/*******************************************************************************
* Copyright (c) 2013 GigaSpaces Technologies Ltd. All rights reserved
*
* 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 org.cloudifysource.rest.events.cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.LoadingCache;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;
import org.cloudifysource.dsl.rest.response.DeploymentEvent;
import org.cloudifysource.dsl.rest.response.DeploymentEvents;
import org.cloudifysource.rest.events.LogEntryMatcherProvider;
import org.openspaces.admin.Admin;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;
/**
* Created with IntelliJ IDEA.
* User: elip
* Date: 5/13/13
* Time: 8:41 AM
* <br/><br/>
*
* This class is the cache implementation for life cycle events.
* Cache entries are deleted automatically in they haven't been accessed to in more than 5 minutes.
*
* Events are populated using a guava based {@link com.google.common.cache.CacheLoader}.
*
* @see EventsCacheLoader
*
*/
public class EventsCache {
private static final Logger logger = Logger.getLogger(EventsCache.class.getName());
private static final int CACHE_EXPIRATION_MINUTES = 5;
private final LoadingCache<EventsCacheKey, EventsCacheValue> eventsLoadingCache;
private final LogEntryMatcherProvider matcherProvider;
private int cacheExpirationPeriod = CACHE_EXPIRATION_MINUTES;
private TimeUnit cacheExpirationTimeunit = TimeUnit.MINUTES;
public void setCacheExpirationPeriod(int cacheExpirationPeriod) {
this.cacheExpirationPeriod = cacheExpirationPeriod;
}
public void setCacheExpirationTimeunit(TimeUnit cacheExpirationTimeunit) {
this.cacheExpirationTimeunit = cacheExpirationTimeunit;
}
public EventsCache(final Admin admin) {
final EventsCacheLoader loader = new EventsCacheLoader(new AdminBasedGridServiceContainerProvider(admin));
this.matcherProvider = loader.getMatcherProvider();
this.eventsLoadingCache = CacheBuilder.newBuilder()
.expireAfterAccess(cacheExpirationPeriod, cacheExpirationTimeunit)
.removalListener(new RemovalListener<Object, Object>() {
@Override
public void onRemoval(final RemovalNotification<Object, Object> notification) {
// the onRemoval will also be triggered on reload (RemovalCause.REPLACED)
// in that case we don't want to remove the matcher.
if (notification.wasEvicted()) {
logger.fine("Entry with key " + notification.getKey() + " was removed from cache.");
final EventsCacheKey key = (EventsCacheKey) notification.getKey();
matcherProvider.removeAll(key);
}
}
})
.build(loader);
}
/**
* Refresh the cache. this results in a call to {@link EventsCacheLoader#reload(EventsCacheKey, EventsCacheValue)}.
* @param key The key to refresh.
*/
public void refresh(final EventsCacheKey key) {
logger.finest("Refreshing events cache for entry " + key);
eventsLoadingCache.refresh(key);
}
/**
* Retrieve a cache entry. if the entry is not found, a cache loading is executed using
* {@link EventsCacheLoader#load(EventsCacheKey)}
* @param key The key of the requested entry.
* @return The cache value. containing also the events.
* @throws java.util.concurrent.ExecutionException Thrown in case a failure happened while loading the cache with a new entry.
*/
public EventsCacheValue get(final EventsCacheKey key) throws ExecutionException {
logger.finest("Retrieving events cache value for entry " + key);
return eventsLoadingCache.get(key);
}
/**
* Retrieves a cache entry only if it exists. otherwise will return null.
* @param key The key of the requested entry.
* @return The cache value. containing also the events. null if doesnt exist.
*/
public EventsCacheValue getIfExists(final EventsCacheKey key) {
logger.finest("Retrieving events cache value for entry " + key + " if exists");
return eventsLoadingCache.getIfPresent(key);
}
/**
* Explicitly put a new entry to the cache. this method is used only when installing or uninstalling the service.
* @param key The key of the requested entry.
* @param value The value of the requested entry.
*/
public void put(final EventsCacheKey key, final EventsCacheValue value) {
if (!eventsLoadingCache.asMap().containsKey(key)) {
logger.finest("Putting new value in events cache for key " + key + " : " + value);
eventsLoadingCache.asMap().put(key, value);
} else {
logger.finest("Not putting new value in events cache for key " + key + " . it already exists.");
}
}
/**
* Adds the latest event to the events of the specified key.
* @param key A key of ServiceDeploymentEvents
* @param event The event to add
*/
public void add(final EventsCacheKey key, final DeploymentEvent event) {
EventsCacheValue eventsCacheValue = eventsLoadingCache.asMap().get(key);
synchronized (eventsCacheValue.getMutex()) {
DeploymentEvents events = eventsCacheValue.getEvents();
event.setIndex(eventsCacheValue.getLastEventIndex() + 1);
logger.finest("Adding event " + event + " to cache value with key " + key);
events.getEvents().add(event);
}
}
}