Fletcher32

Fletcher32 checksum algorithm. More...

Detailed Description

Fletcher32 checksum algorithm.

Files
file	fletcher32.h

Data Structures
struct	fletcher32_ctx_t
	Fletcher's 32 bit checksum context struct. More...

Functions
uint32_t	fletcher32 (const uint16_t *buf, size_t words)
	Fletcher's 32 bit checksum.
void	fletcher32_init (fletcher32_ctx_t *ctx)
	Initialize a fletcher32 context.
void	fletcher32_update (fletcher32_ctx_t *ctx, const void *data, size_t words)
	Incrementally update the fletcher32 context with new data.
uint32_t	fletcher32_finish (fletcher32_ctx_t *ctx)
	Finalize the checksum operation and return the checksum.

Function Documentation

fletcher32()

uint32_t fletcher32	(	const uint16_t *	buf,
		size_t	words
	)

Fletcher's 32 bit checksum.

found on http://en.wikipedia.org/w/index.php?title=Fletcher%27s_checksum&oldid=661273016#Optimizations

Note

the returned sum is never 0

pay attention to the words parameter buffer containing 16 bit words, not bytes.

Parameters

buf	input buffer to hash
words	length of buffer, in 16 bit words

Returns

32 bit sized hash in the interval [1..2^32]

fletcher32_finish()

uint32_t fletcher32_finish

(

fletcher32_ctx_t *

ctx

)

Finalize the checksum operation and return the checksum.

Parameters

[in]

ctx

fletcher32 context

Returns

32 bit sized hash in the interval [1..2^32]

fletcher32_init()

void fletcher32_init

(

fletcher32_ctx_t *

ctx

)

Initialize a fletcher32 context.

Multi-part version of fletcher32.

Parameters

[in]

ctx

fletcher32 context to initialize

fletcher32_update()

void fletcher32_update	(	fletcher32_ctx_t *	ctx,
		const void *	data,
		size_t	words
	)

Incrementally update the fletcher32 context with new data.

Can be an arbitrary amount of times with new data to checksum.

Note

words is the number of 16 bit words in the buffer

data should contain an integer number of 16 bit words

Parameters

[in]	ctx	fletcher32 context
[in]	data	Data to add to the context
[in]	words	Length of the data in 16 bit words