/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
* statements and notices. Redistributions must also contain a
* copy of this document.
*
* 2. 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.
*
* 3. The name "Exolab" must not be used to endorse or promote
* products derived from this Software without prior written
* permission of Intalio, Inc. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Intalio, Inc. Exolab is a registered
* trademark of Intalio, Inc.
*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED 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
* INTALIO, INC. OR ITS 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.
*
* Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
*
* $Id$
*/
package org.exolab.castor.persist;
import javax.transaction.Status;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.castor.persist.TransactionContext;
import org.exolab.castor.jdo.TransactionAbortedException;
/**
* An {@link XAResource} implementation for an {@link XAResourceSource}.
* Provides the XA interface for starting transactions, participating
* in two phase commit and suspending/resuming transactions against
* the XA source. Transactions are shared across all XA sources that
* map to the same cache engine.
*
* @author <a href="arkin@intalio.com">Assaf Arkin</a>
* @version $Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $
* @see TransactionContext
* @see XAResourceSource
*/
public final class XAResourceImpl implements XAResource {
/** The <a href="http://jakarta.apache.org/commons/logging/">Jakarta
* Commons Logging</a> instance used for all logging. */
private static final Log LOG = LogFactory.getLog(XAResourceImpl.class);
/** The cache engine to which this XA resource belongs.
* Will be used to associate Xid with a transaction context. */
private final LockEngine _engine;
/** The XA source which this XA resource manages. Will be
* used to associate/dissociate the source with the
* transaction context. */
private final XAResourceSource _xaSource;
public XAResourceImpl(final LockEngine engine, final XAResourceSource xaSource) {
if ((engine == null) || (xaSource == null)) {
throw new IllegalArgumentException("Argument 'engine' or xaSource' is null");
}
_xaSource = xaSource;
_engine = engine;
}
public synchronized void start(final Xid xid, final int flags) throws XAException {
// General checks.
if (xid == null) {
throw new XAException(XAException.XAER_INVAL);
}
switch (flags) {
case TMNOFLAGS:
TransactionContext tx1;
// Must assure transaction context is created only once
// for a given Xid
synchronized (_engine.getXATransactions()) {
tx1 = _engine.getXATransactions().get(xid);
if (tx1 == null) {
tx1 = _xaSource.createTransactionContext(xid);
_engine.getXATransactions().put(xid, tx1);
}
}
// Associate XAResource with transaction
_xaSource.setTransactionContext(tx1);
break;
case TMJOIN:
case TMRESUME:
TransactionContext tx2 = _engine.getXATransactions().get(xid);
if ((tx2 == null) || !tx2.isOpen()) {
throw new XAException(XAException.XAER_NOTA);
}
// Associate XAResource with transaction
_xaSource.setTransactionContext(tx2);
break;
default:
// No other flags supported in start().
throw new XAException(XAException.XAER_INVAL);
}
}
public synchronized void end(final Xid xid, final int flags) throws XAException {
// General checks.
if (xid == null) {
throw new XAException(XAException.XAER_INVAL);
}
TransactionContext tx = _engine.getXATransactions().get(xid);
if (tx == null) {
throw new XAException(XAException.XAER_NOTA);
}
// Make sure the XA source is associated with any
// transaction otherwise this is an invalid Xid
if (_xaSource.getTransactionContext() == null) {
throw new XAException(XAException.XAER_INVAL);
}
switch (flags) {
case TMSUCCESS:
// Expect prepare/rollback next
break;
case TMFAIL:
// Failure implies rolling back transaction,
// and terminating XA source
_xaSource.xaFailed();
_xaSource.setTransactionContext(null);
if (tx.isOpen()) {
try {
tx.rollback();
} catch (Exception except) {
LOG.debug("Exception at rollback of TransactionContext.");
}
}
break;
case TMSUSPEND:
// Dissociate source from transaction
_xaSource.setTransactionContext(null);
break;
default:
throw new XAException(XAException.XAER_INVAL);
}
}
public synchronized void forget(final Xid xid) throws XAException {
if (xid == null) {
throw new XAException(XAException.XAER_INVAL);
}
synchronized (_engine.getXATransactions()) {
TransactionContext tx = _engine.getXATransactions().remove(xid);
if (tx == null) {
throw new XAException(XAException.XAER_NOTA);
}
// Dissociate XA source from transaction
if (_xaSource.getTransactionContext() == tx) {
_xaSource.setTransactionContext(null);
}
// Forget is never called on an open transaction, but one
// can never tell.
