workingmemoryimpl.java

drools 一个开放源码的规则引擎

package org.drools.reteoo;

/*
 * Copyright 2001-2004 (C) The Werken Company. All Rights Reserved.
 *
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 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 *
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 * "drools" appear in their names without prior written permission of The Werken
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import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.drools.FactException;
import org.drools.FactHandle;
import org.drools.NoSuchFactHandleException;
import org.drools.NoSuchFactObjectException;
import org.drools.RuleBase;
import org.drools.WorkingMemory;
import org.drools.event.AgendaEventListener;
import org.drools.event.AgendaEventSupport;
import org.drools.event.ReteooNodeEventListener;
import org.drools.event.ReteooNodeEventSupport;
import org.drools.event.WorkingMemoryEventListener;
import org.drools.event.WorkingMemoryEventSupport;
import org.drools.rule.Rule;
import org.drools.spi.Activation;
import org.drools.spi.AgendaFilter;
import org.drools.spi.AsyncExceptionHandler;
import org.drools.spi.PropagationContext;
import org.drools.util.IdentityMap;
import org.drools.util.PrimitiveLongMap;
import org.drools.util.PrimitiveLongStack;

/**
 * Implementation of <code>WorkingMemory</code>.
 * 
 * @author <a href="mailto:[e-mail]">bob mcwhirter </a>
 * @author <a href="mailto:[e-mail]">Simon Harris </a>
 */
class WorkingMemoryImpl
    implements
    WorkingMemory,
    PropertyChangeListener
{
    // ------------------------------------------------------------
    // Constants
    // ------------------------------------------------------------
    private static final Class[]            ADD_REMOVE_PROPERTY_CHANGE_LISTENER_ARG_TYPES = new Class[]{PropertyChangeListener.class};

    // ------------------------------------------------------------
    // Instance members
    // ------------------------------------------------------------

    /** The arguments used when adding/removing a property change listener. */
    private final Object[]                  addRemovePropertyChangeListenerArgs           = new Object[]{this};

    /** The actual memory for the <code>JoinNode</code>s. */
    private final PrimitiveLongMap          nodeMemories                                  = new PrimitiveLongMap( 32,
                                                                                                                  8 );

    /** Application data which is associated with this memory. */
    private final Map                       applicationData                               = new HashMap( );

    /** Handle-to-object mapping. */
    private final PrimitiveLongMap          objects                                       = new PrimitiveLongMap( 32,
                                                                                                                  8 );

    /** Object-to-handle mapping. */
    private final Map                       identityMap                                   = new IdentityMap( );
    private final Map                       equalsMap                                     = new HashMap( );
    private final Map                       justifiers                                    = new HashMap( );
    private final PrimitiveLongMap          justified                                     = new PrimitiveLongMap( 8,
                                                                                                                  32 );
    private final PrimitiveLongStack        factHandlePool                                = new PrimitiveLongStack( );
    
   private static final String              STATED                                        = "STATED";    

    /** The eventSupport */
    private final WorkingMemoryEventSupport workingMemoryEventSupport                     = new WorkingMemoryEventSupport( this );
    private final AgendaEventSupport        agendaEventSupport                                   = new AgendaEventSupport( this );
    private final ReteooNodeEventSupport    reteooNodeEventSupport                           = new ReteooNodeEventSupport( this );

    /** The <code>RuleBase</code> with which this memory is associated. */
    private final RuleBaseImpl              ruleBase;

    /** Rule-firing agenda. */
    private final Agenda                    agenda;

    /** Flag to determine if a rule is currently being fired. */
    private boolean                         firing;

    // ------------------------------------------------------------
    // Constructors
    // ------------------------------------------------------------

    /**
     * Construct.
     * 
     * @param ruleBase
     *            The backing rule-base.
     */
    public WorkingMemoryImpl(RuleBaseImpl ruleBase)
    {
        this.ruleBase = ruleBase;
        this.agenda = new Agenda( this,
                                  ruleBase.getConflictResolver( ) );
    }

