/*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* 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.core.rule;
import org.drools.core.WorkingMemory;
import org.drools.core.common.InternalFactHandle;
import org.drools.core.reteoo.RuleTerminalNode;
import org.drools.core.spi.Accumulator;
import org.drools.core.spi.Tuple;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;
/**
* A class to represent the Accumulate CE
*/
public abstract class Accumulate extends ConditionalElement
implements
PatternSource {
private static final long serialVersionUID = 510l;
protected RuleConditionElement source;
protected Declaration[] requiredDeclarations;
protected Declaration[] innerDeclarationCache;
protected List<Accumulate> cloned = Collections.<Accumulate> emptyList();
public Accumulate() { }
public Accumulate(final RuleConditionElement source,
final Declaration[] requiredDeclarations ) {
this.source = source;
this.requiredDeclarations = requiredDeclarations;
initInnerDeclarationCache();
}
@SuppressWarnings("unchecked")
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
source = (RuleConditionElement) in.readObject();
requiredDeclarations = (Declaration[]) in.readObject();
this.cloned = (List<Accumulate>) in.readObject();
initInnerDeclarationCache();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject( this.source );
out.writeObject( this.requiredDeclarations );
out.writeObject( this.cloned );
}
public abstract Accumulator[] getAccumulators();
public abstract Object createContext();
/**
* Executes the initialization block of code
*/
public abstract void init(final Object workingMemoryContext,
final Object context,
final Tuple leftTuple,
final WorkingMemory workingMemory);
/**
* Executes the accumulate (action) code for the given fact handle
*/
public abstract void accumulate(final Object workingMemoryContext,
final Object context,
final Tuple leftTuple,
final InternalFactHandle handle,
final WorkingMemory workingMemory);
/**
* Executes the reverse (action) code for the given fact handle
*/
public abstract void reverse(final Object workingMemoryContext,
final Object context,
final Tuple leftTuple,
final InternalFactHandle handle,
final WorkingMemory workingMemory);
/**
* Gets the result of the accumulation
*/
public abstract Object getResult(final Object workingMemoryContext,
final Object context,
final Tuple leftTuple,
final WorkingMemory workingMemory);
/**
* Returns true if this accumulate supports reverse
*/
public abstract boolean supportsReverse();
public abstract Accumulate clone();
protected void registerClone(Accumulate clone) {
if ( this.cloned == Collections.EMPTY_LIST ) {
this.cloned = new ArrayList<Accumulate>( 1 );
}
this.cloned.add( clone );
}
public RuleConditionElement getSource() {
return this.source;
}
public Map<String, Declaration> getInnerDeclarations() {
return this.source.getInnerDeclarations();
}
public Map<String, Declaration> getOuterDeclarations() {
return Collections.emptyMap();
}
/**
* @inheritDoc
*/
public Declaration resolveDeclaration(final String identifier) {
return this.source.getInnerDeclarations().get( identifier );
}
public abstract Object createWorkingMemoryContext();
public List<RuleConditionElement> getNestedElements() {
return Collections.singletonList( this.source );
}
public boolean isPatternScopeDelimiter() {
return true;
}
public abstract boolean isMultiFunction();
public void replaceDeclaration(Declaration declaration,
Declaration resolved) {
for ( int i = 0; i < this.requiredDeclarations.length; i++ ) {
if ( this.requiredDeclarations[i].equals( declaration ) ) {
this.requiredDeclarations[i] = resolved;
}
}
replaceAccumulatorDeclaration(declaration, resolved);
}
protected abstract void replaceAccumulatorDeclaration(Declaration declaration,
Declaration resolved);
protected Declaration[] getInnerDeclarationCache() {
return this.innerDeclarationCache;
}
private void initInnerDeclarationCache() {
Map<String, Declaration> innerDeclarations = this.source.getInnerDeclarations();
this.innerDeclarationCache = innerDeclarations.values().toArray( new Declaration[innerDeclarations.size()] );
Arrays.sort( this.innerDeclarationCache, RuleTerminalNode.SortDeclarations.instance );
}
public Declaration[] getRequiredDeclarations() {
return requiredDeclarations;
}
public boolean hasRequiredDeclarations() {
return requiredDeclarations != null && requiredDeclarations.length > 0;
}
@Override
public boolean requiresLeftActivation() {
return true;
}
}