| /** |
| * 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.oozie.event; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.ConcurrentLinkedQueue; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.oozie.client.event.Event; |
| import org.apache.oozie.service.ConfigurationService; |
| import org.apache.oozie.service.EventHandlerService; |
| import org.apache.oozie.util.XLog; |
| |
| /** |
| * An implementation of the EventQueue, defining a memory-based data structure |
| * holding the events |
| */ |
| public class MemoryEventQueue implements EventQueue { |
| |
| private static ConcurrentLinkedQueue<EventQueueElement> eventQueue; |
| private static AtomicInteger currentSize; |
| private static int maxSize; |
| private static XLog LOG; |
| private static int batchSize; |
| |
| @Override |
| public void init(Configuration conf) { |
| eventQueue = new ConcurrentLinkedQueue<EventQueueElement>(); |
| maxSize = ConfigurationService.getInt(conf, EventHandlerService.CONF_QUEUE_SIZE); |
| currentSize = new AtomicInteger(); |
| batchSize = ConfigurationService.getInt(conf, EventHandlerService.CONF_BATCH_SIZE); |
| LOG = XLog.getLog(getClass()); |
| LOG.info("Memory Event Queue initialized with Max size = [{0}], Batch drain size = [{1}]", maxSize, batchSize); |
| } |
| |
| @Override |
| public int getBatchSize() { |
| return batchSize; |
| } |
| |
| @Override |
| public void add(Event e) { |
| EventQueueElement eqe = new EventQueueElement(e); |
| try { |
| if (size() <= maxSize) { |
| if (eventQueue.add(eqe)) { |
| currentSize.incrementAndGet(); |
| } |
| } |
| else { |
| LOG.warn("Queue size [{0}] reached max limit. Element [{1}] not added", size(), e); |
| } |
| } |
| catch (IllegalStateException ise) { |
| LOG.warn("Unable to add event due to " + ise); |
| } |
| } |
| |
| @Override |
| public List<Event> pollBatch() { |
| // batch drain |
| List<Event> eventBatch = new ArrayList<Event>(); |
| for (int i = 0; i < batchSize; i++) { |
| EventQueueElement polled = eventQueue.poll(); |
| if (polled != null) { |
| currentSize.decrementAndGet(); |
| eventBatch.add(polled.event); |
| } |
| else { |
| LOG.trace("Current queue size [{0}] less than polling batch size [{1}]", currentSize.get(), batchSize); |
| break; |
| } |
| } |
| return eventBatch; |
| } |
| |
| @Override |
| public Event poll() { |
| EventQueueElement polled = eventQueue.poll(); |
| if (polled != null) { |
| currentSize.decrementAndGet(); |
| return polled.event; |
| } |
| return null; |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return size() == 0; |
| } |
| |
| @Override |
| public int size() { |
| return currentSize.intValue(); |
| } |
| |
| @Override |
| public Event peek() { |
| EventQueueElement peeked = eventQueue.peek(); |
| if (peeked != null) { |
| return peeked.event; |
| } |
| return null; |
| } |
| |
| @Override |
| public void clear() { |
| eventQueue.clear(); |
| currentSize.set(0); |
| } |
| |
| } |