Replace persistent logger after deleting account.

bramble-android/src/main/java/org/briarproject/bramble/account/AndroidAccountManager.java

@@ -9,8 +9,10 @@ import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.logging.PersistentLogManager;
 
 import java.io.File;
+import java.io.IOException;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -20,17 +22,21 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.GuardedBy;
 import javax.inject.Inject;
 
+import static android.content.Context.MODE_PRIVATE;
 import static android.os.Build.VERSION.SDK_INT;
 import static java.util.Arrays.asList;
 import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.IoUtils.deleteFileOrDir;
+import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.logFileOrDir;
 
 class AndroidAccountManager extends AccountManagerImpl
 		implements AccountManager {
 
 	private static final Logger LOG =
-			Logger.getLogger(AndroidAccountManager.class.getName());
+			getLogger(AndroidAccountManager.class.getName());
 
 	/**
 	 * Directories that shouldn't be deleted when deleting the user's account.
@@ -40,13 +46,16 @@ class AndroidAccountManager extends AccountManagerImpl
 
 	protected final Context appContext;
 	private final SharedPreferences prefs;
+	private final PersistentLogManager logManager;
 
 	@Inject
 	AndroidAccountManager(DatabaseConfig databaseConfig,
 			CryptoComponent crypto, IdentityManager identityManager,
-			SharedPreferences prefs, Application app) {
+			SharedPreferences prefs, PersistentLogManager logManager,
+			Application app) {
 		super(databaseConfig, crypto, identityManager);
 		this.prefs = prefs;
+		this.logManager = logManager;
 		appContext = app.getApplicationContext();
 	}
 
@@ -74,6 +83,7 @@ class AndroidAccountManager extends AccountManagerImpl
 				LOG.info("Contents of account directory after deleting:");
 				logFileOrDir(LOG, INFO, getDataDir());
 			}
+			replacePersistentLogger();
 		}
 	}
 
@@ -134,4 +144,13 @@ class AndroidAccountManager extends AccountManagerImpl
 	private void addIfNotNull(Set<File> files, @Nullable File file) {
 		if (file != null) files.add(file);
 	}
+
+	private void replacePersistentLogger() {
+		File logDir = appContext.getDir("log", MODE_PRIVATE);
+		try {
+			logManager.addLogHandler(logDir, getLogger(""));
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/logging/PersistentLogManager.java

@@ -7,6 +7,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.List;
 import java.util.logging.Handler;
+import java.util.logging.Logger;
 
 @NotNullByDefault
 public interface PersistentLogManager {
@@ -24,11 +25,16 @@ public interface PersistentLogManager {
 	/**
 	 * Creates and returns a persistent log handler that stores its logs in
 	 * the given directory.
-	 * <p>
-	 * This method should only be called once.
 	 */
 	Handler createLogHandler(File dir) throws IOException;
 
+	/**
+	 * Creates a persistent log handler that stores its logs in the given
+	 * directory and adds the handler to the given logger, replacing any
+	 * existing persistent log handler.
+	 */
+	void addLogHandler(File dir, Logger logger) throws IOException;
+
 	/**
 	 * Loads and returns the persistent log entries stored in the given
 	 * directory, or an empty list if no log entries are found.

bramble-core/src/main/java/org/briarproject/bramble/logging/PersistentLogManagerImpl.java

@@ -27,7 +27,7 @@ import java.util.List;
 import java.util.Scanner;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Formatter;
 import java.util.logging.Handler;
 import java.util.logging.Logger;
@@ -62,7 +62,8 @@ class PersistentLogManagerImpl implements PersistentLogManager,
 	private final StreamWriterFactory streamWriterFactory;
 	private final Formatter formatter;
 	private final SecretKey logKey;
-	private final AtomicBoolean handlerCreated = new AtomicBoolean(false);
+	private final AtomicReference<Integer> shutdownHookHandle =
+			new AtomicReference<>();
 
 	@Nullable
 	private volatile SecretKey oldLogKey = null;
@@ -103,7 +104,6 @@ class PersistentLogManagerImpl implements PersistentLogManager,
 
 	@Override
 	public Handler createLogHandler(File dir) throws IOException {
-		if (handlerCreated.getAndSet(true)) throw new IllegalStateException();
 		File logFile = new File(dir, LOG_FILE);
 		File oldLogFile = new File(dir, OLD_LOG_FILE);
 		if (oldLogFile.exists() && !oldLogFile.delete())
@@ -117,7 +117,7 @@ class PersistentLogManagerImpl implements PersistentLogManager,
 			StreamHandler handler = new FlushingStreamHandler(scheduler,
 					ioExecutor, writer.getOutputStream(), formatter);
 			// Flush the log and terminate the stream at shutdown
-			shutdownManager.addShutdownHook(() -> {
+			Runnable shutdownHook = () -> {
 				LOG.info("Shutting down");
 				handler.flush();
 				try {
@@ -125,13 +125,27 @@ class PersistentLogManagerImpl implements PersistentLogManager,
 				} catch (IOException e) {
 					logException(LOG, WARNING, e);
 				}
-			});
+			};
+			int handle = shutdownManager.addShutdownHook(shutdownHook);
+			// If a previous handler registered a shutdown hook, remove it
+			Integer oldHandle = shutdownHookHandle.getAndSet(handle);
+			if (oldHandle != null) {
+				shutdownManager.removeShutdownHook(oldHandle);
+			}
 			return handler;
 		} catch (SecurityException e) {
 			throw new IOException(e);
 		}
 	}
 
+	@Override
+	public void addLogHandler(File dir, Logger logger) throws IOException {
+		for (Handler h : logger.getHandlers()) {
+			if (h instanceof FlushingStreamHandler) logger.removeHandler(h);
+		}
+		logger.addHandler(createLogHandler(dir));
+	}
+
 	@Override
 	public List<String> getPersistedLog(File dir, boolean old)
 			throws IOException {

briar-android/src/main/java/org/briarproject/bramble/account/BriarAccountManager.java

@@ -6,6 +6,7 @@ import android.content.SharedPreferences;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.logging.PersistentLogManager;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.Localizer;
 import org.briarproject.briar.android.util.UiUtils;
@@ -17,8 +18,8 @@ class BriarAccountManager extends AndroidAccountManager {
 	@Inject
 	BriarAccountManager(DatabaseConfig databaseConfig, CryptoComponent crypto,
 			IdentityManager identityManager, SharedPreferences prefs,
-			Application app) {
+			PersistentLogManager logManager, Application app) {
-		super(databaseConfig, crypto, identityManager, prefs, app);
+		super(databaseConfig, crypto, identityManager, prefs, logManager, app);
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/BriarApplicationImpl.java

@@ -32,7 +32,6 @@ import org.briarproject.briar.android.util.UiUtils;
 import java.io.File;
 import java.io.IOException;
 import java.util.Collection;
-import java.util.logging.Formatter;
 import java.util.logging.Handler;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
@@ -130,12 +129,9 @@ public class BriarApplicationImpl extends Application
 
 		PersistentLogManager logManager =
 				applicationComponent.persistentLogManager();
-		Formatter formatter = applicationComponent.formatter();
+		File logDir = getDir("log", MODE_PRIVATE);
 		try {
-			File logDir = getDir("log", MODE_PRIVATE);
+			rootLogger.addHandler(logManager.createLogHandler(logDir));
-			Handler handler = logManager.createLogHandler(logDir);
-			handler.setFormatter(formatter);
-			rootLogger.addHandler(handler);
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
 		}