mirror of
https://github.com/GerbilSoft/zlib-ng.git
synced 2025-06-18 11:35:35 -04:00
90 lines
2.9 KiB
C
90 lines
2.9 KiB
C
#ifndef INSERT_STRING_H_
|
|
#define INSERT_STRING_H_
|
|
|
|
/* insert_string.h -- Private insert_string functions shared with more than
|
|
* one insert string implementation
|
|
*
|
|
* Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
|
|
*
|
|
* Copyright (C) 2013 Intel Corporation. All rights reserved.
|
|
* Authors:
|
|
* Wajdi Feghali <wajdi.k.feghali@intel.com>
|
|
* Jim Guilford <james.guilford@intel.com>
|
|
* Vinodh Gopal <vinodh.gopal@intel.com>
|
|
* Erdinc Ozturk <erdinc.ozturk@intel.com>
|
|
* Jim Kukunas <james.t.kukunas@linux.intel.com>
|
|
*
|
|
* Portions are Copyright (C) 2016 12Sided Technology, LLC.
|
|
* Author:
|
|
* Phil Vachon <pvachon@12sidedtech.com>
|
|
*
|
|
* For conditions of distribution and use, see copyright notice in zlib.h
|
|
*
|
|
*/
|
|
|
|
/* ===========================================================================
|
|
* Quick insert string str in the dictionary and set match_head to the previous head
|
|
* of the hash chain (the most recent string with same hash key). Return
|
|
* the previous length of the hash chain.
|
|
*/
|
|
Z_INTERNAL Pos QUICK_INSERT_STRING(deflate_state *const s, const uint32_t str) {
|
|
Pos head;
|
|
uint8_t *strstart = s->window + str;
|
|
uint32_t val, hm, h = 0;
|
|
|
|
#ifdef UNALIGNED_OK
|
|
val = *(uint32_t *)(strstart);
|
|
#else
|
|
val = ((uint32_t)(strstart[0]));
|
|
val |= ((uint32_t)(strstart[1]) << 8);
|
|
val |= ((uint32_t)(strstart[2]) << 16);
|
|
val |= ((uint32_t)(strstart[3]) << 24);
|
|
#endif
|
|
|
|
UPDATE_HASH(s, h, val);
|
|
hm = h & HASH_MASK;
|
|
|
|
head = s->head[hm];
|
|
if (LIKELY(head != str)) {
|
|
s->prev[str & s->w_mask] = head;
|
|
s->head[hm] = (Pos)str;
|
|
}
|
|
return head;
|
|
}
|
|
|
|
/* ===========================================================================
|
|
* Insert string str in the dictionary and set match_head to the previous head
|
|
* of the hash chain (the most recent string with same hash key). Return
|
|
* the previous length of the hash chain.
|
|
* IN assertion: all calls to to INSERT_STRING are made with consecutive
|
|
* input characters and the first STD_MIN_MATCH bytes of str are valid
|
|
* (except for the last STD_MIN_MATCH-1 bytes of the input file).
|
|
*/
|
|
Z_INTERNAL void INSERT_STRING(deflate_state *const s, const uint32_t str, uint32_t count) {
|
|
uint8_t *strstart = s->window + str;
|
|
uint8_t *strend = strstart + count - 1; /* last position */
|
|
|
|
for (Pos idx = (Pos)str; strstart <= strend; idx++, strstart++) {
|
|
uint32_t val, hm, h = 0;
|
|
|
|
#ifdef UNALIGNED_OK
|
|
val = *(uint32_t *)(strstart);
|
|
#else
|
|
val = ((uint32_t)(strstart[0]));
|
|
val |= ((uint32_t)(strstart[1]) << 8);
|
|
val |= ((uint32_t)(strstart[2]) << 16);
|
|
val |= ((uint32_t)(strstart[3]) << 24);
|
|
#endif
|
|
|
|
UPDATE_HASH(s, h, val);
|
|
hm = h & HASH_MASK;
|
|
|
|
Pos head = s->head[hm];
|
|
if (LIKELY(head != idx)) {
|
|
s->prev[idx & s->w_mask] = head;
|
|
s->head[hm] = idx;
|
|
}
|
|
}
|
|
}
|
|
#endif
|