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HashedString.hpp
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the newest version in sPHENIX GitHub for file HashedString.hpp
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// This file is part of the Acts project.
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//
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// Copyright (C) 2022 CERN for the benefit of the Acts project
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this
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// file, You can obtain one at http://mozilla.org/MPL/2.0/.
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#pragma once
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#include <cstddef>
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#include <cstdint>
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#include <string_view>
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#include <utility>
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namespace
Acts {
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using
HashedString
= std::uint32_t;
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// Adapted from https://gist.github.com/Lee-R/3839813
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namespace
detail {
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// FNV-1a 32bit hashing algorithm.
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constexpr
HashedString
fnv1a_32
(
char
const
*
s
, std::size_t
count
) {
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return
count != 0
u
? (
fnv1a_32
(s, count - 1) ^ s[count - 1]) * 16777619
u
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: 2166136261
u
;
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}
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constexpr
HashedString
fnv1a_32
(std::string_view
s
) {
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return
!s.empty() ? (
fnv1a_32
(s.substr(0, s.size() - 1)) ^ s[s.size() - 1]) *
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16777619
u
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: 2166136261
u
;
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}
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constexpr
int
length
(
const
char
*
str
) {
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return
*str != 0 ? 1 +
length
(str + 1) : 0;
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}
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}
// namespace detail
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constexpr
HashedString
hashString
(std::string_view
s
) {
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return
detail::fnv1a_32
(s);
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}
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namespace
HashedStringLiteral {
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constexpr
HashedString
operator
""
_hash(
char
const
*
s
, std::size_t
count
) {
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return
detail::fnv1a_32
(s, count);
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}
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}
// namespace HashedStringLiteral
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}
// namespace Acts
acts
blob
sPHENIX
Core
include
Acts
Utilities
HashedString.hpp
Built by
Jin Huang
. updated:
Sat Feb 17 2024 22:17:35
using
1.8.2 with
sPHENIX GitHub integration