/**
* 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.camel.impl;
import java.util.Map;
import org.apache.camel.CamelContext;
import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.FailedToCreateConsumerException;
import org.apache.camel.IsSingleton;
import org.apache.camel.PollingConsumer;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.ServicePoolAware;
import org.apache.camel.spi.EndpointUtilizationStatistics;
import org.apache.camel.spi.ServicePool;
import org.apache.camel.support.ServiceSupport;
import org.apache.camel.util.CamelContextHelper;
import org.apache.camel.util.LRUCache;
import org.apache.camel.util.ServiceHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Cache containing created {@link org.apache.camel.Consumer}.
*
* @version
*/
public class ConsumerCache extends ServiceSupport {
private static final Logger LOG = LoggerFactory.getLogger(ConsumerCache.class);
private final CamelContext camelContext;
private final ServicePool<Endpoint, PollingConsumer> pool;
private final Map<String, PollingConsumer> consumers;
private final Object source;
private EndpointUtilizationStatistics statistics;
private boolean extendedStatistics;
private int maxCacheSize;
public ConsumerCache(Object source, CamelContext camelContext) {
this(source, camelContext, CamelContextHelper.getMaximumCachePoolSize(camelContext));
}
public ConsumerCache(Object source, CamelContext camelContext, int cacheSize) {
this(source, camelContext, createLRUCache(cacheSize));
}
public ConsumerCache(Object source, CamelContext camelContext, Map<String, PollingConsumer> cache) {
this(source, camelContext, cache, camelContext.getPollingConsumerServicePool());
}
public ConsumerCache(Object source, CamelContext camelContext, Map<String, PollingConsumer> cache, ServicePool<Endpoint, PollingConsumer> pool) {
this.camelContext = camelContext;
this.consumers = cache;
this.source = source;
this.pool = pool;
if (consumers instanceof LRUCache) {
maxCacheSize = ((LRUCache) consumers).getMaxCacheSize();
}
// only if JMX is enabled
if (camelContext.getManagementStrategy().getManagementAgent() != null) {
this.extendedStatistics = camelContext.getManagementStrategy().getManagementAgent().getStatisticsLevel().isExtended();
} else {
this.extendedStatistics = false;
}
}
public boolean isExtendedStatistics() {
return extendedStatistics;
}
/**
* Whether extended JMX statistics is enabled for {@link org.apache.camel.spi.EndpointUtilizationStatistics}
*/
public void setExtendedStatistics(boolean extendedStatistics) {
this.extendedStatistics = extendedStatistics;
}
/**
* Creates the {@link LRUCache} to be used.
* <p/>
* This implementation returns a {@link LRUCache} instance.
* @param cacheSize the cache size
* @return the cache
*/
protected static LRUCache<String, PollingConsumer> createLRUCache(int cacheSize) {
// Use a regular cache as we want to ensure that the lifecycle of the consumers
// being cache is properly handled, such as they are stopped when being evicted
// or when this cache is stopped. This is needed as some consumers requires to
// be stopped so they can shutdown internal resources that otherwise may cause leaks
return new LRUCache<String, PollingConsumer>(cacheSize);
}
/**
* Acquires a pooled PollingConsumer which you <b>must</b> release back again after usage using the
* {@link #releasePollingConsumer(org.apache.camel.Endpoint, org.apache.camel.PollingConsumer)} method.
*
* @param endpoint the endpoint
* @return the PollingConsumer
*/
public PollingConsumer acquirePollingConsumer(Endpoint endpoint) {
return doGetPollingConsumer(endpoint, true);
}
/**
* Releases an acquired producer back after usage.
*
* @param endpoint the endpoint
* @param pollingConsumer the pollingConsumer to release
*/
public void releasePollingConsumer(Endpoint endpoint, PollingConsumer pollingConsumer) {
if (pollingConsumer instanceof ServicePoolAware) {
// release back to the pool
pool.release(endpoint, pollingConsumer);
} else {
boolean singleton = false;
if (pollingConsumer instanceof IsSingleton) {
singleton = ((IsSingleton) pollingConsumer).isSingleton();
}
String key = endpoint.getEndpointUri();
boolean cached = consumers.containsKey(key);
if (!singleton || !cached) {
try {
// stop and shutdown non-singleton/non-cached consumers as we should not leak resources
if (!singleton) {
LOG.debug("Released PollingConsumer: {} is stopped as consumer is not singleton", endpoint);
} else {
LOG.debug("Released PollingConsumer: {} is stopped as consumer cache is full", endpoint);
}
ServiceHelper.stopAndShutdownService(pollingConsumer);
} catch (Throwable ex) {
if (ex instanceof RuntimeCamelException) {
throw (RuntimeCamelException)ex;
} else {
throw new RuntimeCamelException(ex);
}
}
}
}
}
public PollingConsumer getConsumer(Endpoint endpoint) {
return doGetPollingConsumer(endpoint, true);
}
protected synchronized PollingConsumer doGetPollingConsumer(Endpoint endpoint, boolean pooled) {
String key = endpoint.getEndpointUri();
PollingConsumer answer = consumers.get(key);
if (pooled && answer == null) {
pool.acquire(endpoint);
}
if (answer == null) {
