53 lines
1.7 KiB
C++
53 lines
1.7 KiB
C++
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#pragma once
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/*
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MIT License
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Copyright (c) 2024 - 2025 René Amthor (tobid7)
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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*/
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#include <pd/core/common.hpp>
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namespace PD {
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/**
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* FNV-1a 32Bit hasing function
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* https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function
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*/
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constexpr u32 FNV1A32(std::string_view str) {
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u32 ret = 0x811c9dc5; // Offset basis
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for (auto& it : str) {
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ret ^= it;
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ret *= 0x01000193; // Prime
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}
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return ret;
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}
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/**
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* FNV-1a 64Bit hasing function
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* https://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function
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*/
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constexpr u64 FNV1A64(std::string_view str) {
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u64 ret = 0xcbf29ce484222325; // Offset basis
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for (auto& it : str) {
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ret ^= it;
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ret *= 0x00000100000001b3; // Prime
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}
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return ret;
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}
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} // namespace PD
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