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 <cstdint>
17 
18 namespace pw {
19 namespace kvs {
20 namespace internal {
21 
22 // Whether an entry is present or deleted.
23 enum class EntryState : bool { kValid, kDeleted };
24 
25 // Essential metadata for an entry that is stored in memory.
26 struct KeyDescriptor {
27   uint32_t key_hash;
28   uint32_t transaction_id;
29 
30   EntryState state;  // TODO: Pack into transaction ID? or something?
31 };
32 
33 }  // namespace internal
34 }  // namespace kvs
35 }  // namespace pw
36