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/*
 * $Id: FBEventManager.java 56954 2012-04-09 12:23:23Z mrotteveel $
 * 
 * Firebird Open Source J2EE Connector - JDBC Driver
 * 
 * Copyright (C) All Rights Reserved.
 * 
 * This file was created by members of the firebird development team.
 * All individual contributions remain the Copyright (C) of those
 * individuals.  Contributors to this file are either listed here or
 * can be obtained from a CVS history command.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  
 *   - Redistributions of source code must retain the above copyright 
 *     notice, this list of conditions and the following disclaimer.
 *   - 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.
 *   - Neither the name of the firebird development team nor the names
 *     of its contributors may be used to endorse or promote products 
 *     derived from this software without specific prior written 
 *     permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS 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 THE 
 * COPYRIGHT OWNER OR 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.
 */
package org.firebirdsql.event;

import org.firebirdsql.gds.GDS;
import org.firebirdsql.gds.GDSException;
import org.firebirdsql.gds.DatabaseParameterBuffer;
import org.firebirdsql.gds.EventHandle;
import org.firebirdsql.gds.IscDbHandle;

import org.firebirdsql.gds.impl.GDSType;
import org.firebirdsql.gds.impl.GDSFactory;
import org.firebirdsql.jdbc.FBSQLException;

import java.util.Map;
import java.util.Set;
import java.util.List;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.ArrayList;
import java.util.Collections;

import java.sql.SQLException;

/**
 * An EventListener implementation to listen for database events.
 *
 * @author Gabriel Reid
 */
public class FBEventManager implements EventManager {

    private GDS gds;
    private IscDbHandle dbHandle;
    private boolean connected = false;
    private String user = "";
    private String password = "";
    private String database = "";
    private int port = 3050;
    private String host = "localhost";
    private Map listenerMap = Collections.synchronizedMap(new HashMap());
    private Map handlerMap = Collections.synchronizedMap(new HashMap());
    private List eventQueue = new ArrayList();
    private EventDispatcher eventDispatcher;
    private Thread dispatchThread;
    private long waitTimeout = 1000;

    public FBEventManager() {
    	this(GDSFactory.getDefaultGDSType());
    }

    public FBEventManager(GDSType gdsType){
        gds = GDSFactory.getGDSForType(gdsType);
        dbHandle = gds.createIscDbHandle();
    }

    public void connect() throws SQLException {
        if (connected){
            throw new IllegalStateException(
                    "Connect called while already connected");        
        }
        DatabaseParameterBuffer dpb = gds.createDatabaseParameterBuffer();
        dpb.addArgument(DatabaseParameterBuffer.USER, user);
        dpb.addArgument(DatabaseParameterBuffer.PASSWORD, password);
        try {
            String connString = GDSFactory.getDatabasePath(gds.getType(), host, port, database);
            gds.iscAttachDatabase(connString, dbHandle, dpb);
        } catch (GDSException e){
            throw new FBSQLException(e);
        }
        connected = true;
        eventDispatcher = new EventDispatcher();
        dispatchThread = new Thread(eventDispatcher);
        dispatchThread.setDaemon(true);
        dispatchThread.start();
    }

    public void disconnect() throws SQLException {
        if (!connected){
            throw new IllegalStateException(
                    "Disconnect called while not connected");
        }
        for (Iterator eventItr = new HashSet(handlerMap.keySet()).iterator(); 
                eventItr.hasNext();){
            String eventName = (String)eventItr.next();
            try {
                unregisterListener(eventName);
            } catch (GDSException e1){
                throw new FBSQLException(e1);
            }
        }

        handlerMap.clear();
        listenerMap.clear();

        try {
            gds.iscDetachDatabase(dbHandle);
        } catch (GDSException e2){
            throw new FBSQLException(e2);
        }
        connected = false;

        eventDispatcher.stop();
        
        // join the thread and wait until it dies
        try {
            dispatchThread.join();
        } catch(InterruptedException ex) {
            throw new FBSQLException(ex);
        }
    }

    public boolean isConnected() {
        return connected;
    }

    public void setUser(String user){
        this.user = user;
    }

    public String getUser(){
        return this.user;
    }

    public void setPassword(String password){
        this.password = password;
    }

    public String getPassword(){
        return this.password;
    }

    public void setDatabase(String database){
        this.database = database;
    }

    public String getDatabase(){
        return this.database;
    }

    public String getHost(){
        return this.host;
    }

    public void setHost(String host){
        this.host = host;
    }
       
    public int getPort(){
        return this.port;
    }

    public void setPort(int port){
        this.port = port;
    }
    
    /**
     * Get the time in milliseconds, after which the async threa will exit from
     * the {@link Object#wait(long)} method and check whether it was stopped or 
     * not. 
     * 

* Default value is 1000 (1 second); * * @return wait timeout in milliseconds */ public long getWaitTimeout() { return waitTimeout; } /** * Set the time in milliseconds, after which the async threa will exit from * the {@link Object#wait(long)} method and check whether it was stopped or * not. *

