/*
* Syncany, www.syncany.org
* Copyright (C) 2011-2014 Philipp C. Heckel <philipp.heckel@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.syncany.operations.watch;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.syncany.config.Config;
import org.syncany.database.SqlDatabase;
import org.syncany.operations.Operation;
import org.syncany.operations.cleanup.CleanupOperation;
import org.syncany.operations.cleanup.CleanupOperationResult;
import org.syncany.operations.cleanup.CleanupOperationResult.CleanupResultCode;
import org.syncany.operations.down.DownOperation;
import org.syncany.operations.down.DownOperationResult;
import org.syncany.operations.down.DownOperationResult.DownResultCode;
import org.syncany.operations.up.UpOperation;
import org.syncany.operations.up.UpOperationResult;
import org.syncany.operations.up.UpOperationResult.UpResultCode;
import org.syncany.operations.watch.NotificationListener.NotificationListenerListener;
import org.syncany.operations.watch.RecursiveWatcher.WatchListener;
import org.syncany.util.StringUtil;
/**
* The watch operation implements the constant synchronization known from other
* sync tools.
*
* <p>In order to sync instantly, it offers the following strategies:
* <ul>
* <li>It monitors the local file system using the {@link DefaultRecursiveWatcher}.
* Whenever a file or folder changes, the sync is started (after a short
* settlement wait period).</li>
* <li>It subscribes to a repo-specific channel on the Syncany pub/sub server,
* using the {@link NotificationListener}, and publishes updates to this
* channel.</li>
* <li>It periodically runs the sync, i.e. the {@link DownOperation} and
* subsequently the {@link UpOperation}. If the other two mechanisms are
* disabled or fail to register changes, this method will make sure that
* changes are synced eventually.</li>
* </ul>
*
* As of now, this operation never returns, because it runs in a loop. The user
* has to manually abort the operation on the command line.
*
* @author Philipp C. Heckel <philipp.heckel@gmail.com>
*/
public class WatchOperation extends Operation implements NotificationListenerListener, WatchListener {
private static final Logger logger = Logger.getLogger(WatchOperation.class.getSimpleName());
private static final int STOP_GRACE_PERIOD = 15*1000;
private WatchOperationOptions options;
private SqlDatabase localDatabase;
private Thread watchThread;
private AtomicBoolean syncRunning;
private AtomicBoolean syncRequested;
private AtomicBoolean stopRequested;
private AtomicBoolean pauseRequested;
private AtomicInteger upCount;
private RecursiveWatcher recursiveWatcher;
private NotificationListener notificationListener;
private String notificationChannel;
private String notificationInstanceId;
public WatchOperation(Config config, WatchOperationOptions options) {
super(config);
this.options = options;
this.localDatabase = new SqlDatabase(config);
this.watchThread = null;
this.syncRunning = new AtomicBoolean(false);
this.syncRequested = new AtomicBoolean(false);
this.stopRequested = new AtomicBoolean(false);
this.pauseRequested = new AtomicBoolean(false);
this.upCount = new AtomicInteger(0);
this.recursiveWatcher = null;
this.notificationListener = null;
this.notificationChannel = StringUtil.toHex(config.getRepoId());
this.notificationInstanceId = "" + Math.abs(new Random().nextLong());
}
@Override
public WatchOperationResult execute() {
watchThread = Thread.currentThread();
if (options.announcementsEnabled()) {
startNotificationListener();
}
if (options.watcherEnabled()) {
startRecursiveWatcher();
}
syncLoop: while (!stopRequested.get()) {
try {
waitWhilePaused();
}
catch (InterruptedException e) {
logger.log(Level.INFO, "Sleep INTERRUPTED during PAUSE. STOPPING.", e);
break syncLoop;
}
try {
runSync();
if (!syncRequested.get() && !pauseRequested.get() && !stopRequested.get()) {
logger.log(Level.INFO, "Sync done, waiting {0} seconds ...", options.getInterval() / 1000);
Thread.sleep(options.getInterval());
}
}
catch (InterruptedException e) {
logger.log(Level.INFO, "Sync loop INTERRUPTED. STOPPING.", e);
break syncLoop;
}
catch (Exception e) {
if (pauseRequested.get()) {
logger.log(Level.INFO, "Sync FAILED, but PAUSE requested. Normally we would wait a bit and try again, but in this case we don't.", e);
}
else if (stopRequested.get()) {
logger.log(Level.INFO, "Sync FAILED, but STOP requested.", e);
break syncLoop;
}
else {
logger.log(Level.INFO, String.format("Sync FAILED, waiting %d seconds ...", options.getInterval() / 1000), e);
try {
Thread.sleep(options.getInterval());
}
catch (InterruptedException e2) {
logger.log(Level.INFO, "Sleep INTERRUPTED during retry-wait. STOPPING.", e2);
break syncLoop;
}
}
}
}
if (options.announcementsEnabled()) {
stopNotificationListener();
}
if (options.watcherEnabled()) {
stopRecursiveWatcher();
}
localDatabase.shutdown();
return new WatchOperationResult();
}
private void startRecursiveWatcher() {
logger.log(Level.INFO, "Starting recursive watcher for " + config.getLocalDir() + " ...");
Path localDir = Paths.get(config.getLocalDir().getAbsolutePath());
List<Path> ignorePaths = new ArrayList<Path>();
ignorePaths.add(Paths.get(config.getAppDir().getAbsolutePath()));
ignorePaths.add(Paths.get(config.getCacheDir().getAbsolutePath()));
ignorePaths.add(Paths.get(config.getDatabaseDir().getAbsolutePath()));
ignorePaths.add(Paths.get(config.getLogDir().getAbsolutePath()));
recursiveWatcher = RecursiveWatcher.createRecursiveWatcher(localDir, ignorePaths, options.getSettleDelay(), this);
try {
recursiveWatcher.start();
}
catch (Exception e) {
logger.log(Level.WARNING, "Cannot initiate file watcher. Relying on regular tree walks.", e);
}
}
private void startNotificationListener() {
logger.log(Level.INFO, "Starting notification listener for " + config.getLocalDir() + " ...");
notificationListener = new NotificationListener(options.getAnnouncementsHost(), options.getAnnouncementsPort(), this);
notificationListener.start();
notificationListener.subscribe(notificationChannel);
}
private void stopRecursiveWatcher() {
try {
logger.log(Level.INFO, "Stopping recursive watcher for " + config.getLocalDir() + " ...");
recursiveWatcher.stop();
}
catch (Exception e) {
logger.log(Level.WARNING, "Cannot stop file watcher.", e);
}
}
private void stopNotificationListener() {
logger.log(Level.INFO, "Stopping notification listener for " + config.getLocalDir() + " ...");
notificationListener.stop();
}
/**
* Runs one iteration of the main synchronization loop, containing a {@link DownOperation},
* an {@link UpOperation} and (if required), a {@link CleanupOperation}.
