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
@@ -135,11 +136,7 @@ public class CheckP2SH {
 				System.out.println(String.format("Too soon (%s) to redeem based on median block time %s", LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC), LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
 
 			// Check P2SH is funded
-			Long p2shBalance = BTC.getInstance().getBalance(p2shAddress.toString());
-			if (p2shBalance == null) {
-				System.err.println(String.format("Unable to check P2SH address %s balance", p2shAddress));
-				System.exit(2);
-			}
+			long p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
 			System.out.println(String.format("P2SH address %s balance: %s", p2shAddress, BTC.format(p2shBalance)));
 
 			// Grab all P2SH funding transactions (just in case there are more than one)
@@ -164,7 +161,9 @@ public class CheckP2SH {
 				System.exit(2);
 			}
 		} catch (DataException e) {
-			throw new RuntimeException("Repository issue: " + e.getMessage());
+			System.err.println("Repository issue: " + e.getMessage());
+		} catch (BitcoinException e) {
+			System.err.println("Bitcoin issue: " + e.getMessage());
 		}
 	}
 

src/test/java/org/qortal/test/btcacct/ElectrumXTests.java

@@ -11,8 +11,11 @@ import org.bitcoinj.script.ScriptBuilder;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
 import org.junit.Test;
+import org.qortal.crosschain.BitcoinException;
+import org.qortal.crosschain.BitcoinTransaction;
 import org.qortal.crosschain.ElectrumX;
-import org.qortal.crosschain.ElectrumX.UnspentOutput;
+import org.qortal.crosschain.TransactionHash;
+import org.qortal.crosschain.UnspentOutput;
 import org.qortal.utils.BitTwiddling;
 
 import com.google.common.hash.HashCode;
@@ -34,26 +37,36 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetCurrentHeight() {
+	public void testGetCurrentHeight() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
-		Integer height = electrumX.getCurrentHeight();
+		int height = electrumX.getCurrentHeight();
 
-		assertNotNull(height);
 		assertTrue(height > 10000);
 		System.out.println("Current TEST3 height: " + height);
 	}
 
 	@Test
-	public void testGetRecentBlocks() {
+	public void testInvalidRequest() {
+		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+		try {
+			electrumX.getBlockHeaders(-1, -1);
+		} catch (BitcoinException e) {
+			// Should throw due to negative start block height
+			return;
+		}
+
+		fail("Negative start block height should cause error");
+	}
+
+	@Test
+	public void testGetRecentBlocks() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
-		Integer height = electrumX.getCurrentHeight();
-		assertNotNull(height);
+		int height = electrumX.getCurrentHeight();
 		assertTrue(height > 10000);
 
 		List<byte[]> recentBlockHeaders = electrumX.getBlockHeaders(height - 11, 11);
-		assertNotNull(recentBlockHeaders);
 
 		System.out.println(String.format("Returned %d recent blocks", recentBlockHeaders.size()));
 		for (int i = 0; i < recentBlockHeaders.size(); ++i) {
@@ -67,42 +80,39 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetP2PKHBalance() {
+	public void testGetP2PKHBalance() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
 		Address address = Address.fromString(TestNet3Params.get(), "n3GNqMveyvaPvUbH469vDRadqpJMPc84JA");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
-		Long balance = electrumX.getBalance(script);
+		long balance = electrumX.getConfirmedBalance(script);
 
-		assertNotNull(balance);
 		assertTrue(balance > 0L);
 
 		System.out.println(String.format("TestNet address %s has balance: %d sats / %d.%08d BTC", address, balance, (balance / 100000000L), (balance % 100000000L)));
 	}
 
 	@Test
-	public void testGetP2SHBalance() {
+	public void testGetP2SHBalance() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
 		Address address = Address.fromString(TestNet3Params.get(), "2N4szZUfigj7fSBCEX4PaC8TVbC5EvidaVF");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
-		Long balance = electrumX.getBalance(script);
+		long balance = electrumX.getConfirmedBalance(script);
 
-		assertNotNull(balance);
 		assertTrue(balance > 0L);
 
 		System.out.println(String.format("TestNet address %s has balance: %d sats / %d.%08d BTC", address, balance, (balance / 100000000L), (balance % 100000000L)));
 	}
 
 	@Test
-	public void testGetUnspentOutputs() {
+	public void testGetUnspentOutputs() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
 		Address address = Address.fromString(TestNet3Params.get(), "2N4szZUfigj7fSBCEX4PaC8TVbC5EvidaVF");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
-		List<UnspentOutput> unspentOutputs = electrumX.getUnspentOutputs(script);
+		List<UnspentOutput> unspentOutputs = electrumX.getUnspentOutputs(script, false);
 
