/*
* 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.mvel;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;
import org.drools.core.WorkingMemory;
import org.drools.core.common.InternalFactHandle;
import org.drools.core.common.InternalWorkingMemory;
import org.drools.core.definitions.InternalKnowledgePackage;
import org.drools.core.reteoo.LeftTuple;
import org.drools.core.rule.Declaration;
import org.drools.core.rule.MVELDialectRuntimeData;
import org.drools.core.spi.FieldValue;
import org.drools.core.spi.ReturnValueExpression;
import org.drools.core.spi.Tuple;
import org.drools.core.util.MVELSafeHelper;
import org.mvel2.integration.VariableResolverFactory;
public class MVELReturnValueExpression
implements
ReturnValueExpression,
MVELCompileable,
Externalizable {
private static final long serialVersionUID = 510l;
private MVELCompilationUnit unit;
private String id;
private Serializable expr;
public MVELReturnValueExpression() {
}
public MVELReturnValueExpression(final MVELCompilationUnit unit,
final String id) {
this.unit = unit;
this.id = id;
}
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
id = in.readUTF();
unit = (MVELCompilationUnit) in.readObject();
}
public void writeExternal(ObjectOutput out) throws IOException {
out.writeUTF( id );
out.writeObject( unit );
}
public void compile(MVELDialectRuntimeData runtimeData) {
expr = unit.getCompiledExpression( runtimeData );
}
public Object createContext() {
return this.unit.createFactory();
}
public FieldValue evaluate(final InternalFactHandle handle,
final Tuple tuple,
final Declaration[] previousDeclarations,
final Declaration[] requiredDeclarations,
final WorkingMemory workingMemory,
final Object ctx) throws Exception {
VariableResolverFactory factory = ( VariableResolverFactory )ctx;
unit.updateFactory( null,
null,
handle,
(LeftTuple) tuple,
null,
(InternalWorkingMemory) workingMemory,
workingMemory.getGlobalResolver(),
factory );
// do we have any functions for this namespace?
InternalKnowledgePackage pkg = workingMemory.getKnowledgeBase().getPackage( "MAIN" );
if ( pkg != null ) {
MVELDialectRuntimeData data = (MVELDialectRuntimeData) pkg.getDialectRuntimeRegistry().getDialectData( this.id );
factory.setNextFactory( data.getFunctionFactory() );
}
return workingMemory.getKnowledgeBase().getConfiguration().getComponentFactory().getFieldFactory().getFieldValue( MVELSafeHelper.getEvaluator().executeExpression( this.expr,
handle,
factory ) );
}
public String toString() {
return this.unit.getExpression();
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
if ( expr == null ) {
throw new RuntimeException( "this MVELReturnValueExpression must be compiled for hashCode" );
}
result = prime * result + unit.getExpression().hashCode();
return result;
}
@Override
public boolean equals(Object obj) {
if ( this == obj ) return true;
if ( obj == null ) return false;
if ( getClass() != obj.getClass() ) return false;
if ( expr == null ) {
throw new RuntimeException( "this MVELReturnValueExpression must be compiled for equality" );
}
MVELReturnValueExpression other = (MVELReturnValueExpression) obj;
if ( other.expr == null ) {
throw new RuntimeException( "other MVELReturnValueExpression must be compiled for equality" );
}
return this.unit.getExpression().equals( other.unit.getExpression() );
}
public void replaceDeclaration(Declaration declaration,
Declaration resolved) {
this.unit.replaceDeclaration( declaration,
resolved );
}
}