/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.cloudstack.framework.async;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import net.sf.cglib.proxy.Callback;
import net.sf.cglib.proxy.CallbackFilter;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import org.apache.log4j.Logger;
@SuppressWarnings("rawtypes")
public class AsyncCallbackDispatcher<T, R> implements AsyncCompletionCallback {
private static final Logger s_logger = Logger.getLogger(AsyncCallbackDispatcher.class);
private Method _callbackMethod;
private final T _targetObject;
private Object _contextObject;
private Object _resultObject;
private AsyncCallbackDriver _driver = new InplaceAsyncCallbackDriver();
private AsyncCallbackDispatcher(T target) {
assert(target != null);
_targetObject = target;
}
public AsyncCallbackDispatcher<T, R> attachDriver(AsyncCallbackDriver driver) {
assert(driver != null);
_driver = driver;
return this;
}
public Method getCallbackMethod() {
return _callbackMethod;
}
@SuppressWarnings("unchecked")
public T getTarget() {
Enhancer en = new Enhancer();
Class<?> clz = _targetObject.getClass();
String clzName = clz.getName();
if(clzName.contains("EnhancerByCloudStack"))
clz = clz.getSuperclass();
en.setSuperclass(clz);
en.setCallbacks(new Callback[]{new MethodInterceptor() {
@Override
public Object intercept(Object arg0, Method arg1, Object[] arg2,
MethodProxy arg3) throws Throwable {
_callbackMethod = arg1;
_callbackMethod.setAccessible(true);
return null;
}
},
new MethodInterceptor() {
@Override
public Object intercept(Object arg0, Method arg1, Object[] arg2,
MethodProxy arg3) throws Throwable {
return null;
}
}
});
en.setCallbackFilter(new CallbackFilter() {
@Override
public int accept(Method method) {
if (method.getParameterTypes().length == 0 && method.getName().equals("finalize")) {
return 1;
}
return 0;
}}
);
try {
return (T)en.create();
} catch(Throwable e) {
s_logger.error("Unexpected exception", e);
}
return null;
}
public AsyncCallbackDispatcher<T, R> setCallback(Object useless) {
return this;
}
public AsyncCallbackDispatcher<T, R> setContext(Object context) {
_contextObject = context;
return this;
}
@SuppressWarnings("unchecked")
public <P> P getContext() {
return (P)_contextObject;
}
@Override
public void complete(Object resultObject) {
_resultObject = resultObject;
_driver.performCompletionCallback(this);
}
@SuppressWarnings("unchecked")
public R getResult() {
return (R)_resultObject;
}
// for internal use
Object getTargetObject() {
return _targetObject;
}
public static <P, R> AsyncCallbackDispatcher<P, R> create(P target) {
return new AsyncCallbackDispatcher<P, R>(target);
}
public static boolean dispatch(Object target, AsyncCallbackDispatcher callback) {
assert(callback != null);
assert(target != null);
try {
callback.getCallbackMethod().invoke(target, callback, callback.getContext());
} catch (IllegalArgumentException e) {
throw new RuntimeException("IllegalArgumentException when invoking RPC callback for command: " + callback.getCallbackMethod().getName());
} catch (IllegalAccessException e) {
throw new RuntimeException("IllegalAccessException when invoking RPC callback for command: " + callback.getCallbackMethod().getName());
} catch (InvocationTargetException e) {
throw new RuntimeException("InvocationTargetException when invoking RPC callback for command: " + callback.getCallbackMethod().getName(), e);
}
return true;
}
}