resourcemanager.java

来自「OpenJMS是一个开源的Java Message Service API 1.」· Java 代码 · 共 1,362 行 · 第 1/4 页

/**
 * 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 Exoffice Technologies.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "Exolab"
 *    nor may "Exolab" appear in their names without prior written
 *    permission of Exoffice Technologies. Exolab is a registered
 *    trademark of Exoffice Technologies.
 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES 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
 * EXOFFICE TECHNOLOGIES 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 2000-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: ResourceManager.java,v 1.3 2005/08/30 07:26:49 tanderson Exp $
 */
package org.exolab.jms.messagemgr;

import java.io.File;
import java.io.FilenameFilter;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.TreeSet;
import java.util.Vector;
import javax.jms.JMSException;
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.exolab.jms.client.JmsDestination;
import org.exolab.jms.common.uuid.UUID;
import org.exolab.jms.message.MessageImpl;
import org.exolab.jms.persistence.DatabaseService;
import org.exolab.jms.persistence.PersistenceException;
import org.exolab.jms.service.Service;
import org.exolab.jms.tranlog.DataTransactionLogEntry;
import org.exolab.jms.tranlog.ExternalXid;
import org.exolab.jms.tranlog.StateTransactionLogEntry;
import org.exolab.jms.tranlog.TransactionLog;
import org.exolab.jms.tranlog.TransactionLogException;
import org.exolab.jms.tranlog.TransactionState;


/**
 * The resource manager provides XA support for the JMS Server.
 * <p/>
 * The resource manager is responsible for managing the various transaction
 * identifiers and managing the association between transaction ids and
 * connections.
 * <p/>
 * The resource manager will store the global XID's and their state in the
 * database for recovery purposes.
 * <p/>
 * Messages that arrive, and are associated with an XID are not processed
 * through the {@link MessageMgr}. Instead they are routed to this resource
 * managers where they are cached until the associated XID is committed or
 * rolled back. If the transaction is successfully committed, through the 2PC
 * protocol the messages will pass through the system.
 * <p/>
 * Similarly, messages that are sent to consumers, either synchronously or
 * asynchronously are also cached by the resource manager until the global
 * transaction completes.
 * <p/>
 * On startup the resource manager will read all incomplete transactions, which
 * are incompleted into memory. It will then process trnasactions that have
 * timed out.
 * <p/>
 * The transaction manager will call the {@link #recover} method  and obtain a
 * list of incomplete transaction for the purpose of completing them where
 * possible.
 *
 * @author <a href="mailto:[e-mail]">Jim Alateras</a>
 * @version $Revision: 1.3 $ $Date: 2005/08/30 07:26:49 $
 */
public class ResourceManager extends Service {

    /**
     * The extension for all transaction log files
     */
    public final static String RM_LOGFILE_EXTENSION = ".log";

    /**
     * This is used to indicate the garbage collection has been disabled and
     * that the client will take responsibility for all aspects of log file
     * management. This is useful in situations where the client wants to
     * archive the transaction log files
     * <p/>
     * This is the default mode for GC.
     */
    public static final int GC_DISABLED = 0;

    /**
     * Synchronous gabrage collection is used to remove processed log files when
     * the last trnasaction, in that log file, has been successfully processed.
     * This is more efficient means since the log files does not need to be
     * scanned asynchronously to determine whether all the transactions have
     * been processed.
     */
    public static final int GC_SYNCHRONOUS = 1;

    /**
     * Asynchronous garbage collection is used to remove processed log files
     * asynchronous (i.e in a different thread context). This is rather
     * expensive since it must manually scan each log file and determine whether
     * all transactions, in that file, have been closed. If this is the case
     * then it will remove the log file.
     */
    public static final int GC_ASYNCHRONOUS = 2;

    /**
     * The message manager.
     */
    private final MessageManager _messages;

    /**
     * The destination manager.
     */
    private final DestinationManager _destinations;

    /**
     * This is the maximum size, in bytes, of each transaction log file. The
     * value can be overriden by the user
     */
    private int _logFileSize = 1000000;

    /**
     * Maintains a collection of transaction log files currently in use by this
     * resource manager
     */
    private TreeSet _logs = new TreeSet(new TranLogFileComparator());

    /**
     * Maintain a mapping between the TRID (transaction id and the log file it
     * is associated with.
     */
    private HashMap _tridToLogCache = new HashMap();

    /**
     * Maintain a list of open TRIDs for a particular  {@link TransactionLog}
     */
    private HashMap _logToTridCache = new HashMap();

    /**
     * This attribute is used to synchronize the modifications to the _tridToLog
     * _logToTrid attributes
     */
    private final Object _cacheLock = new Object();

