/**************************************************************************************
* Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package org.codehaus.aspectwerkz.transform.delegation;
import org.codehaus.aspectwerkz.definition.SystemDefinition;
import org.codehaus.aspectwerkz.expression.ExpressionContext;
import org.codehaus.aspectwerkz.expression.PointcutType;
import org.codehaus.aspectwerkz.reflect.ClassInfo;
import org.codehaus.aspectwerkz.reflect.ConstructorInfo;
import org.codehaus.aspectwerkz.reflect.impl.javassist.JavassistClassInfo;
import org.codehaus.aspectwerkz.reflect.impl.javassist.JavassistConstructorInfo;
import org.codehaus.aspectwerkz.transform.Context;
import org.codehaus.aspectwerkz.transform.TransformationUtil;
import org.codehaus.aspectwerkz.transform.Transformer;
import java.util.Iterator;
import java.util.List;
import javassist.CannotCompileException;
import javassist.CtClass;
import javassist.CtConstructor;
import javassist.CtMethod;
import javassist.CtNewConstructor;
import javassist.NotFoundException;
import javassist.bytecode.CodeAttribute;
/**
* Advises constructor EXECUTION join points.
*
* @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur </a>
* @author <a href="mailto:jboner@codehaus.org">Jonas Bon�r </a>
*/
public class ConstructorExecutionTransformer implements Transformer {
/**
* The join point index.
*/
//AXprivate int m_joinPointIndex;
/**
* Makes the member method transformations.
*
* @param context the transformation context
* @param klass the class set.
*/
public void transform(final Context context, final Klass klass) throws Exception {
List definitions = context.getDefinitions();
//AXm_joinPointIndex =
// TransformationUtil.getJoinPointIndex(klass.getCtClass()); //TODO
// thread safe and reentrant
for (Iterator it = definitions.iterator(); it.hasNext();) {
SystemDefinition definition = (SystemDefinition) it.next();
final CtClass ctClass = klass.getCtClass();
ClassInfo classInfo = JavassistClassInfo.getClassInfo(ctClass, context.getLoader());
if (classFilter(definition, new ExpressionContext(PointcutType.EXECUTION, classInfo, classInfo), ctClass)) {
continue;
}
final CtConstructor[] constructors = ctClass.getConstructors();
for (int i = 0; i < constructors.length; i++) {
CtConstructor constructor = constructors[i];
ConstructorInfo constructorInfo = JavassistConstructorInfo.getConstructorInfo(constructor, context
.getLoader());
ExpressionContext ctx = new ExpressionContext(PointcutType.EXECUTION, constructorInfo, constructorInfo);
if (constructorFilter(definition, ctx)) {
continue;
}
if (addPrefixToConstructor(ctClass, constructor)) {
context.markAsAdvised();
int constructorHash = JavassistHelper.calculateHash(constructor);
createWrapperConstructor(constructor, constructorHash, klass);
}
}
}
//AXTransformationUtil.setJoinPointIndex(klass.getCtClass(),
// m_joinPointIndex);
klass.flushJoinPointIndex();
}
/**
* Creates a wrapper constructor for the original constructor specified. This constructor has the same signature as
* the original constructor and catches the invocation for further processing by the framework before redirecting to
* the original constructor.
