org.apache.parquet.hadoop.codec

Class NonBlockedDecompressor

java.lang.Object

org.apache.parquet.hadoop.codec.NonBlockedDecompressor

All Implemented Interfaces:

org.apache.hadoop.io.compress.Decompressor

Direct Known Subclasses:

Lz4RawDecompressor, SnappyDecompressor

public abstract class NonBlockedDecompressor
extends Object
implements org.apache.hadoop.io.compress.Decompressor

Constructor Summary

Constructors

Constructor and Description
NonBlockedDecompressor()

Method Summary

Modifier and Type	Method and Description
int	decompress(byte[] buffer, int off, int len) Fills specified buffer with uncompressed data.
void	end()
boolean	finished()
int	getRemaining()
protected abstract int	maxUncompressedLength(ByteBuffer compressed, int maxUncompressedLength) Get the maximum uncompressed byte size of the given compressed input.
boolean	needsDictionary()
boolean	needsInput()
void	reset()
void	setDictionary(byte[] b, int off, int len)
void	setInput(byte[] buffer, int off, int len) Sets input data for decompression.
protected abstract int	uncompress(ByteBuffer compressed, ByteBuffer uncompressed) Uncompress the content in the input buffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

NonBlockedDecompressor

public NonBlockedDecompressor()

Method Detail

decompress

public int decompress(byte[] buffer,
                      int off,
                      int len)
               throws IOException

Fills specified buffer with uncompressed data. Returns actual number of bytes of uncompressed data. A return value of 0 indicates that needsInput() should be called in order to determine if more input data is required.

Specified by:

decompress in interface org.apache.hadoop.io.compress.Decompressor

Parameters:

buffer - Buffer for the compressed data

off - Start offset of the data

len - Size of the buffer

Returns:

The actual number of bytes of uncompressed data.

Throws:

IOException - if reading or decompression fails

setInput

public void setInput(byte[] buffer,
                     int off,
                     int len)

Sets input data for decompression. This should be called if and only if 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 needsInput()--that the buffer may be safely modified. With this requirement, an extra buffer-copy can be avoided.)

Specified by:

setInput in interface org.apache.hadoop.io.compress.Decompressor

Parameters:

buffer - Input data

off - Start offset

len - Length

end

public void end()

Specified by:

end in interface org.apache.hadoop.io.compress.Decompressor

finished

public boolean finished()

Specified by:

finished in interface org.apache.hadoop.io.compress.Decompressor

getRemaining

public int getRemaining()

Specified by:

getRemaining in interface org.apache.hadoop.io.compress.Decompressor

needsInput

public boolean needsInput()

Specified by:

needsInput in interface org.apache.hadoop.io.compress.Decompressor

reset

public void reset()

Specified by:

reset in interface org.apache.hadoop.io.compress.Decompressor

needsDictionary

public boolean needsDictionary()

Specified by:

needsDictionary in interface org.apache.hadoop.io.compress.Decompressor

setDictionary

public void setDictionary(byte[] b,
                          int off,
                          int len)

Specified by:

setDictionary in interface org.apache.hadoop.io.compress.Decompressor

maxUncompressedLength

protected abstract int maxUncompressedLength(ByteBuffer compressed,
                                             int maxUncompressedLength)
                                      throws IOException

Get the maximum uncompressed byte size of the given compressed input. This operation takes O(1) time.

Parameters:

compressed - input data [pos() ... limit())

maxUncompressedLength - maximum length of the uncompressed data

Returns:

uncompressed byte length of the given input

Throws:

IOException

uncompress

protected abstract int uncompress(ByteBuffer compressed,
                                  ByteBuffer uncompressed)
                           throws IOException

Uncompress the content in the input buffer. The result is dumped to the specified output buffer.

Parameters:

compressed - buffer[pos() ... limit()) containing the input data

uncompressed - output of the the uncompressed data. It uses buffer[pos()..]

Returns:

uncompressed data size

Throws:

IOException