org.apache.hadoop.hbase.io.encoding
Interface HFileBlockDecodingContext

All Known Implementing Classes:

HFileBlockDefaultDecodingContext

public interface HFileBlockDecodingContext

A decoding context that is created by a reader's encoder, and is shared across the reader's all read operations.

See Also:

for encoding

Method Summary

Compression.Algorithm	getCompression()
void	prepareDecoding(int onDiskSizeWithoutHeader, int uncompressedSizeWithoutHeader, ByteBuffer blockBufferWithoutHeader, byte[] onDiskBlock, int offset) Perform all actions that need to be done before the encoder's real decoding process.

Method Detail

getCompression

Compression.Algorithm getCompression()

Returns:

the compression algorithm used by this decoding context

prepareDecoding

void prepareDecoding(int onDiskSizeWithoutHeader,
                     int uncompressedSizeWithoutHeader,
                     ByteBuffer blockBufferWithoutHeader,
                     byte[] onDiskBlock,
                     int offset)
                     throws IOException

Perform all actions that need to be done before the encoder's real decoding process. Decompression needs to be done if getCompression() returns a valid compression algorithm.

Parameters:

onDiskSizeWithoutHeader - numBytes after block and encoding headers

uncompressedSizeWithoutHeader - numBytes without header required to store the block after decompressing (not decoding)

blockBufferWithoutHeader - ByteBuffer pointed after the header but before the data

onDiskBlock - on disk bytes to be decoded

offset - data start offset in onDiskBlock

Throws:

IOException