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Hypertable::BlockCompressionCodecSnappy Class Reference

Block compressor that uses the SNAPPY algorithm. More...

#include <BlockCompressionCodecSnappy.h>

Inheritance diagram for Hypertable::BlockCompressionCodecSnappy:
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Collaboration diagram for Hypertable::BlockCompressionCodecSnappy:
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Public Member Functions

 BlockCompressionCodecSnappy (const Args &args)
 Constructor. More...
 
virtual ~BlockCompressionCodecSnappy ()
 Destructor. More...
 
virtual void deflate (const DynamicBuffer &input, DynamicBuffer &output, BlockHeader &header, size_t reserve=0)
 Compresses a buffer using the SNAPPY algorithm. More...
 
virtual void inflate (const DynamicBuffer &input, DynamicBuffer &output, BlockHeader &header)
 Decompresses a buffer compressed with the SNAPPY algorithm. More...
 
virtual int get_type ()
 Returns enum value representing compression type SNAPPY. More...
 
- Public Member Functions inherited from Hypertable::BlockCompressionCodec
virtual ~BlockCompressionCodec ()
 Destructor. More...
 
virtual void set_args (const Args &args)
 Sets arguments to control compression behavior. More...
 

Additional Inherited Members

- Public Types inherited from Hypertable::BlockCompressionCodec
enum  Type {
  UNKNOWN =-1, NONE =0, BMZ =1, ZLIB =2,
  LZO =3, QUICKLZ =4, SNAPPY =5, COMPRESSION_TYPE_LIMIT =6
}
 Enumeration for compression type. More...
 
typedef std::vector< StringArgs
 Compression codec argument vector. More...
 
- Static Public Member Functions inherited from Hypertable::BlockCompressionCodec
static const char * get_compressor_name (uint16_t algo)
 Returns string mnemonic for compression type. More...
 

Detailed Description

Block compressor that uses the SNAPPY algorithm.

This class provides a way to compress and decompress blocks of data using the snappy algorithm, a general purpose compression algorithm that provides good compression and decompression speed at the expense of compression size.

Definition at line 44 of file BlockCompressionCodecSnappy.h.

Constructor & Destructor Documentation

Hypertable::BlockCompressionCodecSnappy::BlockCompressionCodecSnappy ( const Args args)
inline

Constructor.

This constructor passes args to the default implementation of set_args() since it does not support any arguments.

Parameters
argsArguments to control compression behavior
Exceptions
ExceptionCode set to Error::BLOCK_COMPRESSOR_INVALID_ARG

Definition at line 53 of file BlockCompressionCodecSnappy.h.

virtual Hypertable::BlockCompressionCodecSnappy::~BlockCompressionCodecSnappy ( )
inlinevirtual

Destructor.

Definition at line 56 of file BlockCompressionCodecSnappy.h.

Member Function Documentation

void BlockCompressionCodecSnappy::deflate ( const DynamicBuffer input,
DynamicBuffer output,
BlockHeader header,
size_t  reserve = 0 
)
virtual

Compresses a buffer using the SNAPPY algorithm.

This method reserves enough space in output to hold the serialized header followed by the compressed input followed by reserve bytes. If the resulting compressed buffer is larger than the input buffer, then the input buffer is copied directly to the output buffer and the compression type is set to BlockCompressionCodec::NONE. Before serailizing header, the data_length, data_zlength, data_checksum, and compression_type fields are set appropriately. The output buffer is formatted as follows:

headercompressed datareserve
Parameters
inputInput buffer
outputOutput buffer
headerBlock header populated by function
reserveAdditional space to reserve at end of output buffer

Implements Hypertable::BlockCompressionCodec.

Definition at line 38 of file BlockCompressionCodecSnappy.cc.

virtual int Hypertable::BlockCompressionCodecSnappy::get_type ( )
inlinevirtual

Returns enum value representing compression type SNAPPY.

Returns the enum value SNAPPY

See also
BlockCompressionCodec::SNAPPY
Returns
Compression type (SNAPPY)

Implements Hypertable::BlockCompressionCodec.

Definition at line 93 of file BlockCompressionCodecSnappy.h.

void BlockCompressionCodecSnappy::inflate ( const DynamicBuffer input,
DynamicBuffer output,
BlockHeader header 
)
virtual

Decompresses a buffer compressed with the SNAPPY algorithm.

See also
deflate() for description of input buffer format
Parameters
inputInput buffer
outputOutput buffer
headerBlock header

Implements Hypertable::BlockCompressionCodec.

Definition at line 70 of file BlockCompressionCodecSnappy.cc.


The documentation for this class was generated from the following files: