org.openscada.ae.server.common.event.AbstractEventQueryImpl.java Source code

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Here is the source code for org.openscada.ae.server.common.event.AbstractEventQueryImpl.java

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/*
 * This file is part of the OpenSCADA project
 * Copyright (C) 2006-2012 TH4 SYSTEMS GmbH (http://th4-systems.com)
 *
 * OpenSCADA is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenSCADA 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 version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenSCADA. If not, see
 * <http://opensource.org/licenses/lgpl-3.0.html> for a copy of the LGPLv3 License.
 */

package org.openscada.ae.server.common.event;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Executor;

import org.openscada.ae.Event;
import org.openscada.ae.event.EventListener;
import org.openscada.ae.filter.EventMatcher;
import org.openscada.utils.collection.BoundedPriorityQueueSet;
import org.openscada.utils.collection.BoundedQueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Iterators;
import com.google.common.collect.UnmodifiableIterator;

public abstract class AbstractEventQueryImpl implements EventQuery {

    private final static Logger logger = LoggerFactory.getLogger(AbstractEventQueryImpl.class);

    protected final static int chunkSize = Integer.getInteger("org.openscada.ae.common.event.pool.chunkSize", 100);

    private final Set<EventListener> listeners = new HashSet<EventListener>();

    protected final Executor executor;

    protected final BoundedQueue<Event> events;

    public AbstractEventQueryImpl(final Executor executor, final int poolSize) {
        this.executor = executor;

        this.events = new BoundedPriorityQueueSet<Event>(poolSize, new Comparator<Event>() {
            @Override
            public int compare(final Event o1, final Event o2) {
                return Event.comparator.compare(o2, o1);
            }
        });
    }

    protected void notifyEvent(final List<Event> event) {
        final EventListener[] listeners = this.listeners.toArray(new EventListener[this.listeners.size()]);
        this.executor.execute(new Runnable() {

            @Override
            public void run() {
                for (final EventListener listener : listeners) {
                    listener.handleEvent(event);
                }
            }
        });
    }

    @Override
    public synchronized void addListener(final EventListener eventListener) {
        this.listeners.add(eventListener);

        final UnmodifiableIterator<List<Event>> it = Iterators
                .partition(AbstractEventQueryImpl.this.events.iterator(), chunkSize);
        while (it.hasNext()) {
            final List<org.openscada.ae.Event> chunk = it.next();
            this.executor.execute(new Runnable() {

                @Override
                public void run() {
                    eventListener.handleEvent(chunk);
                }
            });
        }

    }

    protected synchronized void addEvents(final List<Event> events, final EventMatcher matcher) {
        final List<Event> toNotify = new ArrayList<Event>(events.size());
        for (final Event event : events) {
            if (matcher == null || matcher.matches(event)) {
                if (this.events.add(event)) {
                    toNotify.add(event);
                }
            }
        }
        logger.debug("new event pool size: {}", this.events.size());
        notifyEvent(toNotify);
    }

    @Override
    public synchronized void removeListener(final EventListener eventListener) {
        this.listeners.remove(eventListener);
    }

    @Override
    public int getCapacity() {
        return this.events.getCapacity();
    }
}