package org.drools.reteoo;
/*
* 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.
*/
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import org.drools.RuleBaseConfiguration;
import org.drools.common.AgendaItem;
import org.drools.common.BaseNode;
import org.drools.common.EventFactHandle;
import org.drools.common.EventSupport;
import org.drools.common.InternalAgenda;
import org.drools.common.InternalRuleFlowGroup;
import org.drools.common.InternalWorkingMemory;
import org.drools.common.NodeMemory;
import org.drools.common.PropagationContextImpl;
import org.drools.common.ScheduledAgendaItem;
import org.drools.event.rule.ActivationCancelledCause;
import org.drools.reteoo.builder.BuildContext;
import org.drools.rule.GroupElement;
import org.drools.rule.Rule;
import org.drools.spi.Activation;
import org.drools.spi.Duration;
import org.drools.spi.PropagationContext;
import org.drools.util.Iterator;
import org.drools.util.LeftTupleList;
/**
* Leaf Rete-OO node responsible for enacting <code>Action</code> s on a
* matched <code>Rule</code>.
*
* @see org.drools.rule.Rule
*
* @author <a href="mailto:bob@eng.werken.com">bob mcwhirter </a>
*/
public final class RuleTerminalNode extends BaseNode
implements
LeftTupleSinkNode,
NodeMemory,
TerminalNode,
Externalizable {
// ------------------------------------------------------------
// Instance members
// ------------------------------------------------------------
private int sequence = -1; // -1 means not set
/**
*
*/
private static final long serialVersionUID = 400L;
/** 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 LeftTupleSource tupleSource;
private LeftTupleSinkNode previousTupleSinkNode;
private LeftTupleSinkNode nextTupleSinkNode;
protected boolean tupleMemoryEnabled;
// ------------------------------------------------------------
// Constructors
// ------------------------------------------------------------
public RuleTerminalNode() {
}
/**
* Construct.
*
* @param inputSource
* The parent tuple source.
* @param rule
* The rule.
*/
public RuleTerminalNode(final int id,
final LeftTupleSource source,
final Rule rule,
final GroupElement subrule,
final BuildContext context) {
super( id,
context.getPartitionId(),
context.getRuleBase().getConfiguration().isMultithreadEvaluation() );
this.rule = rule;
this.tupleSource = source;
this.subrule = subrule;
this.tupleMemoryEnabled = context.isTerminalNodeMemoryEnabled();
}
// ------------------------------------------------------------
// Instance methods
// ------------------------------------------------------------
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
super.readExternal( in );
sequence = in.readInt();
rule = (Rule) in.readObject();
subrule = (GroupElement) in.readObject();
tupleSource = (LeftTupleSource) in.readObject();
previousTupleSinkNode = (LeftTupleSinkNode) in.readObject();
nextTupleSinkNode = (LeftTupleSinkNode) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
super.writeExternal( out );
out.writeInt( sequence );
out.writeObject( rule );
out.writeObject( subrule );
out.writeObject( tupleSource );
out.writeObject( previousTupleSinkNode );
out.writeObject( nextTupleSinkNode );
}
/**
* 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;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// org.drools.impl.TupleSink
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
public void assertLeftTuple(final LeftTuple tuple,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
assertLeftTuple( tuple,
context,
workingMemory,
true );
}
/**
* Assert a new <code>Tuple</code>.
*
* @param tuple
* The <code>Tuple</code> being asserted.
* @param workingMemory
* The working memory session.
* @throws AssertionException
* If an error occurs while asserting.
*/
public void assertLeftTuple(final LeftTuple tuple,
final PropagationContext context,
final InternalWorkingMemory workingMemory,
final boolean fireActivationCreated) {
//check if the rule is effective
if ( !this.rule.isEffective( workingMemory.getTimeMachine(), tuple, workingMemory ) ) {
return;
}
// if the current Rule is no-loop and the origin rule is the same and its the same set of facts (tuple) then return
if ( context.getType() == PropagationContext.MODIFICATION ) {
if ( this.rule.isNoLoop() && this.rule.equals( context.getRuleOrigin() ) && context.getLeftTupleOrigin().equals( tuple ) ) {
return;
}
} else if ( this.rule.isNoLoop() && this.rule.equals( context.getRuleOrigin() ) ) {
return;
}
//we only have to clone the head fact to make sure the graph is not affected during consequence reads after a modify
// @FIXME
final LeftTuple cloned = tuple;//new LeftTuple( tuple );
final InternalAgenda agenda = (InternalAgenda) workingMemory.getAgenda();
final Duration dur = this.rule.getDuration();
if ( dur != null && dur.getDuration( tuple ) > 0 ) {
final ScheduledAgendaItem item = new ScheduledAgendaItem( context.getPropagationNumber(),
cloned,
agenda,
context,
this.rule,
this.subrule );
final TerminalNodeMemory memory = (TerminalNodeMemory) workingMemory.getNodeMemory( this );
agenda.scheduleItem( item );
tuple.setActivation( item );
if ( this.tupleMemoryEnabled ) {
memory.getTupleMemory().add( tuple );
}
item.setActivated( true );
((EventSupport) workingMemory).getAgendaEventSupport().fireActivationCreated( item,
workingMemory );
} else {
// -----------------
// Lazy instantiation and addition to the Agenda of AgendGroup
// implementations
// ----------------
