alluxio.worker.netty.DataServerUFSFileWriteHandler.java Source code

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Here is the source code for alluxio.worker.netty.DataServerUFSFileWriteHandler.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.metrics.MetricsSystem;
import alluxio.network.protocol.RPCProtoMessage;
import alluxio.proto.dataserver.Protocol;
import alluxio.worker.file.FileSystemWorker;

import com.codahale.metrics.Counter;
import io.netty.buffer.ByteBuf;

import java.io.IOException;
import java.io.OutputStream;
import java.util.concurrent.ExecutorService;

import javax.annotation.concurrent.NotThreadSafe;

/**
 * This handler handles file write request. Check more information in
 * {@link DataServerUFSFileWriteHandler}.
 */
@NotThreadSafe
final class DataServerUFSFileWriteHandler extends DataServerWriteHandler {
    /** Filesystem worker which handles file level operations for the worker. */
    private final FileSystemWorker mWorker;
    private static final long UNUSED_SESSION_ID = -1;

    private class FileWriteRequestInternal extends WriteRequestInternal {
        OutputStream mOutputStream;

        FileWriteRequestInternal(Protocol.WriteRequest request) throws Exception {
            super(request.getId(), UNUSED_SESSION_ID);
            mOutputStream = mWorker.getUfsOutputStream(mId);
        }

        @Override
        public void close() throws IOException {
        }

        @Override
        void cancel() throws IOException {
        }
    }

    /**
     * Creates an instance of {@link DataServerUFSFileWriteHandler}.
     *
     * @param executorService the executor service to run {@link PacketWriter}s
     * @param worker the file system worker
     */
    DataServerUFSFileWriteHandler(ExecutorService executorService, FileSystemWorker worker) {
        super(executorService);
        mWorker = worker;
    }

    @Override
    protected boolean acceptMessage(Object object) {
        if (!super.acceptMessage(object)) {
            return false;
        }
        Protocol.WriteRequest request = ((RPCProtoMessage) object).getMessage().getMessage();
        return request.getType() == Protocol.RequestType.UFS_FILE;
    }

    /**
     * Initializes the handler if necessary.
     *
     * @param msg the block write request
     * @throws Exception if it fails to initialize
     */
    @Override
    protected void initializeRequest(RPCProtoMessage msg) throws Exception {
        super.initializeRequest(msg);
        if (mRequest == null) {
            mRequest = new FileWriteRequestInternal(msg.getMessage().<Protocol.WriteRequest>getMessage());
        }
    }

    @Override
    protected void writeBuf(ByteBuf buf, long pos) throws Exception {
        buf.readBytes(((FileWriteRequestInternal) mRequest).mOutputStream, buf.readableBytes());
    }

    @Override
    protected void incrementMetrics(long bytesWritten) {
        Metrics.BYTES_WRITTEN_UFS.inc(bytesWritten);
    }

    /**
     * Class that contains metrics for BlockDataServerHandler.
     */
    private static final class Metrics {
        private static final Counter BYTES_WRITTEN_UFS = MetricsSystem.workerCounter("BytesWrittenUFS");

        private Metrics() {
        } // prevent instantiation
    }
}