/**
* Copyright 2010 JBoss Inc
*
* Licensed 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 bitronix.tm.resource.jms.lrc;
import bitronix.tm.internal.BitronixXAException;
import bitronix.tm.utils.Decoder;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.XAException;
import javax.transaction.xa.Xid;
import javax.jms.Session;
import javax.jms.JMSException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* XAResource implementation for a non-XA JMS connection emulating XA with Last Resource Commit.
* <p>The XA protocol flow is implemented by this state machine:</p>
* <pre>
* NO_TX
* |
* | start(TMNOFLAGS)
* |
* | end(TMFAIL)
* STARTED -------------- NO_TX
* |
* | end(TMSUCCESS)
* |
* | start(TMJOIN)
* ENDED ---------------- STARTED
* |\
* | \ commit (one phase)
* | ----------------- NO_TX
* |
* | prepare()
* |
* | commit() or
* | rollback()
* PREPARED ------------- NO_TX
* </pre>
* {@link XAResource#TMSUSPEND} and {@link XAResource#TMRESUME} are not supported.
* <p>© <a href="http://www.bitronix.be">Bitronix Software</a></p>
*
* @author lorban
*/
public class LrcXAResource implements XAResource {
private final static Logger log = LoggerFactory.getLogger(LrcXAResource.class);
public static final int NO_TX = 0;
public static final int STARTED = 1;
public static final int ENDED = 2;
public static final int PREPARED = 3;
private Session session;
private Xid xid;
private int state = NO_TX;
public LrcXAResource(Session session) {
this.session = session;
}
public int getState() {
return state;
}
private String xlatedState() {
switch (state) {
case NO_TX: return "NO_TX";
case STARTED: return "STARTED";
case ENDED: return "ENDED";
case PREPARED: return "PREPARED";
default: return "!invalid state (" + state + ")!";
}
}
public int getTransactionTimeout() throws XAException {
return 0;
}
public boolean setTransactionTimeout(int seconds) throws XAException {
return false;
}
public void forget(Xid xid) throws XAException {
}
public Xid[] recover(int flags) throws XAException {
return new Xid[0];
}
public boolean isSameRM(XAResource xaResource) throws XAException {
return xaResource == this;
}
public void start(Xid xid, int flag) throws XAException {
if (flag != XAResource.TMNOFLAGS && flag != XAResource.TMJOIN)
throw new BitronixXAException("unsupported start flag " + Decoder.decodeXAResourceFlag(flag), XAException.XAER_RMERR);
if (xid == null)
throw new BitronixXAException("XID cannot be null", XAException.XAER_INVAL);
if (state == NO_TX) {
if (this.xid != null)
throw new BitronixXAException("resource already started on XID " + this.xid, XAException.XAER_PROTO);
else {
if (flag == XAResource.TMJOIN)
throw new BitronixXAException("resource not yet started", XAException.XAER_PROTO);
else {
if (log.isDebugEnabled()) log.debug("OK to start, old state=" + xlatedState() + ", XID=" + xid + ", flag=" + Decoder.decodeXAResourceFlag(flag));
this.xid = xid;
}
}
}
else if (state == STARTED) {
throw new BitronixXAException("resource already started on XID " + this.xid, XAException.XAER_PROTO);
}
else if (state == ENDED) {
if (flag == XAResource.TMNOFLAGS)
throw new BitronixXAException("resource already registered XID " + this.xid, XAException.XAER_DUPID);
else {
if (xid.equals(this.xid)) {
if (log.isDebugEnabled()) log.debug("OK to join, old state=" + xlatedState() + ", XID=" + xid + ", flag=" + Decoder.decodeXAResourceFlag(flag));
}
else
throw new BitronixXAException("resource already started on XID " + this.xid + " - cannot start it on more than one XID at a time", XAException.XAER_RMERR);
}
}
else if (state == PREPARED) {
throw new BitronixXAException("resource already prepared on XID " + this.xid, XAException.XAER_PROTO);
}
this.state = STARTED;
}
public void end(Xid xid, int flag) throws XAException {
if (flag != XAResource.TMSUCCESS && flag != XAResource.TMFAIL)
throw new BitronixXAException("unsupported end flag " + Decoder.decodeXAResourceFlag(flag), XAException.XAER_RMERR);
if (xid == null)
throw new BitronixXAException("XID cannot be null", XAException.XAER_INVAL);
if (state == NO_TX) {
throw new BitronixXAException("resource never started on XID " + xid, XAException.XAER_PROTO);
}
else if (state == STARTED) {
if (this.xid.equals(xid)) {