final TerminalNodeMemory memory = (TerminalNodeMemory) workingMemory.getNodeMemory( this );
final AgendaItem item = new AgendaItem( context.getPropagationNumber(),
cloned,
rule.getSalience().getValue( tuple,
workingMemory ),
context,
this.rule,
this.subrule );
item.setSequenence( this.sequence );
tuple.setActivation( item );
memory.getTupleMemory().add( tuple );
boolean added = agenda.addActivation( item );
item.setActivated( added );
// We only want to fire an event on a truly new Activation and not on an Activation as a result of a modify
if ( added && fireActivationCreated ) {
((EventSupport) workingMemory).getAgendaEventSupport().fireActivationCreated( item,
workingMemory );
}
}
agenda.increaseActiveActivations();
}
public void retractLeftTuple(final LeftTuple leftTuple,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
final TerminalNodeMemory memory = (TerminalNodeMemory) workingMemory.getNodeMemory( this );
memory.getTupleMemory().remove( leftTuple );
final Activation activation = leftTuple.getActivation();
// activation can be null if the LeftTuple previous propagated into a no-loop
if ( activation == null ) {
return;
}
if ( activation.getLogicalDependencies() != null && !activation.getLogicalDependencies().isEmpty() ) {
context.addRetractedTuple( this.rule,
activation );
}
if ( activation.isActivated() ) {
if ( context.getType() == PropagationContext.MODIFICATION ) {
// during a modify if we have either isLockOnActive or the activation has logical dependencies
// then we need to track retractions, so we know which are exising activations and which are truly new
if ( this.rule.isLockOnActive() ) {
context.addRetractedTuple( this.rule,
activation );
}
}
// on fact expiration, we don't remove the activation, but let it fire
if( context.getType() == PropagationContext.EXPIRATION && context.getFactHandleOrigin() != null ) {
EventFactHandle efh = (EventFactHandle) context.getFactHandleOrigin();
efh.increaseActivationsCount();
} else {
activation.remove();
if ( activation.getActivationGroupNode() != null ) {
activation.getActivationGroupNode().getActivationGroup().removeActivation( activation );
}
if ( activation.getRuleFlowGroupNode() != null ) {
final InternalRuleFlowGroup ruleFlowGroup = activation.getRuleFlowGroupNode().getRuleFlowGroup();
ruleFlowGroup.removeActivation( activation );
}
((EventSupport) workingMemory).getAgendaEventSupport().fireActivationCancelled( activation,
workingMemory,
ActivationCancelledCause.WME_MODIFY );
((InternalAgenda) workingMemory.getAgenda()).decreaseActiveActivations();
}
} else {
((InternalAgenda) workingMemory.getAgenda()).decreaseDormantActivations();
}
workingMemory.removeLogicalDependencies( activation,
context,
this.rule );
}
public String toString() {
return "[RuleTerminalNode: 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) {
for ( int i = 0, length = workingMemories.length; i < length; i++ ) {
final InternalWorkingMemory workingMemory = workingMemories[i];
final TerminalNodeMemory memory = (TerminalNodeMemory) workingMemory.getNodeMemory( this );
final Iterator it = memory.getTupleMemory().iterator();
for ( LeftTuple leftTuple = (LeftTuple) it.next(); leftTuple != null; leftTuple = (LeftTuple) it.next() ) {
final Activation activation = leftTuple.getActivation();
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,
this.rule );
leftTuple.unlinkFromLeftParent();
leftTuple.unlinkFromRightParent();
}
workingMemory.executeQueuedActions();
workingMemory.clearNodeMemory( this );
}
if ( !context.alreadyVisited( this.tupleSource ) ) {
this.tupleSource.remove( context,
builder,
this,
workingMemories );
}
}
public boolean isInUse() {
return false;
}
public Object createMemory(final RuleBaseConfiguration config) {
return new TerminalNodeMemory();
}
public boolean isLeftTupleMemoryEnabled() {
return tupleMemoryEnabled;
}
public void setLeftTupleMemoryEnabled(boolean tupleMemoryEnabled) {
this.tupleMemoryEnabled = tupleMemoryEnabled;
}
/**
* 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 TerminalNodeMemory
implements
Externalizable {
private static final long serialVersionUID = 400L;
// private InternalAgendaGroup agendaGroup;
//
// private ActivationGroup activationGroup;
//
// private RuleFlowGroup ruleFlowGroup;
private LeftTupleList tupleMemory;
public TerminalNodeMemory() {
this.tupleMemory = new LeftTupleList();
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
// agendaGroup = (InternalAgendaGroup) in.readObject();
// activationGroup = (ActivationGroup) in.readObject();
// ruleFlowGroup = (RuleFlowGroup) in.readObject();
tupleMemory = (LeftTupleList) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
// out.writeObject( agendaGroup );
// out.writeObject( activationGroup );
// out.writeObject( ruleFlowGroup );
out.writeObject( tupleMemory );
}
// public InternalAgendaGroup getAgendaGroup() {
// return this.agendaGroup;
// }
//
// public void setAgendaGroup(final InternalAgendaGroup agendaGroup) {
// this.agendaGroup = agendaGroup;
// }
//
// public ActivationGroup getActivationGroup() {
// return this.activationGroup;
// }
//
// public void setActivationGroup(final ActivationGroup activationGroup) {
// this.activationGroup = activationGroup;
// }
public LeftTupleList getTupleMemory() {
return this.tupleMemory;
}
// public RuleFlowGroup getRuleFlowGroup() {
// return this.ruleFlowGroup;
// }
//
// public void setRuleFlowGroup(final RuleFlowGroup ruleFlowGroup) {
// this.ruleFlowGroup = ruleFlowGroup;
// }
}
}