org.apache.hama.bsp.message.compress.SnappyCompressor.java Source code

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Here is the source code for org.apache.hama.bsp.message.compress.SnappyCompressor.java

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/**
 * 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.hama.bsp.message.compress;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

import org.apache.commons.io.IOUtils;
import org.apache.hadoop.io.Writable;
import org.xerial.snappy.SnappyInputStream;
import org.xerial.snappy.SnappyOutputStream;

public class SnappyCompressor<M extends Writable> extends BSPMessageCompressor<M> {

    @Override
    public byte[] compress(byte[] bytes) {
        ByteArrayOutputStream bos = null;
        SnappyOutputStream sos = null;
        DataOutputStream dos = null;
        byte[] compressedBytes = null;

        try {
            bos = new ByteArrayOutputStream();
            sos = new SnappyOutputStream(bos);
            dos = new DataOutputStream(sos);

            dos.write(bytes);
            dos.close(); // Flush the stream as no more data will be sent.

            compressedBytes = bos.toByteArray();

        } catch (IOException ioe) {
            LOG.error("Unable to compress", ioe);
        } finally {
            try {
                sos.close();
                bos.close();
            } catch (IOException e) {
                LOG.warn("Failed to close compression streams.", e);
            }
        }
        return compressedBytes;
    }

    /**
     * Decompresses a BSPCompressedBundle and returns the corresponding
     * BSPMessageBundle.
     * 
     * @param compMsgBundle
     * @return
     */
    @Override
    public byte[] decompress(byte[] compressedBytes) {
        ByteArrayInputStream bis = null;
        SnappyInputStream sis = null;
        DataInputStream dis = null;
        byte[] bytes = null;

        try {
            bis = new ByteArrayInputStream(compressedBytes);
            sis = new SnappyInputStream(bis);
            dis = new DataInputStream(sis);

            bytes = IOUtils.toByteArray(dis);
        } catch (IOException ioe) {
            LOG.error("Unable to decompress.", ioe);
        } finally {
            try {
                dis.close();
                sis.close();
                bis.close();
            } catch (IOException e) {
                LOG.warn("Failed to close decompression streams.", e);
            }
        }

        return bytes;
    }

}