1 // Copyright 2020 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 #include <cstddef> 17 #include <string_view> 18 19 namespace pw { 20 namespace kvs { 21 namespace internal { 22 23 // The hash function used to hash keys. Hash(std::string_view string)24constexpr uint32_t Hash(std::string_view string) { 25 uint32_t hash = 0; 26 uint32_t coefficient = 65599u; 27 28 for (char ch : string) { 29 hash += coefficient * uint32_t(ch); 30 coefficient *= 65599u; 31 } 32 33 return hash; 34 } 35 36 } // namespace internal 37 } // namespace kvs 38 } // namespace pw 39