/*
* Copyright 1999,2004-2005 The Apache Software Foundation.
*
* 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 org.apache.catalina.tribes.io;
import java.nio.ByteBuffer;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import org.apache.catalina.tribes.ChannelMessage;
import java.io.IOException;
/**
* The object reader object is an object used in conjunction with
* java.nio TCP messages. This object stores the message bytes in a
* <code>XByteBuffer</code> until a full package has been received.
* When a full package has been received, the append method will call messageDataReceived
* on the callback object associated with this object reader.<BR>
* This object uses an XByteBuffer which is an extendable object buffer that also allows
* for message encoding and decoding.
*
* @author Filip Hanik
* @version $Revision: 377484 $, $Date: 2006-02-13 15:00:05 -0600 (Mon, 13 Feb 2006) $
*/
public class ObjectReader {
protected static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory.getLog(ObjectReader.class);
private SocketChannel channel;
private ListenCallback callback;
private XByteBuffer buffer;
/**
* Create XByteBuffer and store parameter
* @param channel
* @param selector
* @param callback
*/
public ObjectReader(SocketChannel channel, Selector selector, ListenCallback callback) {
this.channel = channel;
this.callback = callback;
try {
this.buffer = new XByteBuffer(channel.socket().getReceiveBufferSize(), true);
}catch ( IOException x ) {
//unable to get buffer size
log.warn("Unable to retrieve the socket channel receiver buffer size, setting to default 43800 bytes.");
this.buffer = new XByteBuffer(43800,true);
}
}
/**
* get the current SimpleTcpCluster
* @return Returns the callback.
*/
public ListenCallback getCallback() {
return callback;
}
/**
* Get underlying NIO channel
* @return The socket
*/
public SocketChannel getChannel() {
return this.channel;
}
/**
* Append new bytes to buffer.
* @see XByteBuffer#countPackages()
* @param data new transfer buffer
* @param off offset
* @param len length in buffer
* @return number of messages that sended to callback
* @throws java.io.IOException
*/
public int append(ByteBuffer data, int len, boolean count) throws java.io.IOException {
buffer.append(data,len);
int pkgCnt = -1;
if ( count ) pkgCnt = buffer.countPackages();
return pkgCnt;
}
public int append(byte[] data,int off,int len, boolean count) throws java.io.IOException {
buffer.append(data,off,len);
int pkgCnt = -1;
if ( count ) pkgCnt = buffer.countPackages();
return pkgCnt;
}
/**
* Send buffer to cluster listener (callback).
* Is message complete receiver send message to callback?
*
* @see org.apache.catalina.tribes.tcp.ClusterReceiverBase#messageDataReceived(ChannelMessage)
* @see XByteBuffer#doesPackageExist()
* @see XByteBuffer#extractPackage(boolean)
*
* @return number of received packages/messages
* @throws java.io.IOException
*/
public int execute() throws java.io.IOException {
int pkgCnt = 0;
boolean pkgExists = buffer.doesPackageExist();
while ( pkgExists ) {
ChannelMessage data = buffer.extractPackage(true);
getCallback().messageDataReceived(data);
pkgCnt++;
pkgExists = buffer.doesPackageExist();
}
return pkgCnt;
}
/**
* Returns the number of packages that the reader has read
* @return int
*/
public int count() {
return buffer.countPackages();
}
/**
* Write Ack to sender
* @param buf
* @return The bytes written count
* @throws java.io.IOException
*/
public int write(ByteBuffer buf) throws java.io.IOException {
return getChannel().write(buf);
}
}