/**
* 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.AsyncCallback;
import org.apache.camel.AsyncProcessor;
import org.apache.camel.AsyncProducerCallback;
import org.apache.camel.CamelContext;
import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.ExchangePattern;
import org.apache.camel.FailedToCreateProducerException;
import org.apache.camel.Processor;
import org.apache.camel.Producer;
import org.apache.camel.ProducerCallback;
import org.apache.camel.ServicePoolAware;
import org.apache.camel.impl.converter.AsyncProcessorTypeConverter;
import org.apache.camel.processor.UnitOfWorkProducer;
import org.apache.camel.spi.ServicePool;
import org.apache.camel.util.CamelContextHelper;
import org.apache.camel.util.EventHelper;
import org.apache.camel.util.LRUCache;
import org.apache.camel.util.LRUSoftCache;
import org.apache.camel.util.ServiceHelper;
import org.apache.camel.util.StopWatch;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Cache containing created {@link Producer}.
*
* @version
*/
public class ProducerCache extends ServiceSupport {
private static final transient Logger LOG = LoggerFactory.getLogger(ProducerCache.class);
private final CamelContext camelContext;
private final ServicePool<Endpoint, Producer> pool;
private final Map<String, Producer> producers;
private final Object source;
public ProducerCache(Object source, CamelContext camelContext) {
this(source, camelContext, CamelContextHelper.getMaximumCachePoolSize(camelContext));
}
public ProducerCache(Object source, CamelContext camelContext, int cacheSize) {
this(source, camelContext, camelContext.getProducerServicePool(), createLRUCache(cacheSize));
}
public ProducerCache(Object source, CamelContext camelContext, ServicePool<Endpoint, Producer> producerServicePool, Map<String, Producer> cache) {
this.source = source;
this.camelContext = camelContext;
this.pool = producerServicePool;
this.producers = cache;
}
/**
* Creates the {@link LRUCache} to be used.
* <p/>
* This implementation returns a {@link LRUSoftCache} instance.
* @param cacheSize the cache size
* @return the cache
*/
protected static LRUCache<String, Producer> createLRUCache(int cacheSize) {
// We use a soft reference cache to allow the JVM to re-claim memory if it runs low on memory.
return new LRUSoftCache<String, Producer>(cacheSize);
}
public CamelContext getCamelContext() {
return camelContext;
}
/**
* Gets the source which uses this cache
*
* @return the source
*/
public Object getSource() {
return source;
}
/**
* Acquires a pooled producer which you <b>must</b> release back again after usage using the
* {@link #releaseProducer(org.apache.camel.Endpoint, org.apache.camel.Producer)} method.
*
* @param endpoint the endpoint
* @return the producer
*/
public Producer acquireProducer(Endpoint endpoint) {
return doGetProducer(endpoint, true);
}
/**
* Releases an acquired producer back after usage.
*
* @param endpoint the endpoint
* @param producer the producer to release
* @throws Exception can be thrown if error stopping producer if that was needed.
*/
public void releaseProducer(Endpoint endpoint, Producer producer) throws Exception {
if (producer instanceof ServicePoolAware) {
// release back to the pool
pool.release(endpoint, producer);
} else if (!producer.isSingleton()) {
// stop non singleton producers as we should not leak resources
producer.stop();
}
}
/**
* Starts the {@link Producer} to be used for sending to the given endpoint
* <p/>
* This can be used to early start the {@link Producer} to ensure it can be created,
* such as when Camel is started. This allows to fail fast in case the {@link Producer}
* could not be started.
*
* @param endpoint the endpoint to send the exchange to
* @throws Exception is thrown if failed to create or start the {@link Producer}
*/
public void startProducer(Endpoint endpoint) throws Exception {
Producer producer = acquireProducer(endpoint);
releaseProducer(endpoint, producer);
}
/**
* Sends the exchange to the given endpoint.