    // ------------------------------------------------------------
    // Instance methods
    // ------------------------------------------------------------

    public void addEventListener(WorkingMemoryEventListener listener)
    {
        this.workingMemoryEventSupport.addEventListener( listener );
    }

    public void removeEventListener(WorkingMemoryEventListener listener)
    {
        this.workingMemoryEventSupport.removeEventListener( listener );
    }

    public List getWorkingMemoryEventListeners()
    {
        return this.workingMemoryEventSupport.getEventListeners( );
    }

    public void addEventListener(AgendaEventListener listener)
    {
        this.agendaEventSupport.addEventListener( listener );
    }

    public void removeEventListener(AgendaEventListener listener)
    {
        this.agendaEventSupport.removeEventListener( listener );
    }

    public List getAgendaEventListeners()
    {
        return this.agendaEventSupport.getEventListeners( );
    }
    
    public void addEventListener(ReteooNodeEventListener listener)
    {
        this.reteooNodeEventSupport.addEventListener( listener );
    }

    public void removeEventListener(ReteooNodeEventListener listener)
    {
        this.reteooNodeEventSupport.removeEventListener( listener );
    }

    public List getReteooNodeEventListeners()
    {
        return this.reteooNodeEventSupport.getEventListeners( );
    }    
    

    /**
     * Create a new <code>FactHandle</code>.
     * 
     * @return The new fact handle.
     */
    FactHandle newFactHandle()
    {
        if ( !this.factHandlePool.isEmpty( ) )
        {
            return this.ruleBase.getFactHandleFactory( ).newFactHandle( this.factHandlePool.pop( ) );
        }
        
        return this.ruleBase.getFactHandleFactory( ).newFactHandle( );
    }

    /**
     * @see WorkingMemory
     */
    public Map getApplicationDataMap()
    {
        return this.applicationData;
    }

    /**
     * @see WorkingMemory
     */
    public void setApplicationData(String name,
                                   Object value)
    {
        // Make sure the application data has been declared in the RuleBase
        Map applicationDataDefintions = this.ruleBase.getApplicationData( );
        Class type = (Class) applicationDataDefintions.get( name );
        if ( (type == null) )
        {
            throw new RuntimeException( "Unexpected application data [" + name + "]" );
        }
        else if ( !type.isInstance( value ) )
        {
            throw new RuntimeException( "Illegal class for application data. " + "Expected [" + type.getName( ) + "], " + "found [" + value.getClass( ).getName( ) + "]." );

        }
        else
        {
            this.applicationData.put( name,
                                      value );
        }
    }

    /**
     * @see WorkingMemory
     */
    public Object getApplicationData(String name)
    {
        return this.applicationData.get( name );
    }

    /**
     * Retrieve the rule-firing <code>Agenda</code> for this
     * <code>WorkingMemory</code>.
     * 
     * @return The <code>Agenda</code>.
     */
    protected Agenda getAgenda()
    {
        return this.agenda;
    }

    /**
     * Clear the Agenda
     */
    public void clearAgenda()
    {
        this.agenda.clearAgenda( );
    }

    /**
     * @see WorkingMemory
     */
    public RuleBase getRuleBase()
    {
        return this.ruleBase;
    }

    public void fireAllRules(AgendaFilter agendaFilter) throws FactException
    {
        // If we're already firing a rule, then it'll pick up
        // the firing for any other assertObject(..) that get
        // nested inside, avoiding concurrent-modification
        // exceptions, depending on code paths of the actions.

        if ( !firing )
        {
            try
            {
                firing = true;

                while ( agenda.fireNextItem( agendaFilter ) );
            }
            finally
            {
                firing = false;
            }
        }
    }

    /**
     * @see WorkingMemory
     */
    public void fireAllRules() throws FactException