alluxio.worker.netty.DataServerHandler.java Source code

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Here is the source code for alluxio.worker.netty.DataServerHandler.java

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/*
 * 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.worker.netty;

import alluxio.Constants;
import alluxio.network.protocol.RPCBlockReadRequest;
import alluxio.network.protocol.RPCBlockWriteRequest;
import alluxio.network.protocol.RPCErrorResponse;
import alluxio.network.protocol.RPCFileReadRequest;
import alluxio.network.protocol.RPCFileWriteRequest;
import alluxio.network.protocol.RPCMessage;
import alluxio.network.protocol.RPCRequest;
import alluxio.network.protocol.RPCResponse;
import alluxio.worker.AlluxioWorkerService;

import com.google.common.base.Preconditions;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

import javax.annotation.concurrent.NotThreadSafe;

/**
 * This class processes {@link RPCRequest} messages and delegates them to the appropriate
 * handlers to return {@link RPCResponse} messages.
 */
@ChannelHandler.Sharable
@NotThreadSafe
final class DataServerHandler extends SimpleChannelInboundHandler<RPCMessage> {
    private static final Logger LOG = LoggerFactory.getLogger(Constants.LOGGER_TYPE);

    /** Handler for any block store requests. */
    private final BlockDataServerHandler mBlockHandler;
    /** Handler for any file system requests. */
    private final UnderFileSystemDataServerHandler mUnderFileSystemHandler;

    /**
     * Creates a new instance of {@link DataServerHandler}.
     *
     * @param worker the Alluxio worker handle
     */
    public DataServerHandler(final AlluxioWorkerService worker) {
        Preconditions.checkNotNull(worker);
        mBlockHandler = new BlockDataServerHandler(worker.getBlockWorker());
        mUnderFileSystemHandler = new UnderFileSystemDataServerHandler(worker.getFileSystemWorker());
    }

    @Override
    public void channelRead0(final ChannelHandlerContext ctx, final RPCMessage msg) throws IOException {
        switch (msg.getType()) {
        case RPC_BLOCK_READ_REQUEST:
            assert msg instanceof RPCBlockReadRequest;
            mBlockHandler.handleBlockReadRequest(ctx, (RPCBlockReadRequest) msg);
            break;
        case RPC_BLOCK_WRITE_REQUEST:
            assert msg instanceof RPCBlockWriteRequest;
            mBlockHandler.handleBlockWriteRequest(ctx, (RPCBlockWriteRequest) msg);
            break;
        case RPC_FILE_READ_REQUEST:
            assert msg instanceof RPCFileReadRequest;
            mUnderFileSystemHandler.handleFileReadRequest(ctx, (RPCFileReadRequest) msg);
            break;
        case RPC_FILE_WRITE_REQUEST:
            assert msg instanceof RPCFileWriteRequest;
            mUnderFileSystemHandler.handleFileWriteRequest(ctx, (RPCFileWriteRequest) msg);
            break;
        case RPC_ERROR_RESPONSE:
            assert msg instanceof RPCErrorResponse;
            LOG.error("Received an error response from the client: " + msg.toString());
            break;
        default:
            RPCErrorResponse resp = new RPCErrorResponse(RPCResponse.Status.UNKNOWN_MESSAGE_ERROR);
            ctx.writeAndFlush(resp);
            throw new IllegalArgumentException("No handler implementation for rpc msg type: " + msg.getType());
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        LOG.warn("Exception thrown while processing request", cause);
        ctx.close();
    }
}