| /* |
| * 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.processor; |
| |
| import java.util.concurrent.RejectedExecutionException; |
| import java.util.concurrent.ScheduledExecutorService; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import org.apache.camel.AsyncCallback; |
| import org.apache.camel.CamelContext; |
| import org.apache.camel.Exchange; |
| import org.apache.camel.Processor; |
| import org.apache.camel.support.processor.DelegateAsyncProcessor; |
| import org.apache.camel.util.ObjectHelper; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A useful base class for any processor which provides some kind of throttling or delayed processing. |
| * <p/> |
| * This implementation will block while waiting. |
| */ |
| public abstract class DelayProcessorSupport extends DelegateAsyncProcessor { |
| |
| private static final Logger LOG = LoggerFactory.getLogger(DelayProcessorSupport.class); |
| |
| private final CamelContext camelContext; |
| private final ScheduledExecutorService executorService; |
| private final boolean shutdownExecutorService; |
| private boolean asyncDelayed = true; |
| private boolean callerRunsWhenRejected = true; |
| private final AtomicInteger delayedCount = new AtomicInteger(); |
| |
| private final class ProcessCall implements Runnable { |
| private final Exchange exchange; |
| private final AsyncCallback callback; |
| |
| ProcessCall(Exchange exchange, AsyncCallback callback) { |
| this.exchange = exchange; |
| this.callback = callback; |
| } |
| |
| @Override |
| public void run() { |
| // we are running now so decrement the counter |
| delayedCount.decrementAndGet(); |
| |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("Delayed task woke up and continues routing for exchangeId: {}", exchange.getExchangeId()); |
| } |
| if (!isRunAllowed()) { |
| exchange.setException(new RejectedExecutionException("Run is not allowed")); |
| } |
| |
| // process the exchange now that we woke up |
| DelayProcessorSupport.this.processor.process(exchange, new AsyncCallback() { |
| @Override |
| public void done(boolean doneSync) { |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("Delayed task done for exchangeId: {}", exchange.getExchangeId()); |
| } |
| // we must done the callback from this async callback as well, to ensure callback is done correctly |
| // must invoke done on callback with false, as that is what the original caller would |
| // expect as we returned false in the process method |
| callback.done(false); |
| } |
| }); |
| } |
| } |
| |
| public DelayProcessorSupport(CamelContext camelContext, Processor processor) { |
| this(camelContext, processor, null, false); |
| } |
| |
| public DelayProcessorSupport(CamelContext camelContext, Processor processor, ScheduledExecutorService executorService, |
| boolean shutdownExecutorService) { |
| super(processor); |
| this.camelContext = camelContext; |
| this.executorService = executorService; |
| this.shutdownExecutorService = shutdownExecutorService; |
| } |
| |
| protected boolean processDelay(Exchange exchange, AsyncCallback callback, long delay) { |
| if (!isAsyncDelayed() || exchange.isTransacted()) { |
| // use synchronous delay (also required if using transactions) |
| try { |
| delay(delay, exchange); |
| // then continue routing |
| return processor.process(exchange, callback); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| // exception occurred so we are done |
| exchange.setException(e); |
| callback.done(true); |
| return true; |
| } catch (Exception e) { |
| // exception occurred so we are done |
| exchange.setException(e); |
| callback.done(true); |
| return true; |
| } |
| } else { |
| // asynchronous delay so schedule a process call task |
| // and increment the counter (we decrement the counter when we run the ProcessCall) |
| delayedCount.incrementAndGet(); |
| ProcessCall call = new ProcessCall(exchange, callback); |
| try { |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("Scheduling delayed task to run in {} millis for exchangeId: {}", |
| delay, exchange.getExchangeId()); |
| } |
| executorService.schedule(call, delay, TimeUnit.MILLISECONDS); |
| // tell Camel routing engine we continue routing asynchronous |
| return false; |
