org.snapscript.cglib.reflect.MulticastDelegate Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of snap-all Show documentation
Show all versions of snap-all Show documentation
Dynamic scripting for the JVM
/*
* Copyright 2003,2004 The Apache Software Foundation
*
* 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.snapscript.cglib.reflect;
import java.lang.reflect.*;
import java.security.ProtectionDomain;
import java.util.*;
import org.snapscript.asm.ClassVisitor;
import org.snapscript.asm.MethodVisitor;
import org.snapscript.asm.Type;
import org.snapscript.cglib.core.*;
abstract public class MulticastDelegate implements Cloneable {
protected Object[] targets = {};
protected MulticastDelegate() {
}
public List getTargets() {
return new ArrayList(Arrays.asList(targets));
}
abstract public MulticastDelegate add(Object target);
protected MulticastDelegate addHelper(Object target) {
MulticastDelegate copy = newInstance();
copy.targets = new Object[targets.length + 1];
System.arraycopy(targets, 0, copy.targets, 0, targets.length);
copy.targets[targets.length] = target;
return copy;
}
public MulticastDelegate remove(Object target) {
for (int i = targets.length - 1; i >= 0; i--) {
if (targets[i].equals(target)) {
MulticastDelegate copy = newInstance();
copy.targets = new Object[targets.length - 1];
System.arraycopy(targets, 0, copy.targets, 0, i);
System.arraycopy(targets, i + 1, copy.targets, i, targets.length - i - 1);
return copy;
}
}
return this;
}
abstract public MulticastDelegate newInstance();
public static MulticastDelegate create(Class iface) {
Generator gen = new Generator();
gen.setInterface(iface);
return gen.create();
}
public static class Generator extends AbstractClassGenerator {
private static final Source SOURCE = new Source(MulticastDelegate.class.getName());
private static final Type MULTICAST_DELEGATE =
TypeUtils.parseType("org.snapscript.cglib.reflect.MulticastDelegate");
private static final Signature NEW_INSTANCE =
new Signature("newInstance", MULTICAST_DELEGATE, new Type[0]);
private static final Signature ADD_DELEGATE =
new Signature("add", MULTICAST_DELEGATE, new Type[]{ Constants.TYPE_OBJECT });
private static final Signature ADD_HELPER =
new Signature("addHelper", MULTICAST_DELEGATE, new Type[]{ Constants.TYPE_OBJECT });
private Class iface;
public Generator() {
super(SOURCE);
}
protected ClassLoader getDefaultClassLoader() {
return iface.getClassLoader();
}
protected ProtectionDomain getProtectionDomain() {
return ReflectUtils.getProtectionDomain(iface);
}
public void setInterface(Class iface) {
this.iface = iface;
}
public MulticastDelegate create() {
setNamePrefix(MulticastDelegate.class.getName());
return (MulticastDelegate)super.create(iface.getName());
}
public void generateClass(ClassVisitor cv) {
final MethodInfo method = ReflectUtils.getMethodInfo(ReflectUtils.findInterfaceMethod(iface));
ClassEmitter ce = new ClassEmitter(cv);
ce.begin_class(Constants.V1_2,
Constants.ACC_PUBLIC,
getClassName(),
MULTICAST_DELEGATE,
new Type[]{ Type.getType(iface) },
Constants.SOURCE_FILE);
EmitUtils.null_constructor(ce);
// generate proxied method
emitProxy(ce, method);
// newInstance
CodeEmitter e = ce.begin_method(Constants.ACC_PUBLIC, NEW_INSTANCE, null);
e.new_instance_this();
e.dup();
e.invoke_constructor_this();
e.return_value();
e.end_method();
// add
e = ce.begin_method(Constants.ACC_PUBLIC, ADD_DELEGATE, null);
e.load_this();
e.load_arg(0);
e.checkcast(Type.getType(iface));
e.invoke_virtual_this(ADD_HELPER);
e.return_value();
e.end_method();
ce.end_class();
}
private void emitProxy(ClassEmitter ce, final MethodInfo method) {
int modifiers = Constants.ACC_PUBLIC;
if ((method.getModifiers() & Constants.ACC_VARARGS) == Constants.ACC_VARARGS) {
modifiers |= Constants.ACC_VARARGS;
}
final CodeEmitter e = EmitUtils.begin_method(ce, method, modifiers);
Type returnType = method.getSignature().getReturnType();
final boolean returns = returnType != Type.VOID_TYPE;
Local result = null;
if (returns) {
result = e.make_local(returnType);
e.zero_or_null(returnType);
e.store_local(result);
}
e.load_this();
e.super_getfield("targets", Constants.TYPE_OBJECT_ARRAY);
final Local result2 = result;
EmitUtils.process_array(e, Constants.TYPE_OBJECT_ARRAY, new ProcessArrayCallback() {
public void processElement(Type type) {
e.checkcast(Type.getType(iface));
e.load_args();
e.invoke(method);
if (returns) {
e.store_local(result2);
}
}
});
if (returns) {
e.load_local(result);
}
e.return_value();
e.end_method();
}
protected Object firstInstance(Class type) {
// make a new instance in case first object is used with a long list of targets
return ((MulticastDelegate)ReflectUtils.newInstance(type)).newInstance();
}
protected Object nextInstance(Object instance) {
return ((MulticastDelegate)instance).newInstance();
}
}
}