org.apache.hadoop.mapred.nativetask.NativeBatchProcessor.java Source code

Introduction

Here is the source code for org.apache.hadoop.mapred.nativetask.NativeBatchProcessor.java

Source

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

package org.apache.hadoop.mapred.nativetask;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapred.nativetask.serde.KVSerializer;

public abstract class NativeBatchProcessor<IK, IV, OK, OV> implements INativeHandler {

    private static Log LOG = LogFactory.getLog(NativeBatchProcessor.class);

    private ByteBuffer inputBuffer;
    private ByteBuffer outputBuffer;

    private String nativeHandlerName;
    private long nativeHandlerAddr;
    private boolean isInputFinished = false;

    protected KVSerializer<IK, IV> serializer;
    protected KVSerializer<OK, OV> deserializer;

    protected NativeDataReader nativeReader;
    protected NativeDataWriter nativeWriter;

    static {
        // InitIDs();
        if (NativeRuntime.isNativeLibraryLoaded()) {
            InitIDs();
        }
    }

    public NativeBatchProcessor(Class<IK> iKClass, Class<IV> iVClass, Class<OK> oKClass, Class<OV> oVClass,
            String nativeHandlerName, int inputBufferCapacity, int outputBufferCapacity) throws IOException {
        if (inputBufferCapacity > 0) {
            this.inputBuffer = ByteBuffer.allocateDirect(inputBufferCapacity);
            this.inputBuffer.order(ByteOrder.BIG_ENDIAN);
        }
        if (outputBufferCapacity > 0) {
            this.outputBuffer = ByteBuffer.allocateDirect(outputBufferCapacity);
            this.outputBuffer.order(ByteOrder.BIG_ENDIAN);
        }
        this.nativeHandlerName = nativeHandlerName;

        this.nativeReader = new NativeInputStream(outputBuffer);
        this.nativeWriter = new NativeOutputStream(inputBuffer) {

            @Override
            public void flush() throws IOException {
                flushInputAndProcess();
            }

            @Override
            public void close() throws IOException {
                finishInput();
            }

        };

        if (null != iKClass && null != iVClass) {
            this.serializer = new KVSerializer<IK, IV>(iKClass, iVClass);
        }
        if (null != oKClass && null != oVClass) {
            this.deserializer = new KVSerializer<OK, OV>(oKClass, oVClass);
        }
    }

    @Override
    public void init(Configuration conf) throws IOException {
        this.nativeHandlerAddr = NativeRuntime.createNativeObject(nativeHandlerName);
        if (this.nativeHandlerAddr == 0) {
            throw new RuntimeException("Native object create failed, class: " + nativeHandlerName);
        }
        setupHandler(nativeHandlerAddr);
    }

    @Override
    public synchronized void close() throws IOException {
        nativeWriter.close();
        if (nativeHandlerAddr != 0) {
            NativeRuntime.releaseNativeObject(nativeHandlerAddr);
            nativeHandlerAddr = 0;
        }
    }

    private void finishInput() throws IOException {
        if (null == inputBuffer) {
            return;
        }

        if (isInputFinished) {
            return;
        }
        if (inputBuffer.position() > 0) {
            flushInputAndProcess();
        }
        nativeFinish(nativeHandlerAddr);
        isInputFinished = true;
    }

    private void flushInputAndProcess() throws IOException {
        nativeProcessInput(nativeHandlerAddr, inputBuffer.position());
        inputBuffer.position(0);
    }

    protected byte[] sendCommandToNative(byte[] cmd) throws IOException {
        return nativeCommand(nativeHandlerAddr, cmd);
    }

    protected byte[] sendCommandToJava(byte[] data) throws IOException {
        return null;
    }

    /**
     * Called by native side, clean output buffer so native side can continue
     * processing
     */
    private void flushOutput(int length) throws IOException {
        outputBuffer.position(0);
        outputBuffer.limit(length);
        flushOutputAndProcess(nativeReader, length);
    }

    /**
     * Cache JNI field & method ids
     */
    private static native void InitIDs();

    /**
     * Setup native side BatchHandler
     */
    private native void setupHandler(long nativeHandlerAddr);

    /**
     * Let native side to process data in inputBuffer
     * 
     * @param handler
     * @param length
     */
    private native void nativeProcessInput(long handler, int length);

    /**
     * Notice native side input is finished
     * 
     * @param handler
     */
    private native void nativeFinish(long handler);

    /**
     * Send control message to native side
     * 
     * @param cmd
     *          command data
     * @return return value
     */
    private native byte[] nativeCommand(long handler, byte[] cmd);

    @Override
    public NativeDataWriter getWriter() {
        return nativeWriter;
    }

    @Override
    public NativeDataReader getReader() {
        return nativeReader;
    }

    protected void finishOutput() {
    }

    /**
     * @param outputbuffer
     * @return true if succeed
     */
    protected boolean flushOutputAndProcess(NativeDataReader outputbuffer, int length) throws IOException {
        return true;
    }
}