* <p>
* This method will <b>not</b> throw an exception. If processing of the given
* Exchange failed then the exception is stored on the provided Exchange
*
* @param endpoint the endpoint to send the exchange to
* @param exchange the exchange to send
*/
public void send(Endpoint endpoint, Exchange exchange) {
sendExchange(endpoint, null, null, exchange);
}
/**
* Sends an exchange to an endpoint using a supplied
* {@link Processor} to populate the exchange
* <p>
* This method will <b>not</b> throw an exception. If processing of the given
* Exchange failed then the exception is stored on the return Exchange
*
* @param endpoint the endpoint to send the exchange to
* @param processor the transformer used to populate the new exchange
* @throws org.apache.camel.CamelExecutionException is thrown if sending failed
* @return the exchange
*/
public Exchange send(Endpoint endpoint, Processor processor) {
return sendExchange(endpoint, null, processor, null);
}
/**
* Sends an exchange to an endpoint using a supplied
* {@link Processor} to populate the exchange
* <p>
* This method will <b>not</b> throw an exception. If processing of the given
* Exchange failed then the exception is stored on the return Exchange
*
* @param endpoint the endpoint to send the exchange to
* @param pattern the message {@link ExchangePattern} such as
* {@link ExchangePattern#InOnly} or {@link ExchangePattern#InOut}
* @param processor the transformer used to populate the new exchange
* @return the exchange
*/
public Exchange send(Endpoint endpoint, ExchangePattern pattern, Processor processor) {
return sendExchange(endpoint, pattern, processor, null);
}
/**
* Sends an exchange to an endpoint using a supplied callback
* <p/>
* If an exception was thrown during processing, it would be set on the given Exchange
*
* @param endpoint the endpoint to send the exchange to
* @param exchange the exchange, can be <tt>null</tt> if so then create a new exchange from the producer
* @param pattern the exchange pattern, can be <tt>null</tt>
* @param callback the callback
* @return the response from the callback
*/
public <T> T doInProducer(Endpoint endpoint, Exchange exchange, ExchangePattern pattern, ProducerCallback<T> callback) {
T answer = null;
// get the producer and we do not mind if its pooled as we can handle returning it back to the pool
Producer producer = doGetProducer(endpoint, true);
if (producer == null) {
if (isStopped()) {
LOG.warn("Ignoring exchange sent after processor is stopped: " + exchange);
return null;
} else {
throw new IllegalStateException("No producer, this processor has not been started: " + this);
}
}
StopWatch watch = null;
if (exchange != null) {
// record timing for sending the exchange using the producer
watch = new StopWatch();
}
try {
// invoke the callback
answer = callback.doInProducer(producer, exchange, pattern);
} catch (Throwable e) {
if (exchange != null) {
exchange.setException(e);
}
} finally {
if (exchange != null) {
long timeTaken = watch.stop();
// emit event that the exchange was sent to the endpoint
EventHelper.notifyExchangeSent(exchange.getContext(), exchange, endpoint, timeTaken);
}
if (producer instanceof ServicePoolAware) {
// release back to the pool
pool.release(endpoint, producer);
} else if (!producer.isSingleton()) {
// stop non singleton producers as we should not leak resources
try {
ServiceHelper.stopService(producer);
} catch (Exception e) {
// ignore and continue
LOG.warn("Error stopping producer: " + producer, e);
}
}
}
return answer;
}
/**
* Sends an exchange to an endpoint using a supplied callback supporting the asynchronous routing engine.