* Default value is 1000 (1 second); * * @param waitTimeout wait timeout in milliseconds */ public void setWaitTimeout(long waitTimeout) { this.waitTimeout = waitTimeout; } public void addEventListener( String eventName, EventListener listener) throws SQLException { if (!connected){ throw new IllegalStateException( "Can't add event listeners to disconnected EventManager"); } if (listener == null || eventName == null){ throw new NullPointerException(); } synchronized (listenerMap){ if (!listenerMap.containsKey(eventName)){ try { registerListener(eventName); } catch (GDSException e){ throw new FBSQLException(e); } listenerMap.put(eventName, new HashSet()); } Set listenerSet = (Set)listenerMap.get(eventName); listenerSet.add(listener); } } public void removeEventListener( String eventName, EventListener listener) throws SQLException { if (eventName == null || listener == null){ throw new NullPointerException(); } Set listenerSet = (Set)listenerMap.get(eventName); if (listenerSet != null){ listenerSet.remove(listener); if (listenerSet.isEmpty()){ listenerMap.remove(eventName); try { unregisterListener(eventName); } catch (GDSException e){ throw new FBSQLException(e); } } } } public int waitForEvent(String eventName) throws InterruptedException, SQLException { return waitForEvent(eventName, 0); } public int waitForEvent(String eventName, final int timeout) throws InterruptedException, SQLException { if (!connected){ throw new IllegalStateException( "Can't wait for events with disconnected EventManager"); } if (eventName == null){ throw new NullPointerException(); } final Object lock = new Object(); OneTimeEventListener listener = new OneTimeEventListener(lock); synchronized (lock){ addEventListener(eventName, listener); lock.wait(timeout); } removeEventListener(eventName, listener); return listener.getEventCount(); } private void registerListener(String eventName) throws GDSException { GdsEventHandler handler = new GdsEventHandler(eventName); handlerMap.put(eventName, handler); handler.register(); } private void unregisterListener(String eventName) throws GDSException { GdsEventHandler handler = (GdsEventHandler)handlerMap.get(eventName); handler.unregister(); handlerMap.remove(eventName); } class GdsEventHandler implements org.firebirdsql.gds.EventHandler { private EventHandle eventHandle; private boolean initialized = false; private boolean cancelled = false; public GdsEventHandler(String eventName) throws GDSException { eventHandle = gds.createEventHandle(eventName); gds.iscEventBlock(eventHandle); } public synchronized void register() throws GDSException { if (cancelled){ throw new IllegalStateException( "Trying to register a cancelled event handler"); } gds.iscQueueEvents(dbHandle, eventHandle, this); } public synchronized void unregister() throws GDSException { if (cancelled){ throw new IllegalStateException( "Trying to cancel a cancelled event handler"); } gds.iscCancelEvents(dbHandle, eventHandle); cancelled = true; } public synchronized void eventOccurred() { if (!cancelled){ try { gds.iscEventCounts(eventHandle); } catch (GDSException e1){ e1.printStackTrace(); } if (initialized && !cancelled){ DatabaseEvent event = new DatabaseEventImpl( eventHandle.getEventName(), eventHandle.getEventCount()); synchronized (eventQueue){ eventQueue.add(event); eventQueue.notify(); } } else { initialized = true; } try { register(); } catch (GDSException e2){ e2.printStackTrace(); } } } } class EventDispatcher implements Runnable { private volatile boolean running = false; public void stop(){ running = false; } public void run(){ running = true; List events = new ArrayList(); while (running){ synchronized (eventQueue){ while (eventQueue.isEmpty() && running){ try { eventQueue.wait(waitTimeout); } catch (InterruptedException ie){ } } events.addAll(eventQueue); eventQueue.clear(); } for (Iterator eItr = events.iterator(); eItr.hasNext();){ DatabaseEvent event = (DatabaseEvent)eItr.next(); Set listenerSet = null; synchronized (listenerMap){ listenerSet = (Set)listenerMap.get(event.getEventName()); if (listenerSet != null){ Iterator listenerItr = listenerSet.iterator(); while (listenerItr.hasNext()){ EventListener listener = (EventListener)listenerItr.next(); listener.eventOccurred(event); } } } } events.clear(); } } } } class OneTimeEventListener implements EventListener { private int eventCount = -1; private Object lock; public OneTimeEventListener(Object lock){ this.lock = lock; } public void eventOccurred(DatabaseEvent event){ if (eventCount == -1){ eventCount = event.getEventCount(); } synchronized (lock){ lock.notify(); } } public int getEventCount(){ return eventCount; } } class DatabaseEventImpl implements DatabaseEvent { private int eventCount; private String eventName; public DatabaseEventImpl(String eventName, int eventCount){ this.eventName = eventName; this.eventCount = eventCount; } public int getEventCount(){ return this.eventCount; } public String getEventName(){ return this.eventName; } public String toString(){ return "DatabaseEvent['" + eventName + " * " + eventCount + "]"; } }





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