Package org.apache.hadoop.io.compress

Class CompressionInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.io.compress.CompressionInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Seekable, IOStatisticsSource

Direct Known Subclasses:

DecompressorStream, SplitCompressionInputStream

@Public
@Evolving
public abstract class CompressionInputStream
extends java.io.InputStream
implements Seekable, IOStatisticsSource

A compression input stream.

Implementations are assumed to be buffered. This permits clients to reposition the underlying input stream then call resetState(), without having to also synchronize client buffers.

Field Summary

Fields

Modifier and Type	Field	Description
protected java.io.InputStream	in	The input stream to be compressed.
protected long	maxAvailableData

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CompressionInputStream(java.io.InputStream in)	Create a compression input stream that reads the decompressed bytes from the given stream.

Method Summary

Modifier and Type	Method	Description
void	close()
IOStatistics	getIOStatistics()	Return any IOStatistics provided by the underlying stream.
long	getPos()	This method returns the current position in the stream.
abstract int	read(byte[] b, int off, int len)	Read bytes from the stream.
abstract void	resetState()	Reset the decompressor to its initial state and discard any buffered data, as the underlying stream may have been repositioned.
void	seek(long pos)	This method is current not supported.
boolean	seekToNewSource(long targetPos)	This method is current not supported.

Methods inherited from class java.io.InputStream

available, mark, markSupported, nullInputStream, read, read, readAllBytes, readNBytes, readNBytes, reset, skip, transferTo

Methods inherited from class java.lang.Object

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

Field Detail

in

protected final java.io.InputStream in

The input stream to be compressed.

maxAvailableData

protected long maxAvailableData

Constructor Detail

CompressionInputStream

protected CompressionInputStream(java.io.InputStream in)
                          throws java.io.IOException

Create a compression input stream that reads the decompressed bytes from the given stream.

Parameters:

in - The input stream to be compressed.

Throws:

java.io.IOException - raised on errors performing I/O.

Method Detail

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException

getIOStatistics

public IOStatistics getIOStatistics()

Return any IOStatistics provided by the underlying stream.

Specified by:

getIOStatistics in interface IOStatisticsSource

Returns:

IO stats from the inner stream.

read

public abstract int read(byte[] b,
                         int off,
                         int len)
                  throws java.io.IOException

Read bytes from the stream. Made abstract to prevent leakage to underlying stream.

Overrides:

read in class java.io.InputStream

Throws:

java.io.IOException

resetState

public abstract void resetState()
                         throws java.io.IOException

Reset the decompressor to its initial state and discard any buffered data, as the underlying stream may have been repositioned.

Throws:

java.io.IOException - raised on errors performing I/O.

getPos

public long getPos()
            throws java.io.IOException

This method returns the current position in the stream.

Specified by:

getPos in interface Seekable

Returns:

Current position in stream as a long

Throws:

java.io.IOException - raised on errors performing I/O.

seek

public void seek(long pos)
          throws java.lang.UnsupportedOperationException

This method is current not supported.

Specified by:

seek in interface Seekable

Parameters:

pos - offset from the start of the file.

Throws:

java.lang.UnsupportedOperationException - Unsupported Operation Exception.

seekToNewSource

public boolean seekToNewSource(long targetPos)
                        throws java.lang.UnsupportedOperationException

This method is current not supported.

Specified by:

seekToNewSource in interface Seekable

Parameters:

targetPos - target position.

Returns:

true if found a new source, false otherwise.

Throws:

java.lang.UnsupportedOperationException - Unsupported Operation Exception.