DroolsCorrelationEngine.java

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 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2007-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
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 * OpenNMS(R) 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenNMS(R).  If not, see:
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 * For more information contact:
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package org.opennms.netmgt.correlation.drools;

import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import org.apache.commons.io.IOUtils;
import org.drools.RuleBase;
import org.drools.RuleBaseConfiguration;
import org.drools.RuleBaseConfiguration.AssertBehaviour;
import org.drools.RuleBaseFactory;
import org.drools.WorkingMemory;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageBuilder;
import org.drools.compiler.PackageBuilderConfiguration;
import org.opennms.core.utils.LogUtils;
import org.opennms.netmgt.correlation.AbstractCorrelationEngine;
import org.opennms.netmgt.xml.event.Event;
import org.springframework.core.io.Resource;

/**
 * <p>DroolsCorrelationEngine class.</p>
 *
 * @author <a href="mailto:brozow@opennms.org">Mathew Brozowski</a>
 * @version $Id: $
 */
public class DroolsCorrelationEngine extends AbstractCorrelationEngine {

    private WorkingMemory m_workingMemory;
    private List<String> m_interestingEvents;
    private List<Resource> m_rules;
    private Map<String, Object> m_globals = new HashMap<String, Object>();
    private String m_name;
    private String m_assertBehaviour;
    
    /** {@inheritDoc} */
    @Override
    public synchronized void correlate(final Event e) {
    	LogUtils.debugf(this, "Begin correlation for Event %d uei: %s", e.getDbid(), e.getUei());
        m_workingMemory.insert(e);
        m_workingMemory.fireAllRules();
    	LogUtils.debugf(this, "End correlation for Event %d uei: %s", e.getDbid(), e.getUei());
    }

    /** {@inheritDoc} */
    @Override
    protected synchronized void timerExpired(final Integer timerId) {
    	LogUtils.infof(this, "Begin correlation for Timer %d", timerId);
        TimerExpired expiration  = new TimerExpired(timerId);
        m_workingMemory.insert(expiration);
        m_workingMemory.fireAllRules();
    	LogUtils.debugf(this, "Begin correlation for Timer %d", timerId);
    }

    /** {@inheritDoc} */
    @Override
    public List<String> getInterestingEvents() {
        return m_interestingEvents;
    }
    
    /**
     * <p>setInterestingEvents</p>
     *
     * @param ueis a {@link java.util.List} object.
     */
    public void setInterestingEvents(final List<String> ueis) {
        m_interestingEvents = ueis;
    }
    
    /**
     * <p>setRulesResources</p>
     *
     * @param rules a {@link java.util.List} object.
     */
    public void setRulesResources(final List<Resource> rules) {
        m_rules = rules;
    }
    
    /**
     * <p>setGlobals</p>
     *
     * @param globals a {@link java.util.Map} object.
     */
    public void setGlobals(final Map<String, Object> globals) {
        m_globals = globals;
    }

    /**
     * <p>initialize</p>
     *
     * @throws java.lang.Exception if any.
     */
    public void initialize() throws Exception {
    	final Properties props = new Properties();
        props.setProperty("drools.dialect.java.compiler.lnglevel", "1.6");
        final PackageBuilderConfiguration conf = new PackageBuilderConfiguration(props);
        final PackageBuilder builder = new PackageBuilder( conf );
        
        loadRules(builder);
        
        AssertBehaviour behaviour = AssertBehaviour.determineAssertBehaviour(m_assertBehaviour);
        RuleBaseConfiguration config = new RuleBaseConfiguration();
        config.setAssertBehaviour(behaviour);

        final RuleBase ruleBase = RuleBaseFactory.newRuleBase( config );
        ruleBase.addPackage( builder.getPackage() );

        m_workingMemory = ruleBase.newStatefulSession();
        m_workingMemory.setGlobal("engine", this);
        
        for (final Map.Entry<String, Object> entry : m_globals.entrySet()) {
            m_workingMemory.setGlobal(entry.getKey(), entry.getValue());
        }

    }

    private void loadRules(final PackageBuilder builder) throws DroolsParserException, IOException {
        
        for (final Resource rulesFile : m_rules) {
            Reader rdr = null;
            try {
                rdr = new InputStreamReader( rulesFile.getInputStream(), "UTF-8" );
                builder.addPackageFromDrl( rdr );
            } finally {
                IOUtils.closeQuietly(rdr);
            }
        }
    }
    
    /**
     * <p>getMemorySize</p>
     *
     * @return a int.
     */
    public int getMemorySize() {
        int count = 0;
        for(final Iterator<?> it = m_workingMemory.iterateObjects(); it.hasNext(); it.next()) {
            count++;
        }
    	return count;
    }
    
    /**
     * <p>getMemoryObjects</p>
     *
     * @return a {@link java.util.List} object.
     */
    public List<Object> getMemoryObjects() {
    	final List<Object> objects = new LinkedList<Object>();
        for(Iterator<?> it = m_workingMemory.iterateObjects(); it.hasNext(); ) {
        	objects.add(it.next());
        }
        return objects;
    }
    
    public WorkingMemory getWorkingMemory() {
    	return m_workingMemory;
    }

    /**
     * <p>setName</p>
     *
     * @param name a {@link java.lang.String} object.
     */
    public void setName(final String name) {
        m_name = name;
    }
    
    /**
     * <p>getName</p>
     *
     * @return a {@link java.lang.String} object.
     */
    public String getName() {
        return m_name;
    }

    /**
     * <p>setGlobal</p>
     *
     * @param name a {@link java.lang.String} object.
     * @param value a {@link java.lang.Object} object.
     */
    public void setGlobal(final String name, final Object value) {
        m_workingMemory.setGlobal(name, value);
    }

	public void setAssertBehaviour(String assertBehaviour) {
		m_assertBehaviour = assertBehaviour;
	}
}