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.base.ClassObjectType;
import org.drools.common.AbstractRuleBase;
import org.drools.common.BaseNode;
import org.drools.common.DroolsObjectInputStream;
import org.drools.common.EventFactHandle;
import org.drools.common.InternalFactHandle;
import org.drools.common.InternalWorkingMemory;
import org.drools.common.NodeMemory;
import org.drools.common.PropagationContextImpl;
import org.drools.reteoo.ReteooWorkingMemory.WorkingMemoryReteExpireAction;
import org.drools.reteoo.builder.BuildContext;
import org.drools.rule.Declaration;
import org.drools.rule.EntryPoint;
import org.drools.rule.EvalCondition;
import org.drools.spi.Constraint;
import org.drools.spi.ObjectType;
import org.drools.spi.PropagationContext;
import org.drools.time.Job;
import org.drools.time.JobContext;
import org.drools.time.JobHandle;
import org.drools.time.TimerService;
import org.drools.time.impl.PointInTimeTrigger;
import org.drools.util.Iterator;
import org.drools.util.ObjectHashSet;
import org.drools.util.ObjectHashSet.ObjectEntry;
/**
* <code>ObjectTypeNodes<code> are responsible for filtering and propagating the matching
* fact assertions propagated from the <code>Rete</code> node using <code>ObjectType</code> interface.
* <p>
* The assert and retract methods do not attempt to filter as this is the role of the <code>Rete</code>
* node which builds up a cache of matching <code>ObjectTypdeNodes</code>s for each asserted object, using
* the <code>matches(Object object)</code> method. Incorrect propagation in these methods is not checked and
* will result in <code>ClassCastExpcections</code> later on in the network.
* <p>
* Filters <code>Objects</code> coming from the <code>Rete</code> using a
* <code>ObjectType</code> semantic module.
*
*
* @see ObjectType
* @see Rete
*
* @author <a href="mailto:mark.proctor@jboss.com">Mark Proctor</a>
* @author <a href="mailto:bob@werken.com">Bob McWhirter</a>
*/
public class ObjectTypeNode extends ObjectSource
implements
ObjectSink,
Externalizable,
NodeMemory
{
// ------------------------------------------------------------
// Instance members
// ------------------------------------------------------------
/**
*
*/
private static final long serialVersionUID = 400L;
/** The <code>ObjectType</code> semantic module. */
private ObjectType objectType;
private boolean skipOnModify = false;
private boolean objectMemoryEnabled;
private long expirationOffset = -1;
private transient ExpireJob job = new ExpireJob();
public ObjectTypeNode() {
}
/**
* Construct given a semantic <code>ObjectType</code> and the provided
* unique id. All <code>ObjectTypdeNode</code> have node memory.
*
* @param id
* The unique id for the node.
* @param objectType
* The semantic object-type differentiator.
*/
public ObjectTypeNode(final int id,
final EntryPointNode source,
final ObjectType objectType,
final BuildContext context) {
super( id,
context.getPartitionId(),
context.getRuleBase().getConfiguration().isMultithreadEvaluation(),
source,
context.getRuleBase().getConfiguration().getAlphaNodeHashingThreshold() );
this.objectType = objectType;
setObjectMemoryEnabled( context.isObjectTypeNodeMemoryEnabled() );
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
super.readExternal( in );
objectType = (ObjectType) in.readObject();
// this is here as not all objectTypeNodes used ClassObjectTypes in packages (i.e. rules with those nodes did not exist yet)
// and thus have no wiring targets
if ( objectType instanceof ClassObjectType ) {
objectType = ((AbstractRuleBase) ((DroolsObjectInputStream) in).getRuleBase()).getClassFieldAccessorCache().getClassObjectType( (ClassObjectType) objectType );
}
skipOnModify = in.readBoolean();
objectMemoryEnabled = in.readBoolean();
}
public void writeExternal(ObjectOutput out) throws IOException {
super.writeExternal( out );
out.writeObject( objectType );
out.writeBoolean( skipOnModify );
out.writeBoolean( objectMemoryEnabled );
}
/**
* Retrieve the semantic <code>ObjectType</code> differentiator.
*
* @return
* The semantic <code>ObjectType</code> differentiator.
*/
public ObjectType getObjectType() {
return this.objectType;
}
public boolean isAssignableFrom(final ObjectType objectType) {
return this.objectType.isAssignableFrom( objectType );
}
/**
* Propagate the <code>FactHandleimpl</code> through the <code>Rete</code> network. All
* <code>FactHandleImpl</code> should be remembered in the node memory, so that later runtime rule attachmnents
* can have the matched facts propagated to them.
*
* @param factHandle
* The fact handle.
* @param object
* The object to assert.
* @param workingMemory
* The working memory session.
