http://www.jboss.org/shrinkwrap-impl-base: Common Base for Implementations of the ShrinkWrap Project (JBoss by Red Hat) 
/*
 ** Authored by Timothy Gerard Endres
 ** <mailto:time@gjt.org>  <http://www.trustice.com>
 **
 ** This work has been placed into the public domain.
 ** You may use this work in any way and for any purpose you wish.
 **
 ** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,
 ** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR
 ** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY
 ** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR
 ** REDISTRIBUTION OF THIS SOFTWARE.
 **
 */

package org.jboss.shrinkwrap.impl.base.io.tar;

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


The TarOutputStream writes a UNIX tar archive as an OutputStream. Methods are provided to put entries, and then write
their contents by writing to this stream using write().
Kerry Menzel  Contributed the code to support file sizes greater than 2GB (longs versus ints).

Author:Timothy Gerard Endres, 
See Also:
Version:$Revision: 1.8 $
/**
 * The TarOutputStream writes a UNIX tar archive as an OutputStream. Methods are provided to put entries, and then write
 * their contents by writing to this stream using write().
 *
 * Kerry Menzel <kmenzel@cfl.rr.com> Contributed the code to support file sizes greater than 2GB (longs versus ints).
 *
 * @version $Revision: 1.8 $
 * @author Timothy Gerard Endres, <time@gjt.org>
 * @see TarBuffer
 * @see TarHeader
 * @see TarEntry
 */

public class TarOutputStreamImpl extends FilterOutputStream {
    protected boolean debug;
    protected long currSize;
    protected long currBytes;
    protected byte[] oneBuf;
    protected byte[] recordBuf;
    protected int assemLen;
    protected byte[] assemBuf;
    protected TarBuffer buffer;

    public TarOutputStreamImpl(OutputStream os) {
        this(os, TarBuffer.DEFAULT_BLKSIZE, TarBuffer.DEFAULT_RCDSIZE);
    }

    public TarOutputStreamImpl(OutputStream os, int blockSize) {
        this(os, blockSize, TarBuffer.DEFAULT_RCDSIZE);
    }

    public TarOutputStreamImpl(OutputStream os, int blockSize, int recordSize) {
        super(os);

        this.buffer = new TarBuffer(os, blockSize, recordSize);

        this.debug = false;
        this.assemLen = 0;
        this.assemBuf = new byte[recordSize];
        this.recordBuf = new byte[recordSize];
        this.oneBuf = new byte[1];
    }

    
Sets the debugging flag.

Params:
  • debugF – 
           True to turn on debugging.
/**
     * Sets the debugging flag.
     *
     * @param debugF
     *            True to turn on debugging.
     */
    public void setDebug(boolean debugF) {
        this.debug = debugF;
    }

    
Sets the debugging flag in this stream's TarBuffer.

Params:
  • debugF – 
           True to turn on debugging.
/**
     * Sets the debugging flag in this stream's TarBuffer.
     *
     * @param debugF
     *            True to turn on debugging.
     */
    public void setBufferDebug(boolean debug) {
        this.buffer.setDebug(debug);
    }

    
Ends the TAR archive without closing the underlying OutputStream. The result is that the EOF record of nulls is
written.

/**
     * Ends the TAR archive without closing the underlying OutputStream. The result is that the EOF record of nulls is
     * written.
     */

    public void finish() throws IOException {
        this.writeEOFRecord();
    }

    
Ends the TAR archive and closes the underlying OutputStream. This means that finish() is called followed by
calling the TarBuffer's close().

/**
     * Ends the TAR archive and closes the underlying OutputStream. This means that finish() is called followed by
     * calling the TarBuffer's close().
     */

    public void close() throws IOException {
        this.finish();
        this.buffer.close();
    }

    
Get the record size being used by this stream's TarBuffer.