*
* @param originalConstructor the original constructor
* @param constructorHash the constructor hash
*/
private void createWrapperConstructor(
final CtConstructor originalConstructor,
final int constructorHash,
final Klass klass) throws CannotCompileException, NotFoundException {
StringBuffer body = new StringBuffer();
body.append('{');
if (originalConstructor.getParameterTypes().length > 0) {
body.append("Object[] args = $args; ");
} else {
body.append("Object[] args = null; ");
}
body.append("Object nullObject = null;");
body.append("return ($r)");
body.append(TransformationUtil.JOIN_POINT_MANAGER_FIELD);
body.append('.');
body.append(TransformationUtil.PROCEED_WITH_EXECUTION_JOIN_POINT_METHOD);
body.append('(');
body.append(constructorHash);
body.append(',');
body.append(klass.getJoinPointIndex());
body.append(',');
body.append("args, this,");
body.append(TransformationUtil.JOIN_POINT_TYPE_CONSTRUCTOR_EXECUTION);
body.append("); }");
klass.incrementJoinPointIndex();
originalConstructor.setBody(body.toString());
}
/**
* @param ctClass the class
* @param constructor the current method
* @return the new prefixed constructor
*/
// private void createStaticMethodWithConstructorBody(
// final CtClass ctClass,
// final CtConstructor constructor,
// final int methodSequence) throws NotFoundException,
// CannotCompileException {
//
// String prefixedMethodName = TransformationUtil.getPrefixedOriginalMethodName(
// constructor.getName(), methodSequence, ctClass.getName()
// );
//
// CtMethod method = CtNewMethod.make(
// CtClass.voidType, prefixedMethodName, constructor.getParameterTypes(),
// constructor.getExceptionTypes(), null, ctClass
// );
// method.setModifiers(Modifier.STATIC | Modifier.FINAL);
//
// CodeAttribute codeAttribute =
// constructor.getMethodInfo().getCodeAttribute();
// method.getMethodInfo().setCodeAttribute(codeAttribute);
//
//// CodeAttribute codeAttribute =
// method.getMethodInfo().getCodeAttribute();
//// codeAttribute.setMaxLocals(codeAttribute.getMaxLocals() + 1);
//
// ctClass.addMethod(method);
// }
/**
* Adds a prefix to the original constructor. To make it callable only from within the framework itself.
*
* @param ctClass the class
* @param constructor the current method
* @return false if the prefixed constructor was already existing
*/
private boolean addPrefixToConstructor(final CtClass ctClass, final CtConstructor constructor) throws NotFoundException,
CannotCompileException {
int accessFlags = constructor.getModifiers();
CtClass[] parameterTypes = constructor.getParameterTypes();
CtClass[] newParameterTypes = new CtClass[parameterTypes.length + 1];
for (int i = 0; i < parameterTypes.length; i++) {
newParameterTypes[i] = parameterTypes[i];
}
newParameterTypes[parameterTypes.length] = ctClass.getClassPool().get(
TransformationUtil.JOIN_POINT_MANAGER_CLASS);
if (!JavassistHelper.hasConstructor(ctClass, newParameterTypes)) {
CtConstructor newConstructor = CtNewConstructor.make(
newParameterTypes,
constructor.getExceptionTypes(),
CtNewConstructor.PASS_NONE,
null,
CtMethod.ConstParameter.string(constructor.getSignature()),
ctClass);
newConstructor.setBody(constructor, null);
newConstructor.setModifiers(accessFlags);
CodeAttribute codeAttribute = newConstructor.getMethodInfo().getCodeAttribute();
codeAttribute.setMaxLocals(codeAttribute.getMaxLocals() + 1);
ctClass.addConstructor(newConstructor);
return true;
} else {
return false;
}
}
/**
* Filters the classes to be transformed.
*
* @param definition the definition
* @param ctx the context
* @param ctClass the class to filter
* @return boolean true if the method should be filtered away
*/
public static boolean classFilter(
final SystemDefinition definition,
final ExpressionContext ctx,
final CtClass ctClass) {
if (ctClass.isInterface()) {
return true;
}
String className = ctClass.getName().replace('/', '.');
if (definition.inExcludePackage(className)) {
return true;
}
if (!definition.inIncludePackage(className)) {
return true;
}
if (definition.isAdvised(ctx)) {
return false;
}
return true;
}
/**
* Filters the methods to be transformed.
*
* @param definition the definition
* @param ctx the context
* @return boolean
*/
public static boolean constructorFilter(final SystemDefinition definition, final ExpressionContext ctx) {
if (definition.hasPointcut(ctx)) {
return false;
} else {
return true;
}
}
}