lz_decoder.h File Reference

LZ out window. More...

#include "common.h"

Go to the source code of this file.

Data Structures
struct	lzma_dict
struct	lzma_lz_options
struct	lzma_lz_decoder

Macros
#define	LZ_DICT_REPEAT_MAX   288
#define	LZMA_LZ_DECODER_INIT

Functions
lzma_ret	lzma_lz_decoder_init (lzma_next_coder *next, const lzma_allocator *allocator, const lzma_filter_info *filters, lzma_ret(*lz_init)(lzma_lz_decoder *lz, const lzma_allocator *allocator, lzma_vli id, const void *options, lzma_lz_options *lz_options))
uint64_t	lzma_lz_decoder_memusage (size_t dictionary_size)

Detailed Description

LZ out window.

Macro Definition Documentation

LZ_DICT_REPEAT_MAX

#define LZ_DICT_REPEAT_MAX   288

Maximum length of a match rounded up to a nice power of 2 which is a good size for aligned memcpy(). The allocated dictionary buffer will be 2 * LZ_DICT_REPEAT_MAX bytes larger than the actual dictionary size:

(1) Every time the decoder reaches the end of the dictionary buffer, the last LZ_DICT_REPEAT_MAX bytes will be copied to the beginning. This way dict_repeat() will only need to copy from one place, never from both the end and beginning of the buffer.

(2) The other LZ_DICT_REPEAT_MAX bytes is kept as a buffer between the oldest byte still in the dictionary and the current write position. This way dict_repeat(dict, dict->size - 1, &len) won't need memmove() as the copying cannot overlap.

Note that memcpy() still cannot be used if distance < len.

LZMA's longest match length is 273 so pick a multiple of 16 above that.

LZMA_LZ_DECODER_INIT

#define LZMA_LZ_DECODER_INIT

Value:

    (lzma_lz_decoder){ \
        .coder = NULL, \
        .code = NULL, \
        .reset = NULL, \
        .set_uncompressed = NULL, \
        .end = NULL, \
    }

Function Documentation

lzma_lz_decoder_init()

lzma_ret lzma_lz_decoder_init ( lzma_next_coder * next, const lzma_allocator * allocator, const lzma_filter_info * filters, lzma_ret(* lz_init )(lzma_lz_decoder *lz, const lzma_allocator *allocator, lzma_vli id, const void *options, lzma_lz_options *lz_options) )

extern

lzma_lz_decoder_memusage()

uint64_t lzma_lz_decoder_memusage ( size_t dictionary_size )

extern