    /**
     * This maintains a cache of all open transactions and the corresponding
     * data. The key is the transaction identifier and the object is a
     * LinkedList transaction entries, which includes both state and data
     */
    private HashMap _activeTransactions = new HashMap();

    /**
     * The directory where the log files are stored. This can be set by the
     * client
     */
    private String _logDirectory = ".";

    /**
     * This is the number of the last log file created by the ResourceManager
     */
    private long _lastLogNumber = 0;

    /**
     * The expiry time for transaction associated with this resource manager.
     * This will either be configured or passed in with the transaction context
     * The value is specified in seconds.
     */
    private int _txExpiryTime = 120;

    /**
     * This attribute caches the garbage collection mode for the resouce
     * managers. Valid values are specified by the GC_* constants.
     * <p/>
     * By default garbage collection is disabled.
     */
    private int _gcMode = GC_SYNCHRONOUS;

    /**
     * This is the id associated with this resource...need to work out who or
     * what sets this.
     */
    private String _rid = UUID.next();

    /**
     * The name of the service
     */
    private final static String RM_SERVICE_NAME = "XAResourceManager";

    /**
     * The prefix used for all transaction log files, which are created and
     * managed by the {@link TransactionLog}
     */
    private final static String RM_LOGFILE_PREFIX = "ojmsrm";

    /**
     * The logger
     */
    private static final Log _log = LogFactory.getLog(ResourceManager.class);


    /**
     * Construct a resource manager using the default directory for its log
     * files.
     * <p/>
     * If the directory does not exist or there is no permisssion to access it,
     * then throw a ResourceManagerException.
     *
     * @param messages     the message manager
     * @param destinations the destination manager
     * @param database     the database service
     * @throws ResourceManagerException
     */
    public ResourceManager(MessageManager messages,
                           DestinationManager destinations,
                           DatabaseService database)
            throws ResourceManagerException {
        super(RM_SERVICE_NAME);

        _messages = messages;
        _destinations = destinations;
        /*

        final String dir = "./logs";
        _logDirectory = dir;
        File file = new File(dir);
        if ((!file.exists()) ||
                (!file.isDirectory())) {
            throw new ResourceManagerException(dir
                                               +
                                               " does not exist or is not a directory");
        }

        // build the list of existing log files.
        buildLogFileList();

        // recover te list of log files
        recover();
        */
    }

    /**
     * Check whether garbage collection has been disabled
     *
     * @return boolean - true if gc is disabled
     */
    public boolean gcDisabled() {
        return (_gcMode == GC_DISABLED) ? true : false;
    }

    /**
     * Log this published message so that it can be passed through the system
     * when the associated global transaction commits.
     *
     * @param xid     - the global transaction identity
     * @param message - the message published
     * @throws TransactionLogException  - error adding the entry
     * @throws ResourceManagerException - error getting the trnasaction log
     * @throws JMSException             - if there is an issue with prep'ing the
     *                                  message
     */
    public synchronized void logPublishedMessage(Xid xid, MessageImpl message)
            throws TransactionLogException, ResourceManagerException,
            JMSException {
        _messages.prepare(message);
        logTransactionData(new ExternalXid(xid), _rid,
                           createPublishedMessageWrapper(message));
    }

    /**
     * Log that this message handle was sent to the consumer within the
     * specified global transaction identity. The message will be acknowledged
     * when the global transaction commits. Alternatively, if the global
     * transaction is rolled back the message handle will be returned to the
     * destination
     *
     * @param xid    the global transaction identity
     * @param id     the consumer receiving this message
     * @param handle - the handle of the message received
     * @throws TransactionLogException  - error adding the entry
     * @throws ResourceManagerException - error getting the transaction log
     */
    public synchronized void logReceivedMessage(Xid xid, long id,
                                                MessageHandle handle)
            throws TransactionLogException, ResourceManagerException {
        logTransactionData(new ExternalXid(xid), _rid,
                           createReceivedMessageWrapper(id, handle));
    }

    /**
     * Add an {@link StateTransactionLogEntry} using the specified txid, rid and
     * state
     *
     * @param xid   - the transaction identifier
     * @param state - the transaction log state
     * @throws TransactionLogException  - error adding the entry
     * @throws ResourceManagerException - error getting the trnasaction log
     */
    public synchronized void logTransactionState(Xid xid,
                                                 TransactionState state)
            throws TransactionLogException, ResourceManagerException {
        ExternalXid txid = new ExternalXid(xid);
        switch (state.getOrd()) {
            case TransactionState.OPENED_ORD:
                {