package org.drools.reteoo;
/*
* Copyright 2001-2004 (C) The Werken Company. All Rights Reserved.
*
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain copyright statements and
* notices. Redistributions must also contain a copy of this document.
*
* 2. 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.
*
* 3. The name "drools" must not be used to endorse or promote products derived
* from this Software without prior written permission of The Werken Company.
* For written permission, please contact bob@werken.com.
*
* 4. Products derived from this Software may not be called "drools" nor may
* "drools" appear in their names without prior written permission of The Werken
* Company. "drools" is a trademark of The Werken Company.
*
* 5. Due credit should be given to The Werken Company. (http://werken.com/)
*
* THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESSED 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 WERKEN COMPANY OR ITS 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.
*
*/
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.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
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.WorkingMemoryEventListener;
import org.drools.event.WorkingMemoryEventSupport;
import org.drools.spi.AgendaFilter;
import org.drools.spi.AsyncExceptionHandler;
import org.drools.util.IdentityMap;
import org.drools.util.PrimitiveLongMap;
import org.drools.util.PrimitiveLongStack;
/**
* Implementation of <code>WorkingMemory</code>.
*
* @author <a href="mailto:bob@werken.com">bob mcwhirter </a>
* @author <a href="mailto:simon@redhillconsulting.com.au">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 Map joinMemories = new HashMap( );
/** 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 handles = new IdentityMap( );
private final PrimitiveLongStack factHandlePool = new PrimitiveLongStack( );
/** The eventSupport */
private final WorkingMemoryEventSupport eventSupport = new WorkingMemoryEventSupport( 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;
private FactHandleFactory factHandleFactory;
// ------------------------------------------------------------
// Constructors
// ------------------------------------------------------------
/**
* Construct.
*
* @param ruleBase
* The backing rule-base.
*/
public WorkingMemoryImpl(RuleBaseImpl ruleBase)
{
this.ruleBase = ruleBase;
this.agenda = new Agenda( this,
ruleBase.getConflictResolver( ) );
this.factHandleFactory = ruleBase.newFactHandleFactory();
}
// ------------------------------------------------------------
// Instance methods
// ------------------------------------------------------------
public void addEventListener(WorkingMemoryEventListener listener)
{
this.eventSupport.addEventListener( listener );
}
public void removeEventListener(WorkingMemoryEventListener listener)
{
this.eventSupport.removeEventListener( listener );
}
public List getEventListeners()
{
return eventSupport.getEventListeners( );
}
/**
* Create a new <code>FactHandle</code>.
*
* @return The new fact handle.
*/
FactHandle newFactHandle()
{
if ( !this.factHandlePool.isEmpty( ) )
{
return factHandleFactory.newFactHandle( this.factHandlePool.pop( ) );
}
else
{
return factHandleFactory.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.isEmpty( ) )
{
agenda.fireNextItem( agendaFilter );
}
}
finally
{
firing = false;
}
}
}
/**
* @see WorkingMemory
*/
public void fireAllRules() throws FactException
{
fireAllRules( null );
}
/**
* @see WorkingMemory
*/
public Object getObject(FactHandle handle) throws NoSuchFactObjectException
{
Object object = this.objects.get( ((FactHandleImpl) handle).getId( ) );
if ( object == null )
{
throw new NoSuchFactObjectException( handle );
}
return object;
}
/**
* @see WorkingMemory
*/
public FactHandle getFactHandle(Object object) throws NoSuchFactHandleException
{
FactHandle factHandle = (FactHandle) this.handles.get( object );
if ( factHandle == null )
{
throw new NoSuchFactHandleException( object );
}
return factHandle;
}
public List getFactHandles()
{
return new ArrayList( this.handles.values( ) );
}
/**
* @see WorkingMemory
*/
public List getObjects()
{
return new ArrayList( this.objects.values( ) );
}
public List getObjects(Class objectClass)
{
List matching = new LinkedList( );
Iterator objIter = this.objects.values( ).iterator( );
Object obj;
while ( objIter.hasNext( ) )
{
obj = objIter.next( );
if ( objectClass.isInstance( obj ) )
