Turn off HSQLDB redo-log "blockchain.log" and periodically call "CHECKPOINT" instead.

Checkpointing interval is 1 hour by default, changable in settings via
"repositoryCheckpointInterval"
plus corresponding "showCheckpointNotifications" SysTray flags (off by default).

Added entries to SysTray_en i18n properties, and converted SysTray_ru to ISO-8559-1.

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

@@ -156,6 +156,7 @@ public class Controller extends Thread {
 	};
 
 	private long repositoryBackupTimestamp = startTime; // ms
+	private long repositoryCheckpointTimestamp = startTime; // ms
 	private long ntpCheckTimestamp = startTime; // ms
 	private long deleteExpiredTimestamp = startTime + DELETE_EXPIRED_INTERVAL; // ms
 
@@ -484,6 +485,7 @@ 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());
@@ -529,6 +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;

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

@@ -47,6 +47,8 @@ public interface Repository extends AutoCloseable {
 
 	public void backup(boolean quick) throws DataException;
 
+	public void checkpoint(boolean quick) throws DataException;
+
 	public void performPeriodicMaintenance() throws DataException;
 
 }

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

@@ -35,6 +35,14 @@ 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/hsqldb/HSQLDBDatabaseUpdates.java

@@ -685,6 +685,12 @@ public class HSQLDBDatabaseUpdates {
 							+ ")");
 					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;
+
 				default:
 					// nothing to do
 					return false;

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

@@ -376,6 +376,15 @@ 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 repositor checkpoint");
+		}
+	}
+
 	@Override
 	public void performPeriodicMaintenance() throws DataException {
 		// Defrag DB - takes a while!

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

@@ -83,6 +83,10 @@ 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
@@ -430,6 +434,14 @@ public class Settings {
 		return this.showBackupNotification;
 	}
 
+	public long getRepositoryCheckpointInterval() {
+		return this.repositoryCheckpointInterval;
+	}
+
+	public boolean getShowCheckpointNotification() {
+		return this.showCheckpointNotification;
+	}
+
 	public long getAtStatesMaxLifetime() {
 		return this.atStatesMaxLifetime;
 	}