/**
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
*
*/
package org.drools.common;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Map;
import java.util.concurrent.locks.ReentrantLock;
import org.drools.FactException;
import org.drools.FactHandle;
import org.drools.RuleBase;
import org.drools.RuntimeDroolsException;
import org.drools.WorkingMemory;
import org.drools.WorkingMemoryEntryPoint;
import org.drools.RuleBaseConfiguration.AssertBehaviour;
import org.drools.base.ClassObjectType;
import org.drools.core.util.ObjectHashSet;
import org.drools.impl.StatefulKnowledgeSessionImpl.ObjectStoreWrapper;
import org.drools.reteoo.EntryPointNode;
import org.drools.reteoo.LeftTuple;
import org.drools.reteoo.ObjectTypeConf;
import org.drools.reteoo.ObjectTypeNode;
import org.drools.reteoo.Rete;
import org.drools.rule.EntryPoint;
import org.drools.rule.Rule;
import org.drools.spi.Activation;
import org.drools.spi.FactHandleFactory;
import org.drools.spi.ObjectType;
import org.drools.spi.PropagationContext;
public class NamedEntryPoint
implements
InternalWorkingMemoryEntryPoint,
WorkingMemoryEntryPoint,
PropertyChangeListener {
protected static final Class[] ADD_REMOVE_PROPERTY_CHANGE_LISTENER_ARG_TYPES = new Class[]{PropertyChangeListener.class};
/** The arguments used when adding/removing a property change listener. */
protected final Object[] addRemovePropertyChangeListenerArgs = new Object[]{this};
private static final long serialVersionUID = 510l;
protected ObjectStore objectStore;
protected transient InternalRuleBase ruleBase;
protected EntryPoint entryPoint;
protected EntryPointNode entryPointNode;
private ObjectTypeConfigurationRegistry typeConfReg;
private final AbstractWorkingMemory wm;
private FactHandleFactory handleFactory;
protected final ReentrantLock lock;
public NamedEntryPoint(EntryPoint entryPoint,
EntryPointNode entryPointNode,
AbstractWorkingMemory wm) {
this( entryPoint,
entryPointNode,
wm,
new ReentrantLock() );
}
public NamedEntryPoint(EntryPoint entryPoint,
EntryPointNode entryPointNode,
AbstractWorkingMemory wm,
ReentrantLock lock) {
this.entryPoint = entryPoint;
this.entryPointNode = entryPointNode;
this.wm = wm;
this.ruleBase = (InternalRuleBase) this.wm.getRuleBase();
this.lock = lock;
this.typeConfReg = new ObjectTypeConfigurationRegistry( this.ruleBase );
this.handleFactory = this.wm.getFactHandleFactory();
this.objectStore = new SingleThreadedObjectStore( this.ruleBase.getConfiguration(),
this.lock );
}
public void reset() {
this.objectStore.clear();
}
public ObjectStore getObjectStore() {
return this.objectStore;
}
public EntryPointNode getEntryPointNode() {
return this.entryPointNode;
}
/**
* @see WorkingMemory
*/
public FactHandle insert(final Object object) throws FactException {
return insert( object, /* Not-Dynamic */
false,
false,
null,
null );
}
public FactHandle insert(final Object object,
final boolean dynamic) throws FactException {
return insert( object,
dynamic,
false,
null,
null );
}
protected FactHandle insert(final Object object,
final boolean dynamic,
boolean logical,
final Rule rule,
final Activation activation) throws FactException {
if ( object == null ) {
// you cannot assert a null object
return null;
}
try {
this.wm.startOperation();
ObjectTypeConf typeConf = this.typeConfReg.getObjectTypeConf( this.entryPoint,
object );
if ( logical && !typeConf.isTMSEnabled()) {
enableTMS(object, typeConf);
}
InternalFactHandle handle = null;
if ( this.wm.isSequential() ) {
handle = createHandle( object,
typeConf );
insert( handle,
object,
rule,
activation,
typeConf );
return handle;
}
try {
this.ruleBase.readLock();
this.lock.lock();
// check if the object already exists in the WM
handle = (InternalFactHandle) this.objectStore.getHandleForObject( object );
if ( typeConf.isTMSEnabled() ) {
EqualityKey key = null;
if ( handle == null ) {
// lets see if the object is already logical asserted
key = this.wm.tms.get( object );
} else {
// Object is already asserted, so check and possibly correct its
// status and then return the handle
key = handle.getEqualityKey();
if ( key.getStatus() == EqualityKey.STATED ) {
// return null as you cannot justify a stated object.