Returns:The TarBuffer record size.
/**
     * Get the record size being used by this stream's TarBuffer.
     *
     * @return The TarBuffer record size.
     */
    public int getRecordSize() {
        return this.buffer.getRecordSize();
    }

    
Put an entry on the output stream. This writes the entry's header record and positions the output stream for
writing the contents of the entry. Once this method is called, the stream is ready for calls to write() to write
the entry's contents. Once the contents are written, closeEntry() MUST be called to ensure that all
buffered data is completely written to the output stream.

Params:
  • entry – 
           The TarEntry to be written to the archive.
/**
     * Put an entry on the output stream. This writes the entry's header record and positions the output stream for
     * writing the contents of the entry. Once this method is called, the stream is ready for calls to write() to write
     * the entry's contents. Once the contents are written, closeEntry() <B>MUST</B> be called to ensure that all
     * buffered data is completely written to the output stream.
     *
     * @param entry
     *            The TarEntry to be written to the archive.
     */
    public void putNextEntry(TarEntry entry) throws IOException {
        StringBuffer name = entry.getHeader().name;

        // NOTE
        // This check is not adequate, because the maximum file length that
        // can be placed into a POSIX (ustar) header depends on the precise
        // locations of the path elements (slashes) within the file's full
        // pathname. For this reason, writeEntryHeader() can still throw an
        // InvalidHeaderException if the file's full pathname will not fit
        // in the header.

        if ((entry.isUnixTarFormat() && name.length() > TarHeader.NAMELEN)
            || (!entry.isUnixTarFormat() && name.length() > (TarHeader.NAMELEN + TarHeader.PREFIXLEN))) {
            throw new InvalidHeaderException("file name '" + name + "' is too long ( " + name.length() + " > "
                + (entry.isUnixTarFormat() ? TarHeader.NAMELEN : (TarHeader.NAMELEN + TarHeader.PREFIXLEN))
                + " bytes )");
        }

        entry.writeEntryHeader(this.recordBuf);

        this.buffer.writeRecord(this.recordBuf);

        this.currBytes = 0;

        if (entry.isDirectory()) {
            this.currSize = 0;
        } else {
            this.currSize = entry.getSize();
        }
    }

    
Close an entry. This method MUST be called for all file entries that contain data. The reason is that we must
buffer data written to the stream in order to satisfy the buffer's record based writes. Thus, there may be data
fragments still being assembled that must be written to the output stream before this entry is closed and the
next entry written.

/**
     * Close an entry. This method MUST be called for all file entries that contain data. The reason is that we must
     * buffer data written to the stream in order to satisfy the buffer's record based writes. Thus, there may be data
     * fragments still being assembled that must be written to the output stream before this entry is closed and the
     * next entry written.
     */
    public void closeEntry() throws IOException {
        if (this.assemLen > 0) {
            for (int i = this.assemLen; i < this.assemBuf.length; ++i) {
                this.assemBuf[i] = 0;
            }

            this.buffer.writeRecord(this.assemBuf);

            this.currBytes += this.assemLen;
            this.assemLen = 0;
        }

        if (this.currBytes < this.currSize) {
            throw new IOException("entry closed at '" + this.currBytes + "' before the '" + this.currSize
                + "' bytes specified in the header were written");
        }
    }

    
Writes a byte to the current tar archive entry.
This method simply calls read( byte[], int, int ).

Params:
  • b – 
           The byte written.
/**
     * Writes a byte to the current tar archive entry.
     *
     * This method simply calls read( byte[], int, int ).
     *
     * @param b
     *            The byte written.
     */
    public void write(int b) throws IOException {
        this.oneBuf[0] = (byte) b;
        this.write(this.oneBuf, 0, 1);
    }

    
Writes bytes to the current tar archive entry.
This method simply calls read( byte[], int, int ).