if (tx.isOpen()) {
try {
tx.rollback();
} catch (Exception except) {
LOG.debug("Exception at rollback of TransactionContext.");
}
throw new XAException(XAException.XAER_PROTO);
}
}
}
public synchronized int prepare(final Xid xid) throws XAException {
if (xid == null) {
throw new XAException(XAException.XAER_INVAL);
}
TransactionContext tx = _engine.getXATransactions().get(xid);
if (tx == null) {
throw new XAException(XAException.XAER_NOTA);
}
switch (tx.getStatus()) {
case Status.STATUS_PREPARED:
case Status.STATUS_ACTIVE:
// Can only prepare an active transaction. And error
// is reported as vote to rollback the transaction.
try {
return tx.prepare() ? XA_OK : XA_RDONLY;
} catch (TransactionAbortedException except) {
throw new XAException(XAException.XA_RBROLLBACK);
} catch (IllegalStateException except) {
throw new XAException(XAException.XAER_PROTO);
}
case Status.STATUS_MARKED_ROLLBACK:
// Report transaction marked for rollback.
throw new XAException(XAException.XA_RBROLLBACK);
default:
throw new XAException(XAException.XAER_PROTO);
}
}
public synchronized void commit(final Xid xid, final boolean onePhase) throws XAException {
if (xid == null) {
throw new XAException(XAException.XAER_INVAL);
}
TransactionContext tx = _engine.getXATransactions().get(xid);
if (tx == null) {
throw new XAException(XAException.XAER_NOTA);
}
switch (tx.getStatus()) {
case Status.STATUS_COMMITTED:
// Allowed to make multiple commit attempts.
return;
case Status.STATUS_ROLLEDBACK:
// This should not happen unless someone interfered
// by calling rollback directly or failing a commit,
// but is still a valid heuristic condition on our behalf.
throw new XAException(XAException.XA_HEURRB);
case Status.STATUS_PREPARED:
// Commit can only occur after a prepare, so must be
// in prepared state first. Any ODMG error is reported
// as a heuristic decision to rollback.
try {
tx.commit();
} catch (TransactionAbortedException except) {
// Transaction cannot commit and was rolledback
throw new XAException(XAException.XA_HEURRB);
} catch (IllegalStateException except) {
throw new XAException(XAException.XAER_PROTO);
}
default:
throw new XAException(XAException.XAER_PROTO);
}
}
public synchronized void rollback(final Xid xid) throws XAException {
if (xid == null) {
throw new XAException(XAException.XAER_INVAL);
}
TransactionContext tx = _engine.getXATransactions().get(xid);
if (tx == null) {
throw new XAException(XAException.XAER_NOTA);
}
switch (tx.getStatus()) {
case Status.STATUS_COMMITTED:
// This should not happen unless someone interfered
// by calling commit directly, but is still a valid
// heuristic condition on our behalf.
throw new XAException(XAException.XA_HEURCOM);
case Status.STATUS_ROLLEDBACK:
// Allowed to make multiple rollback attempts.
return;
case Status.STATUS_ACTIVE:
case Status.STATUS_MARKED_ROLLBACK:
// Rollback never fails with an application exception.
try {
tx.rollback();
} catch (IllegalStateException except) {
throw new XAException(XAException.XAER_PROTO);
}
return;
default:
throw new XAException(XAException.XAER_PROTO);
}
}
public Xid[] recover(final int flags) throws XAException {
// Recovery is not implemented. This XAResource only deals
// with in-memory objects, so recovery has no meaning.
// Actual recovery is provided by underlying persistence
// mechanism (i.e. XADataSource, etc).
return null;
}
public synchronized boolean isSameRM(final XAResource xaRes) throws XAException {
// Two resource managers are equal if they produce equivalent
// connection (i.e. same database, same user). If the two are
// equivalent they would share a transaction by joining.
if ((xaRes == null) || !(xaRes instanceof XAResourceImpl)) {
return false;
}
if (_engine == ((XAResourceImpl) xaRes)._engine) {
return true;
}
return false;
}
public boolean setTransactionTimeout(final int timeout) {
TransactionContext tx;
tx = _xaSource.getTransactionContext();
if ((tx != null) && tx.isOpen()) {
tx.setTransactionTimeout(timeout);
return true;
}
return false;
}
public int getTransactionTimeout() {
TransactionContext tx;
tx = _xaSource.getTransactionContext();
if (tx != null && tx.isOpen()) {
return tx.getTransactionTimeout();
}
return 0;
}
}