com.hadoop.compression.fourmc.Lz4MediumCodec.java Source code

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Here is the source code for com.hadoop.compression.fourmc.Lz4MediumCodec.java

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/**
4MC
Copyright (c) 2014, Carlo Medas
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
    
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
    
* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.
    
* Redistributions in binary form must reproduce the above copyright notice, this
  list of conditions and the following disclaimer in the documentation and/or
  other materials provided with the distribution.
    
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    
  You can contact 4MC author at :
  - 4MC source repository : https://github.com/carlomedas/4mc
    
  LZ4 - Copyright (C) 2011-2014, Yann Collet - BSD 2-Clause License.
  You can contact LZ4 lib author at :
  - LZ4 source repository : http://code.google.com/p/lz4/
**/
package com.hadoop.compression.fourmc;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.compress.*;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * A {@link org.apache.hadoop.io.compress.CompressionCodec} for a streaming
 * <b>LZ4</b> compression/decompression pair.
 * https://code.google.com/p/lz4/
 */
public class Lz4MediumCodec implements Configurable, CompressionCodec {
    private static final Log LOG = LogFactory.getLog(Lz4MediumCodec.class.getName());

    public static final int LZ4_BUFFER_SIZE = 4 * 1024 * 1024;

    private Configuration conf;

    public void setConf(Configuration conf) {
        this.conf = conf;
    }

    public Configuration getConf() {
        return conf;
    }

    private static boolean nativeLoaded = false;

    static {
        if (FourMcNativeCodeLoader.isNativeCodeLoaded()) {
            nativeLoaded = Lz4MediumCompressor.isNativeLoaded() && Lz4Decompressor.isNativeLoaded();

            if (nativeLoaded) {
                LOG.info("Successfully loaded & initialized native-4mc library");
            } else {
                LOG.error("Failed to load/initialize native-4mc library");
            }
        } else {
            LOG.error("Cannot load native-4mc without native-hadoop");
        }
    }

    public static boolean isNativeLoaded(Configuration conf) {
        //assert conf != null : "Configuration cannot be null!";
        return nativeLoaded;
    }

    public CompressionOutputStream createOutputStream(OutputStream out) throws IOException {
        return createOutputStream(out, createCompressor());
    }

    public CompressionOutputStream createOutputStream(OutputStream out, Compressor compressor) throws IOException {

        if (!isNativeLoaded(conf)) {
            throw new RuntimeException("native hadoop-4mc library not available");
        }

        int bufferPlusOverhead = Lz4MediumCompressor.compressBound(LZ4_BUFFER_SIZE);
        return new BlockCompressorStream(out, compressor, LZ4_BUFFER_SIZE, bufferPlusOverhead - LZ4_BUFFER_SIZE);
    }

    public Class<? extends Compressor> getCompressorType() {
        if (!isNativeLoaded(conf)) {
            throw new RuntimeException("native hadoop-4mc library not available");
        }
        return Lz4MediumCompressor.class;
    }

    public Compressor createCompressor() {
        assert conf != null : "Configuration cannot be null! You must call setConf() before creating a compressor.";
        if (!isNativeLoaded(conf)) {
            throw new RuntimeException("native hadoop-4mc library not available");
        }

        return new Lz4MediumCompressor(LZ4_BUFFER_SIZE);
    }

    public CompressionInputStream createInputStream(InputStream in) throws IOException {
        return createInputStream(in, createDecompressor());
    }

    public CompressionInputStream createInputStream(InputStream in, Decompressor decompressor) throws IOException {
        if (!isNativeLoaded(conf)) {
            throw new RuntimeException("native hadoop-4mc library not available");
        }
        return new BlockDecompressorStream(in, decompressor, LZ4_BUFFER_SIZE);
    }

    public Class<? extends Decompressor> getDecompressorType() {
        if (!isNativeLoaded(conf)) {
            throw new RuntimeException("native hadoop-4mc library not available");
        }
        return Lz4Decompressor.class;
    }

    public Decompressor createDecompressor() {
        if (!isNativeLoaded(conf)) {
            throw new RuntimeException("native hadoop-4mc library not available");
        }

        return new Lz4Decompressor(LZ4_BUFFER_SIZE);
    }

    /**
     * Get the default filename extension for this kind of compression.
     *
     * @return the extension including the '.'
     */

    public String getDefaultExtension() {
        return ".lz4_mc";
    }

}