77 lines
2.3 KiB
C++
77 lines
2.3 KiB
C++
#ifndef QUERY_BACKEND_PROVIDER_HPP
|
|
#define QUERY_BACKEND_PROVIDER_HPP
|
|
|
|
#include "matador/utils/library.hpp"
|
|
|
|
#include <memory>
|
|
#include <string>
|
|
#include <unordered_map>
|
|
#include <unordered_set>
|
|
|
|
namespace matador::sql {
|
|
|
|
class connection_impl;
|
|
struct connection_info;
|
|
class dialect;
|
|
|
|
class backend_provider
|
|
{
|
|
private:
|
|
backend_provider();
|
|
|
|
public:
|
|
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);
|
|
|
|
private:
|
|
struct basic_backend_context {
|
|
virtual ~basic_backend_context() = default;
|
|
[[nodiscard]] virtual connection_impl* create(const connection_info&) = 0;
|
|
virtual void destroy(connection_impl*) = 0;
|
|
[[nodiscard]] virtual const sql::dialect* dialect() const = 0;
|
|
};
|
|
|
|
class backend_context final : public basic_backend_context {
|
|
public:
|
|
explicit backend_context(const std::string &connection_type);
|
|
backend_context(const backend_context&) = delete;
|
|
backend_context& operator=(const backend_context&) = delete;
|
|
backend_context(backend_context&&) noexcept = default;
|
|
backend_context& operator=(backend_context&&) noexcept = default;
|
|
~backend_context() 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;
|
|
};
|
|
|
|
class noop_backend_context final : public basic_backend_context {
|
|
public:
|
|
connection_impl *create(const connection_info &info) override;
|
|
void destroy(connection_impl *impl) override;
|
|
[[nodiscard]] const sql::dialect *dialect() const override;
|
|
|
|
private:
|
|
std::unordered_set<std::unique_ptr<connection_impl>> noop_connections_;
|
|
};
|
|
|
|
private:
|
|
using backends_t = std::unordered_map<std::string, std::unique_ptr<basic_backend_context>>;
|
|
backends_t backends_;
|
|
};
|
|
}
|
|
#endif //QUERY_BACKEND_PROVIDER_HPP
|