Bit vectors

Files
file	bitvec.h
	Osmocom bit vector abstraction.
file	bitvec.c
	Osmocom bit vector abstraction.

Data Structures
struct	bitvec
	structure describing a bit vector More...

Macros
#define	BITNUM_FROM_COMP(byte, bit)   ((byte*8)+bit)

Enumerations
enum	bit_value { ZERO = 0, ONE = 1, L = 2, H = 3 }
	A single GSM bit. More...

Functions
enum bit_value	bitvec_get_bit_pos (const struct bitvec *bv, unsigned int bitnr)
	check if the bit is 0 or 1 for a given position inside a bitvec More...
enum bit_value	bitvec_get_bit_pos_high (const struct bitvec *bv, unsigned int bitnr)
	check if the bit is L or H for a given position inside a bitvec More...
unsigned int	bitvec_get_nth_set_bit (const struct bitvec *bv, unsigned int n)
	get the Nth set bit inside the bit vector More...
int	bitvec_set_bit_pos (struct bitvec *bv, unsigned int bitnr, enum bit_value bit)
	set a bit at given position in a bit vector More...
int	bitvec_set_bit (struct bitvec *bv, enum bit_value bit)
	set the next bit inside a bitvec More...
int	bitvec_get_bit_high (struct bitvec *bv)
	get the next bit (low/high) inside a bitvec
int	bitvec_set_bits (struct bitvec *bv, enum bit_value *bits, int count)
	set multiple bits (based on array of bitvals) at current pos More...
int	bitvec_set_uint (struct bitvec *bv, unsigned int ui, int num_bits)
	set multiple bits (based on numeric value) at current pos
int	bitvec_get_uint (struct bitvec *bv, int num_bits)
	get multiple bits (based on numeric value) from current pos
int	bitvec_find_bit_pos (const struct bitvec *bv, unsigned int n, enum bit_value val)
	find first bit set in bit vector
int	bitvec_spare_padding (struct bitvec *bv, unsigned int up_to_bit)
	pad all remaining bits up to num_bits
static unsigned int	bytenum_from_bitnum (unsigned int bitnum)
static uint8_t	bitval2mask (enum bit_value bit, uint8_t bitnum)

Detailed Description

Enumeration Type Documentation

enum bit_value

A single GSM bit.

In GSM mac blocks, every bit can be 0 or 1, or L or H. L/H are defined relative to the 0x2b padding pattern

Enumerator
ZERO	A zero (0) bit.
ONE	A one (1) bit.
L	A CSN.1 "L" bit.
H	A CSN.1 "H" bit.

Function Documentation

enum bit_value bitvec_get_bit_pos	(	const struct bitvec *	bv,
		unsigned int	bitnr
	)

check if the bit is 0 or 1 for a given position inside a bitvec

Parameters

[in]	bv	the bit vector on which to check
[in]	bitnr	the bit number inside the bit vector to check

Returns

References data, data_len, ONE, and ZERO.

Referenced by bitvec_find_bit_pos(), bitvec_get_nth_set_bit(), and bitvec_get_uint().

enum bit_value bitvec_get_bit_pos_high	(	const struct bitvec *	bv,
		unsigned int	bitnr
	)

check if the bit is L or H for a given position inside a bitvec

Parameters

[in]	bv	the bit vector on which to check
[in]	bitnr	the bit number inside the bit vector to check

References data, data_len, H, and L.

Referenced by bitvec_get_bit_high().

unsigned int bitvec_get_nth_set_bit	(	const struct bitvec *	bv,
		unsigned int	n
	)

get the Nth set bit inside the bit vector

Parameters

[in]	bv	the bit vector to use
[in]	n	the bit number to get

Returns

the bit number (offset) of the Nth set bit in bv

References bitvec_get_bit_pos(), data_len, and ONE.

int bitvec_set_bit	(	struct bitvec *	bv,
		enum bit_value	bit
	)

set the next bit inside a bitvec

Parameters

[in]	bv	bit vector to be used
[in]	bit	value of the bit to be set

References bitvec_set_bit_pos(), and cur_bit.

Referenced by bitvec_set_bits(), bitvec_set_uint(), and bitvec_spare_padding().

int bitvec_set_bit_pos	(	struct bitvec *	bv,
		unsigned int	bitnr,
		enum bit_value	bit
	)

set a bit at given position in a bit vector

Parameters

[in]	bv	bit vector on which to operate
[in]	bitnr	number of bit to be set
[in]	bit	value to which the bit is to be set

References data, data_len, and ONE.

Referenced by bitvec_set_bit().

int bitvec_set_bits	(	struct bitvec *	bv,
		enum bit_value *	bits,
		int	count
	)

set multiple bits (based on array of bitvals) at current pos

Parameters

[in]	bv	bit vector
[in]	bits	array of bit_value
[in]	count	number of bits to set

References bitvec_set_bit().