return handle;
}
if ( !logical ) {
// this object was previously justified, so we have to override it to stated
key.setStatus( EqualityKey.STATED );
this.wm.tms.removeLogicalDependencies( handle );
} else {
// this was object is already justified, so just add new logical dependency
this.wm.tms.addLogicalDependency( handle,
activation,
activation.getPropagationContext(),
rule );
}
return handle;
}
// At this point we know the handle is null
if ( key == null ) {
handle = createHandle( object,
typeConf );
key = createEqualityKey(handle);
this.wm.tms.put( key );
if ( !logical ) {
key.setStatus( EqualityKey.STATED );
} else {
key.setStatus( EqualityKey.JUSTIFIED );
this.wm.tms.addLogicalDependency( handle,
activation,
activation.getPropagationContext(),
rule );
}
} else if ( !logical ) {
if ( key.getStatus() == EqualityKey.JUSTIFIED ) {
// Its previous justified, so switch to stated and remove logical dependencies
final InternalFactHandle justifiedHandle = key.getFactHandle();
this.wm.tms.removeLogicalDependencies( justifiedHandle );
if ( this.wm.discardOnLogicalOverride ) {
// override, setting to new instance, and return
// existing handle
key.setStatus( EqualityKey.STATED );
handle = key.getFactHandle();
if ( AssertBehaviour.IDENTITY.equals( this.ruleBase.getConfiguration().getAssertBehaviour() ) ) {
// as assertMap may be using an "identity"
// equality comparator,
// we need to remove the handle from the map,
// before replacing the object
// and then re-add the handle. Otherwise we may
// end up with a leak.
this.objectStore.updateHandle( handle,
object );
} else {
Object oldObject = handle.getObject();
}
return handle;
} else {
// override, then instantiate new handle for
// assertion
key.setStatus( EqualityKey.STATED );
handle = createHandle( object,
typeConf );
handle.setEqualityKey( key );
key.addFactHandle( handle );
}
} else {
handle = createHandle( object,
typeConf );
key.addFactHandle( handle );
handle.setEqualityKey( key );
}
} else {
if ( key.getStatus() == EqualityKey.JUSTIFIED ) {
// only add as logical dependency if this wasn't previously stated
this.wm.tms.addLogicalDependency( key.getFactHandle(),
activation,
activation.getPropagationContext(),
rule );
return key.getFactHandle();
} else {
// You cannot justify a previously stated equality equal object, so return null
return null;
}
}
} else {
if ( handle != null ) {
return handle;
}
handle = createHandle( object,
typeConf );
}
// if the dynamic parameter is true or if the user declared the fact type with the meta tag:
// @propertyChangeSupport
if ( dynamic || typeConf.isDynamic() ) {
addPropertyChangeListener( object );
}
insert( handle,
object,
rule,
activation,
typeConf );
} finally {
this.lock.unlock();
this.ruleBase.readUnlock();
}
return handle;
} finally {
this.wm.endOperation();
}
}
public void insert(final InternalFactHandle handle,
final Object object,
final Rule rule,
final Activation activation,
ObjectTypeConf typeConf) {
this.ruleBase.executeQueuedActions();
this.wm.executeQueuedActions();
if ( activation != null ) {
// release resources so that they can be GC'ed
activation.getPropagationContext().releaseResources();
}
final PropagationContext propagationContext = new PropagationContextImpl( this.wm.getNextPropagationIdCounter(),
PropagationContext.ASSERTION,
rule,
(activation == null) ? null : (LeftTuple) activation.getTuple(),
handle,
this.wm.agenda.getActiveActivations(),
this.wm.agenda.getDormantActivations(),
entryPoint );
this.entryPointNode.assertObject( handle,
propagationContext,
typeConf,
this.wm );
this.wm.executeQueuedActions();
this.wm.workingMemoryEventSupport.fireObjectInserted( propagationContext,
handle,
object,
