com.redis.spring.batch.memcached.reader.LruMetadumpItemReader Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of spring-batch-memcached Show documentation
Spring Batch Memcached
The newest version!
package com.redis.spring.batch.memcached.reader;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.ClassUtils;

import com.redis.spring.batch.item.AbstractPollableItemReader;
import com.redis.spring.batch.memcached.reader.LruCrawlerMetadumpOperation.Callback;

import net.spy.memcached.MemcachedClient;
import net.spy.memcached.ops.OperationStatus;

public class LruMetadumpItemReader extends AbstractPollableItemReader {

	public static final int DEFAULT_QUEUE_CAPACITY = 10000;

	private final MemcachedClient client;

	private int queueCapacity = DEFAULT_QUEUE_CAPACITY;

	protected BlockingQueue queue;
	private CountDownLatch latch;

	public LruMetadumpItemReader(MemcachedClient client) {
		setName(ClassUtils.getShortName(getClass()));
		this.client = client;
	}

	@Override
	protected synchronized void doOpen() throws Exception {
		if (queue == null) {
			queue = new LinkedBlockingQueue<>(queueCapacity);
		}
		if (latch == null) {
			latch = client.broadcastOp((n, l) -> new LruCrawlerMetadumpOperationImpl("all", new MetadumpCallback(l)));
		}
	}

	@Override
	protected LruMetadumpEntry doPoll(long timeout, TimeUnit unit) throws InterruptedException {
		return queue.poll(timeout, unit);
	}

	@Override
	protected synchronized void doClose() throws Exception {
		if (client != null) {
			client.shutdown();
		}
		queue = null;
	}

	@Override
	public boolean isComplete() {
		return latch.getCount() == 0 && queue.isEmpty();
	}

	private class MetadumpCallback implements Callback {

		private final Log log = LogFactory.getLog(getClass());

		private final CountDownLatch latch;

		public MetadumpCallback(CountDownLatch latch) {
			this.latch = latch;
		}

		@Override
		public void gotMetadump(LruMetadumpEntry entry) {
			try {
				queue.put(entry);
			} catch (InterruptedException e) {
				// ignore
			}
		}

		@Override
		public void receivedStatus(OperationStatus status) {
			if (!status.isSuccess()) {
				log.error("Unsuccessful lru_crawler metadump: " + status);
			}
		}

		@Override
		public void complete() {
			latch.countDown();
		}
	}

	public BlockingQueue getQueue() {
		return queue;
	}

	public int getQueueCapacity() {
		return queueCapacity;
	}

	public void setQueueCapacity(int queueCapacity) {
		this.queueCapacity = queueCapacity;
	}

}