/**
* 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.base;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Collections;
import java.util.IdentityHashMap;
import java.util.Map;
import org.drools.FactException;
import org.drools.FactHandle;
import org.drools.WorkingMemory;
import org.drools.common.InternalFactHandle;
import org.drools.common.InternalRuleFlowGroup;
import org.drools.common.InternalWorkingMemoryActions;
import org.drools.common.InternalWorkingMemoryEntryPoint;
import org.drools.common.LogicalDependency;
import org.drools.core.util.LinkedList;
import org.drools.impl.StatefulKnowledgeSessionImpl;
import org.drools.reteoo.ReteooWorkingMemory;
import org.drools.rule.Declaration;
import org.drools.rule.GroupElement;
import org.drools.rule.Rule;
import org.drools.runtime.Channel;
import org.drools.runtime.ExitPoint;
import org.drools.runtime.KnowledgeRuntime;
import org.drools.runtime.process.NodeInstance;
import org.drools.runtime.process.NodeInstanceContainer;
import org.drools.runtime.process.ProcessContext;
import org.drools.runtime.process.ProcessInstance;
import org.drools.runtime.process.WorkflowProcessInstance;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;
import org.drools.spi.Activation;
import org.drools.spi.KnowledgeHelper;
import org.drools.spi.Tuple;
public class DefaultKnowledgeHelper
implements
KnowledgeHelper,
Externalizable {
private static final long serialVersionUID = 510l;
private Rule rule;
private GroupElement subrule;
private Activation activation;
private Tuple tuple;
private InternalWorkingMemoryActions workingMemory;
private IdentityHashMap<Object, FactHandle> identityMap;
private LinkedList previousJustified;
public DefaultKnowledgeHelper() {
}
public DefaultKnowledgeHelper(final WorkingMemory workingMemory) {
this.workingMemory = (InternalWorkingMemoryActions) workingMemory;
this.identityMap = new IdentityHashMap<Object, FactHandle>();
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
rule = (Rule) in.readObject();
subrule = (GroupElement) in.readObject();
activation = (Activation) in.readObject();
tuple = (Tuple) in.readObject();
workingMemory = (InternalWorkingMemoryActions) in.readObject();
identityMap = (IdentityHashMap<Object, FactHandle>) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject( rule );
out.writeObject( subrule );
out.writeObject( activation );
out.writeObject( tuple );
out.writeObject( workingMemory );
out.writeObject( identityMap );
}
public void setActivation(final Activation agendaItem) {
this.rule = agendaItem.getRule();
this.subrule = agendaItem.getSubRule();
this.activation = agendaItem;
// -- JBRULES-2558: logical inserts must be properly preserved
this.previousJustified = agendaItem.getLogicalDependencies();
agendaItem.setLogicalDependencies( null );
// -- JBRULES-2558: end
this.tuple = agendaItem.getTuple();
}
public void reset() {
this.rule = null;
this.subrule = null;
this.activation = null;
this.tuple = null;
this.identityMap.clear();
this.previousJustified = null;
}
public void insert(final Object object) throws FactException {
insert( object,
false );
}
public void insert(final Object object,
final boolean dynamic) throws FactException {
FactHandle handle = this.workingMemory.insert( object,
dynamic,
false,
this.rule,
this.activation );
this.getIdentityMap().put( object,
handle );
}
public void insertLogical(final Object object) throws FactException {
insertLogical( object,
false );
}
public void insertLogical(final Object object,
final boolean dynamic) throws FactException {
// iterate to find previous equal logical insertion
LogicalDependency dep = null;
if ( this.previousJustified != null ) {
for ( dep = (LogicalDependency) this.previousJustified.getFirst(); dep != null; dep = (LogicalDependency) dep.getNext() ) {
if ( object.equals( ((InternalFactHandle) dep.getFactHandle()).getObject() ) ) {
this.previousJustified.remove( dep );
break;
}
}
}
if ( dep != null ) {
// Add the previous matching logical dependency back into the list
this.activation.addLogicalDependency( dep );
} else {
// no previous matching logical dependency, so create a new one
FactHandle handle = this.workingMemory.insert( object,
dynamic,
true,
this.rule,
this.activation );
this.getIdentityMap().put( object,
handle );
}
}
public void cancelRemainingPreviousLogicalDependencies() {
if ( this.previousJustified != null ) {
for ( LogicalDependency dep = (LogicalDependency) this.previousJustified.getFirst(); dep != null; dep = (LogicalDependency) dep.getNext() ) {
this.workingMemory.getTruthMaintenanceSystem().removeLogicalDependency( activation, dep, activation.getPropagationContext() );
}
}
}
public void update(final FactHandle handle,
final Object newObject) throws FactException {
// only update if this fact exists in the wm
((InternalWorkingMemoryEntryPoint) ((InternalFactHandle) handle).getEntryPoint()).update( handle,
newObject,
this.rule,
