| #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 |
| * |
| */ |
| |
| #ifndef HASH_CALC_OFFSET |
| # define HASH_CALC_OFFSET 0 |
| #endif |
| #ifndef HASH_CALC_MASK |
| # define HASH_CALC_MASK HASH_MASK |
| #endif |
| #ifndef HASH_CALC_READ |
| # if BYTE_ORDER == LITTLE_ENDIAN |
| # define HASH_CALC_READ \ |
| memcpy(&val, strstart, sizeof(val)); |
| # else |
| # define HASH_CALC_READ \ |
| val = ((uint32_t)(strstart[0])); \ |
| val |= ((uint32_t)(strstart[1]) << 8); \ |
| val |= ((uint32_t)(strstart[2]) << 16); \ |
| val |= ((uint32_t)(strstart[3]) << 24); |
| # endif |
| #endif |
| |
| /* =========================================================================== |
| * Update a hash value with the given input byte |
| * IN assertion: all calls to to UPDATE_HASH are made with consecutive |
| * input characters, so that a running hash key can be computed from the |
| * previous key instead of complete recalculation each time. |
| */ |
| Z_INTERNAL uint32_t UPDATE_HASH(deflate_state *const s, uint32_t h, uint32_t val) { |
| (void)s; |
| HASH_CALC(s, h, val); |
| return h & HASH_CALC_MASK; |
| } |
| |
| /* =========================================================================== |
| * 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, uint32_t str) { |
| Pos head; |
| uint8_t *strstart = s->window + str + HASH_CALC_OFFSET; |
| uint32_t val, hm; |
| |
| HASH_CALC_VAR_INIT; |
| HASH_CALC_READ; |
| HASH_CALC(s, HASH_CALC_VAR, val); |
| HASH_CALC_VAR &= HASH_CALC_MASK; |
| hm = HASH_CALC_VAR; |
| |
| 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, uint32_t str, uint32_t count) { |
| uint8_t *strstart = s->window + str + HASH_CALC_OFFSET; |
| uint8_t *strend = strstart + count; |
| |
| for (Pos idx = (Pos)str; strstart < strend; idx++, strstart++) { |
| uint32_t val, hm; |
| |
| HASH_CALC_VAR_INIT; |
| HASH_CALC_READ; |
| HASH_CALC(s, HASH_CALC_VAR, val); |
| HASH_CALC_VAR &= HASH_CALC_MASK; |
| hm = HASH_CALC_VAR; |
| |
| Pos head = s->head[hm]; |
| if (LIKELY(head != idx)) { |
| s->prev[idx & s->w_mask] = head; |
| s->head[hm] = idx; |
| } |
| } |
| } |
| #endif |