this.wm );
}
public void update(final org.drools.runtime.rule.FactHandle handle,
final Object object) throws FactException {
update( handle,
object,
null,
null );
}
public void update(final org.drools.runtime.rule.FactHandle factHandle,
final Object object,
final Rule rule,
final Activation activation) throws FactException {
update( (org.drools.FactHandle) factHandle,
object,
rule,
activation );
}
public void update(org.drools.FactHandle factHandle,
final Object object,
final Rule rule,
final Activation activation) throws FactException {
try {
this.ruleBase.readLock();
this.lock.lock();
this.wm.startOperation();
this.ruleBase.executeQueuedActions();
// the handle might have been disconnected, so reconnect if it has
if ( ((InternalFactHandle)factHandle).isDisconnected() ) {
factHandle = this.objectStore.reconnect( factHandle );
}
final ObjectTypeConf typeConf = this.typeConfReg.getObjectTypeConf( this.entryPoint,
object );
// only needed if we maintain tms, but either way we must get it before we do the retract
int status = -1;
if ( typeConf.isTMSEnabled() ) {
status = ((InternalFactHandle) factHandle).getEqualityKey().getStatus();
}
final InternalFactHandle handle = (InternalFactHandle) factHandle;
final Object originalObject = handle.getObject();
if ( handle.getId() == -1 || object == null || (handle.isEvent() && ((EventFactHandle) handle).isExpired()) ) {
// the handle is invalid, most likely already retracted, so return and we cannot assert a null object
return;
}
if ( activation != null ) {
// release resources so that they can be GC'ed
activation.getPropagationContext().releaseResources();
}
if ( originalObject != object || !AssertBehaviour.IDENTITY.equals( this.ruleBase.getConfiguration().getAssertBehaviour() ) ) {
this.objectStore.removeHandle( handle );
// set anyway, so that it updates the hashCodes
handle.setObject( object );
this.objectStore.addHandle( handle,
object );
}
if ( typeConf.isTMSEnabled() ) {
// the hashCode and equality has changed, so we must update the
// EqualityKey
EqualityKey key = handle.getEqualityKey();
key.removeFactHandle( handle );
// If the equality key is now empty, then remove it
if ( key.isEmpty() ) {
this.wm.tms.remove( key );
}
// now use an existing EqualityKey, if it exists, else create a new one
key = this.wm.tms.get( object );
if ( key == null ) {
key = new EqualityKey( handle,
status );
this.wm.tms.put( key );
} else {
key.addFactHandle( handle );
}
handle.setEqualityKey( key );
}
this.handleFactory.increaseFactHandleRecency( handle );
final PropagationContext propagationContext = new PropagationContextImpl( this.wm.getNextPropagationIdCounter(),
PropagationContext.MODIFICATION,
rule,
(activation == null) ? null : (LeftTuple) activation.getTuple(),
handle,
this.wm.agenda.getActiveActivations(),
this.wm.agenda.getDormantActivations(),
entryPoint );
this.entryPointNode.modifyObject( handle,
propagationContext,
typeConf,
this.wm );
this.wm.workingMemoryEventSupport.fireObjectUpdated( propagationContext,
(org.drools.FactHandle) factHandle,
originalObject,
object,
this.wm );
this.wm.executeQueuedActions();
} finally {
this.wm.endOperation();
this.lock.unlock();
this.ruleBase.readUnlock();
}
}
public void retract(final org.drools.runtime.rule.FactHandle handle) throws FactException {
retract( (org.drools.FactHandle) handle,
true,
true,
null,
null );
}
public void retract(final org.drools.FactHandle factHandle,
final boolean removeLogical,
final boolean updateEqualsMap,
final Rule rule,
final Activation activation) throws FactException {
try {
this.ruleBase.readLock();
this.lock.lock();
this.wm.startOperation();
this.ruleBase.executeQueuedActions();