try {
answer = endpoint.createPollingConsumer();
answer.start();
} catch (Throwable e) {
throw new FailedToCreateConsumerException(endpoint, e);
}
if (pooled && answer instanceof ServicePoolAware) {
LOG.debug("Adding to producer service pool with key: {} for producer: {}", endpoint, answer);
answer = pool.addAndAcquire(endpoint, answer);
} else {
boolean singleton = false;
if (answer instanceof IsSingleton) {
singleton = ((IsSingleton) answer).isSingleton();
}
if (singleton) {
LOG.debug("Adding to consumer cache with key: {} for consumer: {}", endpoint, answer);
consumers.put(key, answer);
} else {
LOG.debug("Consumer for endpoint: {} is not singleton and thus not added to consumer cache", key);
}
}
}
if (answer != null) {
// record statistics
if (extendedStatistics) {
statistics.onHit(key);
}
}
return answer;
}
public Exchange receive(Endpoint endpoint) {
LOG.debug("<<<< {}", endpoint);
PollingConsumer consumer = null;
try {
consumer = acquirePollingConsumer(endpoint);
return consumer.receive();
} finally {
if (consumer != null) {
releasePollingConsumer(endpoint, consumer);
}
}
}
public Exchange receive(Endpoint endpoint, long timeout) {
LOG.debug("<<<< {}", endpoint);
PollingConsumer consumer = null;
try {
consumer = acquirePollingConsumer(endpoint);
return consumer.receive(timeout);
} finally {
if (consumer != null) {
releasePollingConsumer(endpoint, consumer);
}
}
}
public Exchange receiveNoWait(Endpoint endpoint) {
LOG.debug("<<<< {}", endpoint);
PollingConsumer consumer = null;
try {
consumer = doGetPollingConsumer(endpoint, true);
return consumer.receiveNoWait();
} finally {
if (consumer != null) {
releasePollingConsumer(endpoint, consumer);
}
}
}
public CamelContext getCamelContext() {
return camelContext;
}
/**
* Gets the source which uses this cache
*
* @return the source
*/
public Object getSource() {
return source;
}
/**
* Returns the current size of the cache
*
* @return the current size
*/
public int size() {
int size = consumers.size();
LOG.trace("size = {}", size);
return size;
}
/**
* Gets the maximum cache size (capacity).
* <p/>
* Will return <tt>-1</tt> if it cannot determine this if a custom cache was used.
*
* @return the capacity
*/
public int getCapacity() {
int capacity = -1;
if (consumers instanceof LRUCache) {
LRUCache<String, PollingConsumer> cache = (LRUCache<String, PollingConsumer>)consumers;
capacity = cache.getMaxCacheSize();
}
return capacity;
}
/**
* Gets the cache hits statistic
* <p/>
* Will return <tt>-1</tt> if it cannot determine this if a custom cache was used.
*
* @return the hits
*/
public long getHits() {
long hits = -1;
if (consumers instanceof LRUCache) {
LRUCache<String, PollingConsumer> cache = (LRUCache<String, PollingConsumer>)consumers;
hits = cache.getHits();
}
return hits;
}
/**
* Gets the cache misses statistic
* <p/>
* Will return <tt>-1</tt> if it cannot determine this if a custom cache was used.
*
* @return the misses
*/
public long getMisses() {
long misses = -1;
if (consumers instanceof LRUCache) {
LRUCache<String, PollingConsumer> cache = (LRUCache<String, PollingConsumer>)consumers;
misses = cache.getMisses();
}
return misses;
}
/**
* Gets the cache evicted statistic
* <p/>
* Will return <tt>-1</tt> if it cannot determine this if a custom cache was used.
*
* @return the evicted
*/
public long getEvicted() {
long evicted = -1;
if (consumers instanceof LRUCache) {
LRUCache<String, PollingConsumer> cache = (LRUCache<String, PollingConsumer>)consumers;
evicted = cache.getEvicted();
}
return evicted;
}
/**
* Resets the cache statistics
*/
public void resetCacheStatistics() {
if (consumers instanceof LRUCache) {
LRUCache<String, PollingConsumer> cache = (LRUCache<String, PollingConsumer>)consumers;
cache.resetStatistics();
}
if (statistics != null) {
statistics.clear();
}
}
/**
* Purges this cache
*/
public synchronized void purge() {
consumers.clear();
if (statistics != null) {
statistics.clear();
}
}
/**
* Cleanup the cache (purging stale entries)
*/
public void cleanUp() {
if (consumers instanceof LRUCache) {
LRUCache<String, PollingConsumer> cache = (LRUCache<String, PollingConsumer>)consumers;
cache.cleanUp();
}
}
public EndpointUtilizationStatistics getEndpointUtilizationStatistics() {
return statistics;
}
@Override
public String toString() {
return "ConsumerCache for source: " + source + ", capacity: " + getCapacity();
}
protected void doStart() throws Exception {
if (extendedStatistics) {
int max = maxCacheSize == 0 ? CamelContextHelper.getMaximumCachePoolSize(camelContext) : maxCacheSize;
statistics = new DefaultEndpointUtilizationStatistics(max);
}
ServiceHelper.startServices(consumers.values());
}
protected void doStop() throws Exception {
// when stopping we intend to shutdown
ServiceHelper.stopAndShutdownServices(statistics, pool);
try {
ServiceHelper.stopAndShutdownServices(consumers.values());
} finally {
// ensure consumers are removed, and also from JMX
for (PollingConsumer consumer : consumers.values()) {
getCamelContext().removeService(consumer);
}
}
consumers.clear();
if (statistics != null) {
statistics.clear();
}
}
}