/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.waveprotocol.box.server.waveserver;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import com.google.inject.Inject;
import com.google.inject.Singleton;
import org.waveprotocol.wave.model.id.WaveId;
import org.waveprotocol.wave.model.id.WaveletId;
import org.waveprotocol.wave.model.id.WaveletName;
import org.waveprotocol.wave.model.wave.ParticipantId;
import org.waveprotocol.wave.util.logging.Log;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
/**
* @author yurize@apache.org (Yuri Zelikov)
*/
@Singleton
public class MemoryPerUserWaveViewHandlerImpl implements PerUserWaveViewHandler {
private static final Log LOG = Log.get(MemoryPerUserWaveViewHandlerImpl.class);
/**
* The period of time in minutes the per user waves view should be actively
* kept up to date after last access.
*/
private static final int PER_USER_WAVES_VIEW_CACHE_MINUTES = 5;
/** The loading cache that holds wave viev per each online user.*/
public LoadingCache<ParticipantId, Multimap<WaveId, WaveletId>> explicitPerUserWaveViews;
@Inject
public MemoryPerUserWaveViewHandlerImpl(final WaveMap waveMap) {
// Let the view expire if it not accessed for some time.
explicitPerUserWaveViews =
CacheBuilder.newBuilder().expireAfterAccess(PER_USER_WAVES_VIEW_CACHE_MINUTES, TimeUnit.MINUTES)
.<ParticipantId, Multimap<WaveId, WaveletId>>build(new CacheLoader<ParticipantId, Multimap<WaveId, WaveletId>>() {
@Override
public Multimap<WaveId, WaveletId> load(final ParticipantId user) {
Multimap<WaveId, WaveletId> userView = HashMultimap.create();
// Create initial per user waves view by looping over all waves
// in the waves store.
Map<WaveId, Wave> waves = waveMap.getWaves();
for (Map.Entry<WaveId, Wave> entry : waves.entrySet()) {
Wave wave = entry.getValue();
for (WaveletContainer c : wave) {
WaveletId waveletId = c.getWaveletName().waveletId;
try {
if (!c.hasParticipant(user)) {
continue;
}
// Add this wave to the user view.
userView.put(entry.getKey(), waveletId);
} catch (WaveletStateException e) {
LOG.warning("Failed to access wavelet " + c.getWaveletName(), e);
}
}
}
LOG.info("Initalized waves view for user: " + user.getAddress()
+ ", number of waves in view: " + userView.size());
return userView;
}
});
}
@Override
public ListenableFuture<Void> onParticipantAdded(WaveletName waveletName, ParticipantId user) {
Multimap<WaveId, WaveletId> perUserView = explicitPerUserWaveViews.getIfPresent(user);
if (perUserView != null) {
if (!perUserView.containsEntry(waveletName.waveId, waveletName.waveletId)) {
perUserView.put(waveletName.waveId, waveletName.waveletId);
if(LOG.isFineLoggable()) {
LOG.fine("Added wavelet: " + waveletName + " to the view of user: " + user.getAddress());
LOG.fine("View size is now: " + perUserView.size());
}
}
}
SettableFuture<Void> task = SettableFuture.create();
task.set(null);
return task;
}
@Override
public ListenableFuture<Void> onParticipantRemoved(WaveletName waveletName, ParticipantId user) {
Multimap<WaveId, WaveletId> perUserView = explicitPerUserWaveViews.getIfPresent(user);
if (perUserView != null) {
if (perUserView.containsEntry(waveletName.waveId, waveletName.waveletId)) {
perUserView.remove(waveletName.waveId, waveletName.waveletId);
LOG.fine("Removed wavelet: " + waveletName
+ " from the view of user: " + user.getAddress());
}
}
SettableFuture<Void> task = SettableFuture.create();
task.set(null);
return task;
}
@Override
public Multimap<WaveId, WaveletId> retrievePerUserWaveView(ParticipantId user) {
try {
return explicitPerUserWaveViews.get(user);
} catch (ExecutionException ex) {
throw new RuntimeException(ex);
}
}
@Override
public ListenableFuture<Void> onWaveInit(WaveletName waveletName) {
// No op.
SettableFuture<Void> task = SettableFuture.create();
task.set(null);
return task;
}
}