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 
18 #include "pw_kvs/key.h"
19 
20 namespace pw {
21 namespace kvs {
22 namespace internal {
23 
24 // The hash function used to hash keys.
Hash(Key string)25 constexpr uint32_t Hash(Key string) {
26   uint32_t hash = 0;
27   uint32_t coefficient = 65599u;
28 
29   for (char ch : string) {
30     hash += coefficient * uint32_t(ch);
31     coefficient *= 65599u;
32   }
33 
34   return hash;
35 }
36 
37 }  // namespace internal
38 }  // namespace kvs
39 }  // namespace pw
40