jenergy.agent.aop.aspectj.aspects.FileOutputStreamAspect.java Source code

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Here is the source code for jenergy.agent.aop.aspectj.aspects.FileOutputStreamAspect.java

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/**
 * Copyright 2013 Contributors
 *
 *    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.
 *
 *    Contributors:
 *          Alessandro Ferreira Leite - the initial implementation.
 */
package jenergy.agent.aop.aspectj.aspects;

import jenergy.agent.aop.aspectj.util.AspectjUtils;
import jenergy.agent.common.Cpu;
import jenergy.agent.common.io.FileOutputStreamDelegate;
import jenergy.agent.common.util.Observer;
import jenergy.agent.common.util.Subject;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.DeclareParents;

@Aspect
public class FileOutputStreamAspect {

    /**
     * Declare the {@link FileOutputStreamDelegate} as a {@link Subject}.
     */
    @DeclareParents(value = "jenergy.agent.common.io.FileOutputStreamDelegate")
    private Subject subject;

    /**
     * Around advice to replace all instances of {@link java.io.FileOutputStream} by {@link FileOutputStreamDelegate}. This is a runtime advice.
     * 
     * @param thisJoinPoint
     *            The joinpoint reference.
     * @return An instance of {@link FileOutputStreamDelegate}.
     * @throws Throwable
     *             May throw any exceptions declared by the joinpoint itself. If this exception is not declared and is not a runtime exception, it
     *             will be encapsulated in a {@link RuntimeException} before being thrown to the basis system.
     */
    @Around("call(java.io.FileOutputStream+.new(..)) && !within(jenergy..*) && !within(org.aspectj..*)")
    public Object invoke(final ProceedingJoinPoint thisJoinPoint) throws Throwable {
        FileOutputStreamDelegate output = AspectjUtils.newInstance(thisJoinPoint, FileOutputStreamDelegate.class,
                thisJoinPoint.proceed(), Cpu.getInstance().currentThread().peekMethodInfo());
        output.getClass().getDeclaredMethod("attach", jenergy.agent.common.util.Observer.class).invoke(output,
                output.getInfo());
        return output;
    }

    /**
     * 
     * @param thisJoinPoint
     *            The joint point reference.
     * @return Returns <code>null</code> since the return type of the advice method is {@link Void}.
     * @throws Throwable
     *             May throw any exceptions declared by the joinpoint itself. If this exception is not declared and is not a runtime exception, it
     *             will be encapsulated in a {@link RuntimeException} before being thrown to the basis system.
     */
    @Around(value = "execution(void jenergy.agent.common.io.FileOutputStreamDelegate.write(..))")
    public Object aroundFileOutputStreamWriteOperation(final ProceedingJoinPoint thisJoinPoint) throws Throwable {
        Object[] args = thisJoinPoint.getArgs();
        Subject observable = (Subject) thisJoinPoint.getTarget();

        Object methodReturn = thisJoinPoint.proceed(args);

        for (Observer obs : observable.getObservers()) {
            int value;

            if (args.length == 3) {
                value = (Integer) args[2] - (Integer) args[1];
            } else {
                if (args[0].getClass().isArray()) {
                    value = ((byte[]) args[0]).length * 4;
                } else if (Integer.class.isAssignableFrom(args[0].getClass())) {
                    value = (Integer) args[0];
                } else {
                    throw new RuntimeException("Unknown FileOuputStream's write method!");
                }
            }

            obs.update(observable, value);
        }
        return methodReturn;
    }
}