{
matching.add( obj );
}
}
return matching;
}
/**
* @see WorkingMemory
*/
public boolean containsObject(FactHandle handle)
{
return this.objects.containsKey( ((FactHandleImpl) handle).getId( ) );
}
/**
* @see WorkingMemory
*/
public FactHandle assertObject(Object object) throws FactException
{
return assertObject( object, /* Not-Dynamic */
false );
}
public FactHandle assertObject(Object object,
boolean dynamic) throws FactException
{
FactHandle handle = (FactHandle) handles.get( object );
if ( handle != null )
{
return handle;
}
handle = newFactHandle( );
putObject( handle,
object );
if ( dynamic )
{
addPropertyChangeListener( object );
}
this.agenda.setMode( Agenda.ASSERT );
ruleBase.assertObject( handle,
object,
this );
eventSupport.fireObjectAsserted( handle,
object );
this.agenda.setMode( Agenda.NONE );
return handle;
}
private void addPropertyChangeListener(Object object)
{
try
{
Method method = object.getClass( ).getMethod( "addPropertyChangeListener",
ADD_REMOVE_PROPERTY_CHANGE_LISTENER_ARG_TYPES );
method.invoke( object,
addRemovePropertyChangeListenerArgs );
}
catch ( NoSuchMethodException e )
{
System.err.println( "Warning: Method addPropertyChangeListener not found"
+ " on the class " + object.getClass( )
+ " so Drools will be unable to process JavaBean"
+ " PropertyChangeEvents on the asserted Object" );
}
catch ( IllegalArgumentException e )
{
System.err.println( "Warning: The addPropertyChangeListener method" + " on the class " + object.getClass( ) + " does not take" + " a simple PropertyChangeListener argument" + " so Drools will be unable to process JavaBean"
+ " PropertyChangeEvents on the asserted Object" );
}
catch ( IllegalAccessException e )
{
System.err.println( "Warning: The addPropertyChangeListener method" + " on the class " + object.getClass( ) + " is not public" + " so Drools will be unable to process JavaBean" + " PropertyChangeEvents on the asserted Object" );
}
catch ( InvocationTargetException e )
{
System.err.println( "Warning: The addPropertyChangeListener method" + " on the class " + object.getClass( ) + " threw an InvocationTargetException" + " so Drools will be unable to process JavaBean"
+ " PropertyChangeEvents on the asserted Object: " + e.getMessage( ) );
}
catch ( SecurityException e )
{
System.err.println( "Warning: The SecurityManager controlling the class " + object.getClass( ) + " did not allow the lookup of a" + " addPropertyChangeListener method" + " so Drools will be unable to process JavaBean"
+ " PropertyChangeEvents on the asserted Object: " + e.getMessage( ) );
}
}
private void removePropertyChangeListener(FactHandle handle) throws NoSuchFactObjectException
{
Object object = null;
try
{
object = getObject( handle );
Method mehod = handle.getClass( ).getMethod( "removePropertyChangeListener",
ADD_REMOVE_PROPERTY_CHANGE_LISTENER_ARG_TYPES );
mehod.invoke( handle,
addRemovePropertyChangeListenerArgs );
}
catch ( NoSuchMethodException e )
{
// The removePropertyChangeListener method on the class
// was not found so Drools will be unable to
// stop processing JavaBean PropertyChangeEvents
// on the retracted Object
}
catch ( IllegalArgumentException e )
{
System.err.println( "Warning: The removePropertyChangeListener method" + " on the class " + object.getClass( ) + " does not take" + " a simple PropertyChangeListener argument" + " so Drools will be unable to stop processing JavaBean"
+ " PropertyChangeEvents on the retracted Object" );
}
catch ( IllegalAccessException e )
{
System.err.println( "Warning: The removePropertyChangeListener method" + " on the class " + object.getClass( ) + " is not public" + " so Drools will be unable to stop processing JavaBean" + " PropertyChangeEvents on the retracted Object" );
}
catch ( InvocationTargetException e )
{
System.err.println( "Warning: The removePropertyChangeL istener method" + " on the class " + object.getClass( ) + " threw an InvocationTargetException" + " so Drools will be unable to stop processing JavaBean"
+ " PropertyChangeEvents on the retracted Object: " + e.getMessage( ) );
}
catch ( SecurityException e )
{
System.err.println( "Warning: The SecurityManager controlling the class " + object.getClass( ) + " did not allow the lookup of a" + " removePropertyChangeListener method" + " so Drools will be unable to stop processing JavaBean"
+ " PropertyChangeEvents on the retracted Object: " + e.getMessage( ) );
}
}
/**
* Associate an object with its handle.
