Package org.apache.hadoop.hbase.io.compress

Class GzipByteBuffDecompressor

java.lang.Object

org.apache.hadoop.hbase.io.compress.GzipByteBuffDecompressor

All Implemented Interfaces:

Closeable, AutoCloseable, ByteBuffDecompressor

@Private
public class GzipByteBuffDecompressor
extends Object
implements ByteBuffDecompressor

Glue for ByteBuffDecompressor on top of Hadoop's native ZlibDecompressor.ZlibDirectDecompressor. Only direct-to-direct decompression is supported, which is zero-copy; callers with on-heap buffers fall back to the stream path.

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	allowByteBuffDecompression
private final org.apache.hadoop.io.compress.zlib.ZlibDecompressor.ZlibDirectDecompressor	decompressor
private static final int	GZIP_HEADER_LENGTH
private static final int	GZIP_TRAILER_LENGTH

Constructor Summary

Constructors

Constructor	Description
GzipByteBuffDecompressor(boolean nativeZlibLoaded)

Method Summary

Modifier and Type	Method	Description
boolean	canDecompress(ByteBuff output, ByteBuff input)	Signals of these two particular ByteBuffs are compatible with this decompressor.
void	close()
int	decompress(ByteBuff output, ByteBuff input, int inputLen)	Fills the ouput buffer with uncompressed data.
private int	decompressOffHeap(ByteBuffer nioInput, ByteBuffer nioOutput, int inputLen)
void	reinit(Compression.HFileDecompressionContext newHFileDecompressionContext)	Call before every use of ByteBuffDecompressor.canDecompress(ByteBuff, ByteBuff) and ByteBuffDecompressor.decompress(ByteBuff, ByteBuff, int) to reinitialize the decompressor with settings from the HFileInfo.

Methods inherited from class java.lang.Object

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

Field Details

GZIP_HEADER_LENGTH

private static final int GZIP_HEADER_LENGTH

See Also:

• Constant Field Values

GZIP_TRAILER_LENGTH

private static final int GZIP_TRAILER_LENGTH

See Also:

• Constant Field Values

decompressor

@Nullable
private final org.apache.hadoop.io.compress.zlib.ZlibDecompressor.ZlibDirectDecompressor decompressor

allowByteBuffDecompression

private boolean allowByteBuffDecompression

Constructor Details

GzipByteBuffDecompressor

GzipByteBuffDecompressor(boolean nativeZlibLoaded)

Method Details

canDecompress

public boolean canDecompress(ByteBuff output,
 ByteBuff input)

Description copied from interface: ByteBuffDecompressor

Signals of these two particular ByteBuffs are compatible with this decompressor. ByteBuffs can have one or multiple backing buffers, and each of these may be stored in heap or direct memory. Different ByteBuffDecompressors may be able to handle different combinations of these, so always check.

Specified by:

canDecompress in interface ByteBuffDecompressor

decompress

public int decompress(ByteBuff output,
 ByteBuff input,
 int inputLen)
               throws IOException

Description copied from interface: ByteBuffDecompressor

Fills the ouput buffer with uncompressed data. Always call ByteBuffDecompressor.canDecompress(ByteBuff, ByteBuff) first to check if this decompressor can handle your input and output buffers.

Specified by:

decompress in interface ByteBuffDecompressor

Returns:

The actual number of bytes of uncompressed data.

Throws:

IOException

decompressOffHeap

private int decompressOffHeap(ByteBuffer nioInput,
 ByteBuffer nioOutput,
 int inputLen)
                       throws IOException

Throws:

IOException

reinit

public void reinit(@Nullable
 Compression.HFileDecompressionContext newHFileDecompressionContext)

Description copied from interface: ByteBuffDecompressor

Call before every use of ByteBuffDecompressor.canDecompress(ByteBuff, ByteBuff) and ByteBuffDecompressor.decompress(ByteBuff, ByteBuff, int) to reinitialize the decompressor with settings from the HFileInfo. This can matter because ByteBuffDecompressors are reused many times.

Specified by:

reinit in interface ByteBuffDecompressor

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable