/*
* Copyright 2007 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.rule.builder.dialect.mvel;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.drools.base.accumulators.MVELAccumulatorFunctionExecutor;
import org.drools.base.mvel.MVELAccumulator;
import org.drools.base.mvel.MVELCompilationUnit;
import org.drools.base.mvel.MVELCompileable;
import org.drools.compiler.AnalysisResult;
import org.drools.compiler.BoundIdentifiers;
import org.drools.compiler.DescrBuildError;
import org.drools.lang.descr.AccumulateDescr;
import org.drools.lang.descr.AccumulateDescr.AccumulateFunctionCallDescr;
import org.drools.lang.descr.BaseDescr;
import org.drools.reteoo.RuleTerminalNode.SortDeclarations;
import org.drools.rule.Accumulate;
import org.drools.rule.Declaration;
import org.drools.rule.MVELDialectRuntimeData;
import org.drools.rule.Pattern;
import org.drools.rule.RuleConditionElement;
import org.drools.rule.builder.AccumulateBuilder;
import org.drools.rule.builder.RuleBuildContext;
import org.drools.rule.builder.RuleConditionBuilder;
import org.drools.runtime.rule.AccumulateFunction;
import org.drools.spi.Accumulator;
import org.drools.spi.InternalReadAccessor;
import org.drools.spi.KnowledgeHelper;
/**
* A builder for the java dialect accumulate version
*/
public class MVELAccumulateBuilder
implements
AccumulateBuilder {
public RuleConditionElement build(final RuleBuildContext context,
final BaseDescr descr) {
return build( context,
descr,
null );
}
@SuppressWarnings("unchecked")
public RuleConditionElement build(final RuleBuildContext context,
final BaseDescr descr,
final Pattern prefixPattern) {
try {
final AccumulateDescr accumDescr = (AccumulateDescr) descr;
if ( !accumDescr.hasValidInput() ) {
return null;
}
final RuleConditionBuilder builder = (RuleConditionBuilder) context.getDialect().getBuilder( accumDescr.getInput().getClass() );
// create source CE
final RuleConditionElement source = builder.build( context,
accumDescr.getInput() );
if ( source == null ) {
return null;
}
MVELDialect dialect = (MVELDialect) context.getDialect();
Map<String, Declaration> decls = context.getDeclarationResolver().getDeclarations(context.getRule());
Map<String, Declaration> sourceOuterDeclr = source.getOuterDeclarations();
Map<String, Class<?>> declarationClasses = context.getDeclarationResolver().getDeclarationClasses( decls );
declarationClasses.putAll( context.getDeclarationResolver().getDeclarationClasses( sourceOuterDeclr ) );
Accumulator accumulator = null;
BoundIdentifiers boundIds = new BoundIdentifiers( declarationClasses, context.getPackageBuilder().getGlobals() ) ;
if ( accumDescr.isExternalFunction() ) {
// build an external function executor
AccumulateFunctionCallDescr func = accumDescr.getFunctions().get( 0 );
AccumulateFunction function = context.getConfiguration().getAccumulateFunction( func.getFunction() );
if( function == null ) {
context.getErrors().add( new DescrBuildError( accumDescr,
context.getRuleDescr(),
null,
"Unknown accumulate function: '"+func.getFunction()+"' on rule '"+context.getRuleDescr().getName()+"'. All accumulate functions must be registered before building a resource." ) );
return null;
}
final AnalysisResult analysis = dialect.analyzeExpression( context,
accumDescr,
func.getParams()[0],
boundIds );
MVELCompilationUnit unit = dialect.getMVELCompilationUnit( func.getParams()[0],
analysis,
getUsedDeclarations( decls, analysis ),
getUsedDeclarations( sourceOuterDeclr, analysis ),
null,
context,
"drools",
KnowledgeHelper.class );
accumulator = new MVELAccumulatorFunctionExecutor( unit,
function );
} else {
// it is a custom accumulate
final MVELAnalysisResult initCodeAnalysis = (MVELAnalysisResult) dialect.analyzeBlock( context,
accumDescr,
accumDescr.getInitCode(),
boundIds);
// need to copy boundIds, as this as a "this" object.
