/*
* Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source 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, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.transaction;
import javax.transaction.xa.Xid;
import com.caucho.util.Hex;
/**
* Transaction identifier implementation.
*/
public class XidImpl implements Xid {
public static final int GLOBAL_LENGTH = 28;
private byte [] _global;
private byte [] _local;
/**
* Creates a new transaction id.
*
* @param id
* the 64 bit number for the id.
*/
public XidImpl(long serverId,
long randomId,
long sequence)
{
_global = new byte[GLOBAL_LENGTH];
_local = new byte[4];
_local[0] = 1;
// the global id has the requirement of being globally unique
// first 4 identify as Resin.
_global[0] = 'R';
_global[1] = 'e';
_global[2] = 's';
_global[3] = 'n';
// next 8 is the crc64 of the caucho.server-id
_global[4] = (byte) (serverId >> 56);
_global[5] = (byte) (serverId >> 48);
_global[6] = (byte) (serverId >> 40);
_global[7] = (byte) (serverId >> 32);
_global[8] = (byte) (serverId >> 24);
_global[9] = (byte) (serverId >> 16);
_global[10] = (byte) (serverId >> 8);
_global[11] = (byte) (serverId);
// next 8 is a 64-bit random long
_global[12] = (byte) (randomId >> 56);
_global[13] = (byte) (randomId >> 48);
_global[14] = (byte) (randomId >> 40);
_global[15] = (byte) (randomId >> 32);
_global[16] = (byte) (randomId >> 24);
_global[17] = (byte) (randomId >> 16);
_global[18] = (byte) (randomId >> 8);
_global[19] = (byte) (randomId);
// next 8 is the current sequence
_global[20] = (byte) (sequence >> 56);
_global[21] = (byte) (sequence >> 48);
_global[22] = (byte) (sequence >> 40);
_global[23] = (byte) (sequence >> 32);
_global[24] = (byte) (sequence >> 24);
_global[25] = (byte) (sequence >> 16);
_global[26] = (byte) (sequence >> 8);
_global[27] = (byte) (sequence);
}
XidImpl(XidImpl base, int branch)
{
_global = new byte[base._global.length];
_local = new byte[4];
_local[0] = (byte) (branch);
System.arraycopy(base._global, 0, _global, 0, _global.length);
}
public XidImpl(byte [] global, byte [] local)
{
_global = new byte[global.length];
_local = new byte[local.length];
System.arraycopy(global, 0, _global, 0, global.length);
System.arraycopy(local, 0, _local, 0, local.length);
}
XidImpl(byte [] global)
{
_global = new byte[global.length];
_local = new byte[4];
System.arraycopy(global, 0, _global, 0, global.length);
_local[0] = 1;
}
@Override
public int getFormatId()
{
return 1234;
}
@Override
public byte [] getBranchQualifier()
{
return _local;
}
@Override
public byte [] getGlobalTransactionId()
{
return _global;
}
boolean isSameServer(long serverId)
{
// first 4 identify as Resin.
if (_global[0] != 'R'
|| _global[1] != 'e'
|| _global[2] != 's'
|| _global[3] != 'n') {
return false;
}
// next 8 is the crc64 of the caucho.server-id
if (_global[4] != (byte) (serverId >> 56)
|| _global[5] != (byte) (serverId >> 48)
|| _global[6] != (byte) (serverId >> 40)
|| _global[7] != (byte) (serverId >> 32)
|| _global[8] != (byte) (serverId >> 24)
|| _global[9] != (byte) (serverId >> 16)
|| _global[10] != (byte) (serverId >> 8)
|| _global[11] != (byte) (serverId)) {
return false;
}
return true;
}
/**
* Clones the xid.
*/
@Override
public Object clone()
{
return new XidImpl(_global, _local);
}
/**
* Returns hashCode.
*/
@Override
public int hashCode()
{
byte [] global = _global;
int hash = 37;
for (int i = global.length - 1; i >= 0; i--)
hash = 65521 * hash + global[i];
return hash;
}
/**
* Returns equality.
*/
@Override
public boolean equals(Object o)
{
if (!(o instanceof Xid))
return false;
Xid xid = (Xid) o;
byte [] global = xid.getGlobalTransactionId();
byte [] local = xid.getBranchQualifier();
if (global.length != _global.length)
return false;
byte [] selfGlobal = _global;
byte [] selfLocal = _local;
for (int i = global.length - 1; i >= 0; i--) {
if (global[i] != selfGlobal[i]) {
return false;
}
}
for (int i = local.length - 1; i >= 0; i--) {
if (local[i] != selfLocal[i]) {
return false;
}
}
return true;
}
/**
* Printable version of the transaction id.
*/
@Override
public String toString()
{
StringBuilder cb = new StringBuilder();
// cb.append(getClass().getSimpleName());
cb.append("Xid");
cb.append("[");
byte [] branch = getBranchQualifier();
addByte(cb, branch[0]);
cb.append(":");
byte [] global = getGlobalTransactionId();
for (int i = 24; i < 28; i++)
addByte(cb, global[i]);
cb.append("]");
return cb.toString();
}
/**
* Adds hex for debug
*
* @param cb
* the character buffer for the new value
* @param b
* the byte value
*/
static private void addByte(StringBuilder cb, int b)
{
b = b & 0xff;
int h = (b / 16) & 0xf;
int l = b & 0xf;
if (h >= 10)
cb.append((char) ('a' + h - 10));
else
cb.append((char) ('0' + h));
if (l >= 10)
cb.append((char) ('a' + l - 10));
else
cb.append((char) ('0' + l));
}
}