1 /* Copyright (C) 2021 Wildfire Games.
3 * Permission is hereby granted, free of charge, to any person obtaining
4 * a copy of this software and associated documentation files (the
5 * "Software"), to deal in the Software without restriction, including
6 * without limitation the rights to use, copy, modify, merge, publish,
7 * distribute, sublicense, and/or sell copies of the Software, and to
8 * permit persons to whom the Software is furnished to do so, subject to
9 * the following conditions:
11 * The above copyright notice and this permission notice shall be included
12 * in all copies or substantial portions of the Software.
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
17 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
18 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
19 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
20 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 #include "precompiled.h"
25 #include "lib/fnv_hash.h"
27 // FNV1-A hash - good for strings.
28 // if len = 0 (default), treat buf as a C-string;
29 // otherwise, hash <len> bytes of buf.
30 u32
fnv_hash(const void* buf
, size_t len
)
33 // give distinct values for different length 0 buffers.
34 // value taken from FNV; it has no special significance.
36 const u8
* p
= (const u8
*)buf
;
38 // expected case: string
49 size_t bytes_left
= len
;
50 while(bytes_left
!= 0)
62 // FNV1-A hash - good for strings.
63 // if len = 0 (default), treat buf as a C-string;
64 // otherwise, hash <len> bytes of buf.
65 u64
fnv_hash64(const void* buf
, size_t len
)
67 u64 h
= 0xCBF29CE484222325ull
;
68 // give distinct values for different length 0 buffers.
69 // value taken from FNV; it has no special significance.
71 const u8
* p
= (const u8
*)buf
;
73 // expected case: string
79 h
*= 0x100000001B3ull
;
84 size_t bytes_left
= len
;
85 while(bytes_left
!= 0)
88 h
*= 0x100000001B3ull
;