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.Broker;
020import org.apache.activemq.broker.region.DurableTopicSubscription;
021import org.apache.activemq.broker.region.Subscription;
022import org.apache.activemq.broker.region.cursors.PendingMessageCursor;
023import org.apache.activemq.broker.region.cursors.StoreDurableSubscriberCursor;
024import org.apache.activemq.kaha.Store;
025
026/**
027 * Creates a PendingMessageCursor that access the persistent store to retrieve
028 * messages
029 * 
030 * @org.apache.xbean.XBean element="storeDurableSubscriberCursor"
031 *                         description="Pending messages for a durable
032 *                         subscriber are referenced from the Store"
033 * 
034 */
035public class StorePendingDurableSubscriberMessageStoragePolicy implements PendingDurableSubscriberMessageStoragePolicy {
036    boolean immediatePriorityDispatch = true;
037    boolean useCache = true;
038
039    public boolean isImmediatePriorityDispatch() {
040        return immediatePriorityDispatch;
041    }
042
043    /**
044     * Ensure that new higher priority messages will get an immediate dispatch
045     * rather than wait for the end of the current cursor batch.
046     * Useful when there is a large message backlog and intermittent high priority messages.
047     *
048     * @param immediatePriorityDispatch
049     */
050    public void setImmediatePriorityDispatch(boolean immediatePriorityDispatch) {
051        this.immediatePriorityDispatch = immediatePriorityDispatch;
052    }
053
054    public boolean isUseCache() {
055        return useCache;
056    }
057
058    public void setUseCache(boolean useCache) {
059        this.useCache = useCache;
060    }
061
062    /**
063     * Retrieve the configured pending message storage cursor;
064     * @param broker 
065     * 
066     * @param clientId
067     * @param name
068     * @param maxBatchSize
069     * @param sub 
070     * @return the Pending Message cursor
071     */
072    public PendingMessageCursor getSubscriberPendingMessageCursor(Broker broker,String clientId, String name, int maxBatchSize, DurableTopicSubscription sub) {
073        StoreDurableSubscriberCursor cursor = new StoreDurableSubscriberCursor(broker,clientId, name, maxBatchSize, sub);
074        cursor.setUseCache(isUseCache());
075        cursor.setImmediatePriorityDispatch(isImmediatePriorityDispatch());
076        return cursor;
077    }
078}