| /* |
| * |
| * 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.airavata.datacat.agent.dispatcher; |
| |
| import org.apache.airavata.datacat.models.OutputMetadataDTO; |
| |
| import java.util.LinkedList; |
| |
| public class MetadataDispatcherQueue { |
| public static MetadataDispatcherQueue instance; |
| private LinkedList<OutputMetadataDTO> queue; |
| |
| private MetadataDispatcherQueue() { |
| queue = new LinkedList<OutputMetadataDTO>(); |
| } |
| |
| /** |
| * Returns a singleton dispatch queue object |
| * |
| * @return Dispatch queue object |
| */ |
| public static MetadataDispatcherQueue getInstance() { |
| if (instance == null) { |
| instance = new MetadataDispatcherQueue(); |
| } |
| return instance; |
| } |
| |
| /** |
| * Put a message into the dispatch queue |
| * |
| * @param outputMetadataDTO |
| */ |
| public synchronized void addMetadataToQueue(OutputMetadataDTO outputMetadataDTO) { |
| queue.add(outputMetadataDTO); |
| notifyAll(); |
| } |
| |
| /** |
| * Returns a FileMetadata object from the dispatcher queue |
| * |
| * @return FileMetadata object |
| */ |
| public synchronized OutputMetadataDTO getMetadataFromQueue() { |
| OutputMetadataDTO outputMetadataDTO = queue.pollFirst(); |
| while (outputMetadataDTO == null) { |
| |
| try { |
| wait(); |
| } catch (InterruptedException e) { |
| e.printStackTrace(); |
| } |
| outputMetadataDTO = queue.pollFirst(); |
| } |
| return outputMetadataDTO; |
| } |
| |
| /** |
| * Returns dispatch queue size |
| * |
| * @return queue size |
| */ |
| public long getQueueSize() { |
| return queue.size(); |
| } |
| } |