/**
* 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.aries.transaction;
import javax.transaction.xa.Xid;
import org.apache.geronimo.transaction.manager.XidFactory;
import org.apache.geronimo.transaction.manager.XidImpl;
/**
* Factory for transaction ids that are ever increasing
* allowing determination of new transactions
* The Xid is constructed of two parts:
* <ol><li>8 byte id (LSB first)</li>
* <li>base id</li>
* <ol>
* can't easily extend geronimo XidFactoryImpl b/c count is private
*/
public class XidFactoryImpl implements XidFactory {
private final byte[] baseId = new byte[Xid.MAXGTRIDSIZE];
private final long start = System.currentTimeMillis();
private long count = start;
public XidFactoryImpl(byte[] tmId) {
System.arraycopy(tmId, 0, baseId, 8, tmId.length);
}
public Xid createXid() {
byte[] globalId = (byte[]) baseId.clone();
long id;
synchronized (this) {
id = count++;
}
insertLong(id, globalId, 0);
return new XidImpl(globalId);
}
public Xid createBranch(Xid globalId, int branch) {
byte[] branchId = (byte[]) baseId.clone();
branchId[0] = (byte) branch;
branchId[1] = (byte) (branch >>> 8);
branchId[2] = (byte) (branch >>> 16);
branchId[3] = (byte) (branch >>> 24);
insertLong(start, branchId, 4);
return new XidImpl(globalId, branchId);
}
public boolean matchesGlobalId(byte[] globalTransactionId) {
if (globalTransactionId.length != Xid.MAXGTRIDSIZE) {
return false;
}
for (int i = 8; i < globalTransactionId.length; i++) {
if (globalTransactionId[i] != baseId[i]) {
return false;
}
}
// for recovery, only match old transactions
long id = extractLong(globalTransactionId, 0);
return (id < start);
}
public boolean matchesBranchId(byte[] branchQualifier) {
if (branchQualifier.length != Xid.MAXBQUALSIZE) {
return false;
}
long id = extractLong(branchQualifier, 4);
if (id >= start) {
// newly created branch, not recoverable
return false;
}
for (int i = 12; i < branchQualifier.length; i++) {
if (branchQualifier[i] != baseId[i]) {
return false;
}
}
return true;
}
public Xid recover(int formatId, byte[] globalTransactionid, byte[] branchQualifier) {
return new XidImpl(formatId, globalTransactionid, branchQualifier);
}
static void insertLong(long value, byte[] bytes, int offset) {
bytes[offset + 0] = (byte) value;
bytes[offset + 1] = (byte) (value >>> 8);
bytes[offset + 2] = (byte) (value >>> 16);
bytes[offset + 3] = (byte) (value >>> 24);
bytes[offset + 4] = (byte) (value >>> 32);
bytes[offset + 5] = (byte) (value >>> 40);
bytes[offset + 6] = (byte) (value >>> 48);
bytes[offset + 7] = (byte) (value >>> 56);
}
static long extractLong(byte[] bytes, int offset) {
return (bytes[offset + 0] & 0xff)
+ (((bytes[offset + 1] & 0xff)) << 8)
+ (((bytes[offset + 2] & 0xff)) << 16)
+ (((bytes[offset + 3] & 0xffL)) << 24)
+ (((bytes[offset + 4] & 0xffL)) << 32)
+ (((bytes[offset + 5] & 0xffL)) << 40)
+ (((bytes[offset + 6] & 0xffL)) << 48)
+ (((long) bytes[offset + 7]) << 56);
}
}