/*
* Copyright 2005 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.reteoo;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Map;
import org.drools.base.mvel.MVELEnabledExpression;
import org.drools.base.mvel.MVELSalienceExpression;
import org.drools.common.AgendaItem;
import org.drools.common.BaseNode;
import org.drools.common.EventSupport;
import org.drools.common.InternalAgenda;
import org.drools.common.InternalFactHandle;
import org.drools.common.InternalWorkingMemory;
import org.drools.common.PropagationContextImpl;
import org.drools.common.ScheduledAgendaItem;
import org.drools.event.rule.ActivationCancelledCause;
import org.drools.reteoo.RuleRemovalContext.CleanupAdapter;
import org.drools.reteoo.builder.BuildContext;
import org.drools.rule.Declaration;
import org.drools.rule.GroupElement;
import org.drools.rule.Rule;
import org.drools.spi.Activation;
import org.drools.spi.PropagationContext;
/**
* Leaf Rete-OO node responsible for enacting <code>Action</code> s on a
* matched <code>Rule</code>.
*
* @see org.drools.rule.Rule
*/
public class RuleTerminalNode extends BaseNode
implements
TerminalNode,
Externalizable {
// ------------------------------------------------------------
// Instance members
// ------------------------------------------------------------
private int sequence = -1; // -1 means not set
private static final long serialVersionUID = 510l;
/** The rule to invoke upon match. */
private Rule rule;
/**
* the subrule reference is needed to resolve declarations
* because declarations may have different offsets in each subrule
*/
private GroupElement subrule;
private int subruleIndex;
private LeftTupleSource tupleSource;
private Declaration[] declarations;
private Declaration[] salienceDeclarations;
private Declaration[] enabledDeclarations;
private LeftTupleSinkNode previousTupleSinkNode;
private LeftTupleSinkNode nextTupleSinkNode;
private boolean fireDirect;
// ------------------------------------------------------------
// Constructors
// ------------------------------------------------------------
public RuleTerminalNode() {
}
/**
* Construct.
*
* @param inputSource
* The parent tuple source.
* @param rule
* The rule.
* @param subruleIndex
*/
public RuleTerminalNode(final int id,
final LeftTupleSource source,
final Rule rule,
final GroupElement subrule,
final int subruleIndex,
final BuildContext context) {
super( id,
context.getPartitionId(),
context.getRuleBase().getConfiguration().isMultithreadEvaluation() );
this.rule = rule;
this.tupleSource = source;
this.subrule = subrule;
this.subruleIndex = subruleIndex;
Map<String, Declaration> decls = this.subrule.getOuterDeclarations();
this.declarations = new Declaration[rule.getRequiredDeclarations().length];
int i = 0;
for ( String str : rule.getRequiredDeclarations() ) {
this.declarations[i++] = decls.get( str );
}
Arrays.sort( this.declarations, SortDeclarations.instance );
setDeclarations(decls);
fireDirect = rule.getActivationListener().equals( "direct" );
}
public void setDeclarations(Map<String, Declaration> decls) {
if ( rule.getSalience() instanceof MVELSalienceExpression ) {
MVELSalienceExpression expr = ( MVELSalienceExpression ) rule.getSalience();
Declaration[] declrs = expr.getMVELCompilationUnit().getPreviousDeclarations();
this.salienceDeclarations = new Declaration[declrs.length];
int i = 0;
for ( Declaration declr : declrs ) {
this.salienceDeclarations[i++] = decls.get( declr.getIdentifier() );
}
Arrays.sort( this.salienceDeclarations, SortDeclarations.instance );
}
if ( rule.getEnabled() instanceof MVELEnabledExpression ) {
MVELEnabledExpression expr = ( MVELEnabledExpression ) rule.getEnabled();
Declaration[] declrs = expr.getMVELCompilationUnit().getPreviousDeclarations();
this.enabledDeclarations = new Declaration[declrs.length];
int i = 0;
for ( Declaration declr : declrs ) {
this.enabledDeclarations[i++] = decls.get( declr.getIdentifier() );
}
Arrays.sort( this.enabledDeclarations, SortDeclarations.instance );
}
}
// ------------------------------------------------------------
// Instance methods
// ------------------------------------------------------------
@SuppressWarnings("unchecked")
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
super.readExternal( in );
sequence = in.readInt();
rule = (Rule) in.readObject();
subrule = (GroupElement) in.readObject();
subruleIndex = in.readInt();
tupleSource = (LeftTupleSource) in.readObject();
previousTupleSinkNode = (LeftTupleSinkNode) in.readObject();
nextTupleSinkNode = (LeftTupleSinkNode) in.readObject();
declarations = ( Declaration[]) in.readObject();
salienceDeclarations = ( Declaration[]) in.readObject();
enabledDeclarations = ( Declaration[]) in.readObject();
fireDirect = rule.getActivationListener().equals( "direct" );
}
public void writeExternal(ObjectOutput out) throws IOException {
super.writeExternal( out );
out.writeInt( sequence );
out.writeObject( rule );
out.writeObject( subrule );
out.writeInt( subruleIndex );
out.writeObject( tupleSource );
out.writeObject( previousTupleSinkNode );
out.writeObject( nextTupleSinkNode );
out.writeObject( declarations );
out.writeObject( salienceDeclarations );
out.writeObject( enabledDeclarations );
}
/**
* Retrieve the <code>Action</code> associated with this node.
