org.apache.camel.component.seda.SedaProducer Maven / Gradle / Ivy
/*
* 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.component.seda;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import org.apache.camel.AsyncCallback;
import org.apache.camel.Exchange;
import org.apache.camel.ExchangeTimedOutException;
import org.apache.camel.ExtendedExchange;
import org.apache.camel.WaitForTaskToComplete;
import org.apache.camel.support.DefaultAsyncProducer;
import org.apache.camel.support.ExchangeHelper;
import org.apache.camel.support.SynchronizationAdapter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SedaProducer extends DefaultAsyncProducer {
private static final Logger LOG = LoggerFactory.getLogger(SedaProducer.class);
private final SedaEndpoint endpoint;
private final WaitForTaskToComplete waitForTaskToComplete;
private final long timeout;
private final boolean blockWhenFull;
private final boolean discardWhenFull;
private final long offerTimeout;
public SedaProducer(SedaEndpoint endpoint, WaitForTaskToComplete waitForTaskToComplete,
long timeout, boolean blockWhenFull, boolean discardWhenFull, long offerTimeout) {
super(endpoint);
this.endpoint = endpoint;
this.waitForTaskToComplete = waitForTaskToComplete;
this.timeout = timeout;
this.blockWhenFull = blockWhenFull;
this.discardWhenFull = discardWhenFull;
this.offerTimeout = offerTimeout;
}
@Override
public boolean process(final Exchange exchange, final AsyncCallback callback) {
WaitForTaskToComplete wait = waitForTaskToComplete;
if (exchange.getProperty(Exchange.ASYNC_WAIT) != null) {
wait = exchange.getProperty(Exchange.ASYNC_WAIT, WaitForTaskToComplete.class);
}
if (wait == WaitForTaskToComplete.Always
|| wait == WaitForTaskToComplete.IfReplyExpected && ExchangeHelper.isOutCapable(exchange)) {
// do not handover the completion as we wait for the copy to complete, and copy its result back when it done
Exchange copy = prepareCopy(exchange, false);
// latch that waits until we are complete
final CountDownLatch latch = new CountDownLatch(1);
// we should wait for the reply so install a on completion so we know when its complete
copy.adapt(ExtendedExchange.class).addOnCompletion(new SynchronizationAdapter() {
@Override
public void onDone(Exchange response) {
// check for timeout, which then already would have invoked the latch
if (latch.getCount() == 0) {
if (LOG.isTraceEnabled()) {
LOG.trace("{}. Timeout occurred so response will be ignored: {}", this, response.getMessage());
}
return;
} else {
if (LOG.isTraceEnabled()) {
LOG.trace("{} with response: {}", this, response.getMessage());
}
try {
ExchangeHelper.copyResults(exchange, response);
} finally {
// always ensure latch is triggered
latch.countDown();
}
}
}
@Override
public boolean allowHandover() {
// do not allow handover as we want to seda producer to have its completion triggered
// at this point in the routing (at this leg), instead of at the very last (this ensure timeout is honored)
return false;
}
@Override
public String toString() {
return "onDone at endpoint: " + endpoint;
}
});
try {
// do not copy as we already did the copy
addToQueue(copy, false);
} catch (SedaConsumerNotAvailableException e) {
exchange.setException(e);
callback.done(true);
return true;
}
if (timeout > 0) {
if (LOG.isTraceEnabled()) {
LOG.trace("Waiting for task to complete using timeout (ms): {} at [{}]", timeout,
endpoint.getEndpointUri());
}
// lets see if we can get the task done before the timeout
boolean done = false;
try {
done = latch.await(timeout, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
// ignore
}
if (!done) {
exchange.setException(new ExchangeTimedOutException(exchange, timeout));
// remove timed out Exchange from queue
endpoint.getQueue().remove(copy);
// count down to indicate timeout
latch.countDown();
}
} else {
if (LOG.isTraceEnabled()) {
LOG.trace("Waiting for task to complete (blocking) at [{}]", endpoint.getEndpointUri());
}
// no timeout then wait until its done
try {
latch.await();
} catch (InterruptedException e) {
// ignore
}
}
} else {
// no wait, eg its a InOnly then just add to queue and return
try {
addToQueue(exchange, true);
} catch (SedaConsumerNotAvailableException e) {
exchange.setException(e);
callback.done(true);
return true;
}
}
// we use OnCompletion on the Exchange to callback and wait for the Exchange to be done
// so we should just signal the callback we are done synchronously
callback.done(true);
return true;
}
protected Exchange prepareCopy(Exchange exchange, boolean handover) {
// use a new copy of the exchange to route async (and use same message id)
// if handover we need to do special handover to avoid handing over
// RestBindingMarshalOnCompletion as it should not be handed over with SEDA
Exchange copy = ExchangeHelper.createCorrelatedCopy(exchange, handover, true);
return copy;
}
@Override
protected void doStart() throws Exception {
super.doStart();
endpoint.onStarted(this);
}
@Override
protected void doStop() throws Exception {
endpoint.onStopped(this);
super.doStop();
}
/**
* Strategy method for adding the exchange to the queue.
*
* Will perform a blocking "put" if blockWhenFull is true, otherwise it will simply add which will throw exception
* if the queue is full
*
* @param exchange the exchange to add to the queue
* @param copy whether to create a copy of the exchange to use for adding to the queue
*/
protected void addToQueue(Exchange exchange, boolean copy) throws SedaConsumerNotAvailableException {
BlockingQueue queue = null;
QueueReference queueReference = endpoint.getQueueReference();
if (queueReference != null) {
queue = queueReference.getQueue();
}
if (queue == null) {
throw new SedaConsumerNotAvailableException("No queue available on endpoint: " + endpoint, exchange);
}
boolean empty = !queueReference.hasConsumers();
if (empty) {
if (endpoint.isFailIfNoConsumers()) {
throw new SedaConsumerNotAvailableException("No consumers available on endpoint: " + endpoint, exchange);
} else if (endpoint.isDiscardIfNoConsumers()) {
LOG.debug("Discard message as no active consumers on endpoint: {}", endpoint);
return;
}
}
Exchange target = exchange;
// handover the completion so its the copy which performs that, as we do not wait
if (copy) {
target = prepareCopy(exchange, true);
}
LOG.trace("Adding Exchange to queue: {}", target);
if (discardWhenFull) {
try {
boolean added = queue.offer(target, 0, TimeUnit.MILLISECONDS);
if (!added) {
LOG.trace("Discarding Exchange as queue is full: {}", target);
}
} catch (InterruptedException e) {
// ignore
LOG.debug("Offer interrupted, are we stopping? {}", isStopping() || isStopped());
}
} else if (blockWhenFull && offerTimeout == 0) {
try {
queue.put(target);
} catch (InterruptedException e) {
// ignore
LOG.debug("Put interrupted, are we stopping? {}", isStopping() || isStopped());
}
} else if (blockWhenFull && offerTimeout > 0) {
try {
boolean added = queue.offer(target, offerTimeout, TimeUnit.MILLISECONDS);
if (!added) {
throw new IllegalStateException(
"Fails to insert element into queue, "
+ "after timeout of " + offerTimeout + " milliseconds");
}
} catch (InterruptedException e) {
// ignore
LOG.debug("Offer interrupted, are we stopping? {}", isStopping() || isStopped());
}
} else {
queue.add(target);
}
}
}