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HSQLDB - Lightweight 100% Java SQL Database Engine
/* Copyright (c) 2001-2019, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb.jdbc.pool;
import java.net.Inet4Address;
import java.util.Arrays;
import java.util.Random;
import javax.transaction.xa.Xid;
/**
* Implementation of Xid for tests.
*
*
* // Example usage:
*
* JDBCXADataSource ds = new JDBCXADataSource();
*
* ds.setUser(user);
* ds.setPassword(password);
* ds.setUrl(jdbcUrl);
*
* XAConnection xaCon = ds.getConnection();
* Connection con = xaCon.getConnection();
* Xid xid = JDBCXID.getUniqueXid((int)Thread.currentThread().getId());
* XAResource xaRes = xaCon.getXAResource();
*
* // Start the transaction.
* System.out.println("Starting XA transaction with xid = " + xid.toString());
*
* xaRes.setTransactionTimeout(0);
* xaRes.start(xid,XAResource.TMNOFLAGS);
*
* // Do work here ....
*
* // Commit the transaction.
* xaRes.end(xid,XAResource.TMSUCCESS);
* xaRes.commit(xid,true);
*
* // Cleanup.
* con.close();
* xaCon.close();
*
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @author Campbell Burnet (campbell-burnet@users dot sourceforge.net)
* @version 2.1
*/
public class JDBCXID implements Xid {
int formatID;
byte[] txID;
byte[] txBranch;
//
int hash;
boolean hashComputed;
public int getFormatId() {
return formatID;
}
public byte[] getGlobalTransactionId() {
return txID;
}
public byte[] getBranchQualifier() {
return txBranch;
}
public JDBCXID(int formatID, byte[] txID, byte[] txBranch) {
this.formatID = formatID;
this.txID = txID;
this.txBranch = txBranch;
}
public int hashCode() {
if (!hashComputed) {
hash = 7;
hash = 83 * hash + this.formatID;
hash = 83 * hash + Arrays.hashCode(this.txID);
hash = 83 * hash + Arrays.hashCode(this.txBranch);
hashComputed = true;
}
return hash;
}
public boolean equals(Object other) {
if (other instanceof Xid) {
Xid o = (Xid) other;
return formatID == o.getFormatId()
&& Arrays.equals(txID, o.getGlobalTransactionId())
&& Arrays.equals(txBranch, o.getBranchQualifier());
}
return false;
}
// inherit doc
public String toString() {
StringBuilder sb = new StringBuilder(512);
//
sb.append("formatId=").append(getFormatId());
//
sb.append(" globalTransactionId(").append(txID.length).append(")={0x");
for (int i = 0; i < txID.length; i++) {
final int hexVal = txID[i] & 0xFF;
if (hexVal < 0x10) {
sb.append("0").append(Integer.toHexString(txID[i] & 0xFF));
}
sb.append(Integer.toHexString(txID[i] & 0xFF));
}
//
sb.append("} branchQualifier(").append(txBranch.length).append(
"))={0x");
for (int i = 0; i < txBranch.length; i++) {
final int hexVal = txBranch[i] & 0xFF;
if (hexVal < 0x10) {
sb.append("0");
}
sb.append(Integer.toHexString(txBranch[i] & 0xFF));
}
sb.append("}");
//
return sb.toString();
}
private static byte[] s_localIp = null;
private static int s_txnSequenceNumber = 0;
//
private static final int UXID_FORMAT_ID = 0xFEED;
private static int nextTxnSequenceNumber() {
s_txnSequenceNumber++;
return s_txnSequenceNumber;
}
private static byte[] getLocalIp() {
if (null == s_localIp) {
try {
s_localIp = Inet4Address.getLocalHost().getAddress();
} catch (Exception ex) {
s_localIp = new byte[] {
0x7F, 0x00, 0x00, 0x01
};
}
}
return s_localIp;
}
/**
* Retrieves a randomly generated JDBCXID.
*
* The newly generated object is based on the local IP address, the given
* threadId and a randomly generated number using the current time
* in milliseconds as the random seed.
*
* Note that java.util.Random is used, not java.security.SecureRandom.
*
* @param threadId can be a real thread id or just some convenient
* tracking value.
*
* @return a randomly generated JDBCXID
*/
public static Xid getUniqueXid(final int threadId) {
final Random random = new Random(System.currentTimeMillis());
//
int txnSequenceNumberValue = nextTxnSequenceNumber();
int threadIdValue = threadId;
int randomValue = random.nextInt();
//
byte[] globalTransactionId = new byte[MAXGTRIDSIZE];
byte[] branchQualifier = new byte[MAXBQUALSIZE];
byte[] localIp = getLocalIp();
System.arraycopy(localIp, 0, globalTransactionId, 0, 4);
System.arraycopy(localIp, 0, branchQualifier, 0, 4);
// Bytes 4 -> 7 - unique transaction id.
// Bytes 8 ->11 - thread id.
// Bytes 12->15 - random.
for (int i = 0; i <= 3; i++) {
globalTransactionId[i + 4] = (byte) (txnSequenceNumberValue
% 0x100);
branchQualifier[i + 4] = (byte) (txnSequenceNumberValue % 0x100);
txnSequenceNumberValue >>= 8;
globalTransactionId[i + 8] = (byte) (threadIdValue % 0x100);
branchQualifier[i + 8] = (byte) (threadIdValue % 0x100);
threadIdValue >>= 8;
globalTransactionId[i + 12] = (byte) (randomValue % 0x100);
branchQualifier[i + 12] = (byte) (randomValue % 0x100);
randomValue >>= 8;
}
return new JDBCXID(UXID_FORMAT_ID, globalTransactionId,
branchQualifier);
}
}