* <p/>
* If an exception was thrown during processing, it would be set on the given Exchange
*
* @param endpoint the endpoint to send the exchange to
* @param exchange the exchange, can be <tt>null</tt> if so then create a new exchange from the producer
* @param pattern the exchange pattern, can be <tt>null</tt>
* @param callback the asynchronous callback
* @param producerCallback the producer template callback to be executed
* @return (doneSync) <tt>true</tt> to continue execute synchronously, <tt>false</tt> to continue being executed asynchronously
*/
public boolean doInAsyncProducer(Endpoint endpoint, Exchange exchange, ExchangePattern pattern, AsyncCallback callback, AsyncProducerCallback producerCallback) {
boolean sync = true;
// get the producer and we do not mind if its pooled as we can handle returning it back to the pool
Producer producer = doGetProducer(endpoint, true);
if (producer == null) {
if (isStopped()) {
LOG.warn("Ignoring exchange sent after processor is stopped: " + exchange);
return false;
} else {
throw new IllegalStateException("No producer, this processor has not been started: " + this);
}
}
StopWatch watch = null;
if (exchange != null) {
// record timing for sending the exchange using the producer
watch = new StopWatch();
}
try {
// invoke the callback
AsyncProcessor asyncProcessor = AsyncProcessorTypeConverter.convert(producer);
sync = producerCallback.doInAsyncProducer(producer, asyncProcessor, exchange, pattern, callback);
} catch (Throwable e) {
// ensure exceptions is caught and set on the exchange
if (exchange != null) {
exchange.setException(e);
}
} finally {
if (exchange != null && exchange.getException() == null) {
long timeTaken = watch.stop();
// emit event that the exchange was sent to the endpoint
EventHelper.notifyExchangeSent(exchange.getContext(), exchange, endpoint, timeTaken);
}
if (producer instanceof ServicePoolAware) {
// release back to the pool
pool.release(endpoint, producer);
} else if (!producer.isSingleton()) {
// stop non singleton producers as we should not leak resources
try {
ServiceHelper.stopService(producer);
} catch (Exception e) {
// ignore and continue
LOG.warn("Error stopping producer: " + producer, e);
}
}
}
return sync;
}
protected Exchange sendExchange(final Endpoint endpoint, ExchangePattern pattern,
final Processor processor, Exchange exchange) {
return doInProducer(endpoint, exchange, pattern, new ProducerCallback<Exchange>() {
public Exchange doInProducer(Producer producer, Exchange exchange, ExchangePattern pattern) {
if (exchange == null) {
exchange = pattern != null ? producer.createExchange(pattern) : producer.createExchange();
}
if (processor != null) {
// lets populate using the processor callback
try {
processor.process(exchange);
} catch (Exception e) {
// populate failed so return
exchange.setException(e);
return exchange;
}
}
// now lets dispatch
LOG.debug(">>>> {} {}", endpoint, exchange);
// set property which endpoint we send to
exchange.setProperty(Exchange.TO_ENDPOINT, endpoint.getEndpointUri());
// send the exchange using the processor
StopWatch watch = new StopWatch();
try {
// ensure we run in an unit of work
Producer target = new UnitOfWorkProducer(producer);
target.process(exchange);
} catch (Throwable e) {
// ensure exceptions is caught and set on the exchange
exchange.setException(e);
} finally {
// emit event that the exchange was sent to the endpoint
long timeTaken = watch.stop();
EventHelper.notifyExchangeSent(exchange.getContext(), exchange, endpoint, timeTaken);
}
return exchange;
}
});
}
protected synchronized Producer doGetProducer(Endpoint endpoint, boolean pooled) {
String key = endpoint.getEndpointUri();
Producer answer = producers.get(key);
if (pooled && answer == null) {
// try acquire from connection pool
answer = pool.acquire(endpoint);
}
if (answer == null) {
// create a new producer
try {
answer = endpoint.createProducer();
// must then start service so producer is ready to be used
ServiceHelper.startService(answer);
} catch (Exception e) {
throw new FailedToCreateProducerException(endpoint, e);
}
// add producer to cache or pool if applicable
if (pooled && answer instanceof ServicePoolAware) {
LOG.debug("Adding to producer service pool with key: {} for producer: {}", endpoint, answer);
answer = pool.addAndAcquire(endpoint, answer);
} else if (answer.isSingleton()) {
LOG.debug("Adding to producer cache with key: {} for producer: {}", endpoint, answer);
producers.put(key, answer);
}
}
return answer;
}
protected void doStop() throws Exception {
ServiceHelper.stopServices(producers, pool);
producers.clear();
}
protected void doStart() throws Exception {
ServiceHelper.startServices(pool, producers);
}
/**
* Returns the current size of the cache
*
* @return the current size
*/
public int size() {
int size = producers.size();
size += pool.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 (producers instanceof LRUCache) {
LRUCache cache = (LRUCache) producers;
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 (producers instanceof LRUCache) {
LRUCache cache = (LRUCache) producers;
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 (producers instanceof LRUCache) {
LRUCache cache = (LRUCache) producers;
misses = cache.getMisses();
}
return misses;
}
/**
* Resets the cache statistics
*/
public void resetCacheStatistics() {
if (producers instanceof LRUCache) {
LRUCache cache = (LRUCache) producers;
cache.resetStatistics();
}
}
/**
* Purges this cache
*/
public synchronized void purge() {
producers.clear();
pool.purge();
}
@Override
public String toString() {
return "ProducerCache for source: " + source + ", capacity: " + getCapacity();
}
}