/*
* This program is free software; you can redistribute it and/or modify it under the terms of
* the GNU AFFERO GENERAL PUBLIC LICENSE as published by the Free Software Foundation; either version 3 of the License,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU AFFERO GENERAL PUBLIC LICENSE for more details.
* You should have received a copy of the GNU AFFERO GENERAL PUBLIC LICENSE along with this program;
* if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
package com.meidusa.amoeba.manager.io;
import com.meidusa.amoeba.manager.ManagerConstant;
import com.meidusa.amoeba.net.io.PacketInputStream;
/**
*
* <b> The Packet Header </b>
*
* <pre>
* Bytes Name
* ----- ----
* 3 Packet Length
* 1 Packet TYPE
* </p>
*
* ���ݰ�Packet Length Ϊ �������ݰ�����(�������ݣ�header)
* @author <a href=mailto:piratebase@sina.com>Struct chen</a>
*
*/
public class ManagerPacketInputStream extends PacketInputStream implements ManagerConstant{
private boolean readPackedWithHead;
public ManagerPacketInputStream(boolean readPackedWithHead){
this.readPackedWithHead = readPackedWithHead;
}
protected int decodeLength() {
/**
* �ж�һ�����ǵ�ǰ�Ѿ���ȡ�����ݰ��������Ƿ�Ȱ�ͷ��,�����:����Լ����������ij���,����-1
*/
if (_have < getHeaderSize()) {
return -1;
}
//_buffer.rewind();
/**
* mysql ���ݲ��֣���ͷ=�������ݰ�����
*/
int length = (_buffer.get(0) & 0xff)
| ((_buffer.get(1) & 0xff) << 8)
| ((_buffer.get(2) & 0xff) << 16)
| ((_buffer.get(3) & 0xff) << 24);
return length;
}
public int getHeaderSize() {
return HEADER_SIZE;
}
protected byte[] readPacket(){
byte[] msg = new byte[_length];
int position = _buffer.position();
if(readPackedWithHead){
_buffer.position(0);
}else{
_buffer.position(this.getHeaderSize());
}
_buffer.get(msg, 0, _length);
try{
_buffer.limit(_have);
_buffer.compact();
_buffer.position(position - _length);
_have -= _length;
_length = this.decodeLength();
}catch(IllegalArgumentException e){
throw new IllegalArgumentException("old position="+_buffer.position()+", new position="+_length+",old limit="+_buffer.limit() +", have(new limit)="+_have,e);
}
return msg;
}
}