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.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import org.drools.RuleBaseConfiguration;
import org.drools.common.BaseNode;
import org.drools.common.InternalFactHandle;
import org.drools.common.InternalWorkingMemory;
import org.drools.common.NodeMemory;
import org.drools.common.PropagationContextImpl;
import org.drools.common.RuleBasePartitionId;
import org.drools.reteoo.builder.BuildContext;
import org.drools.spi.PropagationContext;
import org.drools.util.RightTupleList;
/**
* All asserting Facts must propagated into the right <code>ObjectSink</code> side of a BetaNode, if this is the first Pattern
* then there are no BetaNodes to propagate to. <code>LeftInputAdapter</code> is used to adapt an ObjectSink propagation into a
* <code>TupleSource</code> which propagates a <code>ReteTuple</code> suitable fot the right <code>ReteTuple</code> side
* of a <code>BetaNode</code>.
*
* @author <a href="mailto:mark.proctor@jboss.com">Mark Proctor</a>
* @author <a href="mailto:bob@werken.com">Bob McWhirter</a>
*
*/
public class LeftInputAdapterNode extends LeftTupleSource
implements
ObjectSinkNode,
NodeMemory {
/**
*
*/
private static final long serialVersionUID = 400L;
private ObjectSource objectSource;
private ObjectSinkNode previousRightTupleSinkNode;
private ObjectSinkNode nextRightTupleSinkNode;
private boolean leftTupleMemoryEnabled;
public LeftInputAdapterNode() {
}
/**
* Constructus a LeftInputAdapterNode with a unique id that receives <code>FactHandle</code> from a
* parent <code>ObjectSource</code> and adds it to a given pattern in the resulting Tuples.
*
* @param id
* The unique id of this node in the current Rete network
* @param source
* The parent node, where Facts are propagated from
*/
public LeftInputAdapterNode(final int id,
final ObjectSource source,
final BuildContext context) {
super( id,
context.getPartitionId(),
context.getRuleBase().getConfiguration().isMultithreadEvaluation() );
this.objectSource = source;
this.leftTupleMemoryEnabled = context.isTupleMemoryEnabled();
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
super.readExternal( in );
objectSource = (ObjectSource) in.readObject();
previousRightTupleSinkNode = (ObjectSinkNode) in.readObject();
nextRightTupleSinkNode = (ObjectSinkNode) in.readObject();
leftTupleMemoryEnabled = in.readBoolean();
}
public void writeExternal(ObjectOutput out) throws IOException {
super.writeExternal( out );
out.writeObject( objectSource );
out.writeObject( previousRightTupleSinkNode );
out.writeObject( nextRightTupleSinkNode );
out.writeBoolean( leftTupleMemoryEnabled );
}
/* (non-Javadoc)
* @see org.drools.reteoo.BaseNode#attach()
*/
public void attach() {
this.objectSource.addObjectSink( 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.objectSource.updateSink( this,
propagationContext,
workingMemory );
}
}
public void networkUpdated() {
this.objectSource.networkUpdated();
}
/**
* Takes the asserted <code>FactHandleImpl</code> received from the <code>ObjectSource</code> and puts it
* in a new <code>ReteTuple</code> before propagating to the <code>TupleSinks</code>
*
* @param factHandle
* The asserted <code>FactHandle/code>.
* @param context
* The <code>PropagationContext</code> of the <code>WorkingMemory<code> action.
* @param workingMemory
* the <code>WorkingMemory</code> session.
*/
public void assertObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
if ( !workingMemory.isSequential() ) {
this.sink.createAndPropagateAssertLeftTuple( factHandle,
context,
workingMemory,
this.leftTupleMemoryEnabled );
} else {
workingMemory.addLIANodePropagation( new LIANodePropagation(this, factHandle, context) );
}
}
public void updateSink(final LeftTupleSink sink,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
final RightTupleSinkAdapter adapter = new RightTupleSinkAdapter( sink, this.leftTupleMemoryEnabled );
this.objectSource.updateSink( adapter,
context,
workingMemory );
}
protected void doRemove(final RuleRemovalContext context,
final ReteooBuilder builder,
final BaseNode node,
final InternalWorkingMemory[] workingMemories) {
context.visitTupleSource( this );
if ( !node.isInUse() ) {
removeTupleSink( (LeftTupleSink) node );
}
if ( !this.isInUse() ) {
for ( int i = 0, length = workingMemories.length; i < length; i++ ) {
workingMemories[i].clearNodeMemory( this );
}
}
this.objectSource.remove( context,
builder,
this,
workingMemories );
}
/**
* Returns the next node
* @return
* The next ObjectSinkNode
*/
public ObjectSinkNode getNextObjectSinkNode() {
return this.nextRightTupleSinkNode;
}
/**
* Sets the next node
* @param next
* The next ObjectSinkNode
*/
public void setNextObjectSinkNode(final ObjectSinkNode next) {
this.nextRightTupleSinkNode = next;
}
/**
* Returns the previous node
* @return
* The previous ObjectSinkNode
*/
public ObjectSinkNode getPreviousObjectSinkNode() {
return this.previousRightTupleSinkNode;
}
/**
* Sets the previous node
* @param previous
* The previous ObjectSinkNode
*/
public void setPreviousObjectSinkNode(final ObjectSinkNode previous) {
this.previousRightTupleSinkNode = previous;
}
public int hashCode() {
return this.objectSource.hashCode();
}
public boolean equals(final Object object) {
if ( object == this ) {
return true;
}
if ( object == null || !(object instanceof LeftInputAdapterNode) ) {
return false;
}
final LeftInputAdapterNode other = (LeftInputAdapterNode) object;
return this.objectSource.equals( other.objectSource );
}
public Object createMemory(final RuleBaseConfiguration config) {
return new RightTupleList();
}
/**
* Used with the updateSink method, so that the parent ObjectSource
* can update the TupleSink
* @author mproctor
*
*/
private static class RightTupleSinkAdapter
implements
ObjectSink {
private LeftTupleSink sink;
private boolean leftTupleMemoryEnabled;
public RightTupleSinkAdapter(final LeftTupleSink sink, boolean leftTupleMemoryEnabled) {
this.sink = sink;
this.leftTupleMemoryEnabled = leftTupleMemoryEnabled;
}
public void assertObject(final InternalFactHandle factHandle,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
final LeftTuple tuple = new LeftTuple( factHandle,
this.sink,
this.leftTupleMemoryEnabled );
this.sink.assertLeftTuple( tuple,
context,
workingMemory );
}
public void retractRightTuple(final RightTuple rightTuple,
final PropagationContext context,
final InternalWorkingMemory workingMemory) {
throw new UnsupportedOperationException( "ObjectSinkAdapter onlys supports assertObject method calls" );
}
public int getId() {
return 0;
}
public RuleBasePartitionId getPartitionId() {
return sink.getPartitionId();
}
public void writeExternal( ObjectOutput out ) throws IOException {
// this is a short living adapter class used only during an update operation, and
// as so, no need for serialization code
}
public void readExternal( ObjectInput in ) throws IOException, ClassNotFoundException {
// this is a short living adapter class used only during an update operation, and
// as so, no need for serialization code
}
}
}