this.activation );
this.getIdentityMap().put( newObject,
handle );
}
public void update(final Object object) throws FactException {
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 );
}
public void retract(final FactHandle handle) throws FactException {
((InternalWorkingMemoryEntryPoint) ((InternalFactHandle) handle).getEntryPoint()).retract( handle,
true,
true,
this.rule,
this.activation );
this.getIdentityMap().remove( ((InternalFactHandle) handle).getObject() );
}
public void retract(final Object object) throws FactException {
FactHandle handle = getFactHandle( object );
if ( handle == null ) {
throw new FactException( "Retract error: handle not found for object: " + object + ". Is it in the working memory?" );
}
retract( handle );
}
public Rule getRule() {
return this.rule;
}
public Tuple getTuple() {
return this.tuple;
}
public WorkingMemory getWorkingMemory() {
return this.workingMemory;
}
public KnowledgeRuntime getKnowledgeRuntime() {
return ((ReteooWorkingMemory) this.workingMemory).getKnowledgeRuntime();
}
public Activation getActivation() {
return this.activation;
}
public void setFocus(final String focus) {
this.workingMemory.setFocus( focus );
}
public Object get(final Declaration declaration) {
InternalWorkingMemoryEntryPoint wmTmp = ((InternalWorkingMemoryEntryPoint) (this.tuple.get( declaration )).getEntryPoint());
if ( wmTmp != null ) {
Object object = declaration.getValue( wmTmp.getInternalWorkingMemory(),
this.tuple.get( declaration ).getObject() );
getIdentityMap().put( object,
wmTmp.getFactHandleByIdentity( object ) );
return object;
}
return null;
}
public Declaration getDeclaration(final String identifier) {
return (Declaration) this.subrule.getOuterDeclarations().get( identifier );
}
public void halt() {
this.workingMemory.halt();
}
public WorkingMemoryEntryPoint getEntryPoint(String id) {
return this.workingMemory.getEntryPoints().get( id );
}
/**
* @deprecated use {@link #getChannel(String)} instead
*/
@Deprecated
public ExitPoint getExitPoint(String id) {
return this.workingMemory.getExitPoints().get( id );
}
public Channel getChannel(String id) {
return this.workingMemory.getChannels().get( id );
}
public Map<String, WorkingMemoryEntryPoint> getEntryPoints() {
return Collections.unmodifiableMap( this.workingMemory.getEntryPoints() );
}
/**
* @deprecated use {@link #getChannels()} instead
*/
@Deprecated
public Map<String, ExitPoint> getExitPoints() {
return Collections.unmodifiableMap( this.workingMemory.getExitPoints() );
}
public Map<String, Channel> getChannels() {
return Collections.unmodifiableMap( this.workingMemory.getChannels() );
}
/**
* @return the identityMap
*/
public IdentityHashMap<Object, FactHandle> getIdentityMap() {
return identityMap;
}
/**
* @param identityMap the identityMap to set
*/
public void setIdentityMap(IdentityHashMap<Object, FactHandle> identityMap) {
this.identityMap = identityMap;
}
private FactHandle getFactHandle(final Object object) {
FactHandle handle = identityMap.get( object );
// entry point null means it is a generated fact, not a regular inserted fact
// NOTE: it would probably be a good idea to create a specific attribute for that
if ( handle == null || ((InternalFactHandle) handle).getEntryPoint() == null ) {
for ( WorkingMemoryEntryPoint ep : workingMemory.getEntryPoints().values() ) {
handle = (FactHandle) ep.getFactHandle( object );
if ( handle != null ) {
identityMap.put( object,
handle );
break;
}
}
}
return handle;
}
@SuppressWarnings("unchecked")
public <T> T getContext(Class<T> contextClass) {
if (ProcessContext.class.equals(contextClass)) {
String ruleflowGroupName = getActivation().getRule().getRuleFlowGroup();
if (ruleflowGroupName != null) {
Map<Long, String> nodeInstances = ((InternalRuleFlowGroup) workingMemory.getAgenda().getRuleFlowGroup(ruleflowGroupName)).getNodeInstances();
if (!nodeInstances.isEmpty()) {
if (nodeInstances.size() > 1) {
// TODO
throw new UnsupportedOperationException(
"Not supporting multiple node instances for the same ruleflow group");
}
Map.Entry<Long, String> entry = nodeInstances.entrySet().iterator().next();
ProcessInstance processInstance = workingMemory.getProcessInstance(entry.getKey());
org.drools.spi.ProcessContext context = new org.drools.spi.ProcessContext(workingMemory.getKnowledgeRuntime());
context.setProcessInstance(processInstance);
String nodeInstance = entry.getValue();
String[] nodeInstanceIds = nodeInstance.split(":");
NodeInstanceContainer container = (WorkflowProcessInstance) processInstance;
for (int i = 0; i < nodeInstanceIds.length; i++) {
for (NodeInstance subNodeInstance: container.getNodeInstances()) {
if (subNodeInstance.getId() == new Long(nodeInstanceIds[i])) {
if (i == nodeInstanceIds.length - 1) {
context.setNodeInstance(subNodeInstance);
break;
} else {
container = (NodeInstanceContainer) subNodeInstance;
}
}
}
}
return (T) context;
}
}
}
return null;
}
}