org.apache.hadoop.io.compress.CompressorStream.java Source code

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Here is the source code for org.apache.hadoop.io.compress.CompressorStream.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.hadoop.io.compress;

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

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.io.compress.CompressionOutputStream;
import org.apache.hadoop.io.compress.Compressor;

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class CompressorStream extends CompressionOutputStream {
    protected Compressor compressor;
    protected byte[] buffer;
    protected boolean closed = false;

    public CompressorStream(OutputStream out, Compressor compressor, int bufferSize) {
        super(out);

        if (out == null || compressor == null) {
            throw new NullPointerException();
        } else if (bufferSize <= 0) {
            throw new IllegalArgumentException("Illegal bufferSize");
        }

        this.compressor = compressor;
        buffer = new byte[bufferSize];
    }

    public CompressorStream(OutputStream out, Compressor compressor) {
        this(out, compressor, 512);
    }

    /**
     * Allow derived classes to directly set the underlying stream.
     * 
     * @param out Underlying output stream.
     */
    protected CompressorStream(OutputStream out) {
        super(out);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        // Sanity checks
        if (compressor.finished()) {
            throw new IOException("write beyond end of stream");
        }
        if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
            throw new IndexOutOfBoundsException();
        } else if (len == 0) {
            return;
        }

        compressor.setInput(b, off, len);
        while (!compressor.needsInput()) {
            compress();
        }
    }

    protected void compress() throws IOException {
        int len = compressor.compress(buffer, 0, buffer.length);
        if (len > 0) {
            out.write(buffer, 0, len);
        }
    }

    @Override
    public void finish() throws IOException {
        if (!compressor.finished()) {
            compressor.finish();
            while (!compressor.finished()) {
                compress();
            }
        }
    }

    @Override
    public void resetState() throws IOException {
        compressor.reset();
    }

    @Override
    public void close() throws IOException {
        if (!closed) {
            try {
                super.close();
            } finally {
                closed = true;
            }
        }
    }

    private byte[] oneByte = new byte[1];

    @Override
    public void write(int b) throws IOException {
        oneByte[0] = (byte) (b & 0xff);
        write(oneByte, 0, oneByte.length);
    }

}