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The file system driver family for TAR and related archive file types. Add the JAR artifact of this module to the run time class path to make its file system drivers available for service location in the client API modules.

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/*
 * Copyright (C) 2005-2015 Schlichtherle IT Services.
 * All rights reserved. Use is subject to license terms.
 */
package de.schlichtherle.truezip.fs.archive.tar;

import de.schlichtherle.truezip.entry.Entry;
import de.schlichtherle.truezip.fs.FsController;
import de.schlichtherle.truezip.fs.FsEntryName;
import de.schlichtherle.truezip.fs.FsModel;
import de.schlichtherle.truezip.fs.FsOutputOption;
import static de.schlichtherle.truezip.fs.FsOutputOption.STORE;
import de.schlichtherle.truezip.io.Streams;
import de.schlichtherle.truezip.socket.IOPoolProvider;
import de.schlichtherle.truezip.socket.OutputSocket;
import de.schlichtherle.truezip.util.BitField;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.annotation.CheckForNull;
import javax.annotation.concurrent.Immutable;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream;

/**
 * An archive driver for BZIP2 compressed TAR files (TAR.BZIP2).
 * 
 * Subclasses must be thread-safe and should be immutable!
 * 
 * @author Christian Schlichtherle
 */
@Immutable
public class TarBZip2Driver extends TarDriver {

    public TarBZip2Driver(IOPoolProvider provider) {
        super(provider);
    }

    /**
     * The buffer size used for reading and writing.
     * Optimized for performance.
     */
    public static final int BUFFER_SIZE = Streams.BUFFER_SIZE;

    /**
     * Returns the size of the I/O buffer.
     * 

     * The implementation in the class {@link TarBZip2Driver} returns
     * {@link #BUFFER_SIZE}.
     *
     * @return The size of the I/O buffer.
     */
    public int getBufferSize() {
        return BUFFER_SIZE;
    }

    /**
     * Returns the compression level to use when writing a BZIP2 output stream.
     * 
     * The implementation in the class {@link TarBZip2Driver} returns
     * {@link org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream#MAX_BLOCKSIZE}.
     * 
     * @return The compression level to use when writing a BZIP2 output stream.
     */
    public int getLevel() {
        return FixedBZip2CompressorOutputStream.MAX_BLOCKSIZE;
    }

    /**
     * Sets {@link FsOutputOption#STORE} in {@code options} before
     * forwarding the call to {@code controller}.
     */
    @Override
    public OutputSocket getOutputSocket( FsController controller,
                                            FsEntryName name,
                                            BitField options,
                                            @CheckForNull Entry template) {
        return controller.getOutputSocket(name, options.set(STORE), template);
    }

    @Override
    protected TarInputShop newTarInputShop(
            final FsModel model, final InputStream in)
    throws IOException {
        return super.newTarInputShop(model,
                new BZip2CompressorInputStream(
                    new BufferedInputStream(in, getBufferSize())));
    }

    @Override
    protected TarOutputShop newTarOutputShop(
            final FsModel model,
            final OutputStream out,
            final TarInputShop source)
    throws IOException {
        return super.newTarOutputShop(model,
                new FixedBZip2CompressorOutputStream(
                    new FixedBufferedOutputStream(out, getBufferSize()),
                    getLevel()),
                source);
    }

    private static final class FixedBZip2CompressorOutputStream
    extends BZip2CompressorOutputStream {
        final FixedBufferedOutputStream out;

        FixedBZip2CompressorOutputStream(
                final FixedBufferedOutputStream out,
                final int level)
        throws IOException {
            super(out, level);
            this.out = out;
        }

        @Override
        public void close() throws IOException {
            // Workaround for super class implementation which fails to close
            // the decorated stream on a subsequent call if the initial attempt
            // failed with an IOException.
            // See http://java.net/jira/browse/TRUEZIP-234
            out.ignoreClose = true;
            super.close();
            out.ignoreClose = false;
            out.close();
        }
    } //FixedBZip2CompressorOutputStream
}