| } catch (RejectedExecutionException e) { |
| // we were not allowed to run the ProcessCall, so need to decrement the counter here |
| delayedCount.decrementAndGet(); |
| if (isCallerRunsWhenRejected()) { |
| if (!isRunAllowed()) { |
| exchange.setException(new RejectedExecutionException()); |
| } else { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug( |
| "Scheduling rejected task, so letting caller run, delaying at first for {} millis for exchangeId: {}", |
| delay, exchange.getExchangeId()); |
| } |
| // let caller run by processing |
| try { |
| delay(delay, exchange); |
| } catch (InterruptedException ie) { |
| exchange.setException(ie); |
| Thread.currentThread().interrupt(); |
| } |
| // then continue routing |
| return processor.process(exchange, callback); |
| } |
| } else { |
| exchange.setException(e); |
| } |
| // caller don't run the task so we are done |
| callback.done(true); |
| return true; |
| } |
| } |
| } |
| |
| @Override |
| public boolean process(Exchange exchange, AsyncCallback callback) { |
| if (!isRunAllowed()) { |
| exchange.setException(new RejectedExecutionException("Run is not allowed")); |
| callback.done(true); |
| return true; |
| } |
| |
| // calculate delay and wait |
| long delay; |
| try { |
| delay = calculateDelay(exchange); |
| if (delay <= 0) { |
| // no delay then continue routing |
| if (LOG.isTraceEnabled()) { |
| LOG.trace("No delay for exchangeId: {}", exchange.getExchangeId()); |
| } |
| return processor.process(exchange, callback); |
| } |
| } catch (Exception e) { |
| exchange.setException(e); |
| callback.done(true); |
| return true; |
| } |
| |
| return processDelay(exchange, callback, delay); |
| } |
| |
| public boolean isAsyncDelayed() { |
| return asyncDelayed; |
| } |
| |
| public void setAsyncDelayed(boolean asyncDelayed) { |
| this.asyncDelayed = asyncDelayed; |
| } |
| |
| public boolean isCallerRunsWhenRejected() { |
| return callerRunsWhenRejected; |
| } |
| |
| public void setCallerRunsWhenRejected(boolean callerRunsWhenRejected) { |
| this.callerRunsWhenRejected = callerRunsWhenRejected; |
| } |
| |
| protected abstract long calculateDelay(Exchange exchange); |
| |
| /** |
| * Gets the current number of {@link Exchange}s being delayed (hold back due throttle limit hit) |
| */ |
| public int getDelayedCount() { |
| return delayedCount.get(); |
| } |
| |
| /** |
| * Delays the given time before continuing. |
| * <p/> |
| * This implementation will block while waiting |
| * |
| * @param delay the delay time in millis |
| * @param exchange the exchange being processed |
| */ |
| protected void delay(long delay, Exchange exchange) throws InterruptedException { |
| // only run is we are started |
| if (!isRunAllowed()) { |
| return; |
| } |
| |
| if (delay >= 0) { |
| try { |
| // keep track on delayer counter while we sleep |
| delayedCount.incrementAndGet(); |
| sleep(delay); |
| } catch (InterruptedException e) { |
| handleSleepInterruptedException(e, exchange); |
| } finally { |
| delayedCount.decrementAndGet(); |
| } |
| } |
| } |
| |
| /** |
| * Called when a sleep is interrupted; allows derived classes to handle this case differently |
| */ |
| protected void handleSleepInterruptedException(InterruptedException e, Exchange exchange) throws InterruptedException { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Sleep interrupted, are we stopping? {}", isStopping() || isStopped()); |
| } |
| Thread.currentThread().interrupt(); |
| throw e; |
| } |
| |
| protected long currentSystemTime() { |
| return System.currentTimeMillis(); |
| } |
| |
| private void sleep(long delay) throws InterruptedException { |
| if (delay <= 0) { |
| return; |
| } |
| LOG.trace("Sleeping for: {} millis", delay); |
| Thread.sleep(delay); |
| } |
| |
| @Override |
| protected void doStart() throws Exception { |
| if (isAsyncDelayed()) { |
| ObjectHelper.notNull(executorService, "executorService", this); |
| } else if (executorService != null) { |
| asyncDelayed = true; |
| } |
| super.doStart(); |
| } |
| |
| @Override |
| protected void doShutdown() throws Exception { |
| if (shutdownExecutorService && executorService != null) { |
| camelContext.getExecutorServiceManager().shutdownNow(executorService); |
| } |
| super.doShutdown(); |
| } |
| |
| } |