InternalFactHandle handle = (InternalFactHandle) factHandle;
if ( handle.getId() == -1 ) {
// can't retract an already retracted handle
return;
}
// the handle might have been disconnected, so reconnect if it has
if ( handle.isDisconnected() ) {
handle = this.objectStore.reconnect( handle );
}
removePropertyChangeListener( handle );
if ( activation != null ) {
// release resources so that they can be GC'ed
activation.getPropagationContext().releaseResources();
}
final PropagationContext propagationContext = new PropagationContextImpl( this.wm.getNextPropagationIdCounter(),
PropagationContext.RETRACTION,
rule,
(activation == null) ? null : (LeftTuple) activation.getTuple(),
handle,
this.wm.agenda.getActiveActivations(),
this.wm.agenda.getDormantActivations(),
this.entryPoint );
final Object object = handle.getObject();
final ObjectTypeConf typeConf = this.typeConfReg.getObjectTypeConf( this.entryPoint,
object );
this.entryPointNode.retractObject( handle,
propagationContext,
typeConf,
this.wm );
if ( typeConf.isTMSEnabled() ) {
// Update the equality key, which maintains a list of stated
// FactHandles
final EqualityKey key = handle.getEqualityKey();
// Its justified so attempt to remove any logical dependencies
// for
// the handle
if ( key.getStatus() == EqualityKey.JUSTIFIED ) {
this.wm.tms.removeLogicalDependencies( handle );
}
key.removeFactHandle( handle );
handle.setEqualityKey( null );
// If the equality key is now empty, then remove it
if ( key.isEmpty() ) {
this.wm.tms.remove( key );
}
}
this.wm.workingMemoryEventSupport.fireObjectRetracted( propagationContext,
handle,
object,
this.wm );
this.objectStore.removeHandle( handle );
this.handleFactory.destroyFactHandle( handle );
this.wm.executeQueuedActions();
} finally {
this.wm.endOperation();
this.lock.unlock();
this.ruleBase.readUnlock();
}
}
protected void addPropertyChangeListener(final Object object) {
try {
final Method method = object.getClass().getMethod( "addPropertyChangeListener",
NamedEntryPoint.ADD_REMOVE_PROPERTY_CHANGE_LISTENER_ARG_TYPES );
method.invoke( object,
this.addRemovePropertyChangeListenerArgs );
} catch ( final 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 ( final 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 ( final 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 ( final 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 ( final 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() );
}
}
protected void removePropertyChangeListener(final FactHandle handle) {
Object object = null;
try {
object = ((InternalFactHandle) handle).getObject();
if ( object != null ) {
final Method mehod = object.getClass().getMethod( "removePropertyChangeListener",
NamedEntryPoint.ADD_REMOVE_PROPERTY_CHANGE_LISTENER_ARG_TYPES );
mehod.invoke( object,
this.addRemovePropertyChangeListenerArgs );
}
} catch ( final 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 ( final IllegalArgumentException e ) {
throw new RuntimeDroolsException( "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 ( final IllegalAccessException e ) {
throw new RuntimeDroolsException( "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 ( final InvocationTargetException e ) {
throw new RuntimeDroolsException( "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 ( final SecurityException e ) {
throw new RuntimeDroolsException( "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() );
}
}
public WorkingMemoryEntryPoint getWorkingMemoryEntryPoint(String name) {
return this.wm.getWorkingMemoryEntryPoint( name );
}
public ObjectTypeConfigurationRegistry getObjectTypeConfigurationRegistry() {
return this.typeConfReg;
}
public RuleBase getRuleBase() {
return this.ruleBase;
