Class TarBuffer


  • public class TarBuffer
    extends java.lang.Object
    The TarBuffer class implements the tar archive concept of a buffered input stream. This concept goes back to the days of blocked tape drives and special io devices. In the Java universe, the only real function that this class performs is to ensure that files have the correct "block" size, or other tars will complain.

    You should never have a need to access this class directly. TarBuffers are created by Tar IO Streams.

    Version:
    $Revision: 1.10 $
    See Also:
    TarArchive
    • Constructor Summary

      Constructors 
      Constructor Description
      TarBuffer​(java.io.InputStream inStream)  
      TarBuffer​(java.io.InputStream inStream, int blockSize)  
      TarBuffer​(java.io.InputStream inStream, int blockSize, int recordSize)  
      TarBuffer​(java.io.OutputStream outStream)  
      TarBuffer​(java.io.OutputStream outStream, int blockSize)  
      TarBuffer​(java.io.OutputStream outStream, int blockSize, int recordSize)  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Close the TarBuffer.
      private void flushBlock()
      Flush the current data block if it has any data in it.
      int getBlockSize()
      Get the TAR Buffer's block size.
      int getCurrentBlockNum()
      Get the current block number, zero based.
      int getCurrentRecordNum()
      Get the current record number, within the current block, zero based.
      int getRecordSize()
      Get the TAR Buffer's record size.
      private void initialize​(int blockSize, int recordSize)
      Initialization common to all constructors.
      boolean isEOFRecord​(byte[] record)
      Determine if an archive record indicate End of Archive.
      private boolean readBlock()  
      byte[] readRecord()
      Read a record from the input stream and return the data.
      void setDebug​(boolean debug)
      Set the debugging flag for the buffer.
      void skipRecord()
      Skip over a record on the input stream.
      private void writeBlock()
      Write a TarBuffer block to the archive.
      void writeRecord​(byte[] record)
      Write an archive record to the archive.
      void writeRecord​(byte[] buf, int offset)
      Write an archive record to the archive, where the record may be inside of a larger array buffer.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • inStream

        private java.io.InputStream inStream
      • outStream

        private java.io.OutputStream outStream
      • blockBuffer

        private byte[] blockBuffer
      • currBlkIdx

        private int currBlkIdx
      • currRecIdx

        private int currRecIdx
      • blockSize

        private int blockSize
      • recordSize

        private int recordSize
      • recsPerBlock

        private int recsPerBlock
      • debug

        private boolean debug
    • Constructor Detail

      • TarBuffer

        public TarBuffer​(java.io.InputStream inStream)
      • TarBuffer

        public TarBuffer​(java.io.InputStream inStream,
                         int blockSize)
      • TarBuffer

        public TarBuffer​(java.io.InputStream inStream,
                         int blockSize,
                         int recordSize)
      • TarBuffer

        public TarBuffer​(java.io.OutputStream outStream)
      • TarBuffer

        public TarBuffer​(java.io.OutputStream outStream,
                         int blockSize)
      • TarBuffer

        public TarBuffer​(java.io.OutputStream outStream,
                         int blockSize,
                         int recordSize)
    • Method Detail

      • initialize

        private void initialize​(int blockSize,
                                int recordSize)
        Initialization common to all constructors.
      • getBlockSize

        public int getBlockSize()
        Get the TAR Buffer's block size. Blocks consist of multiple records.
      • getRecordSize

        public int getRecordSize()
        Get the TAR Buffer's record size.
      • setDebug

        public void setDebug​(boolean debug)
        Set the debugging flag for the buffer.
        Parameters:
        debug - If true, print debugging output.
      • isEOFRecord

        public boolean isEOFRecord​(byte[] record)
        Determine if an archive record indicate End of Archive. End of archive is indicated by a record that consists entirely of null bytes.
        Parameters:
        record - The record data to check.
      • skipRecord

        public void skipRecord()
                        throws java.io.IOException
        Skip over a record on the input stream.
        Throws:
        java.io.IOException
      • readRecord

        public byte[] readRecord()
                          throws java.io.IOException
        Read a record from the input stream and return the data.
        Returns:
        The record data.
        Throws:
        java.io.IOException
      • readBlock

        private boolean readBlock()
                           throws java.io.IOException
        Returns:
        false if End-Of-File, else true
        Throws:
        java.io.IOException
      • getCurrentBlockNum

        public int getCurrentBlockNum()
        Get the current block number, zero based.
        Returns:
        The current zero based block number.
      • getCurrentRecordNum

        public int getCurrentRecordNum()
        Get the current record number, within the current block, zero based. Thus, current offset = (currentBlockNum * recsPerBlk) + currentRecNum.
        Returns:
        The current zero based record number.
      • writeRecord

        public void writeRecord​(byte[] record)
                         throws java.io.IOException
        Write an archive record to the archive.
        Parameters:
        record - The record data to write to the archive.
        Throws:
        java.io.IOException
      • writeRecord

        public void writeRecord​(byte[] buf,
                                int offset)
                         throws java.io.IOException
        Write an archive record to the archive, where the record may be inside of a larger array buffer. The buffer must be "offset plus record size" long.
        Parameters:
        buf - The buffer containing the record data to write.
        offset - The offset of the record data within buf.
        Throws:
        java.io.IOException
      • writeBlock

        private void writeBlock()
                         throws java.io.IOException
        Write a TarBuffer block to the archive.
        Throws:
        java.io.IOException
      • flushBlock

        private void flushBlock()
                         throws java.io.IOException
        Flush the current data block if it has any data in it.
        Throws:
        java.io.IOException
      • close

        public void close()
                   throws java.io.IOException
        Close the TarBuffer. If this is an output buffer, also flush the current block before closing.
        Throws:
        java.io.IOException