xref: /aosp_15_r20/external/flac/oss-fuzz/fuzzing/datasource/id.hpp (revision 600f14f40d737144c998e2ec7a483122d3776fbc)
1*600f14f4SXin Li /* Copyright 2019 Guido Vranken
2*600f14f4SXin Li  *
3*600f14f4SXin Li  * Permission is hereby granted, free of charge, to any person obtaining
4*600f14f4SXin Li  * a copy of this software and associated documentation files (the
5*600f14f4SXin Li  * "Software"), to deal in the Software without restriction, including
6*600f14f4SXin Li  * without limitation the rights to use, copy, modify, merge, publish,
7*600f14f4SXin Li  * distribute, sublicense, and/or sell copies of the Software, and to
8*600f14f4SXin Li  * permit persons to whom the Software is furnished to do so, subject
9*600f14f4SXin Li  * to the following conditions:
10*600f14f4SXin Li  *
11*600f14f4SXin Li  * The above copyright notice and this permission notice shall be
12*600f14f4SXin Li  * included in all copies or substantial portions of the Software.
13*600f14f4SXin Li  *
14*600f14f4SXin Li  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15*600f14f4SXin Li  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16*600f14f4SXin Li  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17*600f14f4SXin Li  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
18*600f14f4SXin Li  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
19*600f14f4SXin Li  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20*600f14f4SXin Li  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21*600f14f4SXin Li  * SOFTWARE.
22*600f14f4SXin Li  */
23*600f14f4SXin Li 
24*600f14f4SXin Li #pragma once
25*600f14f4SXin Li 
26*600f14f4SXin Li #include <stdio.h>
27*600f14f4SXin Li #include <stdint.h>
28*600f14f4SXin Li #include <utility>
29*600f14f4SXin Li #include <map>
30*600f14f4SXin Li 
31*600f14f4SXin Li namespace fuzzing {
32*600f14f4SXin Li namespace datasource  {
33*600f14f4SXin Li 
34*600f14f4SXin Li /* From: https://gist.github.com/underscorediscovery/81308642d0325fd386237cfa3b44785c */
hash_64_fnv1a(const void * key,const uint64_t len)35*600f14f4SXin Li inline uint64_t hash_64_fnv1a(const void* key, const uint64_t len) {
36*600f14f4SXin Li 
37*600f14f4SXin Li     const char* data = (char*)key;
38*600f14f4SXin Li     uint64_t hash = 0xcbf29ce484222325;
39*600f14f4SXin Li     uint64_t prime = 0x100000001b3;
40*600f14f4SXin Li 
41*600f14f4SXin Li     for(uint64_t i = 0; i < len; ++i) {
42*600f14f4SXin Li         uint8_t value = data[i];
43*600f14f4SXin Li         hash = hash ^ value;
44*600f14f4SXin Li         hash *= prime;
45*600f14f4SXin Li     }
46*600f14f4SXin Li 
47*600f14f4SXin Li     return hash;
48*600f14f4SXin Li 
49*600f14f4SXin Li } //hash_64_fnv1a
50*600f14f4SXin Li 
51*600f14f4SXin Li // FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit
52*600f14f4SXin Li // str should be a null terminated string literal, value should be left out
53*600f14f4SXin Li // e.g hash_32_fnv1a_const("example")
54*600f14f4SXin Li // code license: public domain or equivalent
55*600f14f4SXin Li // post: https://notes.underscorediscovery.com/constexpr-fnv1a/
56*600f14f4SXin Li 
57*600f14f4SXin Li constexpr uint32_t val_32_const = 0x811c9dc5;
58*600f14f4SXin Li constexpr uint32_t prime_32_const = 0x1000193;
59*600f14f4SXin Li constexpr uint64_t val_64_const = 0xcbf29ce484222325;
60*600f14f4SXin Li constexpr uint64_t prime_64_const = 0x100000001b3;
61*600f14f4SXin Li 
62*600f14f4SXin Li 
ID(const char * const str,const uint64_t value=val_64_const)63*600f14f4SXin Li inline constexpr uint64_t ID(const char* const str, const uint64_t value = val_64_const) noexcept {
64*600f14f4SXin Li     auto ret = (str[0] == '\0') ? value : ID(&str[1], (value ^ uint64_t(str[0])) * prime_64_const);
65*600f14f4SXin Li     return ret;
66*600f14f4SXin Li }
67*600f14f4SXin Li 
IDPair(const char * const str,const uint64_t value=val_64_const)68*600f14f4SXin Li inline constexpr std::pair<const char*, uint64_t> IDPair(const char* const str, const uint64_t value = val_64_const) noexcept {
69*600f14f4SXin Li     return {str, ID(str, value)};
70*600f14f4SXin Li }
71*600f14f4SXin Li 
72*600f14f4SXin Li using IDMap = std::map<const char*, uint64_t>;
73*600f14f4SXin Li 
74*600f14f4SXin Li } /* namespace datasource */
75*600f14f4SXin Li } /* namespace fuzzing */
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