org.apache.avro.file.XZCodec.java Source code

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Here is the source code for org.apache.avro.file.XZCodec.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.avro.file;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;

import org.apache.commons.compress.compressors.xz.XZCompressorInputStream;
import org.apache.commons.compress.compressors.xz.XZCompressorOutputStream;
import org.apache.commons.compress.utils.IOUtils;

/** * Implements xz compression and decompression. */
public class XZCodec extends Codec {

    static class Option extends CodecFactory {
        private int compressionLevel;

        Option(int compressionLevel) {
            this.compressionLevel = compressionLevel;
        }

        @Override
        protected Codec createInstance() {
            return new XZCodec(compressionLevel);
        }
    }

    private ByteArrayOutputStream outputBuffer;
    private int compressionLevel;

    public XZCodec(int compressionLevel) {
        this.compressionLevel = compressionLevel;
    }

    @Override
    public String getName() {
        return DataFileConstants.XZ_CODEC;
    }

    @Override
    public ByteBuffer compress(ByteBuffer data) throws IOException {
        ByteArrayOutputStream baos = getOutputBuffer(data.remaining());
        OutputStream ios = new XZCompressorOutputStream(baos, compressionLevel);
        writeAndClose(data, ios);
        return ByteBuffer.wrap(baos.toByteArray());
    }

    @Override
    public ByteBuffer decompress(ByteBuffer data) throws IOException {
        ByteArrayOutputStream baos = getOutputBuffer(data.remaining());
        InputStream bytesIn = new ByteArrayInputStream(data.array(), data.arrayOffset() + data.position(),
                data.remaining());
        InputStream ios = new XZCompressorInputStream(bytesIn);
        try {
            IOUtils.copy(ios, baos);
        } finally {
            ios.close();
        }
        return ByteBuffer.wrap(baos.toByteArray());
    }

    private void writeAndClose(ByteBuffer data, OutputStream to) throws IOException {
        byte[] input = data.array();
        int offset = data.arrayOffset() + data.position();
        int length = data.remaining();
        try {
            to.write(input, offset, length);
        } finally {
            to.close();
        }
    }

    // get and initialize the output buffer for use.
    private ByteArrayOutputStream getOutputBuffer(int suggestedLength) {
        if (null == outputBuffer) {
            outputBuffer = new ByteArrayOutputStream(suggestedLength);
        }
        outputBuffer.reset();
        return outputBuffer;
    }

    @Override
    public int hashCode() {
        return compressionLevel;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (getClass() != obj.getClass())
            return false;
        XZCodec other = (XZCodec) obj;
        return (this.compressionLevel == other.compressionLevel);
    }

    @Override
    public String toString() {
        return getName() + "-" + compressionLevel;
    }
}