API ?

txt

API

    option {
        bool instantaneous = false
        sync_level sync_level = write_file
        handle snapshoot = nullptr
    }

    // column
    void create_column(option, name, key_type, value_type, callback)
        key_type
            var_binary, fixed_binary, integer_u32, integer_u64, integer_i32, integer_i64, float_32, float_64
        value_type
            var_binary, fixed_binary, integer_u32, integer_i32, integer_u64, integer_i64, integer_u128, integer_i128, float_32, float_64
        callback(error_code, column_id, name, key_type, value_type)

    void get_column(option, column_id, callback)
        callback(error_code, column_id, name, key_type, value_type)

    void get_column(option, name, callback)
        callback(error_code, column_id, name, key_type, value_type)

    void enum_column(option, callback)
        callback(error_code, column_id, name, key_type, value_type)

    void delete_column(option, column_id, callback)
        callback(error_code, column_id)

    // record

    handle get_snapshoot()

    void get(option, column_id, key, callback)
        callback(error_code, column_id, key, value, snapshoot)

    void put(option, column_id, key, value, callback)
        callback(error_code, column_id, key, value, snapshoot)

    void del(option, column_id, key, callback)
        callback(error_code, column_id, key, snapshoot)

    void scan(option, column_id, scan_type, key, callback)
        seek_type
            front, back, for_next, for_less
        callback(error_code, column_id, key, value, snapshoot)

    void eliminate_range(option, column_id, key_left, key_right, include_left, include_right, callback)
        callback(error_code, column_id, key)

    // info

    size_t estimate(option, column_id, key_left, key_right, callback)
        callback(error_code, column_id, key_left, key_right, key_count)

    ...

DEMO

uint32_t cid = uint32_t(-1);
db->create_column(option{true}, "default", var_binary, var_binary,
    [&](error_code, column_id, key_type, value_type){
        assert(!error_code);
        cid = column_id;
    }
);
db->put(option{false}, cid, "abc", "123",
    [](error_code, column_id, key, value, snapshoot){
        assert(!error_code);
        fprintf(stderr, "async put abc sunccess\n");
    }
);  // sync
db->put(option{true}, cid, "def", "456",
    [](error_code, column_id, key, value, snapshoot){
        assert(!error_code);
        fprintf(stderr, "sync put def success\n");
    }
);  // async
db->scan(option{true}, cid, front, nullptr,
    [](error_code, column_id, key, value, snapshoot) {
        if (error_code == scan_invalid) {
            return false;
        }
        fprintf(stderr, "key %s value %s\n", key, value);
        return true;
    }
);