Fixed-length binary vector operations. More...

Data Structures
struct	bitvector
	Fixed-length bit vector structure. More...

Functions
int	bitvector_init (bitvector_t *bv, size_t num_bits)
	Initialize a bit vector with specified length.

void	bitvector_zero (bitvector_t *bv)
	Set all bits to zero.

void	bitvector_copy (bitvector_t dest, const bitvector_t src)
	Copy bit vector contents.

static int	bitvector_get_bit (const bitvector_t *bv, size_t pos)
	Get bit value at position (inline for performance).

static void	bitvector_set_bit (bitvector_t *bv, size_t pos, int value)
	Set bit value at position (inline for performance).

void	bitvector_xor (bitvector_t result, const bitvector_t a, const bitvector_t *b)
	Bitwise XOR operation.

void	bitvector_or (bitvector_t result, const bitvector_t a, const bitvector_t *b)
	Bitwise OR operation.

void	bitvector_and (bitvector_t result, const bitvector_t a, const bitvector_t *b)
	Bitwise AND operation.

void	bitvector_not (bitvector_t result, const bitvector_t a)
	Bitwise NOT operation.

void	bitvector_left_shift (bitvector_t result, const bitvector_t a)
	Left shift by one bit.

void	bitvector_reverse (bitvector_t result, const bitvector_t a)
	Reverse bit order.

size_t	bitvector_hamming_weight (const bitvector_t *bv)
	Count number of set bits (Hamming weight).

int	bitvector_equals (const bitvector_t a, const bitvector_t b)
	Compare two bit vectors for equality.

int	bitvector_from_bytes (bitvector_t bv, const uint8_t data, size_t num_bytes)
	Load bit vector from byte array.

int	bitvector_to_bytes (const bitvector_t bv, uint8_t data, size_t num_bytes)
	Store bit vector to byte array.

Detailed Description

Fixed-length binary vector operations.

Bit vectors are the fundamental data structure for CCSDS 124.0-B-1 compression. They represent fixed-length binary sequences with operations for bitwise logic, shifting, and counting.

Note: Uses 32-bit words with big-endian byte packing to match ESA reference.

Function Documentation

◆ bitvector_and()

void bitvector_and	(	bitvector_t *	result,
		const bitvector_t *	a,
		const bitvector_t *	b
	)

Bitwise AND operation.

Parameters

[out]	result	Result vector (result = a AND b)
[in]	a	First operand
[in]	b	Second operand

Definition at line 127 of file bitvector.c.

References data, length, and num_words.

◆ bitvector_copy()

void bitvector_copy	(	bitvector_t *	dest,
		const bitvector_t *	src
	)

Copy bit vector contents.

Parameters

[out]	dest	Destination bit vector
[in]	src	Source bit vector

Definition at line 72 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_compress_packet(), ccsds124_compressor_init(), ccsds124_compressor_reset(), ccsds124_compute_robustness_window(), ccsds124_decompress_packet_internal(), ccsds124_decompressor_init(), and ccsds124_decompressor_reset().

◆ bitvector_equals()

int bitvector_equals	(	const bitvector_t *	a,
		const bitvector_t *	b
	)

Compare two bit vectors for equality.

Parameters

[in]	a	First bit vector
[in]	b	Second bit vector

Returns: 1 if equal, 0 if different

Definition at line 247 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_decompress_packet_internal().

◆ bitvector_from_bytes()

int bitvector_from_bytes	(	bitvector_t *	bv,
		const uint8_t *	data,
		size_t	num_bytes
	)

Load bit vector from byte array.

Loads bytes in big-endian order (first byte contains MSB bits).

Parameters

[out]	bv	Bit vector to load into
[in]	data	Source byte array
[in]	num_bytes	Number of bytes to load

Returns: CCSDS124_OK on success

Definition at line 269 of file bitvector.c.

References CCSDS124_ERROR_INVALID_ARG, CCSDS124_ERROR_OVERFLOW, CCSDS124_OK, data, length, and num_words.

Referenced by ccsds124_compress().

◆ bitvector_get_bit()

static int bitvector_get_bit	(	const bitvector_t *	bv,
		size_t	pos
	)

inlinestatic

Get bit value at position (inline for performance).

Parameters

[in]	bv	Bit vector
[in]	pos	Bit position (0 = LSB, length-1 = MSB)

Returns: Bit value (0 or 1)

Definition at line 169 of file ccsds124.h.

References data.

Referenced by bitbuffer_append_bitvector(), bitvector_reverse(), and ccsds124_decompress_packet_internal().

◆ bitvector_hamming_weight()

size_t bitvector_hamming_weight ( const bitvector_t * bv )

Count number of set bits (Hamming weight).

Parameters

[in] bv Bit vector

Returns: Number of bits set to 1

Definition at line 222 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_bit_insert(), ccsds124_compress_packet(), ccsds124_compute_effective_robustness(), and ccsds124_decompress_packet_internal().

◆ bitvector_init()

int bitvector_init	(	bitvector_t *	bv,
		size_t	num_bits
	)

Initialize a bit vector with specified length.

Allocates internal storage and sets all bits to zero.

Parameters

[out]	bv	Bit vector to initialize (caller-allocated)
[in]	num_bits	Number of bits (1 to CCSDS124_MAX_PACKET_LENGTH)

Returns: CCSDS124_OK on success, CCSDS124_ERROR_INVALID_ARG if out of range

Definition at line 44 of file bitvector.c.

References CCSDS124_ERROR_INVALID_ARG, CCSDS124_MAX_PACKET_LENGTH, CCSDS124_OK, data, length, and num_words.

Referenced by ccsds124_compress(), ccsds124_compressor_init(), ccsds124_decompress_packet_internal(), ccsds124_decompressor_init(), ccsds124_rle_decode(), ccsds124_update_build(), and ccsds124_update_mask().

◆ bitvector_left_shift()

void bitvector_left_shift	(	bitvector_t *	result,
		const bitvector_t *	a
	)

Left shift by one bit.

Shifts all bits left, inserting 0 at LSB position.

Parameters

[out]	result	Result vector (result = a << 1)
[in]	a	Operand

Definition at line 178 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_compress_packet().

◆ bitvector_not()

void bitvector_not	(	bitvector_t *	result,
		const bitvector_t *	a
	)

Bitwise NOT operation.

Parameters

[out]	result	Result vector (result = NOT a)
[in]	a	Operand

Definition at line 144 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_compress_packet().

◆ bitvector_or()

void bitvector_or	(	bitvector_t *	result,
		const bitvector_t *	a,
		const bitvector_t *	b
	)

Bitwise OR operation.

Parameters

[out]	result	Result vector (result = a OR b)
[in]	a	First operand
[in]	b	Second operand

Definition at line 110 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_compress_packet(), ccsds124_decompress_packet_internal(), ccsds124_update_build(), and ccsds124_update_mask().

◆ bitvector_reverse()

void bitvector_reverse	(	bitvector_t *	result,
		const bitvector_t *	a
	)

Reverse bit order.

Reverses the bit order: MSB becomes LSB and vice versa. CCSDS notation: result =

Parameters

[out]	result	Result vector with reversed bits
[in]	a	Operand

Definition at line 200 of file bitvector.c.

References bitvector_get_bit(), bitvector_set_bit(), bitvector_zero(), length, and num_words.

◆ bitvector_set_bit()

static void bitvector_set_bit	(	bitvector_t *	bv,
		size_t	pos,
		int	value
	)

inlinestatic

Set bit value at position (inline for performance).

Parameters

[out]	bv	Bit vector to modify
[in]	pos	Bit position (0 = LSB, length-1 = MSB)
[in]	value	Bit value (0 or 1)

Definition at line 188 of file ccsds124.h.

References data.

Referenced by bitvector_reverse(), ccsds124_bit_insert(), ccsds124_decompress_packet_internal(), and ccsds124_rle_decode().

◆ bitvector_to_bytes()

int bitvector_to_bytes	(	const bitvector_t *	bv,
		uint8_t *	data,
		size_t	num_bytes
	)

Store bit vector to byte array.

Stores bytes in big-endian order (first byte contains MSB bits).

Parameters

[in]	bv	Bit vector to store
[out]	data	Destination byte array
[in]	num_bytes	Number of bytes to store

Returns: CCSDS124_OK on success

Definition at line 311 of file bitvector.c.

References CCSDS124_ERROR_INVALID_ARG, CCSDS124_ERROR_UNDERFLOW, CCSDS124_OK, data, length, and num_words.

Referenced by ccsds124_decompress().

◆ bitvector_xor()

void bitvector_xor	(	bitvector_t *	result,
		const bitvector_t *	a,
		const bitvector_t *	b
	)

Bitwise XOR operation.

Parameters

[out]	result	Result vector (result = a XOR b)
[in]	a	First operand
[in]	b	Second operand

Definition at line 93 of file bitvector.c.

References data, length, and num_words.

Referenced by ccsds124_compress_packet(), ccsds124_compute_change(), ccsds124_update_build(), and ccsds124_update_mask().

◆ bitvector_zero()

void bitvector_zero ( bitvector_t * bv )

Set all bits to zero.

Parameters

[out] bv Bit vector to clear

Definition at line 65 of file bitvector.c.

References data, and num_words.

Referenced by bitvector_reverse(), ccsds124_compressor_init(), ccsds124_compressor_reset(), ccsds124_decompress_packet_internal(), ccsds124_decompressor_init(), ccsds124_decompressor_reset(), ccsds124_rle_decode(), and ccsds124_update_build().

Data Structures

Functions

Detailed Description

Function Documentation

◆ bitvector_and()

◆ bitvector_copy()

◆ bitvector_equals()

◆ bitvector_from_bytes()

◆ bitvector_get_bit()

◆ bitvector_hamming_weight()

◆ bitvector_init()

◆ bitvector_left_shift()

◆ bitvector_not()

◆ bitvector_or()

◆ bitvector_reverse()

◆ bitvector_set_bit()

◆ bitvector_to_bytes()

◆ bitvector_xor()

◆ bitvector_zero()