/*
* Copyright 2015 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.
*
* 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.builder.dialect.asm;
import org.drools.core.WorkingMemory;
import org.drools.core.common.InternalFactHandle;
import org.drools.core.common.InternalWorkingMemory;
import org.drools.core.reteoo.LeftTuple;
import org.drools.core.reteoo.RuleTerminalNode;
import org.drools.core.reteoo.Sink;
import org.drools.core.rule.Declaration;
import org.drools.core.rule.builder.dialect.asm.GeneratorHelper.DeclarationMatcher;
import org.drools.core.spi.Activation;
import org.drools.core.spi.CompiledInvoker;
import org.drools.core.spi.Consequence;
import org.drools.core.spi.KnowledgeHelper;
import org.drools.core.spi.Tuple;
import org.kie.api.runtime.rule.FactHandle;
import org.mvel2.asm.MethodVisitor;
import java.util.List;
import static org.drools.core.rule.builder.dialect.asm.GeneratorHelper.createInvokerClassGenerator;
import static org.drools.core.rule.builder.dialect.asm.GeneratorHelper.matchDeclarationsToTuple;
import static org.mvel2.asm.Opcodes.*;
public class ConsequenceGenerator {
public static void generate(final ConsequenceStub stub, KnowledgeHelper knowledgeHelper, WorkingMemory workingMemory) {
RuleTerminalNode rtn = (RuleTerminalNode) knowledgeHelper.getMatch().getTuple().getTupleSink();
final Declaration[] declarations = rtn.getRequiredDeclarations();
final Tuple tuple = knowledgeHelper.getTuple();
// Sort declarations based on their offset, so it can ascend the tuple's parents stack only once
final List<DeclarationMatcher> declarationMatchers = matchDeclarationsToTuple(declarations);
final ClassGenerator generator = createInvokerClassGenerator(stub, workingMemory).setInterfaces(Consequence.class, CompiledInvoker.class);
generator.addMethod(ACC_PUBLIC, "getName", generator.methodDescr(String.class), new ClassGenerator.MethodBody() {
public void body(MethodVisitor mv) {
push(stub.getGeneratedInvokerClassName());
mv.visitInsn(ARETURN);
}
}).addMethod(ACC_PUBLIC, "evaluate", generator.methodDescr(null, KnowledgeHelper.class, WorkingMemory.class), new String[]{"java/lang/Exception"}, new GeneratorHelper.EvaluateMethod() {
public void body(MethodVisitor mv) {
// Tuple tuple = knowledgeHelper.getTuple();
mv.visitVarInsn(ALOAD, 1);
invokeInterface(KnowledgeHelper.class, "getTuple", Tuple.class);
cast(LeftTuple.class);
mv.visitVarInsn(ASTORE, 3); // LeftTuple
// Declaration[] declarations = ((RuleTerminalNode)knowledgeHelper.getMatch().getTuple().getTupleSink()).getDeclarations();
mv.visitVarInsn(ALOAD, 1);
invokeInterface(KnowledgeHelper.class, "getMatch", Activation.class);
invokeInterface(Activation.class, "getTuple", Tuple.class);
invokeInterface(Tuple.class, "getTupleSink", Sink.class);
cast(RuleTerminalNode.class);
invokeVirtual(RuleTerminalNode.class, "getRequiredDeclarations", Declaration[].class);
mv.visitVarInsn(ASTORE, 4);
Tuple currentTuple = tuple;
objAstorePos = 6; // astore start position for objects to store in loop
int[] paramsPos = new int[declarations.length];
// declarationMatchers is already sorted by offset with tip declarations now first
for (DeclarationMatcher matcher : declarationMatchers) {
int i = matcher.getOriginalIndex(); // original index refers to the array position with RuleTerminalNode.getDeclarations()
int handlePos = objAstorePos;
int objPos = ++objAstorePos;
paramsPos[i] = handlePos;
currentTuple = traverseTuplesUntilDeclaration(currentTuple, matcher.getRootDistance(), 3);
// handle = tuple.getFactHandle()
mv.visitVarInsn(ALOAD, 3);
invokeInterface(Tuple.class, "getOriginalFactHandle", InternalFactHandle.class);
mv.visitVarInsn(ASTORE, handlePos);
String declarationType = declarations[i].getTypeName();
if (stub.getNotPatterns()[i]) {
// notPattern indexes field declarations
// declarations[i].getValue((InternalWorkingMemory)workingMemory, fact[i].getObject());
mv.visitVarInsn(ALOAD, 4); // org.kie.rule.Declaration[]
push(i); // i
mv.visitInsn(AALOAD); // declarations[i]
mv.visitVarInsn(ALOAD, 2); // WorkingMemory
cast(InternalWorkingMemory.class);
mv.visitVarInsn(ALOAD, handlePos); // handle[i]
invokeInterface(InternalFactHandle.class, "getObject", Object.class);
storeObjectFromDeclaration(declarations[i], declarationType);
// The facthandle should be set to that of the field, if it's an object, otherwise this will return null
// fact[i] = (InternalFactHandle)workingMemory.getFactHandle(obj);
mv.visitVarInsn(ALOAD, 2);
loadAsObject(objPos);
invokeInterface(WorkingMemory.class, "getFactHandle", FactHandle.class, Object.class);
cast(InternalFactHandle.class);
mv.visitVarInsn(ASTORE, handlePos);
} else {
mv.visitVarInsn(ALOAD, handlePos); // handle[i]
invokeInterface(InternalFactHandle.class, "getObject", Object.class);
mv.visitTypeInsn(CHECKCAST, internalName(declarationType));
objAstorePos += store(objPos, declarationType); // obj[i]
}
}
// @{ruleClassName}.@{methodName}(KnowledgeHelper, @foreach{declr : declarations} Object, FactHandle @end)
StringBuilder consequenceMethodDescr = new StringBuilder("(L" + KnowledgeHelper.class.getName().replace('.', '/') +";");
mv.visitVarInsn(ALOAD, 1); // KnowledgeHelper
for (int i = 0; i < declarations.length; i++) {
load(paramsPos[i] + 1); // obj[i]
mv.visitVarInsn(ALOAD, paramsPos[i]); // handle[i]
consequenceMethodDescr.append(typeDescr(declarations[i].getTypeName())).append("L" + FactHandle.class.getName().replace('.', '/') + ";");
}
// @foreach{type : globalTypes, identifier : globals} @{type} @{identifier} = ( @{type} ) workingMemory.getGlobal( "@{identifier}" );
parseGlobals(stub.getGlobals(), stub.getGlobalTypes(), 2, consequenceMethodDescr);
consequenceMethodDescr.append(")V");
mv.visitMethodInsn(INVOKESTATIC, stub.getInternalRuleClassName(), stub.getMethodName(), consequenceMethodDescr.toString());
mv.visitInsn(RETURN);
}
});
stub.setConsequence(generator.<Consequence>newInstance());
}
}