xaresourcemngr.java

一个类似于openJMS分布在ObjectWeb之下的JMS消息中间件。

/*
 * JORAM: Java(TM) Open Reliable Asynchronous Messaging
 * Copyright (C) 2004 - ScalAgent Distributed Technologies
 * Copyright (C) 2004 - Bull SA
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 * 
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA.
 *
 * Initial developer(s): Frederic Maistre (Bull SA)
 * Contributor(s): ScalAgent Distributed Technologies
 */
package org.objectweb.joram.client.jms;

import javax.jms.JMSException;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import org.objectweb.joram.shared.client.ProducerMessages;
import org.objectweb.joram.shared.client.SessAckRequest;
import org.objectweb.joram.shared.client.XACnxPrepare;
import org.objectweb.joram.shared.client.XACnxCommit;
import org.objectweb.joram.shared.client.XACnxRecoverReply;
import org.objectweb.joram.shared.client.XACnxRecoverRequest;
import org.objectweb.joram.shared.client.XACnxRollback;

import org.objectweb.util.monolog.api.BasicLevel;

/**
 * Utility class used by XA connections for managing XA resources.
 */
public class XAResourceMngr {
  /** Transaction active. */
  public static final int STARTED = 0;
  /** Transaction suspended. */
  public static final int SUSPENDED = 1;
  /** Transaction successful. */
  public static final int SUCCESS = 2;
  /** Failed transaction. */
  public static final int ROLLBACK_ONLY = 3;
  /** Prepared transaction. */
  public static final int PREPARED = 4;

  /**
   * The table of known transactions.
   * <p>
   * <b>Key:</b> transaction identifier<br>
   * <b>Object:</b> <code>XAContext</code> instance
   */
  private Hashtable transactions;

  /** The connection this manager belongs to. */
  Connection cnx;

  /** table of Session (key Xid). */
  Hashtable sessionTable;


  /**
   * Creates a <code>XAResourceMngr</code> instance.
   *
   * @param cnx   The connection this manager belongs to.
   */
  public XAResourceMngr(Connection cnx) {
    this.cnx = cnx;
    transactions = new Hashtable();
    sessionTable = new Hashtable();

    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                 " XAResourceMngr cnx = " + cnx);
  }

  /**
   * Notifies the RM that a transaction is starting.
   *
   * @exception XAException  If the specified transaction is already known by
   *                         the RM in an incompatible state with the start
   *                         request.
   */
  synchronized void start(Xid xid, int flag, Session sess) 
    throws XAException {
    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                 " XAResourceMngr start(" + xid +
                                 ", " + flag +
                                 ", " + sess +")");

    sess.setTransacted(true); // for XAResource.TMRESUME
    sessionTable.put(xid,sess);

    // New transaction.
    if (flag == XAResource.TMNOFLAGS) {
      if (transactions.containsKey(xid))
        throw new XAException("Can't start transaction already known by RM.");

      transactions.put(xid, new XAContext());

      if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
        JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                   "--- "
                                   + this
                                   + ": involved in transaction "
                                   + xid.toString()); 
    }
    // Resumed transaction.
    else if (flag == XAResource.TMRESUME) {
      if (! transactions.containsKey(xid))
        throw new XAException("Can't resume unknown transaction.");

      if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
        JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                   "--- "
                                   + this
                                   + ": resumes transaction "
                                   + xid.toString()); 
    }
    // Already known transaction.
    else if (flag == XAResource.TMJOIN) {
      if (! transactions.containsKey(xid))
        throw new XAException("Can't join unknown transaction.");

      if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
        JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                   "--- "
                                   + this
                                   + ": joins transaction "
                                   + xid.toString()); 
    }
    else
      throw new XAException("Invalid flag: " + flag);

    setStatus(xid, STARTED);
  } 

  /**
   * Notifies the RM that a transaction is ended.
   *
   * @exception XAException  If the specified transaction is in an
   *                         incompatible state with the end request.
   */
  synchronized void end(Xid xid, int flag, Session sess) 
    throws XAException {
    boolean saveResourceState = true;

    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                 "--- "
                                 + this
                                 + ": end(" + xid
                                 + ", " + flag
                                 + ", " + sess + ")"); 
    
    if (flag == XAResource.TMSUSPEND) {
      if (getStatus(xid) != STARTED)
        throw new XAException("Can't suspend non started transaction.");

      setStatus(xid, SUSPENDED);
    }
    else {
      if (getStatus(xid) != STARTED && getStatus(xid) != SUSPENDED)
        throw new XAException("Can't end non active or non "
                              + "suspended transaction.");

      // No need to save the resource's state as it has already been done
      // when suspending it.
      if (getStatus(xid) == SUSPENDED)
        saveResourceState = false;

      if (flag == XAResource.TMSUCCESS)
        setStatus(xid, SUCCESS);
      else if (flag == XAResource.TMFAIL)
        setStatus(xid, ROLLBACK_ONLY);
      else
        throw new XAException("Invalid flag: " + flag);
    }

    if (saveResourceState) {
      XAContext xaC = (XAContext) transactions.get(xid);
      xaC.addSendings(sess.sendings);
      xaC.addDeliveries(sess.deliveries);
    }

    Session session = (Session) sessionTable.get(xid);
    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                 "--- "
                                 + this
                                 + ": end(...) session=" 
                                 + session);

    if (session != null) {
      session.setTransacted(false);
      sessionTable.remove(xid);
    }
  }

  /** 
   * Notifies the RM that a transaction is prepared.
   *
   * @exception XAException  If the specified transaction is in an
   *                         incompatible state with the prepare request,
   *                         or if the request fails.
   */
  synchronized void prepare(Xid xid) 
    throws XAException {

    if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
      JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                 "--- "
                                 + this
                                 + ": prepare(" + xid + ")"); 
    
    try {
      if (getStatus(xid) == ROLLBACK_ONLY)
        throw new XAException("Can't prepare resource in ROLLBACK_ONLY state.");

      XAContext xaC = (XAContext) transactions.get(xid);

      if (JoramTracing.dbgClient.isLoggable(BasicLevel.DEBUG))
        JoramTracing.dbgClient.log(BasicLevel.DEBUG,
                                   "--- "
                                   + this
                                   + ": prepares transaction "
                                   + xid.toString()); 

      Enumeration targets;    
      String target;
      Vector pMs = new Vector();
      MessageAcks acks;
      Vector sessAcks = new Vector();

      // Getting all the ProducerMessages to send:
      targets = xaC.sendings.keys();
      while (targets.hasMoreElements()) {
        target = (String) targets.nextElement();
        pMs.add(xaC.sendings.remove(target));
      }

      // Getting all the SessAckRequest to send:
      targets = xaC.deliveries.keys();
      while (targets.hasMoreElements()) {
        target = (String) targets.nextElement();
        acks = (MessageAcks) xaC.deliveries.remove(target);
        sessAcks.add(new SessAckRequest(target, acks.getIds(),
                                        acks.getQueueMode()));
      }

      // Sending to the proxy:
      cnx.syncRequest(new XACnxPrepare(xid.getBranchQualifier(),
                                        xid.getFormatId(),
                                        xid.getGlobalTransactionId(),
                                        pMs,
                                        sessAcks));

      setStatus(xid, PREPARED);

    } catch (JMSException exc) {
      setStatus(xid, ROLLBACK_ONLY);
      throw new XAException("Prepare request failed: " + exc);
    } catch (XAException exc) {
      setStatus(xid, ROLLBACK_ONLY);
      throw exc;
    }
  }

  /** 
   * Notifies the RM that a transaction is commited.
   *