query/include/matador/sql/backend_provider.hpp

69 lines
2.1 KiB
C++

#ifndef QUERY_BACKEND_PROVIDER_HPP
#define QUERY_BACKEND_PROVIDER_HPP
#include "matador/utils/library.hpp"
#include <memory>
#include <string>
#include <unordered_map>
namespace matador::sql {
class connection_impl;
struct connection_info;
class dialect;
class backend_provider
{
private:
backend_provider();
public:
struct basic_backend_service {
virtual ~basic_backend_service() = default;
[[nodiscard]] virtual connection_impl* create(const connection_info&) = 0;
virtual void destroy(connection_impl*) = 0;
[[nodiscard]] virtual const sql::dialect* dialect() const = 0;
};
static backend_provider& instance();
connection_impl* create_connection(const std::string &connection_type, const connection_info &info);
void destroy_connection(const std::string &connection_type, connection_impl *c);
const dialect& connection_dialect(const std::string &connection_type);
void register_backend(const std::string &connection_type, std::unique_ptr<basic_backend_service> &&service);
private:
class backend_service final : public basic_backend_service {
public:
explicit backend_service(const std::string &connection_type);
backend_service(const backend_service&) = delete;
backend_service& operator=(const backend_service&) = delete;
backend_service(backend_service&&) noexcept = default;
backend_service& operator=(backend_service&&) noexcept = default;
~backend_service() override;
[[nodiscard]] connection_impl* create(const connection_info&) override;
void destroy(connection_impl *conn) override;
[[nodiscard]] const class dialect* dialect() const override;
private:
typedef connection_impl*(*create_func)(const connection_info&);
typedef void (*destroy_func)(connection_impl*);
typedef const class dialect*(*dialect_func)();
create_func create_connection{};
destroy_func destroy_connection{};
dialect_func get_dialect{};
utils::library lib;
};
private:
using backends_t = std::unordered_map<std::string, std::unique_ptr<basic_backend_service>>;
backends_t backends_;
};
}
#endif //QUERY_BACKEND_PROVIDER_HPP