/*********************************************************************************************************************** * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu) * * 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. **********************************************************************************************************************/ package eu.stratosphere.nephele.instance.cluster; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import eu.stratosphere.nephele.instance.InstanceType; /** * This class represents a pending request, i.e. a request for a particular type and number of {@link AbstractInstance} * objects which could not be fulfilled yet. * <p> * This class is not thread-safe. * */ public final class PendingRequestsMap { /** * The map storing the pending instance requests for the job this pending request object belongs to. */ private final Map<InstanceType, Integer> pendingRequests = new HashMap<InstanceType, Integer>(); /** * Checks if the job this object belongs to has pending instance requests. * * @return <code>true</code> if the job this object belongs to has pending instance requests, <code>false</code> * otherwise */ boolean hasPendingRequests() { return !(this.pendingRequests.isEmpty()); } /** * Adds the a pending request for the given number of instances of the given type to this map. * * @param instanceType * the requested instance type * @param numberOfInstances * the requested number of instances of this type */ void addRequest(final InstanceType instanceType, final int numberOfInstances) { Integer numberOfRemainingInstances = this.pendingRequests.get(instanceType); if (numberOfRemainingInstances == null) { numberOfRemainingInstances = Integer.valueOf(numberOfInstances); } else { numberOfRemainingInstances = Integer.valueOf(numberOfRemainingInstances.intValue() + numberOfInstances); } this.pendingRequests.put(instanceType, numberOfRemainingInstances); } /** * Returns an iterator for the pending requests encapsulated in this map. * * @return an iterator for the pending requests encapsulated in this map */ Iterator<Map.Entry<InstanceType, Integer>> iterator() { return this.pendingRequests.entrySet().iterator(); } /** * Decreases the number of remaining instances to request of the given type. * * @param instanceType * the instance type for which the number of remaining instances shall be decreased */ void decreaseNumberOfPendingInstances(final InstanceType instanceType) { Integer numberOfRemainingInstances = this.pendingRequests.get(instanceType); if (numberOfRemainingInstances == null) { return; } numberOfRemainingInstances = Integer.valueOf(numberOfRemainingInstances.intValue() - 1); if (numberOfRemainingInstances.intValue() == 0) { this.pendingRequests.remove(instanceType); } else { this.pendingRequests.put(instanceType, numberOfRemainingInstances); } } }