| #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 <[email protected]> |
| * Jim Guilford <[email protected]> |
| * Vinodh Gopal <[email protected]> |
| * Erdinc Ozturk <[email protected]> |
| * Jim Kukunas <[email protected]> |
| * |
| * Portions are Copyright (C) 2016 12Sided Technology, LLC. |
| * Author: |
| * Phil Vachon <[email protected]> |
| * |
| * 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] = 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 MIN_MATCH bytes of str are valid |
| * (except for the last 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 = 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 |
