/*
* Bitronix Transaction Manager
*
* Copyright (c) 2010, Bitronix Software.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package bitronix.tm.resource.jdbc.lrc;
import bitronix.tm.internal.BitronixXAException;
import bitronix.tm.utils.Decoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;
import java.sql.Connection;
import java.sql.SQLException;
/**
* XAResource implementation for a non-XA JDBC 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.
*
* @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 final Connection connection;
private volatile Xid xid;
private volatile boolean autocommitActiveBeforeStart;
private volatile int state = NO_TX;
public LrcXAResource(Connection connection) {
this.connection = connection;
}
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);
}
try {
autocommitActiveBeforeStart = connection.getAutoCommit();
if (autocommitActiveBeforeStart) {
if (log.isDebugEnabled()) log.debug("disabling autocommit mode on non-XA connection");
connection.setAutoCommit(false);
}
this.state = STARTED;
} catch (SQLException ex) {
throw new BitronixXAException("cannot disable autocommit on non-XA connection", XAException.XAER_RMERR);
}
}
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 {
connection.rollback();
state = NO_TX;
this.xid = null;
return;
} catch (SQLException 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 {
connection.commit();
this.state = PREPARED;
return XAResource.XA_OK;
} catch (SQLException 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 {
connection.commit();
} catch (SQLException 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;
try {
if (autocommitActiveBeforeStart) {
if (log.isDebugEnabled()) log.debug("enabling back autocommit mode on non-XA connection");
connection.setAutoCommit(true);
}
} catch (SQLException ex) {
throw new BitronixXAException("cannot reset autocommit on non-XA connection", XAException.XAER_RMERR);
}
}
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) {
this.state = NO_TX;
throw new BitronixXAException("resource committed during prepare on XID " + this.xid, XAException.XA_HEURCOM);
}
try {
connection.rollback();
} catch (SQLException ex) {
throw new BitronixXAException("error preparing non-XA resource", XAException.XAER_RMERR, ex);
} finally {
this.state = NO_TX;
this.xid = null;
}
try {
if (autocommitActiveBeforeStart) {
if (log.isDebugEnabled()) log.debug("enabling back autocommit mode on non-XA connection");
connection.setAutoCommit(true);
}
} catch (SQLException ex) {
throw new BitronixXAException("cannot reset autocommit on non-XA connection", XAException.XAER_RMERR);
}
}
public String toString() {
return "a JDBC LrcXAResource in state " + xlatedState();
}
}