bitwise.hpp File Reference

Contains common functions related to bitwise operations. More...

#include "exceptions.hpp"
#include <stddef.h>
#include <stdint.h>

Include dependency graph for bitwise.hpp:

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Functions
__JAFFAR_COMMON_INLINE__ void	jaffarCommon::bitwise::bitcopy (void *dstBufferPtr, const size_t dstBufferSize, const size_t dstBufferOffset, const void *srcBufferPtr, const size_t srcBufferSize, const size_t srcBufferOffset, const size_t count, const size_t elementBitSize)
__JAFFAR_COMMON_INLINE__ size_t	jaffarCommon::bitwise::getEncodingBitsForElementCount (const size_t elementCount)
__JAFFAR_COMMON_INLINE__ size_t	jaffarCommon::bitwise::getByteStorageForBitCount (const size_t bitCount)
__JAFFAR_COMMON_INLINE__ void	jaffarCommon::bitwise::setBitValue (void *dst, const size_t idx, const bool value)
__JAFFAR_COMMON_INLINE__ bool	jaffarCommon::bitwise::getBitValue (const void *src, const size_t idx)
__JAFFAR_COMMON_INLINE__ bool	jaffarCommon::bitwise::getBitFlag (const uint8_t value, const uint8_t idx)

Variables
constexpr uint8_t	jaffarCommon::bitwise::bitMaskTable [8] = {0b00000001, 0b00000010, 0b00000100, 0b00001000, 0b00010000, 0b00100000, 0b01000000, 0b10000000}
constexpr uint8_t	jaffarCommon::bitwise::bitNotMaskTable [8] = {0b11111110, 0b11111101, 0b11111011, 0b11110111, 0b11101111, 0b11011111, 0b10111111, 0b01111111}

Detailed Description

Contains common functions related to bitwise operations.

Function Documentation

bitcopy()

__JAFFAR_COMMON_INLINE__ void jaffarCommon::bitwise::bitcopy	(	void *	dstBufferPtr,
		const size_t	dstBufferSize,
		const size_t	dstBufferOffset,
		const void *	srcBufferPtr,
		const size_t	srcBufferSize,
		const size_t	srcBufferOffset,
		const size_t	count,
		const size_t	elementBitSize
	)

This function copies a contiguous set of k elements of size n bits from a source buffer plus an offset s_off * n to a destination buffer plus an offset of d_off * n

Parameters

[out]	dstBufferPtr	The destination buffer
[in]	dstBufferSize	The size of the destination buffer (expressed in bytes). This is necessary to guard possible overflows before they happen
[in]	dstBufferOffset	The size of the destination buffer (expressed in elements)
[in]	srcBufferPtr	The source buffer
[in]	srcBufferSize	The size of the source buffer (expressed in bytes). This is necessary to guard possible overflows before they happen
[in]	srcBufferOffset	The size of the source buffer (expressed in elements)
[in]	count	The number of elements to copy
[in]	elementBitSize	The size of each element (expressed in bits)

getBitFlag()

__JAFFAR_COMMON_INLINE__ bool jaffarCommon::bitwise::getBitFlag	(	const uint8_t	value,
		const uint8_t	idx
	)

Gets the value of a given bit inside an 8-bit word

Parameters

[in]	value	The 8-bit word
[in]	idx	Index (position) of the bit to get inside the value (only accepted values: 0-7)

Returns

Whether the specified bit was true or false

getBitValue()

__JAFFAR_COMMON_INLINE__ bool jaffarCommon::bitwise::getBitValue	(	const void *	src,
		const size_t	idx
	)

Gets the value of a given bit inside a buffer of any size

Parameters

[in]	src	The buffer containing the bit to set
[in]	idx	Index (position) of the bit to get inside value

Returns

Whether the specified bit was true or false

getByteStorageForBitCount()

__JAFFAR_COMMON_INLINE__ size_t jaffarCommon::bitwise::getByteStorageForBitCount

(

const size_t

bitCount

)

Calculates how many bytes if needed to store a certain amount of bits

Parameters

[in]

bitCount

The number of bits to store

Returns

The bytes required to store them

getEncodingBitsForElementCount()

__JAFFAR_COMMON_INLINE__ size_t jaffarCommon::bitwise::getEncodingBitsForElementCount

(

const size_t

elementCount

)

Calculates the number of bits necessary encode a number of distinct elements.

Parameters

[in]

elementCount

The number of elements to encode

Returns

The number of bits required. Examples: (Element Count, Bits Required) => (0,0), (1,1), (2,1), (3,2), (4,2), (5,3), (6,3), (7,3), (8,3), (9,4)

Note

A single element is given 1 bit (not 0): downstream storage (e.g. bit-packed buffers and bitcopy) requires a positive element bit size.

setBitValue()

__JAFFAR_COMMON_INLINE__ void jaffarCommon::bitwise::setBitValue	(	void *	dst,
		const size_t	idx,
		const bool	value
	)

Sets to value for a given bit inside a buffer of any size

Parameters

[out]	dst	The buffer containing the bit to set
[in]	idx	Index (position) of the bit to set inside the buffer
[in]	value	Value to set (true or false)

Variable Documentation

bitMaskTable

constexpr uint8_t jaffarCommon::bitwise::bitMaskTable[8] = {0b00000001, 0b00000010, 0b00000100, 0b00001000, 0b00010000, 0b00100000, 0b01000000, 0b10000000}

inlineconstexpr

A reference table that maps a given bit index to its corresponding bit map (one in the indicates position, zeros in all other bits)

bitNotMaskTable

constexpr uint8_t jaffarCommon::bitwise::bitNotMaskTable[8] = {0b11111110, 0b11111101, 0b11111011, 0b11110111, 0b11101111, 0b11011111, 0b10111111, 0b01111111}

inlineconstexpr

A reference table that maps a given bit index to its corresponding negated bit map (zero in the indicates position, ones in all other bits)