| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef __LOG_STORAGE_HPP__ |
| #define __LOG_STORAGE_HPP__ |
| |
| #include <stdint.h> |
| |
| #include <string> |
| |
| #include <stout/interval.hpp> |
| #include <stout/nothing.hpp> |
| #include <stout/try.hpp> |
| |
| #include "messages/log.hpp" |
| |
| namespace mesos { |
| namespace internal { |
| namespace log { |
| |
| // Abstract interface for reading and writing records. |
| class Storage |
| { |
| public: |
| struct State |
| { |
| Metadata metadata; // The metadata for the replica. |
| uint64_t begin; // Beginning position of the log. |
| uint64_t end; // Ending position of the log. |
| |
| // Note that we use interval set here to store learned/unlearned |
| // positions in a more compact way. Adjacent positions will be |
| // merged and represented using an interval. |
| IntervalSet<uint64_t> learned; |
| IntervalSet<uint64_t> unlearned; |
| }; |
| |
| virtual ~Storage() {} |
| |
| virtual Try<State> restore(const std::string& path) = 0; |
| virtual Try<Nothing> persist(const Metadata& metadata) = 0; |
| virtual Try<Nothing> persist(const Action& action) = 0; |
| virtual Try<Action> read(uint64_t position) = 0; |
| }; |
| |
| } // namespace log { |
| } // namespace internal { |
| } // namespace mesos { |
| |
| #endif // __LOG_STORAGE_HPP__ |