package com.netflix.eventbus.impl;
import com.netflix.eventbus.spi.SubscriberConfigProvider;
import com.netflix.eventbus.utils.EventBusUtils;
import java.lang.reflect.Method;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.atomic.AtomicLong;
/**
* The default implementation for {@link com.netflix.eventbus.impl.EventBusImpl.ConsumerQueueSupplier}. Our
*
* @author Nitesh Kant (nkant@netflix.com)
*/
class DefaultConsumerQueueSupplier implements EventBusImpl.ConsumerQueueSupplier {
@Override
public ConsumerQueue get(Method subscriber, final SubscriberConfigProvider.SubscriberConfig subscriberConfig, final AtomicLong queueSizeCounter) {
switch (subscriberConfig.getBatchingStrategy()) {
case Age:
return new AgeBatchingQueue(subscriber, subscriberConfig, queueSizeCounter);
case SizeOrAge:
return new SizeAndAgeBatchingQueue(subscriber, subscriberConfig, queueSizeCounter);
}
return new ConsumerQueue() {
private LinkedBlockingQueue delegate = new LinkedBlockingQueue(EventBusUtils.getQueueSize(subscriberConfig));
@Override
@SuppressWarnings("unchecked")
public boolean offer(Object event) {
boolean offered = delegate.offer(event);
if(offered) {
queueSizeCounter.incrementAndGet();
}
return offered;
}
@Override
public Object nonBlockingTake() {
Object retrievedItem = delegate.poll();
if (null != retrievedItem) {
queueSizeCounter.decrementAndGet();
}
return retrievedItem;
}
@Override
public Object blockingTake() throws InterruptedException {
Object retrieved = delegate.take();
queueSizeCounter.decrementAndGet();
return retrieved;
}
@Override
public void clear() {
delegate.clear();
queueSizeCounter.set(0);
}
};
}
}