org.openscada.ae.server.common.event.pool.internal.EventPoolImpl.java Source code

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Here is the source code for org.openscada.ae.server.common.event.pool.internal.EventPoolImpl.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.pool.internal;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Collection;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.concurrent.Executor;

import org.openscada.ae.Event;
import org.openscada.ae.event.EventListener;
import org.openscada.ae.event.EventManager;
import org.openscada.ae.filter.EventMatcher;
import org.openscada.ae.filter.internal.EventMatcherImpl;
import org.openscada.ae.server.common.event.AbstractEventQueryImpl;
import org.openscada.ae.server.storage.Query;
import org.openscada.ae.server.storage.Storage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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

public class EventPoolImpl extends AbstractEventQueryImpl implements EventListener {
    private final static Logger logger = LoggerFactory.getLogger(EventPoolImpl.class);

    private final static int daysToRetrieve = Integer
            .getInteger("org.openscada.ae.common.event.pool.daysToRetrieve", 90);

    private static final String isoDatePattern = "yyyy-MM-dd HH:mm:ss.SSS";

    private static final DateFormat isoDateFormat = new SimpleDateFormat(isoDatePattern);

    private final Storage storage;

    private final EventManager eventManager;

    private final String filter;

    private final EventMatcher matcher;

    public EventPoolImpl(final Executor executor, final Storage storage, final EventManager eventManager,
            final String filter, final int poolSize) {
        super(executor, poolSize);

        this.storage = storage;
        this.eventManager = eventManager;
        this.filter = filter;
        this.matcher = new EventMatcherImpl(filter);
    }

    public synchronized void start() throws Exception {
        // add to event manager
        this.eventManager.addEventListener(this);

        this.executor.execute(new Runnable() {
            @Override
            public void run() {
                loadFromStorage();
            }
        });
    }

    public synchronized void stop() {
        this.eventManager.removeEventListener(this);
    }

    private void loadFromStorage() {
        // load initial set from storage, but restrict it to *daysToRetrieve* days
        try {
            final long t = System.currentTimeMillis();
            // retrieve data per day, to restrict database load
            for (int daysBack = 1; daysBack <= daysToRetrieve; daysBack++) {
                final Calendar calStart = new GregorianCalendar();
                final Calendar calEnd = new GregorianCalendar();
                calStart.setTimeInMillis(t);
                calStart.add(Calendar.DAY_OF_YEAR, -daysBack);
                calEnd.setTimeInMillis(t);
                calEnd.add(Calendar.DAY_OF_YEAR, -daysBack + 1);
                final StringBuilder filter = new StringBuilder();
                filter.append("(&");
                filter.append(this.filter);
                filter.append("(sourceTimestamp>=" + isoDateFormat.format(calStart.getTime()) + ")");
                if (daysBack > 1) {
                    filter.append("(sourceTimestamp<" + isoDateFormat.format(calEnd.getTime()) + ")");
                }
                filter.append(")");
                logger.debug("load events from filter: " + filter);
                final Query query = this.storage.query(filter.toString());
                try {
                    int count;
                    synchronized (this) {
                        count = this.events.getCapacity();
                    }

                    final Collection<Event> result = query.getNext(count);

                    logger.debug("Loaded {} entries from storage", result.size());
                    synchronized (this) {
                        this.events.addAll(result);

                        final UnmodifiableIterator<List<Event>> it = Iterators.partition(this.events.iterator(),
                                chunkSize);
                        while (it.hasNext()) {
                            final List<org.openscada.ae.Event> chunk = it.next();
                            notifyEvent(chunk);
                        }
                    }
                } finally {
                    query.dispose();
                }
                if (this.events.size() >= this.events.getCapacity()) {
                    return;
                }
            }
            logger.debug("load of events complete");
        } catch (final Exception e) {
            logger.error("loadFromStorage failed", e);
        }
    }

    @Override
    public synchronized void handleEvent(final List<Event> events) {
        addEvents(events, this.matcher);
    }

}