*/
public void assertObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
if ( context.getType() == PropagationContext.MODIFICATION && this.skipOnModify && context.getDormantActivations() == 0 ) {
// we do this after the shadowproxy update, just so that its up to date for the future
return;
}
if ( this.objectMemoryEnabled ) {
final ObjectHashSet memory = (ObjectHashSet) workingMemory.getNodeMemory( this );
memory.add( factHandle,
false );
}
this.sink.propagateAssertObject( factHandle,
context,
workingMemory );
if ( this.expirationOffset >= 0 ) {
// schedule expiration
WorkingMemoryReteExpireAction expire = new WorkingMemoryReteExpireAction( factHandle,
this );
TimerService clock = workingMemory.getTimerService();
long nextTimestamp = Math.max( clock.getCurrentTime() + this.expirationOffset,
((EventFactHandle)factHandle).getStartTimestamp() + this.expirationOffset );
JobContext jobctx = new ExpireJobContext( expire,
workingMemory );
JobHandle handle = clock.scheduleJob( job,
jobctx,
new PointInTimeTrigger( nextTimestamp ) );
jobctx.setJobHandle( handle );
}
}
/**
* Retract the <code>FactHandleimpl</code> from the <code>Rete</code> network. Also remove the
* <code>FactHandleImpl</code> from the node memory.
*
* @param rightTuple
* The fact handle.
* @param object
* The object to assert.
* @param workingMemory
* The working memory session.
*/
public void retractObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
if ( context.getType() == PropagationContext.MODIFICATION && this.skipOnModify && context.getDormantActivations() == 0 ) {
return;
}
if ( this.objectMemoryEnabled ) {
final ObjectHashSet memory = (ObjectHashSet) workingMemory.getNodeMemory( this );
memory.remove( factHandle );
}
for ( RightTuple rightTuple = factHandle.getRightTuple(); rightTuple != null; rightTuple = (RightTuple) rightTuple.getHandleNext() ) {
rightTuple.getRightTupleSink().retractRightTuple( rightTuple,
context,
workingMemory );
}
factHandle.setRightTuple( null );
for ( LeftTuple leftTuple = factHandle.getLeftTuple(); leftTuple != null; leftTuple = (LeftTuple) leftTuple.getLeftParentNext() ) {
leftTuple.getLeftTupleSink().retractLeftTuple( leftTuple,
context,
workingMemory );
}
factHandle.setLeftTuple( null );
}
public void updateSink(final ObjectSink sink,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
final ObjectHashSet memory = (ObjectHashSet) workingMemory.getNodeMemory( this );
Iterator it = memory.iterator();
for ( ObjectEntry entry = (ObjectEntry) it.next(); entry != null; entry = (ObjectEntry) it.next() ) {
sink.assertObject( (InternalFactHandle) entry.getValue(),
context,
workingMemory );
}
}
/**
* Rete needs to know that this ObjectTypeNode has been added
*/
public void attach() {
this.source.addObjectSink( this );
}
public void attach(final InternalWorkingMemory[] workingMemories) {
attach();
// we need to call updateSink on Rete, because someone
// might have already added facts matching this ObjectTypeNode
// to working memories
for ( int i = 0, length = workingMemories.length; i < length; i++ ) {
final InternalWorkingMemory workingMemory = workingMemories[i];
final PropagationContextImpl propagationContext = new PropagationContextImpl( workingMemory.getNextPropagationIdCounter(),
PropagationContext.RULE_ADDITION,
null,
null,
null );
propagationContext.setEntryPoint( ((EntryPointNode) this.source).getEntryPoint() );
this.source.updateSink( this,
propagationContext,
workingMemory );
}
}
public void networkUpdated() {
this.skipOnModify = canSkipOnModify( this.sink.getSinks() );
}
/**
* OTN needs to override remove to avoid releasing the node ID, since OTN are
* never removed from the rulebase in the current implementation
*
* @inheritDoc
*
* @see org.drools.common.BaseNode#remove(org.drools.reteoo.RuleRemovalContext, org.drools.reteoo.ReteooBuilder, org.drools.common.BaseNode, org.drools.common.InternalWorkingMemory[])
*/
public void remove(RuleRemovalContext context,
ReteooBuilder builder,
BaseNode node,
InternalWorkingMemory[] workingMemories) {
doRemove( context,
builder,
node,
workingMemories );
}
protected void doRemove(final RuleRemovalContext context,
final ReteooBuilder builder,
final BaseNode node,
final InternalWorkingMemory[] workingMemories) {
if ( !node.isInUse() ) {
removeObjectSink( (ObjectSink) node );
}
}
/**
* Creates memory for the node using PrimitiveLongMap as its optimised for storage and reteivals of Longs.
* However PrimitiveLongMap is not ideal for spase data. So it should be monitored incase its more optimal
* to switch back to a standard HashMap.
*/
public Object createMemory(final RuleBaseConfiguration config) {
return new ObjectHashSet();
}
public boolean isObjectMemoryEnabled() {
return this.objectMemoryEnabled;
}
public void setObjectMemoryEnabled(boolean objectMemoryEnabled) {
this.objectMemoryEnabled = objectMemoryEnabled;
}
public String toString() {
return "[ObjectTypeNode(" + this.id + ")::" + ((EntryPointNode) this.source).getEntryPoint() + " objectType=" + this.objectType + " expiration="+this.expirationOffset+"ms ]";
}
/**
* Uses he hashCode() of the underlying ObjectType implementation.
