org.apache.hadoop.io.compress

Class PassthroughCodec.StubDecompressor

java.lang.Object

org.apache.hadoop.io.compress.PassthroughCodec.StubDecompressor

All Implemented Interfaces:

Decompressor

Enclosing class:

PassthroughCodec

protected static final class PassthroughCodec.StubDecompressor
extends Object
implements Decompressor

The decompressor is a no-op. It is not needed other than to complete the methods offered by the interface.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	StubDecompressor()

Method Summary

Modifier and Type	Method and 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.
int	getRemaining() Returns the number of bytes remaining in the compressed data buffer.
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 decompressor and input and output buffers so that a new set of input data can be processed.
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 Detail

StubDecompressor

protected StubDecompressor()

Method Detail

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

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.

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

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

getRemaining

public int getRemaining()

Description copied from interface: Decompressor

Returns the number of bytes remaining in the compressed data buffer. Indicates a concatenated data stream if Decompressor.finished() returns true and getRemaining() returns a positive value. If Decompressor.finished() returns true and getRemaining() returns a zero value, indicates that the end of data stream has been reached and is not a concatenated data stream.

Specified by:

getRemaining in interface Decompressor

Returns:

The number of bytes remaining in the compressed data buffer.

reset

public void reset()

Description copied from interface: Decompressor

Resets decompressor and input and output buffers so that a new set of input data can be processed. If Decompressor.finished()} returns true and Decompressor.getRemaining() returns a positive value, reset() is called before processing of the next data stream in the concatenated data stream. Decompressor.finished() will be reset and will return false when reset() is called.

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