if (log.isDebugEnabled()) log.debug("OK to end, old state=" + xlatedState() + ", XID=" + xid + ", flag=" + Decoder.decodeXAResourceFlag(flag));
}
else
throw new BitronixXAException("resource already started on XID " + this.xid + " - cannot end it on another XID " + xid, XAException.XAER_PROTO);
}
else if (state == ENDED) {
throw new BitronixXAException("resource already ended on XID " + xid, XAException.XAER_PROTO);
}
else if (state == PREPARED) {
throw new BitronixXAException("cannot end, resource already prepared on XID " + xid, XAException.XAER_PROTO);
}
if (flag == XAResource.TMFAIL) {
try {
session.rollback();
state = NO_TX;
this.xid = null;
return;
} catch (JMSException ex) {
throw new BitronixXAException("error rolling back resource on end", XAException.XAER_RMERR, ex);
}
}
this.state = ENDED;
}
public int prepare(Xid xid) throws XAException {
if (xid == null)
throw new BitronixXAException("XID cannot be null", XAException.XAER_INVAL);
if (state == NO_TX) {
throw new BitronixXAException("resource never started on XID " + xid, XAException.XAER_PROTO);
}
else if (state == STARTED) {
throw new BitronixXAException("resource never ended on XID " + xid, XAException.XAER_PROTO);
}
else if (state == ENDED) {
if (this.xid.equals(xid)) {
if (log.isDebugEnabled()) log.debug("OK to prepare, old state=" + xlatedState() + ", XID=" + xid);
}
else
throw new BitronixXAException("resource already started on XID " + this.xid + " - cannot prepare it on another XID " + xid, XAException.XAER_PROTO);
}
else if (state == PREPARED) {
throw new BitronixXAException("resource already prepared on XID " + this.xid, XAException.XAER_PROTO);
}
try {
session.commit();
this.state = PREPARED;
return XAResource.XA_OK;
} catch (JMSException ex) {
throw new BitronixXAException("error preparing non-XA resource", XAException.XAER_RMERR, ex);
}
}
public void commit(Xid xid, boolean onePhase) throws XAException {
if (xid == null)
throw new BitronixXAException("XID cannot be null", XAException.XAER_INVAL);
if (state == NO_TX) {
throw new BitronixXAException("resource never started on XID " + xid, XAException.XAER_PROTO);
}
else if (state == STARTED) {
throw new BitronixXAException("resource never ended on XID " + xid, XAException.XAER_PROTO);
}
else if (state == ENDED) {
if (onePhase) {
if (log.isDebugEnabled()) log.debug("OK to commit with 1PC, old state=" + xlatedState() + ", XID=" + xid);
try {
session.commit();
} catch (JMSException ex) {
throw new BitronixXAException("error committing (one phase) non-XA resource", XAException.XAER_RMERR, ex);
}
}
else
throw new BitronixXAException("resource never prepared on XID " + xid, XAException.XAER_PROTO);
}
else if (state == PREPARED) {
if (!onePhase) {
if (this.xid.equals(xid)) {
if (log.isDebugEnabled()) log.debug("OK to commit, old state=" + xlatedState() + ", XID=" + xid);
}
else
throw new BitronixXAException("resource already started on XID " + this.xid + " - cannot commit it on another XID " + xid, XAException.XAER_PROTO);
}
else
throw new BitronixXAException("cannot commit in one phase as resource has been prepared on XID " + xid, XAException.XAER_PROTO);
}
this.state = NO_TX;
this.xid = null;
}
public void rollback(Xid xid) throws XAException {
if (xid == null)
throw new BitronixXAException("XID cannot be null", XAException.XAER_INVAL);
if (state == NO_TX) {
throw new BitronixXAException("resource never started on XID " + xid, XAException.XAER_PROTO);
}
else if (state == STARTED) {
throw new BitronixXAException("resource never ended on XID " + xid, XAException.XAER_PROTO);
}
else if (state == ENDED) {
if (this.xid.equals(xid)) {
if (log.isDebugEnabled()) log.debug("OK to rollback, old state=" + xlatedState() + ", XID=" + xid);
}
else
throw new BitronixXAException("resource already started on XID " + this.xid + " - cannot roll it back on another XID " + xid, XAException.XAER_PROTO);
}
else if (state == PREPARED) {
throw new BitronixXAException("resource committed during prepare on XID " + this.xid, XAException.XAER_RMERR);
}
try {
session.rollback();
this.state = NO_TX;
this.xid = null;
} catch (JMSException ex) {
throw new BitronixXAException("error preparing non-XA resource", XAException.XAER_RMERR, ex);
}
}
public String toString() {
return "a JMS LrcXAResource in state " + xlatedState() + " of session " + session;
}
}