*/
public int hashCode() {
return this.objectType.hashCode() ^ this.source.hashCode();
}
public boolean equals(final Object object) {
if ( this == object ) {
return true;
}
if ( object == null || !(object instanceof ObjectTypeNode) ) {
return false;
}
final ObjectTypeNode other = (ObjectTypeNode) object;
return this.objectType.equals( other.objectType ) && this.source.equals( other.source );
}
/**
* @inheritDoc
*/
protected void addObjectSink(final ObjectSink objectSink) {
super.addObjectSink( objectSink );
}
/**
* @inheritDoc
*/
protected void removeObjectSink(final ObjectSink objectSink) {
super.removeObjectSink( objectSink );
}
/**
* Checks if a modify action on this object type may
* be skipped because no constraint is applied to it
*
* @param sinks
* @return
*/
private boolean canSkipOnModify(final Sink[] sinks) {
// If we have no alpha or beta node with constraints on this ObjectType, we can just skip modifies
boolean hasConstraints = false;
for ( int i = 0; i < sinks.length && !hasConstraints; i++ ) {
if ( sinks[i] instanceof AlphaNode || sinks[i] instanceof AccumulateNode || sinks[i] instanceof CollectNode || sinks[i] instanceof FromNode ) {
hasConstraints = true;
} else if ( sinks[i] instanceof BetaNode && ((BetaNode) sinks[i]).getConstraints().length > 0 ) {
hasConstraints = this.usesDeclaration( ((BetaNode) sinks[i]).getConstraints() );
} else if ( sinks[i] instanceof EvalConditionNode ) {
hasConstraints = this.usesDeclaration( ((EvalConditionNode) sinks[i]).getCondition() );
}
if ( !hasConstraints && sinks[i] instanceof ObjectSource ) {
hasConstraints = !this.canSkipOnModify( ((ObjectSource) sinks[i]).getSinkPropagator().getSinks() );
} else if ( !hasConstraints && sinks[i] instanceof LeftTupleSource ) {
hasConstraints = !this.canSkipOnModify( ((LeftTupleSource) sinks[i]).getSinkPropagator().getSinks() );
}
}
// Can only skip if we have no constraints
return !hasConstraints;
}
private boolean usesDeclaration(final Constraint[] constraints) {
boolean usesDecl = false;
for ( int i = 0; !usesDecl && i < constraints.length; i++ ) {
usesDecl = this.usesDeclaration( constraints[i] );
}
return usesDecl;
}
private boolean usesDeclaration(final Constraint constraint) {
boolean usesDecl = false;
final Declaration[] declarations = constraint.getRequiredDeclarations();
for ( int j = 0; !usesDecl && j < declarations.length; j++ ) {
usesDecl = (declarations[j].getPattern().getObjectType() == this.objectType);
}
return usesDecl;
}
private boolean usesDeclaration(final EvalCondition condition) {
boolean usesDecl = false;
final Declaration[] declarations = condition.getRequiredDeclarations();
for ( int j = 0; !usesDecl && j < declarations.length; j++ ) {
usesDecl = (declarations[j].getPattern().getObjectType() == this.objectType);
}
return usesDecl;
}
/**
* @return the entryPoint
*/
public EntryPoint getEntryPoint() {
return ((EntryPointNode) this.source).getEntryPoint();
}
public long getExpirationOffset() {
return expirationOffset;
}
public void setExpirationOffset(long expirationOffset) {
this.expirationOffset = expirationOffset;
if ( this.expirationOffset > 0 || this.expirationOffset == -1 ) {
// override memory enabled settings
this.setObjectMemoryEnabled( true );
} else {
this.setObjectMemoryEnabled( false );
}
}
private static class ExpireJob
implements
Job {
public void execute(JobContext ctx) {
ExpireJobContext context = (ExpireJobContext) ctx;
context.workingMemory.queueWorkingMemoryAction( context.expireAction );
}
}
private static class ExpireJobContext
implements
JobContext,
Externalizable {
public WorkingMemoryReteExpireAction expireAction;
public InternalWorkingMemory workingMemory;
public JobHandle handle;
/**
* @param workingMemory
* @param behavior
* @param behaviorContext
*/
public ExpireJobContext(WorkingMemoryReteExpireAction expireAction,
InternalWorkingMemory workingMemory) {
super();
this.expireAction = expireAction;
this.workingMemory = workingMemory;
}
public JobHandle getJobHandle() {
return this.handle;
}
public void setJobHandle(JobHandle jobHandle) {
this.handle = jobHandle;
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
//this.behavior = (O)
}
public void writeExternal(ObjectOutput out) throws IOException {
// TODO Auto-generated method stub
}
}
}