alluxio.worker.netty.DataServerBlockWriteHandler.java Source code

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Here is the source code for alluxio.worker.netty.DataServerBlockWriteHandler.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.Configuration;
import alluxio.PropertyKey;
import alluxio.StorageTierAssoc;
import alluxio.WorkerStorageTierAssoc;
import alluxio.metrics.MetricsSystem;
import alluxio.network.protocol.RPCProtoMessage;
import alluxio.proto.dataserver.Protocol;
import alluxio.worker.block.BlockWorker;
import alluxio.worker.block.io.BlockWriter;

import com.codahale.metrics.Counter;
import com.google.common.base.Preconditions;
import io.netty.buffer.ByteBuf;

import java.io.IOException;
import java.nio.channels.GatheringByteChannel;
import java.util.concurrent.ExecutorService;

import javax.annotation.concurrent.NotThreadSafe;

/**
 * This handler handles block write request. Check more information in
 * {@link DataServerWriteHandler}.
 */
@NotThreadSafe
public final class DataServerBlockWriteHandler extends DataServerWriteHandler {
    private static final long FILE_BUFFER_SIZE = Configuration.getBytes(PropertyKey.WORKER_FILE_BUFFER_SIZE);

    /** The Block Worker which handles blocks stored in the Alluxio storage of the worker. */
    private final BlockWorker mWorker;
    /** An object storing the mapping of tier aliases to ordinals. */
    private final StorageTierAssoc mStorageTierAssoc = new WorkerStorageTierAssoc();
    private long mBytesReserved = 0;

    private class BlockWriteRequestInternal extends WriteRequestInternal {
        final BlockWriter mBlockWriter;

        BlockWriteRequestInternal(Protocol.WriteRequest request) throws Exception {
            super(request.getId(), request.getSessionId());
            Preconditions.checkState(request.getOffset() == 0);
            mWorker.createBlockRemote(request.getSessionId(), request.getId(),
                    mStorageTierAssoc.getAlias(request.getTier()), FILE_BUFFER_SIZE);
            mBytesReserved = FILE_BUFFER_SIZE;
            mBlockWriter = mWorker.getTempBlockWriterRemote(request.getSessionId(), request.getId());
        }

        @Override
        public void close() throws IOException {
            mBlockWriter.close();
            // TODO(peis): We can call mWorker.commitBlock() here.
        }

        @Override
        void cancel() throws IOException {
            mBlockWriter.close();
            // TODO(peis): We can call mWorker.abortBlock() here.
        }
    }

    /**
     * Creates an instance of {@link DataServerBlockWriteHandler}.
     *
     * @param executorService the executor service to run {@link PacketWriter}s
     * @param blockWorker the block worker
     */
    DataServerBlockWriteHandler(ExecutorService executorService, BlockWorker blockWorker) {
        super(executorService);
        mWorker = blockWorker;
    }

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

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

    @Override
    protected void writeBuf(ByteBuf buf, long pos) throws Exception {
        if (mBytesReserved < pos) {
            long bytesToReserve = Math.max(FILE_BUFFER_SIZE, pos - mBytesReserved);
            // Allocate enough space in the existing temporary block for the write.
            mWorker.requestSpace(mRequest.mSessionId, mRequest.mId, bytesToReserve);
            mBytesReserved += bytesToReserve;
        }
        BlockWriter blockWriter = ((BlockWriteRequestInternal) mRequest).mBlockWriter;
        GatheringByteChannel outputChannel = blockWriter.getChannel();
        int sz = buf.readableBytes();
        Preconditions.checkState(buf.readBytes(outputChannel, sz) == sz);
    }

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

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

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