Java tutorial
/* * (C) 2007-2012 Alibaba Group Holding Limited. * * Licensed 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. * Authors: * wuhua <wq163@163.com> , boyan <killme2008@gmail.com> */ package com.taobao.metamorphosis.storm.spout; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.Executor; import java.util.concurrent.TimeUnit; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import backtype.storm.spout.Scheme; import backtype.storm.spout.SpoutOutputCollector; import backtype.storm.task.TopologyContext; import backtype.storm.topology.OutputFieldsDeclarer; import backtype.storm.topology.base.BaseRichSpout; import com.taobao.gecko.core.util.LinkedTransferQueue; import com.taobao.metamorphosis.Message; import com.taobao.metamorphosis.client.MessageSessionFactory; import com.taobao.metamorphosis.client.MetaClientConfig; import com.taobao.metamorphosis.client.MetaMessageSessionFactory; import com.taobao.metamorphosis.client.consumer.ConsumerConfig; import com.taobao.metamorphosis.client.consumer.MessageConsumer; import com.taobao.metamorphosis.client.consumer.MessageListener; import com.taobao.metamorphosis.exception.MetaClientException; /** * metamorphosisstorm spout * * @author boyan(boyan@taobao.com) * @date 2011-11-8 * */ public class MetaSpout extends BaseRichSpout { private static final long serialVersionUID = 4382748324382L; public static final String FETCH_MAX_SIZE = "meta.fetch.max_size"; public static final String TOPIC = "meta.topic"; public static final int DEFAULT_MAX_SIZE = 128 * 1024; private transient MessageConsumer messageConsumer; private transient MessageSessionFactory sessionFactory; private final MetaClientConfig metaClientConfig; private final ConsumerConfig consumerConfig; static final Log log = LogFactory.getLog(MetaSpout.class); private final Scheme scheme; /** * Time in milliseconds to wait for a message from the queue if there is no * message ready when the topology requests a tuple (via * {@link #nextTuple()}). */ public static final long WAIT_FOR_NEXT_MESSAGE = 1L; private transient ConcurrentHashMap<Long, MetaMessageWrapper> id2wrapperMap; private transient SpoutOutputCollector collector; private transient LinkedTransferQueue<MetaMessageWrapper> messageQueue; public MetaSpout(final MetaClientConfig metaClientConfig, final ConsumerConfig consumerConfig, final Scheme scheme) { super(); this.metaClientConfig = metaClientConfig; this.consumerConfig = consumerConfig; this.scheme = scheme; } @Override public void open(final Map conf, final TopologyContext context, final SpoutOutputCollector collector) { final String topic = (String) conf.get(TOPIC); if (topic == null) { throw new IllegalArgumentException(TOPIC + " is null"); } Integer maxSize = (Integer) conf.get(FETCH_MAX_SIZE); if (maxSize == null) { log.warn("Using default FETCH_MAX_SIZE"); maxSize = DEFAULT_MAX_SIZE; } this.id2wrapperMap = new ConcurrentHashMap<Long, MetaMessageWrapper>(); this.messageQueue = new LinkedTransferQueue<MetaMessageWrapper>(); try { this.collector = collector; this.setUpMeta(topic, maxSize); } catch (final MetaClientException e) { log.error("Setup meta consumer failed", e); } } private void setUpMeta(final String topic, final Integer maxSize) throws MetaClientException { this.sessionFactory = new MetaMessageSessionFactory(this.metaClientConfig); this.messageConsumer = this.sessionFactory.createConsumer(this.consumerConfig); this.messageConsumer.subscribe(topic, maxSize, new MessageListener() { @Override public void recieveMessages(final Message message) { final MetaMessageWrapper wrapper = new MetaMessageWrapper(message); MetaSpout.this.id2wrapperMap.put(message.getId(), wrapper); MetaSpout.this.messageQueue.offer(wrapper); try { wrapper.latch.await(); } catch (final InterruptedException e) { Thread.currentThread().interrupt(); } // if (!wrapper.success) { message.setRollbackOnly(); } } @Override public Executor getExecutor() { return null; } }).completeSubscribe(); } @Override public void close() { try { this.messageConsumer.shutdown(); } catch (final MetaClientException e) { log.error("Shutdown consumer failed", e); } try { this.sessionFactory.shutdown(); } catch (final MetaClientException e) { log.error("Shutdown session factory failed", e); } } @Override public void nextTuple() { if (this.messageConsumer != null) { try { final MetaMessageWrapper wrapper = this.messageQueue.poll(WAIT_FOR_NEXT_MESSAGE, TimeUnit.MILLISECONDS); if (wrapper == null) { return; } final Message message = wrapper.message; this.collector.emit(this.scheme.deserialize(message.getData()), message.getId()); } catch (final InterruptedException e) { // interrupted while waiting for message, big deal } } } @Override public void ack(final Object msgId) { if (msgId instanceof Long) { final long id = (Long) msgId; final MetaMessageWrapper wrapper = this.id2wrapperMap.remove(id); if (wrapper == null) { log.warn(String.format("don't know how to ack(%s: %s)", msgId.getClass().getName(), msgId)); return; } wrapper.success = true; wrapper.latch.countDown(); } else { log.warn(String.format("don't know how to ack(%s: %s)", msgId.getClass().getName(), msgId)); } } @Override public void fail(final Object msgId) { if (msgId instanceof Long) { final long id = (Long) msgId; final MetaMessageWrapper wrapper = this.id2wrapperMap.remove(id); if (wrapper == null) { log.warn(String.format("don't know how to reject(%s: %s)", msgId.getClass().getName(), msgId)); return; } wrapper.success = false; wrapper.latch.countDown(); } else { log.warn(String.format("don't know how to reject(%s: %s)", msgId.getClass().getName(), msgId)); } } @Override public void declareOutputFields(final OutputFieldsDeclarer declarer) { declarer.declare(this.scheme.getOutputFields()); } public boolean isDistributed() { return true; } }