final MVELAnalysisResult actionCodeAnalysis = (MVELAnalysisResult) dialect.analyzeBlock( context,
accumDescr,
null,
accumDescr.getActionCode(),
boundIds,
initCodeAnalysis.getMvelVariables(),
"drools",
KnowledgeHelper.class );
final MVELAnalysisResult resultCodeAnalysis = (MVELAnalysisResult) dialect.analyzeExpression( context,
accumDescr,
accumDescr.getResultCode(),
boundIds,
initCodeAnalysis.getMvelVariables() );
AnalysisResult reverseCodeAnalysis = null;
if ( accumDescr.getReverseCode() != null ) {
reverseCodeAnalysis = dialect.analyzeBlock( context,
accumDescr,
null,
accumDescr.getActionCode(),
boundIds,
initCodeAnalysis.getMvelVariables(),
"drools",
KnowledgeHelper.class );
}
MVELCompilationUnit initUnit = dialect.getMVELCompilationUnit( (String) accumDescr.getInitCode(),
initCodeAnalysis,
getUsedDeclarations( decls, initCodeAnalysis ),
getUsedDeclarations( sourceOuterDeclr, initCodeAnalysis ),
initCodeAnalysis.getMvelVariables(),
context,
"drools",
KnowledgeHelper.class );
MVELCompilationUnit actionUnit = dialect.getMVELCompilationUnit( (String) accumDescr.getActionCode(),
actionCodeAnalysis,
getUsedDeclarations( decls, actionCodeAnalysis ),
getUsedDeclarations( sourceOuterDeclr, actionCodeAnalysis ),
initCodeAnalysis.getMvelVariables(),
context,
"drools",
KnowledgeHelper.class );
MVELCompilationUnit reverseUnit = null;
if ( accumDescr.getReverseCode() != null ) {
reverseUnit = dialect.getMVELCompilationUnit( (String) accumDescr.getReverseCode(),
reverseCodeAnalysis,
getUsedDeclarations( decls, reverseCodeAnalysis ),
getUsedDeclarations( sourceOuterDeclr, reverseCodeAnalysis ),
initCodeAnalysis.getMvelVariables(),
context,
"drools",
KnowledgeHelper.class );
}
MVELCompilationUnit resultUnit = dialect.getMVELCompilationUnit( (String) accumDescr.getResultCode(),
resultCodeAnalysis,
getUsedDeclarations( decls, resultCodeAnalysis ),
getUsedDeclarations( sourceOuterDeclr, resultCodeAnalysis ),
initCodeAnalysis.getMvelVariables(),
context,
"drools",
KnowledgeHelper.class );
if ( reverseUnit != null ) {
Set<String> shadow = new HashSet<String>( source.getOuterDeclarations().keySet() );
shadow.retainAll( reverseCodeAnalysis.getNotBoundedIdentifiers() );
shadow.addAll( reverseCodeAnalysis.getBoundIdentifiers().getDeclarations().keySet() );
String[] shadowVars = (String[]) shadow.toArray( new String[shadow.size()] );
actionUnit.setShadowIdentifiers( shadowVars );
reverseUnit.setShadowIdentifiers( shadowVars );
}
accumulator = new MVELAccumulator( initUnit,
actionUnit,
reverseUnit,
resultUnit );
}
final Accumulate accumulate = new Accumulate( source,
null,
null,
new Accumulator[] { accumulator } );
MVELDialectRuntimeData data = (MVELDialectRuntimeData) context.getPkg().getDialectRuntimeRegistry().getDialectData( "mvel" );
data.addCompileable( accumulate,
(MVELCompileable) accumulator );
((MVELCompileable) accumulator).compile( context.getPackageBuilder().getRootClassLoader() );
return accumulate;
} catch ( Exception e ) {
context.getErrors().add( new DescrBuildError( context.getParentDescr(),
descr,
e,
"Unable to build expression for 'accumulate' : " + e.getMessage() ) );
return null;
}
}
private Declaration[] getUsedDeclarations(Map<String, Declaration> decls, AnalysisResult analysis) {
final BoundIdentifiers usedIdentifiers = analysis.getBoundIdentifiers();
int i = usedIdentifiers.getDeclarations().keySet().size();
List<Declaration> usedDeclarations = new ArrayList<Declaration>();
for ( String id : usedIdentifiers.getDeclarations().keySet() ) {
if ( decls.containsKey( id )) {
usedDeclarations.add( decls.get( id ) );
}
}
if ( !usedDeclarations.isEmpty() ) {
Collections.sort( usedDeclarations, SortDeclarations.instance );
}
return usedDeclarations.toArray( new Declaration[usedDeclarations.size()] );
}
}