Compact the database at startup.

bramble-api/src/main/java/org/briarproject/bramble/api/StringMap.java

@@ -38,4 +38,18 @@ public abstract class StringMap extends Hashtable<String, String> {
 	public void putInt(String key, int value) {
 		put(key, String.valueOf(value));
 	}
+
+	public long getLong(String key, long defaultValue) {
+		String s = get(key);
+		if (s == null) return defaultValue;
+		try {
+			return Long.valueOf(s);
+		} catch (NumberFormatException e) {
+			return defaultValue;
+		}
+	}
+
+	public void putLong(String key, long value) {
+		put(key, String.valueOf(value));
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/db/MigrationListener.java

@@ -6,6 +6,10 @@ public interface MigrationListener {
 	 * This is called when a migration is started while opening the database.
 	 * It will be called once for each migration being applied.
 	 */
-	void onMigrationRun();
+	void onDatabaseMigration();
 
+	/**
+	 * This is called when compaction is started while opening the database.
+	 */
+	void onDatabaseCompaction();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/LifecycleManager.java

@@ -34,7 +34,8 @@ public interface LifecycleManager {
 	 */
 	enum LifecycleState {
 
-		STARTING, MIGRATING_DATABASE, STARTING_SERVICES, RUNNING, STOPPING;
+		STARTING, MIGRATING_DATABASE, COMPACTING_DATABASE, STARTING_SERVICES,
+		RUNNING, STOPPING;
 
 		public boolean isAfter(LifecycleState state) {
 			return ordinal() > state.ordinal();

bramble-api/src/test/java/org/briarproject/bramble/test/SettableClock.java

@@ -0,0 +1,24 @@
+package org.briarproject.bramble.test;
+
+import org.briarproject.bramble.api.system.Clock;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+public class SettableClock implements Clock {
+
+	private final AtomicLong time;
+
+	public SettableClock(AtomicLong time) {
+		this.time = time;
+	}
+
+	@Override
+	public long currentTimeMillis() {
+		return time.get();
+	}
+
+	@Override
+	public void sleep(long milliseconds) throws InterruptedException {
+		Thread.sleep(milliseconds);
+	}
+}