*/
private void runSync() throws Exception {
if (!syncRunning.get()) {
syncRunning.set(true);
syncRequested.set(false);
logger.log(Level.INFO, "RUNNING SYNC ...");
try {
boolean notifyChanges = false;
// Run down
DownOperationResult downResult = new DownOperation(config, options.getDownOptions()).execute();
if (downResult.getResultCode() == DownResultCode.OK_WITH_REMOTE_CHANGES) {
// TODO [low] Do something?
}
// Run up
UpOperationResult upOperationResult = new UpOperation(config, options.getUpOptions()).execute();
if (upOperationResult.getResultCode() == UpResultCode.OK_CHANGES_UPLOADED && upOperationResult.getChangeSet().hasChanges()) {
upCount.incrementAndGet();
notifyChanges = true;
}
CleanupOperationResult cleanupOperationResult = new CleanupOperation(config, options.getCleanupOptions()).execute();
if (cleanupOperationResult.getResultCode() == CleanupResultCode.OK) {
notifyChanges = true;
}
// Fire change event if up and/or cleanup
if (notifyChanges) {
notifyChanges();
}
}
finally {
logger.log(Level.INFO, "SYNC DONE.");
syncRunning.set(false);
}
}
else {
// Can't do a log message here, because this bit is called thousand
// of times when file system events occur.
syncRequested.set(true);
}
}
@Override
public void pushNotificationReceived(String channel, String message) {
if (channel.equals(notificationChannel) && !message.equals(notificationInstanceId)) {
try {
waitWhilePaused();
runSync();
}
catch (Exception e) {
logger.log(Level.INFO, "Sync FAILED (event-triggered).");
}
}
}
@Override
public void watchEventsOccurred() {
try {
waitWhilePaused();
runSync();
}
catch (Exception e) {
logger.log(Level.INFO, "Sync FAILED (event-triggered).");
}
}
private void notifyChanges() {
if (notificationListener != null) {
notificationListener.announce(notificationChannel, notificationInstanceId);
}
}
public void pause() {
pauseRequested.set(true);
}
public void resume() {
pauseRequested.set(false);
}
public void stop() {
if (!stopRequested.get()) {
stopRequested.set(true);
if (syncRunning.get()) {
logger.log(Level.INFO, "Stop requested, but sync process currently running. Waiting max. " + STOP_GRACE_PERIOD + "ms for sync to finish.");
scheduleForceKill();
}
else {
logger.log(Level.INFO, "Stop requested, but sync is NOT running. Immediately stopping thread.");
forceKillWatchThread();
}
}
else {
logger.log(Level.INFO, "Stop requested AGAIN, but was requested before. IGNORING.");
}
}
public boolean isSyncRunning() {
return syncRunning.get();
}
public boolean isSyncRequested() {
return syncRequested.get();
}
private void waitWhilePaused() throws InterruptedException {
while (pauseRequested.get()) {
Thread.sleep(1000);
}
}
private void scheduleForceKill() {
String killTimerName = "Kill/" + config.getLocalDir().getName();
new Timer(killTimerName).schedule(new TimerTask() {
@Override
public void run() {
try {
logger.log(Level.INFO, "STOP GRACE PERIOD OVER. STOPPING WATCH " + config.getLocalDir() + " ...");
if (watchThread != null && !watchThread.isInterrupted()) {
watchThread.interrupt();
}
}
catch (Exception e) {
logger.log(Level.INFO, "Forcefully stopping watch thread FAILED at " + config.getLocalDir() + ". Giving up.");
}
}
}, STOP_GRACE_PERIOD);
}
private void forceKillWatchThread() {
try {
logger.log(Level.INFO, "STOPPING WATCH " + config.getLocalDir() + " ...");
if (watchThread != null && !watchThread.isInterrupted()) {
watchThread.interrupt();
}
}
catch (Exception e) {
logger.log(Level.INFO, "Forcefully stopping watch thread FAILED at " + config.getLocalDir() + ". Giving up.");
}
}
}