35 lines
1.1 KiB
C++
35 lines
1.1 KiB
C++
/***
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Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.
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File: fnv1.hpp
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Date: 2021-6-10
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Author: Reece
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***/
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#pragma once
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namespace Aurora::Hashing
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{
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namespace CE
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{
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constexpr uint64_t val_64_const = 0xcbf29ce484222325;
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constexpr uint64_t prime_64_const = 0x100000001b3;
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inline constexpr uint64_t fnv1a(const char *const str, const uint64_t value = val_64_const) noexcept
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{
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return (str[0] == '\0') ? value : fnv1a(&str[1], (value ^ uint64_t(str[0])) * prime_64_const);
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}
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inline constexpr uint32_t fnv1a_trunc(const char *const str) noexcept
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{
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return static_cast<uint32_t>(fnv1a(str));
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}
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constexpr uint64_t val_32_const = 0x811c9dc5;
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constexpr uint64_t prime_32_const = 0x01000193;
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inline constexpr uint32_t fnv1a_32(const char *const str, const uint32_t value = val_32_const) noexcept
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{
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return (str[0] == '\0') ? value : fnv1a_32(&str[1], (value ^ uint32_t(str[0])) * prime_32_const);
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}
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}
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} |