-		assertNotNull(unspentOutputs);
 		assertFalse(unspentOutputs.isEmpty());
 
 		for (UnspentOutput unspentOutput : unspentOutputs)
@@ -110,27 +120,68 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetRawTransaction() {
+	public void testGetRawTransaction() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
 		byte[] txHash = HashCode.fromString("7653fea9ffcd829d45ed2672938419a94951b08175982021e77d619b553f29af").asBytes();
 
 		byte[] rawTransactionBytes = electrumX.getRawTransaction(txHash);
 
-		assertNotNull(rawTransactionBytes);
+		assertFalse(rawTransactionBytes.length == 0);
 	}
 
 	@Test
-	public void testGetAddressTransactions() {
+	public void testGetUnknownRawTransaction() {
+		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+
+		byte[] txHash = HashCode.fromString("f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0").asBytes();
+
+		try {
+			electrumX.getRawTransaction(txHash);
+			fail("Bitcoin transaction should be unknown and hence throw exception");
+		} catch (BitcoinException e) {
+			if (!(e instanceof BitcoinException.NotFoundException))
+				fail("Bitcoin transaction should be unknown and hence throw NotFoundException");
+		}
+	}
+
+	@Test
+	public void testGetTransaction() throws BitcoinException {
+		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+
+		String txHash = "7653fea9ffcd829d45ed2672938419a94951b08175982021e77d619b553f29af";
+
+		BitcoinTransaction transaction = electrumX.getTransaction(txHash);
+
+		assertNotNull(transaction);
+		assertTrue(transaction.txHash.equals(txHash));
+	}
+
+	@Test
+	public void testGetUnknownTransaction() {
+		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+
+		String txHash = "f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0";
+
+		try {
+			electrumX.getTransaction(txHash);
+			fail("Bitcoin transaction should be unknown and hence throw exception");
+		} catch (BitcoinException e) {
+			if (!(e instanceof BitcoinException.NotFoundException))
+				fail("Bitcoin transaction should be unknown and hence throw NotFoundException");
+		}
+	}
+
+	@Test
+	public void testGetAddressTransactions() throws BitcoinException {
 		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
 
 		Address address = Address.fromString(TestNet3Params.get(), "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
 
-		List<byte[]> rawTransactions = electrumX.getAddressTransactions(script);
+		List<TransactionHash> transactionHashes = electrumX.getAddressTransactions(script, false);
 
-		assertNotNull(rawTransactions);
-		assertFalse(rawTransactions.isEmpty());
+		assertFalse(transactionHashes.isEmpty());
 	}
 
 }

src/test/java/org/qortal/test/btcacct/GetTransaction.java

@@ -7,6 +7,7 @@ import org.bitcoinj.core.AddressFormatException;
 import org.bitcoinj.core.TransactionOutput;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.qortal.crosschain.BTC;
+import org.qortal.crosschain.BitcoinException;
 import org.qortal.settings.Settings;
 
 import com.google.common.hash.HashCode;
@@ -46,9 +47,11 @@ public class GetTransaction {
 		}
 
 		// Grab all outputs from transaction
-		List<TransactionOutput> fundingOutputs = BTC.getInstance().getOutputs(transactionId);
-		if (fundingOutputs == null) {
-			System.out.println(String.format("Transaction not found"));
+		List<TransactionOutput> fundingOutputs;
+		try {
+			fundingOutputs = BTC.getInstance().getOutputs(transactionId);
+		} catch (BitcoinException e) {
+			System.out.println(String.format("Transaction not found (or error occurred)"));
 			return;
 		}
 

src/test/java/org/qortal/test/btcacct/P2shTests.java

@@ -0,0 +1,53 @@
+package org.qortal.test.btcacct;
+
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.crosschain.BTC;
+import org.qortal.crosschain.BTCP2SH;
+import org.qortal.crosschain.BitcoinException;
+import org.qortal.repository.DataException;
+import org.qortal.test.common.Common;
+
+public class P2shTests extends Common {
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings(); // TestNet3
+	}
+
+	@After
+	public void afterTest() {
+		BTC.resetForTesting();
+	}
+
+	@Test
+	public void testFindP2shSecret() throws BitcoinException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		List<byte[]> rawTransactions = BTC.getInstance().getAddressTransactions(p2shAddress);
+
+		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
+		byte[] secret = BTCP2SH.findP2shSecret(p2shAddress, rawTransactions);
+
+		assertNotNull(secret);
+		assertTrue("secret incorrect", Arrays.equals(expectedSecret, secret));
+	}
+
+	@Test
+	public void testDetermineP2shStatus() throws BitcoinException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		BTCP2SH.Status p2shStatus = BTCP2SH.determineP2shStatus(p2shAddress, 1L);
+
+		System.out.println(String.format("P2SH %s status: %s", p2shAddress, p2shStatus.name()));
+	}
+
+}

src/test/java/org/qortal/test/btcacct/Redeem.java

@@ -19,6 +19,7 @@ import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.qortal.controller.Controller;
 import org.qortal.crosschain.BTC;
 import org.qortal.crosschain.BTCP2SH;
+import org.qortal.crosschain.BitcoinException;
 import org.qortal.crypto.Crypto;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
@@ -136,7 +137,14 @@ public class Redeem {
 
