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Diffstat (limited to 'oss-fuzz/fuzzing/datasource/id.hpp')
-rw-r--r-- | oss-fuzz/fuzzing/datasource/id.hpp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/oss-fuzz/fuzzing/datasource/id.hpp b/oss-fuzz/fuzzing/datasource/id.hpp new file mode 100644 index 00000000..3ba38d71 --- /dev/null +++ b/oss-fuzz/fuzzing/datasource/id.hpp @@ -0,0 +1,52 @@ +#pragma once + +#include <stdio.h> +#include <stdint.h> +#include <utility> +#include <map> + +namespace fuzzing { +namespace datasource { + +/* From: https://gist.github.com/underscorediscovery/81308642d0325fd386237cfa3b44785c */ +inline uint64_t hash_64_fnv1a(const void* key, const uint64_t len) { + + const char* data = (char*)key; + uint64_t hash = 0xcbf29ce484222325; + uint64_t prime = 0x100000001b3; + + for(uint64_t i = 0; i < len; ++i) { + uint8_t value = data[i]; + hash = hash ^ value; + hash *= prime; + } + + return hash; + +} //hash_64_fnv1a + +// FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit +// str should be a null terminated string literal, value should be left out +// e.g hash_32_fnv1a_const("example") +// code license: public domain or equivalent +// post: https://notes.underscorediscovery.com/constexpr-fnv1a/ + +constexpr uint32_t val_32_const = 0x811c9dc5; +constexpr uint32_t prime_32_const = 0x1000193; +constexpr uint64_t val_64_const = 0xcbf29ce484222325; +constexpr uint64_t prime_64_const = 0x100000001b3; + + +inline constexpr uint64_t ID(const char* const str, const uint64_t value = val_64_const) noexcept { + auto ret = (str[0] == '\0') ? value : ID(&str[1], (value ^ uint64_t(str[0])) * prime_64_const); + return ret; +} + +inline constexpr std::pair<const char*, uint64_t> IDPair(const char* const str, const uint64_t value = val_64_const) noexcept { + return {str, ID(str, value)}; +} + +using IDMap = std::map<const char*, uint64_t>; + +} /* namespace datasource */ +} /* namespace fuzzing */ |