org.apache.hadoop.io.compress.zlib

类 ZlibDecompressor

java.lang.Object

org.apache.hadoop.io.compress.zlib.ZlibDecompressor

所有已实现的接口:

Decompressor

public class ZlibDecompressor
extends Object
implements Decompressor

A Decompressor based on the popular zlib compression algorithm. http://www.zlib.net/

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	ZlibDecompressor.CompressionHeader The headers to detect from compressed data.

构造器概要

构造器

构造器和说明
ZlibDecompressor()
ZlibDecompressor(ZlibDecompressor.CompressionHeader header, int directBufferSize) Creates a new decompressor.

方法概要

方法

限定符和类型	方法和说明
int	decompress(byte[] b, int off, int len) Fills specified buffer with uncompressed data.
void	end() Closes the decompressor and discards any unprocessed input.
protected void	finalize()
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.

从类继承的方法 java.lang.Object

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

构造器详细资料

ZlibDecompressor

public ZlibDecompressor(ZlibDecompressor.CompressionHeader header,
                int directBufferSize)

Creates a new decompressor.

ZlibDecompressor

public ZlibDecompressor()

方法详细资料

setInput

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

从接口复制的说明: 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.)

指定者:

setInput 在接口中 Decompressor

参数:

b - Input data

off - Start offset

len - Length

setDictionary

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

从接口复制的说明: Decompressor

Sets preset dictionary for compression. A preset dictionary is used when the history buffer can be predetermined.

指定者:

setDictionary 在接口中 Decompressor

参数:

b - Dictionary data bytes

off - Start offset

len - Length

needsInput

public boolean needsInput()

从接口复制的说明: Decompressor

Returns true if the input data buffer is empty and Decompressor.setInput(byte[], int, int) should be called to provide more input.

指定者:

needsInput 在接口中 Decompressor

返回:

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()

从接口复制的说明: Decompressor

Returns true if a preset dictionary is needed for decompression.

指定者:

needsDictionary 在接口中 Decompressor

返回:

true if a preset dictionary is needed for decompression

finished

public boolean finished()

从接口复制的说明: Decompressor

Returns true if the end of the decompressed data output stream has been reached.

指定者:

finished 在接口中 Decompressor

返回:

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

从接口复制的说明: 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.

指定者:

decompress 在接口中 Decompressor

参数:

b - Buffer for the compressed data

off - Start offset of the data

len - Size of the buffer

返回:

The actual number of bytes of compressed data.

抛出:

IOException

getBytesWritten

public long getBytesWritten()

Returns the total number of uncompressed bytes output so far.

返回:

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.

返回:

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.

指定者:

getRemaining 在接口中 Decompressor

返回:

the total (non-negative) number of unprocessed bytes in input

reset

public void reset()

Resets everything including the input buffers (user and direct).

指定者:

reset 在接口中 Decompressor

end

public void end()

从接口复制的说明: Decompressor

Closes the decompressor and discards any unprocessed input.

指定者:

end 在接口中 Decompressor

finalize

protected void finalize()

覆盖:

finalize 在类中 Object