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.transport;
018
019import java.io.ByteArrayOutputStream;
020import java.io.DataInputStream;
021import java.io.IOException;
022
023import org.apache.activemq.command.Command;
024import org.apache.activemq.command.LastPartialCommand;
025import org.apache.activemq.command.PartialCommand;
026import org.apache.activemq.openwire.OpenWireFormat;
027import org.apache.activemq.util.ByteArrayInputStream;
028import org.slf4j.Logger;
029import org.slf4j.LoggerFactory;
030
031/**
032 * Joins together of partial commands which were split into individual chunks of
033 * data.
034 * 
035 * 
036 */
037public class CommandJoiner extends TransportFilter {
038    private static final Logger LOG = LoggerFactory.getLogger(CommandJoiner.class);
039
040    private ByteArrayOutputStream out = new ByteArrayOutputStream();
041    private OpenWireFormat wireFormat;
042
043    public CommandJoiner(Transport next, OpenWireFormat wireFormat) {
044        super(next);
045        this.wireFormat = wireFormat;
046    }
047
048    public void onCommand(Object o) {
049        Command command = (Command)o;
050        byte type = command.getDataStructureType();
051        if (type == PartialCommand.DATA_STRUCTURE_TYPE || type == LastPartialCommand.DATA_STRUCTURE_TYPE) {
052            PartialCommand header = (PartialCommand)command;
053            byte[] partialData = header.getData();
054            try {
055                out.write(partialData);
056            } catch (IOException e) {
057                getTransportListener().onException(e);
058            }
059            if (type == LastPartialCommand.DATA_STRUCTURE_TYPE) {
060                try {
061                    byte[] fullData = out.toByteArray();
062                    out.reset();
063                    DataInputStream dataIn = new DataInputStream(new ByteArrayInputStream(fullData));
064                    Command completeCommand = (Command)wireFormat.unmarshal(dataIn);
065
066                    LastPartialCommand lastCommand = (LastPartialCommand)command;
067                    lastCommand.configure(completeCommand);
068
069                    getTransportListener().onCommand(completeCommand);
070                } catch (IOException e) {
071                    LOG.warn("Failed to unmarshal partial command: " + command);
072                    getTransportListener().onException(e);
073                }
074            }
075        } else {
076            getTransportListener().onCommand(command);
077        }
078    }
079
080    public void stop() throws Exception {
081        super.stop();
082        out = null;
083    }
084
085    public String toString() {
086        return next.toString();
087    }
088}