alluxio.network.protocol.MessageSavingHandler.java Source code

Introduction

Here is the source code for alluxio.network.protocol.MessageSavingHandler.java

Source

/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio.network.protocol;

import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import org.junit.Assert;

import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

/**
 * This is a simple handler for the channel pipelines. This simply saves the message it receives.
 * The stored message can be retrieved with {@link #getMessage()} which is blocking until the
 * message is received.
 *
 * This is for encoder/decoder testing in {@link RPCMessageIntegrationTest}.
 */
@ChannelHandler.Sharable
public class MessageSavingHandler extends SimpleChannelInboundHandler<RPCMessage> {
    public RPCMessage mMessage = null;
    private Semaphore mMessageAvailable = new Semaphore(0);

    @Override
    public void channelRead0(ChannelHandlerContext ctx, RPCMessage message) {
        mMessage = message;
        mMessageAvailable.release();
    }

    // Returns the received message. This is blocking.
    public RPCMessage getMessage() {
        try {
            if (!mMessageAvailable.tryAcquire(1, 1, TimeUnit.SECONDS)) {
                Assert.fail("Timed out receiving message.");
            }
        } catch (InterruptedException e) {
            Assert.fail("Failed with exception: " + e.getMessage());
        }
        return mMessage;
    }

    public void reset() {
        mMessage = null;
        mMessageAvailable = new Semaphore(0);
    }
}