Params:
  • wBuf – 
           The buffer to write to the archive.
Returns:The number of bytes read, or -1 at EOF.
/**
     * Writes bytes to the current tar archive entry.
     *
     * This method simply calls read( byte[], int, int ).
     *
     * @param wBuf
     *            The buffer to write to the archive.
     * @return The number of bytes read, or -1 at EOF.
     */
    public void write(byte[] wBuf) throws IOException {
        this.write(wBuf, 0, wBuf.length);
    }

    
Writes bytes to the current tar archive entry. This method is aware of the current entry and will throw an
exception if you attempt to write bytes past the length specified for the current entry. The method is also
(painfully) aware of the record buffering required by TarBuffer, and manages buffers that are not a multiple of
recordsize in length, including assembling records from small buffers.
This method simply calls read( byte[], int, int ).

Params:
  • wBuf – 
           The buffer to write to the archive.
  • wOffset – 
           The offset in the buffer from which to get bytes.
  • numToWrite – 
           The number of bytes to write.
/**
     * Writes bytes to the current tar archive entry. This method is aware of the current entry and will throw an
     * exception if you attempt to write bytes past the length specified for the current entry. The method is also
     * (painfully) aware of the record buffering required by TarBuffer, and manages buffers that are not a multiple of
     * recordsize in length, including assembling records from small buffers.
     *
     * This method simply calls read( byte[], int, int ).
     *
     * @param wBuf
     *            The buffer to write to the archive.
     * @param wOffset
     *            The offset in the buffer from which to get bytes.
     * @param numToWrite
     *            The number of bytes to write.
     */
    public void write(byte[] wBuf, int wOffset, int numToWrite) throws IOException {
        if ((this.currBytes + numToWrite) > this.currSize) {
            throw new IOException("request to write '" + numToWrite + "' bytes exceeds size in header of '"
                + this.currSize + "' bytes");
        }

        //
        // We have to deal with assembly!!!
        // The programmer can be writing little 32 byte chunks for all
        // we know, and we must assemble complete records for writing.
        // REVIEW Maybe this should be in TarBuffer? Could that help to
        // eliminate some of the buffer copying.
        //
        if (this.assemLen > 0) {
            if ((this.assemLen + numToWrite) >= this.recordBuf.length) {
                int aLen = this.recordBuf.length - this.assemLen;

                System.arraycopy(this.assemBuf, 0, this.recordBuf, 0, this.assemLen);

                System.arraycopy(wBuf, wOffset, this.recordBuf, this.assemLen, aLen);

                this.buffer.writeRecord(this.recordBuf);

                this.currBytes += this.recordBuf.length;

                wOffset += aLen;
                numToWrite -= aLen;
                this.assemLen = 0;
            } else // ( (this.assemLen + numToWrite ) < this.recordBuf.length )
            {
                System.arraycopy(wBuf, wOffset, this.assemBuf, this.assemLen, numToWrite);
                wOffset += numToWrite;
                this.assemLen += numToWrite;
                numToWrite -= numToWrite;
            }
        }

        //
        // When we get here we have EITHER:
        // o An empty "assemble" buffer.
        // o No bytes to write (numToWrite == 0)
        //

        for (; numToWrite > 0;) {
            if (numToWrite < this.recordBuf.length) {
                System.arraycopy(wBuf, wOffset, this.assemBuf, this.assemLen, numToWrite);
                this.assemLen += numToWrite;
                break;
            }

            this.buffer.writeRecord(wBuf, wOffset);

            long num = this.recordBuf.length;
            this.currBytes += num;
            numToWrite -= num;
            wOffset += num;
        }
    }

    
Write an EOF (end of archive) record to the tar archive. An EOF record consists of a record of all zeros.

/**
     * Write an EOF (end of archive) record to the tar archive. An EOF record consists of a record of all zeros.
     */
    private void writeEOFRecord() throws IOException {
        for (int i = 0; i < this.recordBuf.length; ++i) {
            this.recordBuf[i] = 0;
        }
        this.buffer.writeRecord(this.recordBuf);
    }

}