*
* @param handle
* The handle.
* @param object
* The object.
*/
Object putObject(FactHandle handle,
Object object)
{
Object oldValue = this.objects.put( ((FactHandleImpl) handle).getId( ),
object );
this.handles.put( object,
handle );
return oldValue;
}
Object removeObject(FactHandle handle)
{
Object object = this.objects.remove( ((FactHandleImpl) handle).getId( ) );
this.handles.remove( object );
return object;
}
/**
* @see WorkingMemory
*/
public void retractObject(FactHandle handle) throws FactException
{
removePropertyChangeListener( handle );
this.agenda.setMode( Agenda.RETRACT );
ruleBase.retractObject( handle,
this );
Object oldObject = removeObject( handle );
factHandlePool.push( ((FactHandleImpl) handle).getId( ) );
eventSupport.fireObjectRetracted( handle,
oldObject );
this.agenda.setMode( Agenda.NONE );
((FactHandleImpl) handle).invalidate( );
}
/**
* @see WorkingMemory
*/
public void modifyObject(FactHandle handle,
Object object) throws FactException
{
Object originalObject = removeObject( handle );
if ( originalObject == null )
{
throw new NoSuchFactObjectException( handle );
}
putObject( handle,
object );
this.agenda.setMode( Agenda.MODIFY );
this.ruleBase.retractObject( handle,
this );
this.ruleBase.assertObject( handle,
object,
this );
this.agenda.removeMarkedItemsFromAgenda( );
this.agenda.setMode( Agenda.NONE );
/*
* this.ruleBase.modifyObject( handle, object, this );
*/
this.eventSupport.fireObjectModified( handle,
originalObject,
object );
}
/**
* Retrieve the <code>JoinMemory</code> for a particular
* <code>JoinNode</code>.
*
* @param node
* The <code>JoinNode</code> key.
*
* @return The node's memory.
*/
public JoinMemory getJoinMemory(JoinNode node)
{
JoinMemory memory = (JoinMemory) this.joinMemories.get( node );
if ( memory == null )
{
memory = new JoinMemory( node.getTupleDeclarations( ),
node.getCommonDeclarations( ) );
this.joinMemories.put( node,
memory );
}
return memory;
}
public WorkingMemoryEventSupport getEventSupport()
{
return eventSupport;
}
/**
* Sets the AsyncExceptionHandler to handle exceptions thrown by the Agenda
* Scheduler used for duration rules.
*
* @param handler
*/
public void setAsyncExceptionHandler(AsyncExceptionHandler handler)
{
this.agenda.setAsyncExceptionHandler( handler );
}
public void dumpMemory()
{
Iterator it = this.joinMemories.keySet( ).iterator( );
while ( it.hasNext( ) )
{
((JoinMemory) this.joinMemories.get( it.next( ) )).dump( );
}
}
public void propertyChange(PropertyChangeEvent event)
{
Object object = event.getSource( );
try
{
modifyObject( getFactHandle( object ),
object );
}
catch ( NoSuchFactHandleException e )
{
// Not a fact so unable to process the chnage event
}
catch ( FactException e )
{
throw new RuntimeException( e.getMessage( ) );
}
}
public FactHandleFactory getFactHandleFactory()
{
return factHandleFactory;
}
}