1 /* 2 * Copyright 2021 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #ifndef FCP_CLIENT_OPSTATS_OPSTATS_DB_H_ 17 #define FCP_CLIENT_OPSTATS_OPSTATS_DB_H_ 18 19 #include <functional> 20 21 #include "absl/status/status.h" 22 #include "absl/status/statusor.h" 23 #include "fcp/protos/opstats.pb.h" 24 25 namespace fcp { 26 namespace client { 27 namespace opstats { 28 29 // Base no-op class for the OpStats database that always contains an empty 30 // OpStatsSequence and performs no file i/o. 31 class OpStatsDb { 32 public: 33 virtual ~OpStatsDb() = default; 34 // The returned OpStatsSequence message should contain the operational stats 35 // for all runs. The operational stats for each run is wrapped inside a 36 // OperationalStats message, and the OperationalStats messages are ordered 37 // sequentially (first run to last run) within OpStatsSequence. Read()38 virtual absl::StatusOr<OpStatsSequence> Read() { return OpStatsSequence(); } 39 40 // OpStatsDb has a Transform method instead of a Write method because 41 // OpStatsSequence message already contains the operational stats for every 42 // run, and the user only need to update the existing OpStatsSequence message 43 // to add/remove/update data. In addition, by having a Transform method allows 44 // the implementations to perform atomic read-update-write operations. Transform(std::function<void (OpStatsSequence &)> func)45 virtual absl::Status Transform(std::function<void(OpStatsSequence&)> func) { 46 return absl::OkStatus(); 47 } 48 }; 49 50 } // namespace opstats 51 } // namespace client 52 } // namespace fcp 53 54 #endif // FCP_CLIENT_OPSTATS_OPSTATS_DB_H_ 55