bitarr.h File Reference

An implementation bit array - memory efficient storage for digit int and float data. More...

#include <string.h>
#include <sphinxbase/prim_type.h>
#include <sphinxbase/sphinxbase_export.h>

Go to the source code of this file.

Data Structures
struct	bitarr_mask_s
	Structure that specifies bits required to efficiently store certain data. More...
struct	bitarr_address_s
	Structure that stores address of certain value in bit array. More...

Typedefs
typedef struct bitarr_mask_s	bitarr_mask_t
	Structure that specifies bits required to efficiently store certain data.
typedef struct bitarr_address_s	bitarr_address_t
	Structure that stores address of certain value in bit array.

Functions
SPHINXBASE_EXPORT uint64	bitarr_read_int57 (bitarr_address_t address, uint8 length, uint64 mask)
	Read uint64 value from bit array. More...
SPHINXBASE_EXPORT void	bitarr_write_int57 (bitarr_address_t address, uint8 length, uint64 value)
	Write specified value into bit array. More...
SPHINXBASE_EXPORT uint32	bitarr_read_int25 (bitarr_address_t address, uint8 length, uint32 mask)
	Read uint32 value from bit array. More...
SPHINXBASE_EXPORT void	bitarr_write_int25 (bitarr_address_t address, uint8 length, uint32 value)
	Write specified value into bit array. More...
SPHINXBASE_EXPORT void	bitarr_mask_from_max (bitarr_mask_t *bit_mask, uint32 max_value)
	Fills mask for certain int range according to provided max value. More...
SPHINXBASE_EXPORT uint8	bitarr_required_bits (uint32 max_value)
	Computes amount of bits required ti store integers upto value provided. More...

Detailed Description

An implementation bit array - memory efficient storage for digit int and float data.

Implementation of basic operations of read/write digits consuming as little space as possible.

Definition in file bitarr.h.

Function Documentation

SPHINXBASE_EXPORT void bitarr_mask_from_max	(	bitarr_mask_t *	bit_mask,
		uint32	max_value
	)

Fills mask for certain int range according to provided max value.

Parameters

bit_mask	mask that is filled
max_value	bigest integer that is going to be stored using this mask

Definition at line 125 of file bitarr.c.

References bitarr_required_bits().

SPHINXBASE_EXPORT uint32 bitarr_read_int25	(	bitarr_address_t	address,
		uint8	length,
		uint32	mask
	)

Read uint32 value from bit array.

Assumes mask == (1 << length) - 1 where length <= 25

Parameters

address	to read from
length	number of bits for value
mask	of read value

Returns

uint32 value that was read

Definition at line 100 of file bitarr.c.

SPHINXBASE_EXPORT uint64 bitarr_read_int57	(	bitarr_address_t	address,
		uint8	length,
		uint64	mask
	)

Read uint64 value from bit array.

Assumes mask == (1 << length) - 1 where length <= 57

Parameters

address	to read from
length	number of bits for value
mask	of read value

Returns

uint64 value that was read

Definition at line 82 of file bitarr.c.

SPHINXBASE_EXPORT uint8 bitarr_required_bits

(

uint32

max_value

)

Computes amount of bits required ti store integers upto value provided.

Parameters

max_value

bigest integer that going to be stored using this amount of bits

Returns

amount of bits required to store integers from range with maximum provided

Definition at line 131 of file bitarr.c.

Referenced by bitarr_mask_from_max().

SPHINXBASE_EXPORT void bitarr_write_int25	(	bitarr_address_t	address,
		uint8	length,
		uint32	value
	)

Write specified value into bit array.

Assumes value < (1 << length) and length <= 25. Assumes the memory is zero initially.

Parameters

address	in bit array ti write to
length	amount of active bytes in value to write
value	integer to write

Definition at line 112 of file bitarr.c.

SPHINXBASE_EXPORT void bitarr_write_int57	(	bitarr_address_t	address,
		uint8	length,
		uint64	value
	)

Write specified value into bit array.

Assumes value < (1 << length) and length <= 57. Assumes the memory is zero initially.

Parameters

address	to write to
length	amount of active bytes in value to write
value	integer to write

Definition at line 87 of file bitarr.c.