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/* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.qpid.dtx;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.qpid.AMQInvalidArgumentException;
import javax.transaction.xa.Xid;
import java.io.*;
import java.util.Arrays;
/**
* Implements javax.transaction.dtx.Xid
*/
public class XidImpl implements Xid
{
/**
* this session's logger
*/
private static final Logger _logger = LoggerFactory.getLogger(XidImpl.class);
/**
* the transaction branch identifier part of XID as an array of bytes
*/
private byte[] _branchQualifier;
/**
* the format identifier part of the XID.
*/
private int _formatID;
/**
* the global transaction identifier part of XID as an array of bytes.
*/
private byte[] _globalTransactionID;
//--- Constructors
/**
* Create new Xid.
* this is an empty constructor.
*/
public XidImpl()
{
}
/**
* Create a new XidImpl from an existing Xid.
* <p> Usefull for casting external Xids
*
* @param xid Foreign Xid.
*/
public XidImpl(Xid xid)
{
_branchQualifier = xid.getBranchQualifier();
_formatID = xid.getFormatId();
_globalTransactionID = xid.getGlobalTransactionId();
}
/**
* Create a new Xid.
*
* @param branchQualifier The transaction branch identifier part of XID as an array of bytes.
* @param format The format identifier part of the XID.
* @param globalTransactionID The global transaction identifier part of XID as an array of bytes.
*/
public XidImpl(byte[] branchQualifier, int format, byte[] globalTransactionID)
{
_branchQualifier = branchQualifier;
_formatID = format;
_globalTransactionID = globalTransactionID;
}
/**
* Create a new Xid form its String form
* 4 1 1 g b
* +---+---+---+---+---+---+---+- -+---+---+- -+---+
* | format_id | g | b | txn-id | br-id |
* +---+---+---+---+---+---+---+- -+---+---+- -+---+
* 0 4 5 6 6+g 6+g+b
* format_id: an implementation specific format identifier
* <p/>
* gtrid_length: how many bytes of this form the transaction id
* <p/>
* bqual_length: how many bytes of this form the branch id
* <p/>
* data: a sequence of octets of at most 128 bytes containing the txn id and the
* branch id
* <p/>
* Note - The sum of the two lengths must equal the length of the data field.
*
* @param xid an XID STring Form
* @throws AMQInvalidArgumentException If the string does not represent a valid Xid
*/
public XidImpl(String xid) throws AMQInvalidArgumentException
{
if (_logger.isDebugEnabled())
{
_logger.debug("converting string " + xid + " into XidImpl");
}
try
{
DataInputStream input = new DataInputStream(new ByteArrayInputStream(xid.getBytes()));
_formatID = (int) input.readLong();
int g = input.readByte();
int b = input.readByte();
_globalTransactionID = new byte[g];
_branchQualifier = new byte[b];
if (input.read(_globalTransactionID, 0, g) != g)
{
throw new AMQInvalidArgumentException("Cannot convert the string " + xid + " into an Xid", null);
}
if (input.read(_branchQualifier, 0, b) != b)
{
throw new AMQInvalidArgumentException("Cannot convert the string " + xid + " into an Xid", null);
}
}
catch (IOException e)
{
throw new AMQInvalidArgumentException("cannot convert the string " + xid + " into an Xid", e);
}
}
//--- Xid interface implementation
/**
* Format identifier. O means the OSI CCR format.
*
* @return Global transaction identifier.
*/
public byte[] getGlobalTransactionId()
{
return _globalTransactionID;
}
/**
* Obtain the transaction branch identifier part of XID as an array of bytes.
*
* @return Branch identifier part of XID.
*/
public byte[] getBranchQualifier()
{
return _branchQualifier;
}
/**
* Obtain the format identifier part of the XID.
*
* @return Format identifier. O means the OSI CCR format.
*/
public int getFormatId()
{
return _formatID;
}
//--- Object operations
/**
* Indicates whether some other Xid is "equal to" this one.
* <p> Two Xids are equal if and only if their three elementary parts are equal
*
* @param o the object to compare this <code>XidImpl</code> against.
* @return true if the <code>XidImpl</code> are equal, false otherwise.
*/
public boolean equals(Object o)
{
if (this == o)
{
return true;
}
if (o instanceof XidImpl)
{
XidImpl other = (XidImpl) o;
if (_formatID == other.getFormatId())
{
if (_branchQualifier.length == other.getBranchQualifier().length)
{
for (int i = 0; i < _branchQualifier.length; i++)
{
if (_branchQualifier[i] != other.getBranchQualifier()[i])
{
return false;
}
}
if (_globalTransactionID.length == other.getGlobalTransactionId().length)
{
for (int i = 0; i < _globalTransactionID.length; i++)
{
if (_globalTransactionID[i] != other.getGlobalTransactionId()[i])
{
return false;
}
}
// everithing is equal
return true;
}
}
}
}
return false;
}
@Override
public int hashCode()
{
int result = _branchQualifier != null ? Arrays.hashCode(_branchQualifier) : 0;
result = 31 * result + _formatID;
result = 31 * result + (_globalTransactionID != null ? Arrays.hashCode(_globalTransactionID) : 0);
return result;
}
//-- Static helper method
/**
* Convert an Xid into the AMQP String format.
*
* 4 1 1 g b
* +---+---+---+---+---+---+---+- -+---+---+- -+---+
* | format_id | g | b | txn-id | br-id |
* +---+---+---+---+---+---+---+- -+---+---+- -+---+
* 0 4 5 6 6+g 6+g+b
* format_id: an implementation specific format identifier
* <p/>
* gtrid_length: how many bytes of this form the transaction id
* <p/>
* bqual_length: how many bytes of this form the branch id
* <p/>
* data: a sequence of octets of at most 128 bytes containing the txn id and the
* branch id
* <p/>
* Note - The sum of the two lengths must equal the length of the data field.
*
* @param xid an Xid to convert.
* @return The String representation of this Xid
*/
public static org.apache.qpid.transport.Xid convert(Xid xid)
{
return new org.apache.qpid.transport.Xid(xid.getFormatId(),
xid.getGlobalTransactionId(),
xid.getBranchQualifier());
}
}
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