*
* @return The <code>Action</code> associated with this node.
*/
public Rule getRule() {
return this.rule;
}
public GroupElement getSubRule() {
return this.subrule;
}
public void setSequence(int seq) {
this.sequence = seq;
}
public int getSequence() {
return this.sequence;
}
public LeftTupleSource getLeftTupleSource() {
return this.tupleSource;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// org.drools.impl.TupleSink
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
public void assertLeftTuple(final LeftTuple leftTuple,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
//check if the rule is not effective or
// if the current Rule is no-loop and the origin rule is the same then return
if ( (!this.rule.isEffective( leftTuple,
this,
workingMemory )) ||
(this.rule.isNoLoop() && this.rule.equals( context.getRuleOrigin() )) ) {
leftTuple.setObject( Boolean.TRUE );
return;
}
final InternalAgenda agenda = (InternalAgenda) workingMemory.getAgenda();
boolean fire = agenda.createActivation( leftTuple,
context,
workingMemory,
this,
false );
if( fire && !fireDirect ) {
agenda.addActivation( (AgendaItem) leftTuple.getObject() );
}
}
public void modifyLeftTuple(LeftTuple leftTuple,
PropagationContext context,
InternalWorkingMemory workingMemory) {
InternalAgenda agenda = (InternalAgenda) workingMemory.getAgenda();
// we need the inserted facthandle so we can update the network with new Activation
Object o = leftTuple.getObject();
if ( o != Boolean.TRUE) { // would be true due to lock-on-active blocking activation creation
AgendaItem match = (AgendaItem) o;
if ( match != null && match.isActivated() ) {
// already activated, do nothing
// although we need to notify the inserted Activation, as it's declarations may have changed.
agenda.modifyActivation( match, true );
return;
}
}
// if the current Rule is no-loop and the origin rule is the same then return
if ( (!this.rule.isEffective( leftTuple,
this,
workingMemory )) ||
(this.rule.isNoLoop() && this.rule.equals( context.getRuleOrigin() )) ) {
agenda.increaseDormantActivations();
return;
}
boolean reuseActivation = true;
if ( o == Boolean.TRUE ) {
// set to Boolean.TRUE when lock-on-active stops an Activation being created
// We set this instead of doing a null check, as it's a little safer due to intent.
reuseActivation = false;
leftTuple.setObject( null );
}
boolean fire = agenda.createActivation( leftTuple, context, workingMemory, this, reuseActivation );
if ( fire && !isFireDirect() ) {
// This activation is currently dormant and about to reactivated, so decrease the dormant count.
agenda.decreaseDormantActivations();
agenda.modifyActivation( (AgendaItem) leftTuple.getObject(), false );
}
}
public void modifyLeftTuple(InternalFactHandle factHandle,
ModifyPreviousTuples modifyPreviousTuples,
PropagationContext context,
InternalWorkingMemory workingMemory) {
LeftTuple leftTuple = modifyPreviousTuples.removeLeftTuple( this );
if ( leftTuple != null ) {
leftTuple.reAdd(); //
// LeftTuple previously existed, so continue as modify
modifyLeftTuple( leftTuple,
context,
workingMemory );
} else {
// LeftTuple does not exist, so create and continue as assert
assertLeftTuple( createLeftTuple( factHandle,
this,
true ),
context,
workingMemory );
}
}
public void retractLeftTuple(final LeftTuple leftTuple,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
Object obj = leftTuple.getObject();
// activation can be null if the LeftTuple previous propagated into a no-loop
// or could be true due to lock-on-active blocking activation creation
if ( obj == null || obj == Boolean.TRUE) {
return;
}
final Activation activation = (Activation) leftTuple.getObject();
activation.setMatched( false );
final InternalAgenda agenda = (InternalAgenda) workingMemory.getAgenda();
agenda.cancelActivation( leftTuple,
context,
workingMemory,
activation,
this );
}
public String toString() {
return "[RuleTerminalNode(" + this.getId() + "): rule=" + this.rule.getName() + "]";
}
public void ruleAttached() {
}
public void attach() {
this.tupleSource.addTupleSink( this );
}
public void attach(final InternalWorkingMemory[] workingMemories) {
attach();
for ( int i = 0, length = workingMemories.length; i < length; i++ ) {
final InternalWorkingMemory workingMemory = workingMemories[i];
final PropagationContext propagationContext = new PropagationContextImpl( workingMemory.getNextPropagationIdCounter(),
PropagationContext.RULE_ADDITION,
null,
null,
null );
this.tupleSource.updateSink( this,
propagationContext,
workingMemory );
}
}
public void networkUpdated() {
this.tupleSource.networkUpdated();
}
protected void doRemove(final RuleRemovalContext context,
