001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.broker.region.policy;
018
019import org.apache.activemq.broker.region.TopicSubscription;
020
021/**
022 * This PendingMessageLimitStrategy sets the maximum pending message limit value to be
023 * a multiplier of the prefetch limit of the subscription.
024 * 
025 * @org.apache.xbean.XBean
026 * 
027 * 
028 */
029public class PrefetchRatePendingMessageLimitStrategy implements PendingMessageLimitStrategy {
030
031    private double multiplier = 0.5;
032
033    public int getMaximumPendingMessageLimit(TopicSubscription subscription) {
034        int prefetchSize = subscription.getConsumerInfo().getPrefetchSize();
035        return (int) (prefetchSize * multiplier);
036    }
037
038    public double getMultiplier() {
039        return multiplier;
040    }
041
042    /**
043     * Sets the multiplier of the prefetch size which will be used to define the maximum number of pending
044     * messages for non-durable topics before messages are discarded.
045     */
046    public void setMultiplier(double rate) {
047        this.multiplier = rate;
048    }
049
050}