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JDBC Driver for the Firebird RDBMS
/*
* $Id$
*
* Firebird Open Source JavaEE Connector - JDBC Driver
*
* Distributable under LGPL license.
* You may obtain a copy of the License at http://www.gnu.org/copyleft/lgpl.html
*
* 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
* LGPL License for more details.
*
* This file was created by members of the firebird development team.
* All individual contributions remain the Copyright (C) of those
* individuals. Contributors to this file are either listed here or
* can be obtained from a source control history command.
*
* All rights reserved.
*/
package org.firebirdsql.jca;
import javax.resource.ResourceException;
import javax.transaction.xa.Xid;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
/**
* The class FBXid has methods for serializing xids for
* firebird use, and reading them back into instances of itself. It is
* a key component in adapting xa semantics and recovery to firebird
* native operations and data format.
*
* @author David Jencks
* @version 1.0
*/
class FBXid implements Xid {
//Constants from alice.h
public static final int TDR_VERSION = 1;
public static final int TDR_HOST_SITE = 1;
public static final int TDR_DATABASE_PATH = 2;
public static final int TDR_TRANSACTION_ID = 3;
public static final int TDR_REMOTE_SITE = 4;
//new constants for xid encoding
public static final int TDR_XID_FORMAT_ID = 5;
public static final int TDR_XID_GLOBAL_ID = 6;
public static final int TDR_XID_BRANCH_ID = 4;
private int formatId;
/**
* Global transaction id of this instance.
*/
private final byte[] globalId;
/**
* Branch qualifier of this instance.
* This identifies the branch of a transaction.
*/
private final byte[] branchId;
private final long firebirdTransactionId;
/**
* Return a string that describes any Xid instance.
*/
static String toString(Xid id) {
if (id == null)
return "[NULL Xid]";
String s = id.getClass().getName();
s = s.substring(s.lastIndexOf('.') + 1);
s = s + " [FormatId=" + id.getFormatId() +
", GlobalId=" + new String(id.getGlobalTransactionId()).trim() +
", BranchQual=" + new String(id.getBranchQualifier()).trim() + "]";
return s;
}
/**
* Create a new instance copying an existing one.
*/
public FBXid(Xid xid) {
formatId = xid.getFormatId();
globalId = xid.getGlobalTransactionId();
branchId = xid.getBranchQualifier();
firebirdTransactionId = 0;
}
/**
* Creates a new FBXid instance from the byte representation
* supplied. This is called by recover to reconstruct an xid
* from the toBytes() representation.
*
* @param rawIn
* Xid serialized in format of {@link #toBytes()} as {@link java.io.InputStream}
* @param firebirdTransactionId
* The Firebird transactionId of the recovered Xid.
* @throws ResourceException
* if an error occurs
*/
FBXid(InputStream rawIn, long firebirdTransactionId) throws ResourceException {
this.firebirdTransactionId = firebirdTransactionId;
try {
if (read(rawIn) != TDR_VERSION) {
throw new FBIncorrectXidException("Wrong TDR_VERSION for xid");
}
if (read(rawIn) != TDR_XID_FORMAT_ID) {
throw new FBIncorrectXidException("Wrong TDR_XID_FORMAT_ID for xid");
}
formatId = readInt(rawIn);
if (read(rawIn) != TDR_XID_GLOBAL_ID) {
throw new FBIncorrectXidException("Wrong TDR_XID_GLOBAL_ID for xid");
}
globalId = readBuffer(rawIn);
if (read(rawIn) != TDR_XID_BRANCH_ID) {
throw new FBIncorrectXidException("Wrong TDR_XID_BRANCH_ID for xid");
}
branchId = readBuffer(rawIn);
} catch (IOException ioe) {
throw new FBResourceException("IOException: " + ioe, ioe);
}
}
/**
* @return the global transaction id of this transaction.
*/
public byte[] getGlobalTransactionId() {
return globalId.clone();
}
/**
* @return the branch qualifier of this transaction.
*/
public byte[] getBranchQualifier() {
return branchId.clone();
}
/**
* The format identifier augments the global id and specifies
* how the global id and branch qualifier should be interpreted.
*
* @return the format identifier of this transaction.
*/
public int getFormatId() {
return formatId;
}
/**
* @return Firebird transaction ID or 0 if no transaction id is available.
*/
public long getFirebirdTransactionId() {
return firebirdTransactionId;
}
/**
* Compare for equality.
*
* Instances are considered equal if they are both instances of XidImpl,
* and if they have the same global transaction id and transaction
* branch qualifier.
*
*/
public boolean equals(Object obj) {
if (this == obj) return true;
if (!(obj instanceof Xid)) return false;
Xid other = (Xid) obj;
boolean result = formatId == other.getFormatId();
byte[] otherGlobalID = other.getGlobalTransactionId();
byte[] otherBranchID = other.getBranchQualifier();
result &= Arrays.equals(globalId, otherGlobalID);
result &= Arrays.equals(branchId, otherBranchID);
return result;
}
public int hashCode() {
int hashCode = 1109;
hashCode = 43 * hashCode + formatId;
hashCode = 43 * hashCode + Arrays.hashCode(globalId);
hashCode = 43 * hashCode + Arrays.hashCode(branchId);
return hashCode;
}
public String toString() {
return toString(this);
}
//package
/**
* @return Length of the serialized byte representation.
*/
int getLength() {
return 1 + 1 + 4 + 1 + 4 + globalId.length + 1 + 4 + branchId.length;
}
/**
* @return Serialized byte representation of this Xid
*/
byte[] toBytes() {
byte[] b = new byte[getLength()];
int i = 0;
b[i++] = (byte) TDR_VERSION;
b[i++] = (byte) TDR_XID_FORMAT_ID;
b[i++] = (byte) ((formatId >>> 24) & 0xff);
b[i++] = (byte) ((formatId >>> 16) & 0xff);
b[i++] = (byte) ((formatId >>> 8) & 0xff);
b[i++] = (byte) ((formatId) & 0xff);
b[i++] = (byte) TDR_XID_GLOBAL_ID;
b[i++] = (byte) ((globalId.length >>> 24) & 0xff);
b[i++] = (byte) ((globalId.length >>> 16) & 0xff);
b[i++] = (byte) ((globalId.length >>> 8) & 0xff);
b[i++] = (byte) ((globalId.length) & 0xff);
System.arraycopy(globalId, 0, b, i, globalId.length);
i += globalId.length;
b[i++] = (byte) TDR_XID_BRANCH_ID;
b[i++] = (byte) ((branchId.length >>> 24) & 0xff);
b[i++] = (byte) ((branchId.length >>> 16) & 0xff);
b[i++] = (byte) ((branchId.length >>> 8) & 0xff);
b[i++] = (byte) ((branchId.length) & 0xff);
System.arraycopy(branchId, 0, b, i, branchId.length);
return b;
}
private int read(InputStream in) throws IOException {
return in.read();
}
private int readInt(InputStream in) throws IOException {
return (read(in) << 24) | (read(in) << 16) | (read(in) << 8) | (read(in));
}
private byte[] readBuffer(InputStream in) throws IOException {
int len = readInt(in);
byte[] buffer = new byte[len];
readFully(in, buffer, 0, len);
return buffer;
}
private void readFully(InputStream in, byte[] buffer, int offset, int length) throws IOException {
if (length == 0)
return;
do {
int counter = in.read(buffer, offset, length);
if (counter == -1)
throw new EOFException();
offset += counter;
length -= counter;
} while (length > 0);
}
}
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