Package org.apache.hadoop.io.compress.bzip2

Class Bzip2Decompressor

java.lang.Object
org.apache.hadoop.io.compress.bzip2.Bzip2Decompressor
All Implemented Interfaces:
Decompressor
public class Bzip2Decompressor extends Object implements Decompressor
A Decompressor based on the popular bzip2 compression algorithm. http://www.bzip2.org/

  • Constructor Summary

    Constructors
    Constructor
    Description
    Bzip2Decompressor()
     
    Bzip2Decompressor(boolean conserveMemory, int directBufferSize)
    Creates a new decompressor.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    decompress(byte[] b, int off, int len)
    Fills specified buffer with uncompressed data.
    void
    end()
    Closes the decompressor and discards any unprocessed input.
    boolean
    finished()
    Returns true if the end of the decompressed data output stream has been reached.
    long
    getBytesRead()
    Returns the total number of compressed bytes input so far.
    long
    getBytesWritten()
    Returns the total number of uncompressed bytes output so far.
    int
    getRemaining()
    Returns the number of bytes remaining in the input buffers; normally called when finished() is true to determine amount of post-gzip-stream data.
    boolean
    needsDictionary()
    Returns true if a preset dictionary is needed for decompression.
    boolean
    needsInput()
    Returns true if the input data buffer is empty and Decompressor.setInput(byte[], int, int) should be called to provide more input.
    void
    reset()
    Resets everything including the input buffers (user and direct).
    void
    setDictionary(byte[] b, int off, int len)
    Sets preset dictionary for compression.
    void
    setInput(byte[] b, int off, int len)
    Sets input data for decompression.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Bzip2Decompressor

      public Bzip2Decompressor(boolean conserveMemory, int directBufferSize)
      Creates a new decompressor.
      Parameters:
      conserveMemory - conserveMemory.
      directBufferSize - directBufferSize.

    • Bzip2Decompressor

      public Bzip2Decompressor()

  • Method Details

    • setInput

      public void setInput(byte[] b, int off, int len)
      Description copied from interface: Decompressor
      Sets input data for decompression. This should be called if and only if Decompressor.needsInput() returns true indicating that more input data is required. (Both native and non-native versions of various Decompressors require that the data passed in via b[] remain unmodified until the caller is explicitly notified--via Decompressor.needsInput()--that the buffer may be safely modified. With this requirement, an extra buffer-copy can be avoided.)
      Specified by:
      setInput in interface Decompressor
      Parameters:
      b - Input data
      off - Start offset
      len - Length

    • setDictionary

      public void setDictionary(byte[] b, int off, int len)
      Description copied from interface: Decompressor
      Sets preset dictionary for compression. A preset dictionary is used when the history buffer can be predetermined.
      Specified by:
      setDictionary in interface Decompressor
      Parameters:
      b - Dictionary data bytes
      off - Start offset
      len - Length

    • needsInput

      public boolean needsInput()
      Description copied from interface: Decompressor
      Returns true if the input data buffer is empty and Decompressor.setInput(byte[], int, int) should be called to provide more input.
      Specified by:
      needsInput in interface Decompressor
      Returns:
      true if the input data buffer is empty and Decompressor.setInput(byte[], int, int) should be called in order to provide more input.

    • needsDictionary

      public boolean needsDictionary()
      Description copied from interface: Decompressor
      Returns true if a preset dictionary is needed for decompression.
      Specified by:
      needsDictionary in interface Decompressor
      Returns:
      true if a preset dictionary is needed for decompression

    • finished

      public boolean finished()
      Description copied from interface: Decompressor
      Returns true if the end of the decompressed data output stream has been reached. Indicates a concatenated data stream when finished() returns true and Decompressor.getRemaining() returns a positive value. finished() will be reset with the Decompressor.reset() method.
      Specified by:
      finished in interface Decompressor
      Returns:
      true if the end of the decompressed data output stream has been reached.

    • decompress

      public int decompress(byte[] b, int off, int len) throws IOException
      Description copied from interface: Decompressor
      Fills specified buffer with uncompressed data. Returns actual number of bytes of uncompressed data. A return value of 0 indicates that Decompressor.needsInput() should be called in order to determine if more input data is required.
      Specified by:
      decompress in interface Decompressor
      Parameters:
      b - Buffer for the uncompressed data
      off - Start offset of the data
      len - Size of the buffer
      Returns:
      The actual number of bytes of uncompressed data.
      Throws:
      IOException - raised on errors performing I/O.

    • getBytesWritten

      public long getBytesWritten()
      Returns the total number of uncompressed bytes output so far.
      Returns:
      the total (non-negative) number of uncompressed bytes output so far

    • getBytesRead

      public long getBytesRead()
      Returns the total number of compressed bytes input so far.
      Returns:
      the total (non-negative) number of compressed bytes input so far

    • getRemaining

      public int getRemaining()
      Returns the number of bytes remaining in the input buffers; normally called when finished() is true to determine amount of post-gzip-stream data.
      Specified by:
      getRemaining in interface Decompressor
      Returns:
      the total (non-negative) number of unprocessed bytes in input

    • reset

      public void reset()
      Resets everything including the input buffers (user and direct).
      Specified by:
      reset in interface Decompressor

    • end

      public void end()
      Description copied from interface: Decompressor
      Closes the decompressor and discards any unprocessed input.
      Specified by:
      end in interface Decompressor