zpack.64.c File Reference

LZ77 compression algorithm implementation with simple encoding. More...

#include <zpack.h>
#include <utils.h>

Classes
struct	zpack_match_t
	match structure More...
struct	zpack_hashtable_t
	hashtable structure More...

Macros
#define	ZPACK_MAX_MATCH   (0x3f + 0x40 + 4)
#define	ZPACK_MIN_MATCH   (4)
#define	ZPACK_WINDOW_SIZE   16383
#define	ZPACK_HASHTABLE_SIZE   15
#define	ZPACK_HASHTABLE_MUL   2654435761U
#define	ZPACK_HASHTABLE_PREV_SIZE   16384
#define	ZPACK_NO_POS   (-1)

Typedefs
typedef struct zpack_match_t	zpack_match_t
	match structure
typedef struct zpack_hashtable_t	zpack_hashtable_t
	hashtable structure

Functions
	MODULE ("turnstone.lib")
static uint32_t	zpack_hash4 (uint32_t data)
	hash function
static void	zpack_hash_insert (int64_t pos, uint32_t h, zpack_hashtable_t *ht)
	insert position to hashtable
static zpack_match_t	zpack_find_bestmatch (buffer_t *in, int64_t in_len, int64_t in_p, zpack_hashtable_t *ht)
	find best match
int8_t	zpack_pack (buffer_t *in, buffer_t *out)
	packs data at input buffer to output buffer with z77 algorithm
int8_t	zpack_unpack (buffer_t *in, buffer_t *out)
	unpacks data at input buffer to output buffer with z77 algorithm

Detailed Description

LZ77 compression algorithm implementation with simple encoding.

This work is licensed under TURNSTONE OS Public License. Please read and understand latest version of Licence.

Macro Definition Documentation

ZPACK_HASHTABLE_MUL

#define ZPACK_HASHTABLE_MUL   2654435761U

hash4 multiplier

ZPACK_HASHTABLE_PREV_SIZE

#define ZPACK_HASHTABLE_PREV_SIZE   16384

hashtable previous size, backward item count

ZPACK_HASHTABLE_SIZE

#define ZPACK_HASHTABLE_SIZE   15

hashtable size 2^15

ZPACK_MAX_MATCH

#define ZPACK_MAX_MATCH   (0x3f + 0x40 + 4)

maximum match length

ZPACK_MIN_MATCH

#define ZPACK_MIN_MATCH   (4)

minimum match length

ZPACK_NO_POS

#define ZPACK_NO_POS   (-1)

no position

ZPACK_WINDOW_SIZE

#define ZPACK_WINDOW_SIZE   16383

window size

Function Documentation

MODULE()

MODULE

(

"turnstone.lib"

)

module name

zpack_find_bestmatch()

static zpack_match_t zpack_find_bestmatch ( buffer_t * in, int64_t in_len, int64_t in_p, zpack_hashtable_t * ht )

static

find best match

Parameters

[in]	in	input buffer
[in]	in_len	input buffer length
[in]	in_p	input buffer position
[in]	ht	hashtable

Returns

best match

zpack_hash4()

static uint32_t zpack_hash4 ( uint32_t data )

inlinestatic

hash function

Parameters

[in]

data

data to hash

Returns

hash value

zpack_hash_insert()

static void zpack_hash_insert ( int64_t pos, uint32_t h, zpack_hashtable_t * ht )

inlinestatic

insert position to hashtable

Parameters

[in]	pos	position
[in]	h	hash value
[in]	ht	hashtable

zpack_pack()

int8_t zpack_pack	(	buffer_t *	in,
		buffer_t *	out )

packs data at input buffer to output buffer with z77 algorithm

Parameters

[in]	in	input buffer
[in]	out	output buffer

Returns

size of output buffer

zpack_unpack()

int8_t zpack_unpack	(	buffer_t *	in,
		buffer_t *	out )

unpacks data at input buffer to output buffer with z77 algorithm

Parameters

[in]	in	input buffer
[in]	out	output buffer

Returns

size of output buffer