log_store.hpp

Go to the documentation of this file.

// Copyright (c) 2021 MIT Digital Currency Initiative,
//                    Federal Reserve Bank of Boston
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef OPENCBDC_TX_SRC_RAFT_LOG_STORE_H_
#define OPENCBDC_TX_SRC_RAFT_LOG_STORE_H_
 
#include "index_comparator.hpp"
 
#include <leveldb/db.h>
#include <libnuraft/log_store.hxx>
#include <mutex>
 
namespace cbdc::raft {
    class log_store : public nuraft::log_store {
      public:
        log_store() = default;
        ~log_store() override = default;
 
        log_store(const log_store& other) = delete;
        auto operator=(const log_store& other) -> log_store& = delete;
 
        log_store(log_store&& other) noexcept;
        auto operator=(log_store&& other) noexcept -> log_store&;
 
        [[nodiscard]] auto load(const std::string& db_dir) -> bool;
 
        [[nodiscard]] auto next_slot() const -> uint64_t override;
 
        [[nodiscard]] auto start_index() const -> uint64_t override;
 
        [[nodiscard]] auto last_entry() const
            -> nuraft::ptr<nuraft::log_entry> override;
 
        auto append(nuraft::ptr<nuraft::log_entry>& entry)
            -> uint64_t override;
 
        void write_at(uint64_t index,
                      nuraft::ptr<nuraft::log_entry>& entry) override;
 
        using log_entries_t
            = nuraft::ptr<std::vector<nuraft::ptr<nuraft::log_entry>>>;
 
        [[nodiscard]] auto log_entries(uint64_t start, uint64_t end)
            -> log_entries_t override;
 
        [[nodiscard]] auto entry_at(uint64_t index)
            -> nuraft::ptr<nuraft::log_entry> override;
 
        [[nodiscard]] auto term_at(uint64_t index) -> uint64_t override;
 
        [[nodiscard]] auto pack(uint64_t index, int32_t cnt)
            -> nuraft::ptr<nuraft::buffer> override;
 
        void apply_pack(uint64_t index, nuraft::buffer& pack) override;
 
        auto compact(uint64_t last_log_index) -> bool override;
 
        auto flush() -> bool override;
 
      private:
        std::unique_ptr<leveldb::DB> m_db{};
        mutable std::mutex m_db_mut{};
        uint64_t m_next_idx{};
        uint64_t m_start_idx{};
 
        leveldb::ReadOptions m_read_opt;
        leveldb::WriteOptions m_write_opt;
 
        index_comparator m_cmp;
    };
}
 
#endif // OPENCBDC_TX_SRC_RAFT_LOG_STORE_H_