| // Copyright (C) 2013 The Android Open Source Project |
| // |
| // 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.googlesource.gerrit.plugins.replication; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.flogger.FluentLogger; |
| import com.google.gerrit.common.FileUtil; |
| import com.google.gerrit.extensions.annotations.PluginData; |
| import com.google.gerrit.server.config.SitePaths; |
| import com.google.gerrit.server.git.WorkQueue; |
| import com.google.inject.Inject; |
| import com.google.inject.Provider; |
| import com.google.inject.Singleton; |
| import java.io.IOException; |
| import java.nio.file.Path; |
| import java.util.List; |
| import org.eclipse.jgit.errors.ConfigInvalidException; |
| |
| @Singleton |
| public class AutoReloadConfigDecorator implements ReplicationConfig { |
| private static final FluentLogger logger = FluentLogger.forEnclosingClass(); |
| |
| private volatile ReplicationFileBasedConfig currentConfig; |
| private long currentConfigTs; |
| private long lastFailedConfigTs; |
| |
| private final SitePaths site; |
| private final Destination.Factory destinationFactory; |
| private final Path pluginDataDir; |
| // Use Provider<> instead of injecting the ReplicationQueue because of circular dependency with |
| // ReplicationConfig |
| private final Provider<ReplicationQueue> replicationQueue; |
| |
| private volatile boolean shuttingDown; |
| |
| @Inject |
| public AutoReloadConfigDecorator( |
| SitePaths site, |
| Destination.Factory destinationFactory, |
| Provider<ReplicationQueue> replicationQueue, |
| @PluginData Path pluginDataDir) |
| throws ConfigInvalidException, IOException { |
| this.site = site; |
| this.destinationFactory = destinationFactory; |
| this.pluginDataDir = pluginDataDir; |
| this.currentConfig = loadConfig(); |
| this.currentConfigTs = getLastModified(currentConfig); |
| this.replicationQueue = replicationQueue; |
| } |
| |
| private static long getLastModified(ReplicationFileBasedConfig cfg) { |
| return FileUtil.lastModified(cfg.getCfgPath()); |
| } |
| |
| private ReplicationFileBasedConfig loadConfig() throws ConfigInvalidException, IOException { |
| return new ReplicationFileBasedConfig(site, destinationFactory, pluginDataDir); |
| } |
| |
| private synchronized boolean isAutoReload() { |
| return currentConfig.getConfig().getBoolean("gerrit", "autoReload", false); |
| } |
| |
| @Override |
| public synchronized List<Destination> getDestinations(FilterType filterType) { |
| reloadIfNeeded(); |
| return currentConfig.getDestinations(filterType); |
| } |
| |
| private void reloadIfNeeded() { |
| reload(false); |
| } |
| |
| @VisibleForTesting |
| public void forceReload() { |
| reload(true); |
| } |
| |
| private void reload(boolean force) { |
| if (force || isAutoReload()) { |
| ReplicationQueue queue = replicationQueue.get(); |
| |
| long lastModified = getLastModified(currentConfig); |
| try { |
| if (force |
| || (!shuttingDown |
| && lastModified > currentConfigTs |
| && lastModified > lastFailedConfigTs |
| && queue.isRunning() |
| && !queue.isReplaying())) { |
| queue.stop(); |
| currentConfig = loadConfig(); |
| currentConfigTs = lastModified; |
| lastFailedConfigTs = 0; |
| logger.atInfo().log( |
| "Configuration reloaded: %d destinations", |
| currentConfig.getDestinations(FilterType.ALL).size()); |
| } |
| } catch (Exception e) { |
| logger.atSevere().withCause(e).log( |
| "Cannot reload replication configuration: keeping existing settings"); |
| lastFailedConfigTs = lastModified; |
| return; |
| } finally { |
| queue.start(); |
| } |
| } |
| } |
| |
| @Override |
| public synchronized boolean isReplicateAllOnPluginStart() { |
| return currentConfig.isReplicateAllOnPluginStart(); |
| } |
| |
| @Override |
| public synchronized boolean isDefaultForceUpdate() { |
| return currentConfig.isDefaultForceUpdate(); |
| } |
| |
| @Override |
| public synchronized boolean isEmpty() { |
| return currentConfig.isEmpty(); |
| } |
| |
| @Override |
| public Path getEventsDirectory() { |
| return currentConfig.getEventsDirectory(); |
| } |
| |
| /* shutdown() cannot be set as a synchronized method because |
| * it may need to wait for pending events to complete; |
| * e.g. when enabling the drain of replication events before |
| * shutdown. |
| * |
| * As a rule of thumb for synchronized methods, because they |
| * implicitly define a critical section and associated lock, |
| * they should never hold waiting for another resource, otherwise |
| * the risk of deadlock is very high. |
| * |
| * See more background about deadlocks, what they are and how to |
| * prevent them at: https://en.wikipedia.org/wiki/Deadlock |
| */ |
| @Override |
| public int shutdown() { |
| this.shuttingDown = true; |
| return currentConfig.shutdown(); |
| } |
| |
| @Override |
| public synchronized void startup(WorkQueue workQueue) { |
| shuttingDown = false; |
| currentConfig.startup(workQueue); |
| } |
| |
| @Override |
| public synchronized int getSshConnectionTimeout() { |
| return currentConfig.getSshConnectionTimeout(); |
| } |
| |
| @Override |
| public synchronized int getSshCommandTimeout() { |
| return currentConfig.getSshCommandTimeout(); |
| } |
| } |