/*
* Copyright 2013 Christopher Pheby
*
* 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.jadira.reflection.access.invokedynamic;
import static org.objectweb.asm.Opcodes.ACC_PUBLIC;
import static org.objectweb.asm.Opcodes.ACC_SUPER;
import static org.objectweb.asm.Opcodes.ALOAD;
import static org.objectweb.asm.Opcodes.ARETURN;
import static org.objectweb.asm.Opcodes.DUP;
import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
import static org.objectweb.asm.Opcodes.INVOKEVIRTUAL;
import static org.objectweb.asm.Opcodes.NEW;
import static org.objectweb.asm.Opcodes.POP;
import static org.objectweb.asm.Opcodes.RETURN;
import static org.objectweb.asm.Opcodes.V1_7;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.concurrent.ConcurrentHashMap;
import org.jadira.reflection.access.AbstractClassAccess;
import org.jadira.reflection.access.api.ClassAccess;
import org.jadira.reflection.access.api.FieldAccess;
import org.jadira.reflection.access.api.MethodAccess;
import org.jadira.reflection.access.classloader.AccessClassLoader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.MethodVisitor;
/**
* ClassAccess implementation which uses ASM and the invokeDynamic instruction.
* InvokeDynamic requests are accessed using a caching callpoint (via Dynalang) which means performance is
* similar to standard ASM based access
* @param <C> The Class to be accessed
*/
public abstract class InvokeDynamicClassAccess<C> extends AbstractClassAccess<C> implements ClassAccess<C> {
private static final ConcurrentHashMap<Class<?>, InvokeDynamicClassAccess<?>> CLASS_ACCESSES = new ConcurrentHashMap<Class<?>, InvokeDynamicClassAccess<?>>();
private static final String CLASS_ACCESS_NM = ClassAccess.class.getName().replace('.', '/');
private static final String INVOKEDYNAMIC_CLASS_ACCESS_NM = InvokeDynamicClassAccess.class.getName().replace('.', '/');
private boolean isNonStaticMemberClass;
/**
* Indicates if the class being accessed is a non-static member class
* @return True if the class is a non-static member class
*/
public boolean isNonStaticMemberClass() {
return isNonStaticMemberClass;
}
/**
* Constructor, intended for use by generated subclasses
* @param clazz The Class to be accessed
*/
protected InvokeDynamicClassAccess(Class<C> clazz) {
super(clazz);
}
/**
* Get a new instance that can access the given Class. If the ClassAccess for this class
* has not been obtained before, then the specific InvokeDynamicClassAccess is created by
* generating a specialised subclass of this class and returning it.
* @param clazz Class to be accessed
* @param <C> The type of class
* @return New InvokeDynamicClassAccess instance
*/
public static <C> InvokeDynamicClassAccess<C> get(Class<C> clazz) {
@SuppressWarnings("unchecked")
InvokeDynamicClassAccess<C> access = (InvokeDynamicClassAccess<C>) CLASS_ACCESSES.get(clazz);
if (access != null) {
return access;
}
Class<?> enclosingType = clazz.getEnclosingClass();
final boolean isNonStaticMemberClass = determineNonStaticMemberClass(clazz, enclosingType);
String clazzName = clazz.getName();
String accessClassName = constructAccessClassName(clazzName);
Class<?> accessClass = null;
AccessClassLoader loader = AccessClassLoader.get(clazz);
synchronized (loader) {
try {
accessClass = loader.loadClass(accessClassName);
} catch (ClassNotFoundException ignored) {
String accessClassNm = accessClassName.replace('.', '/');
String clazzNm = clazzName.replace('.', '/');
String enclosingClassNm = determineEnclosingClassNm(clazz, enclosingType, isNonStaticMemberClass);
String signatureString = "L" + INVOKEDYNAMIC_CLASS_ACCESS_NM + "<L" + clazzNm + ";>;L" + CLASS_ACCESS_NM + "<L" + clazzNm + ";>;";
ClassWriter cw = new ClassWriter(0);
// TraceClassVisitor tcv = new TraceClassVisitor(cv, new PrintWriter(System.err));
// CheckClassAdapter cw = new CheckClassAdapter(tcv);