 			System.out.println("\nProcessing:");
 
-			long medianBlockTime = BTC.getInstance().getMedianBlockTime();
+			long medianBlockTime;
+			try {
+				medianBlockTime = BTC.getInstance().getMedianBlockTime();
+			} catch (BitcoinException e1) {
+				System.err.println("Unable to determine median block time");
+				System.exit(2);
+				return;
+			}
 			System.out.println(String.format("Median block time: %s", LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
 
 			long now = System.currentTimeMillis();
@@ -147,18 +155,24 @@ public class Redeem {
 			}
 
 			// Check P2SH is funded
-			Long p2shBalance = BTC.getInstance().getBalance(p2shAddress.toString());
-			if (p2shBalance == null) {
+			long p2shBalance;
+			try {
+				p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
+			} catch (BitcoinException e) {
 				System.err.println(String.format("Unable to check P2SH address %s balance", p2shAddress));
 				System.exit(2);
+				return;
 			}
 			System.out.println(String.format("P2SH address %s balance: %s", p2shAddress, BTC.format(p2shBalance)));
 
 			// Grab all P2SH funding transactions (just in case there are more than one)
-			List<TransactionOutput> fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
-			if (fundingOutputs == null) {
+			List<TransactionOutput> fundingOutputs;
+			try {
+				fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
+			} catch (BitcoinException e) {
 				System.err.println(String.format("Can't find outputs for P2SH"));
 				System.exit(2);
+				return;
 			}
 
 			System.out.println(String.format("Found %d output%s for P2SH", fundingOutputs.size(), (fundingOutputs.size() != 1 ? "s" : "")));

src/test/java/org/qortal/test/btcacct/Refund.java

@@ -19,6 +19,7 @@ import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.qortal.controller.Controller;
 import org.qortal.crosschain.BTC;
 import org.qortal.crosschain.BTCP2SH;
+import org.qortal.crosschain.BitcoinException;
 import org.qortal.crypto.Crypto;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
@@ -135,7 +136,14 @@ public class Refund {
 
 			System.out.println("\nProcessing:");
 
-			long medianBlockTime = BTC.getInstance().getMedianBlockTime();
+			long medianBlockTime;
+			try {
+				medianBlockTime = BTC.getInstance().getMedianBlockTime();
+			} catch (BitcoinException e) {
+				System.err.println("Unable to determine median block time");
+				System.exit(2);
+				return;
+			}
 			System.out.println(String.format("Median block time: %s", LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
 
 			long now = System.currentTimeMillis();
@@ -151,18 +159,24 @@ public class Refund {
 			}
 
 			// Check P2SH is funded
-			Long p2shBalance = BTC.getInstance().getBalance(p2shAddress.toString());
-			if (p2shBalance == null) {
+			long p2shBalance;
+			try {
+				p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
+			} catch (BitcoinException e) {
 				System.err.println(String.format("Unable to check P2SH address %s balance", p2shAddress));
 				System.exit(2);
+				return;
 			}
 			System.out.println(String.format("P2SH address %s balance: %s", p2shAddress, BTC.format(p2shBalance)));
 
 			// Grab all P2SH funding transactions (just in case there are more than one)
-			List<TransactionOutput> fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
-			if (fundingOutputs == null) {
+			List<TransactionOutput> fundingOutputs;
+			try {
+				fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
+			} catch (BitcoinException e) {
 				System.err.println(String.format("Can't find outputs for P2SH"));
 				System.exit(2);
+				return;
 			}
 
 			System.out.println(String.format("Found %d output%s for P2SH", fundingOutputs.size(), (fundingOutputs.size() != 1 ? "s" : "")));
@@ -186,7 +200,7 @@ public class Refund {
 			Coin refundAmount = Coin.valueOf(p2shBalance).subtract(bitcoinFee);
 			System.out.println(String.format("Spending %s of output, with %s as mining fee", BTC.format(refundAmount), BTC.format(bitcoinFee)));
 
-			Transaction redeemTransaction = BTCP2SH.buildRefundTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime);
+			Transaction redeemTransaction = BTCP2SH.buildRefundTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundKey.getPubKeyHash());
 
 			byte[] redeemBytes = redeemTransaction.bitcoinSerialize();