From 282b58c5ea8f7df19e0d95660775baaffc95b18e Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Sun, 12 Aug 2012 02:44:08 +0200
Subject: [PATCH] Add a BlockImporter tool to examples.

---
 .../bitcoin/examples/BlockImporter.java       | 76 +++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100644 examples/src/main/java/com/google/bitcoin/examples/BlockImporter.java

diff --git a/examples/src/main/java/com/google/bitcoin/examples/BlockImporter.java b/examples/src/main/java/com/google/bitcoin/examples/BlockImporter.java
new file mode 100644
index 00000000..f7b8c220
--- /dev/null
+++ b/examples/src/main/java/com/google/bitcoin/examples/BlockImporter.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2012 Matt Corallo.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.bitcoin.examples;
+
+import com.google.bitcoin.core.Block;
+import com.google.bitcoin.core.FullPrunedBlockChain;
+import com.google.bitcoin.core.NetworkParameters;
+import com.google.bitcoin.core.Utils;
+import com.google.bitcoin.store.FullPrunedBlockStore;
+import com.google.bitcoin.store.H2FullPrunedBlockStore;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+/**
+ * This class reads block files stored in the reference/Satoshi clients format. This is simply a way to concatenate
+ * blocks together. Importing block data with this tool can be a lot faster than syncing over the network, if you
+ * have the files available.
+ */
+public class BlockImporter {
+    public static void main(String[] args) throws Exception {
+        NetworkParameters params = NetworkParameters.prodNet();
+        FullPrunedBlockStore store = new H2FullPrunedBlockStore(params, "toy-full.blockchain", 100);
+        FullPrunedBlockChain chain = new FullPrunedBlockChain(params, store);
+        
+        String defaultDataDir;
+        if (System.getProperty("os.name").toLowerCase().indexOf("win") >= 0) {
+            defaultDataDir = System.getenv("APPDATA") + "\\.bitcoin/";
+        } else {
+            defaultDataDir = System.getProperty("user.home") + "/.bitcoin/";
+        }
+        
+        // TODO: Move this to a library function
+        FileInputStream stream = new FileInputStream(new File(defaultDataDir + "blk0001.dat"));
+        int i = 0;
+        while (stream.available() > 0) {
+            try {
+                while(stream.read() != ((params.packetMagic >>> 24) & 0xff) || stream.read() != ((params.packetMagic >>> 16) & 0xff) ||
+                        stream.read() != ((params.packetMagic >>> 8) & 0xff) || stream.read() != (params.packetMagic & 0xff))
+                    ;
+            } catch (IOException e) {
+                break;
+            }
+            byte[] bytes = new byte[4];
+            stream.read(bytes, 0, 4);
+            long size = Utils.readUint32BE(Utils.reverseBytes(bytes), 0);
+            if (size > Block.MAX_BLOCK_SIZE || size <= 0)
+                continue;
+            bytes = new byte[(int) size];
+            stream.read(bytes, 0, (int)size);
+            Block block = new Block(params, bytes);
+            if (store.get(block.getHash()) == null)
+                chain.add(block);
+            
+            if (i % 10000 == 0)
+                System.out.println(i);
+            i++;
+        }
+        System.out.println("Imported " + chain.getChainHead().getHeight() + " blocks.");
+    }
+}