}
public FactHandle getFactHandle(Object object) {
return this.objectStore.getHandleForObject( object );
}
public EntryPoint getEntryPoint() {
return this.entryPoint;
}
public InternalWorkingMemory getInternalWorkingMemory() {
return this.wm;
}
public FactHandle getFactHandleByIdentity(final Object object) {
return this.objectStore.getHandleForObjectIdentity( object );
}
public Object getObject(org.drools.runtime.rule.FactHandle factHandle) {
return this.objectStore.getObjectForHandle( (InternalFactHandle) factHandle );
}
@SuppressWarnings("unchecked")
public <T extends org.drools.runtime.rule.FactHandle> Collection<T> getFactHandles() {
return new ObjectStoreWrapper( this.objectStore,
null,
ObjectStoreWrapper.FACT_HANDLE );
}
@SuppressWarnings("unchecked")
public <T extends org.drools.runtime.rule.FactHandle> Collection<T> getFactHandles(org.drools.runtime.ObjectFilter filter) {
return new ObjectStoreWrapper( this.objectStore,
filter,
ObjectStoreWrapper.FACT_HANDLE );
}
@SuppressWarnings("unchecked")
public Collection<Object> getObjects() {
return new ObjectStoreWrapper( this.objectStore,
null,
ObjectStoreWrapper.OBJECT );
}
@SuppressWarnings("unchecked")
public Collection<Object> getObjects(org.drools.runtime.ObjectFilter filter) {
return new ObjectStoreWrapper( this.objectStore,
filter,
ObjectStoreWrapper.OBJECT );
}
public String getEntryPointId() {
return this.entryPoint.getEntryPointId();
}
public long getFactCount() {
return this.objectStore.size();
}
private InternalFactHandle createHandle(final Object object,
ObjectTypeConf typeConf) {
InternalFactHandle handle;
handle = this.handleFactory.newFactHandle( object,
typeConf,
this.wm,
this );
this.objectStore.addHandle( handle,
object );
return handle;
}
/** Side-effects, will add the created key to the handle. */
private EqualityKey createEqualityKey(InternalFactHandle handle) {
EqualityKey key = new EqualityKey( handle );
handle.setEqualityKey( key );
return key;
}
/**
* TMS will be automatically enabled when the first logical insert happens.
*
* We will take all the already asserted objects of the same type and initialize
* the equality map.
*
* @param object the logically inserted object.
* @param conf the type's configuration.
*/
private void enableTMS(Object object, ObjectTypeConf conf) {
final Rete source = this.ruleBase.getRete();
final ClassObjectType cot = new ClassObjectType( object.getClass() );
final Map<ObjectType, ObjectTypeNode> map = source.getObjectTypeNodes( EntryPoint.DEFAULT );
final ObjectTypeNode node = map.get( cot );
final ObjectHashSet memory = (ObjectHashSet) this.wm.getNodeMemory( node );
// All objects of this type that are already there were certainly stated,
// since this method call happens at the first logical insert, for any given type.
org.drools.core.util.Iterator it = memory.iterator();
for ( Object obj = it.next(); obj != null; obj = it.next() ) {
org.drools.core.util.ObjectHashSet.ObjectEntry holder = (org.drools.core.util.ObjectHashSet.ObjectEntry) obj;
InternalFactHandle handle = (InternalFactHandle) holder.getValue();
if ( handle != null) {
EqualityKey key = createEqualityKey(handle);
key.setStatus(EqualityKey.STATED);
this.wm.tms.put(key);
}
}
// Enable TMS for this type.
conf.enableTMS();
}
public void propertyChange(final PropertyChangeEvent event) {
final Object object = event.getSource();
try {
FactHandle handle = getFactHandle( object );
if ( handle == null ) {
throw new FactException( "Update error: handle not found for object: " + object + ". Is it in the working memory?" );
}
update( handle,
object );
} catch ( final FactException e ) {
throw new RuntimeDroolsException( e.getMessage() );
}
}
}