/*
* Copyright 2010 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.core.base.accumulators;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import org.drools.core.WorkingMemory;
import org.drools.core.common.InternalFactHandle;
import org.drools.core.rule.Declaration;
import org.drools.core.spi.Accumulator;
import org.drools.core.spi.CompiledInvoker;
import org.drools.core.spi.ReturnValueExpression;
import org.drools.core.spi.ReturnValueExpression.SafeReturnValueExpression;
import org.drools.core.spi.Tuple;
import org.drools.core.spi.Wireable;
import org.kie.internal.security.KiePolicyHelper;
/**
* A Java accumulator function executor implementation
*/
public class JavaAccumulatorFunctionExecutor
implements
Accumulator,
Externalizable,
Wireable {
private static final long serialVersionUID = 510l;
private ReturnValueExpression expression;
private org.kie.api.runtime.rule.AccumulateFunction function;
public JavaAccumulatorFunctionExecutor() {
}
public JavaAccumulatorFunctionExecutor(final org.kie.api.runtime.rule.AccumulateFunction function) {
super();
this.function = function;
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
expression = (ReturnValueExpression) in.readObject();
function = (org.kie.api.runtime.rule.AccumulateFunction) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
if ( this.expression instanceof CompiledInvoker ) {
out.writeObject( null );
} else {
out.writeObject( this.expression );
}
out.writeObject( function );
}
/* (non-Javadoc)
* @see org.kie.spi.Accumulator#createContext()
*/
public Serializable createContext() {
JavaAccumulatorFunctionContext context = new JavaAccumulatorFunctionContext();
context.context = this.function.createContext();
if ( this.function.supportsReverse() ) {
context.reverseSupport = new HashMap<Integer, Object>();
}
return context;
}
/* (non-Javadoc)
* @see org.kie.spi.Accumulator#init(java.lang.Object, org.kie.spi.Tuple, org.kie.rule.Declaration[], org.kie.WorkingMemory)
*/
public void init(Object workingMemoryContext,
Object context,
Tuple leftTuple,
Declaration[] declarations,
WorkingMemory workingMemory) throws Exception {
this.function.init( ((JavaAccumulatorFunctionContext) context).context );
}
/* (non-Javadoc)
* @see org.kie.spi.Accumulator#accumulate(java.lang.Object, org.kie.spi.Tuple, org.kie.common.InternalFactHandle, org.kie.rule.Declaration[], org.kie.rule.Declaration[], org.kie.WorkingMemory)
*/
public void accumulate(Object workingMemoryContext,
Object context,
Tuple leftTuple,
InternalFactHandle handle,
Declaration[] declarations,
Declaration[] innerDeclarations,
WorkingMemory workingMemory) throws Exception {
final Object value = this.expression.evaluate( handle.getObject(),
leftTuple,
declarations,
innerDeclarations,
workingMemory,
workingMemoryContext ).getValue();
if ( this.function.supportsReverse() ) {
((JavaAccumulatorFunctionContext) context).reverseSupport.put( Integer.valueOf( handle.getId() ),
value );
}
this.function.accumulate( ((JavaAccumulatorFunctionContext) context).context,
value );
}
public void reverse(Object workingMemoryContext,
Object context,
Tuple leftTuple,
InternalFactHandle handle,
Declaration[] declarations,
Declaration[] innerDeclarations,
WorkingMemory workingMemory) throws Exception {
final Object value = ((JavaAccumulatorFunctionContext) context).reverseSupport.remove( Integer.valueOf( handle.getId() ) );
this.function.reverse( ((JavaAccumulatorFunctionContext) context).context,
value );
}
/* (non-Javadoc)
* @see org.kie.spi.Accumulator#getResult(java.lang.Object, org.kie.spi.Tuple, org.kie.rule.Declaration[], org.kie.WorkingMemory)
*/
public Object getResult(Object workingMemoryContext,
Object context,
Tuple leftTuple,
Declaration[] declarations,
WorkingMemory workingMemory) throws Exception {
return this.function.getResult( ((JavaAccumulatorFunctionContext) context).context );
}
public boolean supportsReverse() {
return this.function.supportsReverse();
}
public ReturnValueExpression getExpression() {
return expression;
}
public void wire(Object object) {
setExpression( KiePolicyHelper.isPolicyEnabled() ? new SafeReturnValueExpression((ReturnValueExpression) object ) : (ReturnValueExpression) object );
}
public void setExpression(ReturnValueExpression expression) {
this.expression = expression;
}
public Object createWorkingMemoryContext() {
// no working memory context needed
return null;
}
private static class JavaAccumulatorFunctionContext
implements
Externalizable {
public Serializable context;
public Map<Integer, Object> reverseSupport;
public JavaAccumulatorFunctionContext() {
}
@SuppressWarnings("unchecked")
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
context = (Externalizable) in.readObject();
reverseSupport = (Map<Integer, Object>) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject( context );
out.writeObject( reverseSupport );
}
}
}