函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:lib\xz\xz_dec_lzma2.c Create Date:2022-07-27 08:06:38
Last Modify:2020-03-12 14:18:49 Copyright©Brick
首页 函数Tree
注解内核,赢得工具下载SCCTEnglish

函数名称：Decode a match. The distance will be stored in s->lzma.rep0.

函数原型：static void lzma_match(struct xz_dec_lzma2 *s, uint32_t pos_state)

返回类型：void

参数：

类型参数名称
struct xz_dec_lzma2 *s
uint32_tpos_state
652  Indicate that the latest symbol was a match.
654  rep3等于rep2
655  rep2等于rep1
656  rep1等于 Distances of latest four matches
658  Decode the length of the match into s->lzma.len.
660  probs等于* Probability tree for the highest two bits of the match * distance. There is a separate probability tree for match * lengths of 2 (i.e. MATCH_LEN_MIN), 3, 4, and [5, 273].[Get the index of the appropriate probability array for decoding* the distance slot.]
661  dist_slot等于Decode a bittree starting from the most significant bit. 减DIST_SLOTS
663  如果dist_slot小于Match distances up to 127 are fully encoded using probabilities. Since* the highest two bits (distance slot) are always encoded using six bits,* the distances 0-3 don't need any additional bits to encode, since the则
664  Distances of latest four matches 等于dist_slot
665  否则
666  limit等于dist_slot右移1位的值减1
667  Distances of latest four matches 等于2加dist_slot按位与1的值
669  如果dist_slot小于Match distances greater than 127 are encoded in three pieces:* - distance slot: the highest two bits* - direct bits: 2-26 bits below the highest two bits* - alignment bits: four lowest bits* Direct bits don't use any probabilities.则
670  Distances of latest four matches 左移等于limit位
671  probs等于* Probility trees for additional bits for match distance * when the distance is in the range [4, 127].加 Distances of latest four matches 减dist_slot减1
673  Decode a bittree starting from the least significant bit.
675  否则
676  Decode direct bits (fixed fifty-fifty probability)
677  Distances of latest four matches 左移等于For match distances greater than 127, only the highest two bits and the* lowest four bits (alignment) is encoded using probabilities.位
678  Decode a bittree starting from the least significant bit.
调用者
名称描述
lzma_mainLZMA decoder core