cw.visit(V1_7, ACC_PUBLIC + ACC_SUPER, accessClassNm, signatureString, INVOKEDYNAMIC_CLASS_ACCESS_NM, null);
enhanceForConstructor(cw, accessClassNm, clazzNm);
if (isNonStaticMemberClass) {
enhanceForNewInstanceInner(cw, clazzNm, enclosingClassNm);
} else {
enhanceForNewInstance(cw, clazzNm);
}
cw.visitEnd();
loader.registerClass(accessClassName, cw.toByteArray());
try {
accessClass = loader.findClass(accessClassName);
} catch (ClassNotFoundException e) {
throw new IllegalStateException("AccessClass unexpectedly could not be found", e);
}
}
}
try {
@SuppressWarnings("unchecked")
Constructor<InvokeDynamicClassAccess<C>> c = (Constructor<InvokeDynamicClassAccess<C>>) accessClass.getConstructor(new Class[] { Class.class });
access = c.newInstance(clazz);
access.isNonStaticMemberClass = isNonStaticMemberClass;
CLASS_ACCESSES.putIfAbsent(clazz, access);
return access;
} catch (Exception ex) {
throw new RuntimeException("Error constructing constructor access class: " + accessClassName + "{ " + ex.getMessage() + " }", ex);
}
}
private static boolean determineNonStaticMemberClass(Class<?> clazz, Class<?> enclosingType) {
final boolean isNonStaticMemberClass;
if (enclosingType != null && clazz.isMemberClass() && !Modifier.isStatic(clazz.getModifiers())) {
isNonStaticMemberClass = true;
} else {
isNonStaticMemberClass = false;
}
;
return isNonStaticMemberClass;
}
private static <C> String determineEnclosingClassNm(Class<C> clazz, Class<?> enclosingType, final boolean isNonStaticMemberClass) {
final String enclosingClassNm;
if (!isNonStaticMemberClass) {
enclosingClassNm = null;
} else {
enclosingClassNm = enclosingType.getName().replace('.', '/');
}
return enclosingClassNm;
}
private static String constructAccessClassName(String clazzName) {
String accessClassName = clazzName + InvokeDynamicClassAccess.class.getSimpleName();
if (accessClassName.startsWith("java.")) {
accessClassName = InvokeDynamicClassAccess.class.getSimpleName().toLowerCase() + accessClassName;
}
return accessClassName;
}
private static void enhanceForConstructor(ClassVisitor cw, String accessClassNm, String clazzNm) {
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "<init>", "(Ljava/lang/Class;)V", "(L" + clazzNm + ";)V", null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(ALOAD, 1);
mv.visitMethodInsn(INVOKESPECIAL, INVOKEDYNAMIC_CLASS_ACCESS_NM, "<init>", "(Ljava/lang/Class;)V");
mv.visitInsn(RETURN);
mv.visitMaxs(2, 2);
mv.visitEnd();
}
private static void enhanceForNewInstance(ClassVisitor cw, String classNm) {
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "newInstance", "()Ljava/lang/Object;", null, null);
mv.visitCode();
mv.visitTypeInsn(NEW, classNm);
mv.visitInsn(DUP);
mv.visitMethodInsn(INVOKESPECIAL, classNm, "<init>", "()V");
mv.visitInsn(ARETURN);
mv.visitMaxs(2, 1);
mv.visitEnd();
}
private static void enhanceForNewInstanceInner(ClassVisitor cw, String classNm, String enclosingClassNm) {
MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, "newInstance", "()LLjava/lang/Object;", null, null);
mv.visitCode();
mv.visitTypeInsn(NEW, classNm);
mv.visitInsn(DUP);
mv.visitTypeInsn(NEW, enclosingClassNm);
mv.visitInsn(DUP);
mv.visitMethodInsn(INVOKESPECIAL, enclosingClassNm, "<init>", "()V");
mv.visitInsn(DUP);
mv.visitMethodInsn(INVOKEVIRTUAL, classNm, "getClass", "()Ljava/lang/Class;");
mv.visitInsn(POP);
mv.visitMethodInsn(INVOKESPECIAL, classNm, "<init>", "(L" + enclosingClassNm + ";)V");
mv.visitInsn(ARETURN);
mv.visitMaxs(4, 1);
mv.visitEnd();
}
@Override
public abstract C newInstance();
@Override
protected MethodAccess<C> constructMethodAccess(Method method) {
return InvokeDynamicMethodAccess.get(method);
}
@Override
protected FieldAccess<C> constructFieldAccess(Field field) {
return InvokeDynamicFieldAccess.get(this, field);
}
@Override
protected <X> ClassAccess<X> constructClassAccess(Class<X> clazz) {
return InvokeDynamicClassAccess.get(clazz);
}
}