// 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.apache.cloudstack.ratelimit;
import net.sf.ehcache.Ehcache;
import net.sf.ehcache.Element;
import net.sf.ehcache.constructs.blocking.BlockingCache;
import net.sf.ehcache.constructs.blocking.LockTimeoutException;
/**
* A Limit store implementation using Ehcache.
*
*/
public class EhcacheLimitStore implements LimitStore {
private BlockingCache cache;
public void setCache(Ehcache cache) {
BlockingCache ref;
if (!(cache instanceof BlockingCache)) {
ref = new BlockingCache(cache);
cache.getCacheManager().replaceCacheWithDecoratedCache(cache, new BlockingCache(cache));
} else {
ref = (BlockingCache)cache;
}
this.cache = ref;
}
@Override
public StoreEntry create(Long key, int timeToLive) {
StoreEntryImpl result = new StoreEntryImpl(timeToLive);
Element element = new Element(key, result);
element.setTimeToLive(timeToLive);
cache.put(element);
return result;
}
@Override
public StoreEntry get(Long key) {
Element entry = null;
try {
/* This may block. */
entry = cache.get(key);
} catch (LockTimeoutException e) {
throw new RuntimeException();
} catch (RuntimeException e) {
/* Release the lock that may have been acquired. */
cache.put(new Element(key, null));
}
StoreEntry result = null;
if (entry != null) {
/*
* We don't need to check isExpired() on the result, since ehcache takes care of expiring entries for us.
* c.f. the get(Key) implementation in this class.
*/
result = (StoreEntry)entry.getObjectValue();
}
return result;
}
@Override
public void resetCounters() {
cache.removeAll();
}
}