org.apache.hadoop.io.compress

类 BlockCompressorStream

java.lang.Object

java.io.OutputStream

org.apache.hadoop.io.compress.CompressionOutputStream

org.apache.hadoop.io.compress.CompressorStream

org.apache.hadoop.io.compress.BlockCompressorStream

所有已实现的接口:

Closeable, Flushable, AutoCloseable

public class BlockCompressorStream
extends CompressorStream

A CompressorStream which works with 'block-based' based compression algorithms, as opposed to 'stream-based' compression algorithms. It should be noted that this wrapper does not guarantee that blocks will be sized for the compressor. If the Compressor requires buffering to effect meaningful compression, it is responsible for it.

字段概要

从类继承的字段 org.apache.hadoop.io.compress.CompressorStream

buffer, closed, compressor

从类继承的字段 org.apache.hadoop.io.compress.CompressionOutputStream

out

构造器概要

构造器

构造器和说明
BlockCompressorStream(OutputStream out, Compressor compressor) Create a BlockCompressorStream with given output-stream and compressor.
BlockCompressorStream(OutputStream out, Compressor compressor, int bufferSize, int compressionOverhead) Create a BlockCompressorStream.

方法概要

方法

限定符和类型	方法和说明
protected void	compress()
void	finish() Finishes writing compressed data to the output stream without closing the underlying stream.
void	write(byte[] b, int off, int len) Write the data provided to the compression codec, compressing no more than the buffer size less the compression overhead as specified during construction for each block.

从类继承的方法 org.apache.hadoop.io.compress.CompressorStream

close, resetState, write

从类继承的方法 org.apache.hadoop.io.compress.CompressionOutputStream

flush

从类继承的方法 java.io.OutputStream

write

从类继承的方法 java.lang.Object

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

构造器详细资料

BlockCompressorStream

public BlockCompressorStream(OutputStream out,
                     Compressor compressor,
                     int bufferSize,
                     int compressionOverhead)

Create a BlockCompressorStream.

参数:

out - stream

compressor - compressor to be used

bufferSize - size of buffer

compressionOverhead - maximum 'overhead' of the compression algorithm with given bufferSize

BlockCompressorStream

public BlockCompressorStream(OutputStream out,
                     Compressor compressor)

Create a BlockCompressorStream with given output-stream and compressor. Use default of 512 as bufferSize and compressionOverhead of (1% of bufferSize + 12 bytes) = 18 bytes (zlib algorithm).

参数:

out - stream

compressor - compressor to be used

方法详细资料

write

public void write(byte[] b,
         int off,
         int len)
           throws IOException

Write the data provided to the compression codec, compressing no more than the buffer size less the compression overhead as specified during construction for each block. Each block contains the uncompressed length for the block, followed by one or more length-prefixed blocks of compressed data.

覆盖:

write 在类中 CompressorStream

抛出:

IOException

finish

public void finish()
            throws IOException

从类复制的说明: CompressionOutputStream

Finishes writing compressed data to the output stream without closing the underlying stream.

覆盖:

finish 在类中 CompressorStream

抛出:

IOException

compress

protected void compress()
                 throws IOException

覆盖:

compress 在类中 CompressorStream

抛出:

IOException