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 */ 017 package org.apache.activemq.store; 018 019 import java.io.IOException; 020 import org.apache.activemq.Service; 021 import org.apache.activemq.broker.ConnectionContext; 022 import org.apache.activemq.command.ActiveMQDestination; 023 import org.apache.activemq.command.Message; 024 import org.apache.activemq.command.MessageAck; 025 import org.apache.activemq.command.MessageId; 026 import org.apache.activemq.usage.MemoryUsage; 027 028 /** 029 * Represents a message store which is used by the persistent implementations 030 * 031 * @version $Revision: 1.5 $ 032 */ 033 public interface MessageStore extends Service { 034 035 /** 036 * Adds a message to the message store 037 * 038 * @param context context 039 * @param message 040 * @throws IOException 041 */ 042 void addMessage(ConnectionContext context, Message message) throws IOException; 043 044 /** 045 * Looks up a message using either the String messageID or the 046 * messageNumber. Implementations are encouraged to fill in the missing key 047 * if its easy to do so. 048 * 049 * @param identity which contains either the messageID or the messageNumber 050 * @return the message or null if it does not exist 051 * @throws IOException 052 */ 053 Message getMessage(MessageId identity) throws IOException; 054 055 /** 056 * Removes a message from the message store. 057 * 058 * @param context 059 * @param ack the ack request that cause the message to be removed. It 060 * conatins the identity which contains the messageID of the 061 * message that needs to be removed. 062 * @throws IOException 063 */ 064 void removeMessage(ConnectionContext context, MessageAck ack) throws IOException; 065 066 /** 067 * Removes all the messages from the message store. 068 * 069 * @param context 070 * @throws IOException 071 */ 072 void removeAllMessages(ConnectionContext context) throws IOException; 073 074 /** 075 * Recover any messages to be delivered. 076 * 077 * @param container 078 * @throws Exception 079 */ 080 void recover(MessageRecoveryListener container) throws Exception; 081 082 /** 083 * The destination that the message store is holding messages for. 084 * 085 * @return the destination 086 */ 087 ActiveMQDestination getDestination(); 088 089 /** 090 * @param memoeyUSage The SystemUsage that is controlling the 091 * destination's memory usage. 092 */ 093 void setMemoryUsage(MemoryUsage memoeyUSage); 094 095 /** 096 * @return the number of messages ready to deliver 097 * @throws IOException 098 * 099 */ 100 int getMessageCount() throws IOException; 101 102 /** 103 * A hint to the Store to reset any batching state for the Destination 104 * 105 */ 106 void resetBatching(); 107 108 void recoverNextMessages(int maxReturned, MessageRecoveryListener listener) throws Exception; 109 110 void dispose(ConnectionContext context); 111 112 /** 113 * allow caching cursors to set the current batch offset when cache is exhausted 114 * @param messageId 115 * @throws Exception 116 */ 117 void setBatch(MessageId messageId) throws Exception; 118 119 /** 120 * flag to indicate if the store is empty 121 * @return true if the message count is 0 122 * @throws Exception 123 */ 124 boolean isEmpty() throws Exception; 125 126 }