final ReteooBuilder builder,
final BaseNode node,
final InternalWorkingMemory[] workingMemories) {
CleanupAdapter adapter = context.getCleanupAdapter();
context.setCleanupAdapter( new RTNCleanupAdapter( this ) );
this.tupleSource.remove( context,
builder,
this,
workingMemories );
for ( InternalWorkingMemory workingMemory : workingMemories ) {
workingMemory.executeQueuedActions();
}
context.setCleanupAdapter( adapter );
}
public boolean isInUse() {
return false;
}
public boolean isLeftTupleMemoryEnabled() {
return false;
}
public void setLeftTupleMemoryEnabled(boolean tupleMemoryEnabled) {
}
public Declaration[] getDeclarations() {
return this.declarations;
}
public Declaration[] getSalienceDeclarations() {
return salienceDeclarations;
}
public void setSalienceDeclarations(Declaration[] salienceDeclarations) {
this.salienceDeclarations = salienceDeclarations;
}
public Declaration[] getEnabledDeclarations() {
return enabledDeclarations;
}
public void setEnabledDeclarations(Declaration[] enabledDeclarations) {
this.enabledDeclarations = enabledDeclarations;
}
public static class SortDeclarations
implements
Comparator<Declaration> {
public final static SortDeclarations instance = new SortDeclarations();
public int compare(Declaration d1,
Declaration d2) {
return (d1.getIdentifier().compareTo( d2.getIdentifier() ));
}
}
/**
* Returns the next node
* @return
* The next TupleSinkNode
*/
public LeftTupleSinkNode getNextLeftTupleSinkNode() {
return this.nextTupleSinkNode;
}
/**
* Sets the next node
* @param next
* The next TupleSinkNode
*/
public void setNextLeftTupleSinkNode(final LeftTupleSinkNode next) {
this.nextTupleSinkNode = next;
}
/**
* Returns the previous node
* @return
* The previous TupleSinkNode
*/
public LeftTupleSinkNode getPreviousLeftTupleSinkNode() {
return this.previousTupleSinkNode;
}
/**
* Sets the previous node
* @param previous
* The previous TupleSinkNode
*/
public void setPreviousLeftTupleSinkNode(final LeftTupleSinkNode previous) {
this.previousTupleSinkNode = previous;
}
public int hashCode() {
return this.rule.hashCode();
}
public boolean equals(final Object object) {
if ( object == this ) {
return true;
}
if ( object == null || !(object instanceof RuleTerminalNode) ) {
return false;
}
final RuleTerminalNode other = (RuleTerminalNode) object;
return this.rule.equals( other.rule );
}
public short getType() {
return NodeTypeEnums.RuleTerminalNode;
}
public static class RTNCleanupAdapter
implements
CleanupAdapter {
private RuleTerminalNode node;
public RTNCleanupAdapter(RuleTerminalNode node) {
this.node = node;
}
public void cleanUp(final LeftTuple leftTuple,
final InternalWorkingMemory workingMemory) {
if ( leftTuple.getLeftTupleSink() != node ) {
return;
}
final Activation activation = (Activation) leftTuple.getObject();
// this is to catch a race condition as activations are activated and unactivated on timers
if ( activation instanceof ScheduledAgendaItem ) {
ScheduledAgendaItem scheduled = (ScheduledAgendaItem) activation;
workingMemory.getTimerService().removeJob( scheduled.getJobHandle() );
scheduled.getJobHandle().setCancel( true );
}
if ( activation.isActivated() ) {
activation.remove();
((EventSupport) workingMemory).getAgendaEventSupport().fireActivationCancelled( activation,
workingMemory,
ActivationCancelledCause.CLEAR );
}
final PropagationContext propagationContext = new PropagationContextImpl( workingMemory.getNextPropagationIdCounter(),
PropagationContext.RULE_REMOVAL,
null,
null,
null );
workingMemory.getTruthMaintenanceSystem().removeLogicalDependencies( activation,
propagationContext,
node.getRule() );
leftTuple.unlinkFromLeftParent();
leftTuple.unlinkFromRightParent();
}
}
public LeftTuple createLeftTuple(InternalFactHandle factHandle,
LeftTupleSink sink,
boolean leftTupleMemoryEnabled) {
return new RuleTerminalNodeLeftTuple( factHandle, sink, leftTupleMemoryEnabled );
}
public LeftTuple createLeftTuple(LeftTuple leftTuple,
LeftTupleSink sink,
boolean leftTupleMemoryEnabled) {
return new RuleTerminalNodeLeftTuple( leftTuple, sink, leftTupleMemoryEnabled );
}
public LeftTuple createLeftTuple(LeftTuple leftTuple,
RightTuple rightTuple,
LeftTupleSink sink) {
return new RuleTerminalNodeLeftTuple( leftTuple, rightTuple, sink );
}
public LeftTuple createLeftTuple(LeftTuple leftTuple,
RightTuple rightTuple,
LeftTuple currentLeftChild,
LeftTuple currentRightChild,
LeftTupleSink sink,
boolean leftTupleMemoryEnabled) {
return new RuleTerminalNodeLeftTuple(leftTuple, rightTuple, currentLeftChild, currentRightChild, sink, leftTupleMemoryEnabled );
}
public boolean isFireDirect() {
return this.fireDirect;
}
}