/**
* 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.WaitForTaskToComplete;
import org.apache.camel.impl.DefaultAsyncProducer;
import org.apache.camel.support.SynchronizationAdapter;
import org.apache.camel.util.ExchangeHelper;
/**
* @version
*/
public class SedaProducer extends DefaultAsyncProducer {
protected final BlockingQueue<Exchange> queue;
private final SedaEndpoint endpoint;
private final WaitForTaskToComplete waitForTaskToComplete;
private final long timeout;
private final boolean blockWhenFull;
/**
* @deprecated use the other constructor
*/
@Deprecated
public SedaProducer(SedaEndpoint endpoint, BlockingQueue<Exchange> queue, WaitForTaskToComplete waitForTaskToComplete, long timeout) {
this(endpoint, queue, waitForTaskToComplete, timeout, false);
}
public SedaProducer(SedaEndpoint endpoint, BlockingQueue<Exchange> queue, WaitForTaskToComplete waitForTaskToComplete,
long timeout, boolean blockWhenFull) {
super(endpoint);
this.queue = queue;
this.endpoint = endpoint;
this.waitForTaskToComplete = waitForTaskToComplete;
this.timeout = timeout;
this.blockWhenFull = blockWhenFull;
}
@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.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.hasOut() ? response.getOut() : response.getIn());
}
return;
} else {
if (log.isTraceEnabled()) {
log.trace("{} with response: {}", this, response.hasOut() ? response.getOut() : response.getIn());
}
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;
}
});
log.trace("Adding Exchange to queue: {}", copy);
addToQueue(copy);
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
queue.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
// handover the completion so its the copy which performs that, as we do not wait
Exchange copy = prepareCopy(exchange, true);
log.trace("Adding Exchange to queue: {}", copy);
addToQueue(copy);
}
// 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
Exchange copy = ExchangeHelper.createCorrelatedCopy(exchange, handover);
// set a new from endpoint to be the seda queue
copy.setFromEndpoint(endpoint);
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.
* <p>
* 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
*/
protected void addToQueue(Exchange exchange) {
if (blockWhenFull) {
try {
queue.put(exchange);
} catch (InterruptedException e) {
// ignore
log.debug("Put interrupted, are we stopping? {}", isStopping() || isStopped());
}
} else {
queue.add(exchange);
}
}
}