initial matador ng commit

source/orm/sql/backend_provider.cpp

@@ -0,0 +1,82 @@
+#include "matador/sql/backend_provider.hpp"
+// #include "matador/sql/noop_connection.hpp"
+// #include "matador/sql/dialect_builder.hpp"
+
+#include "matador/sql/interface/connection_impl.hpp"
+
+#include <algorithm>
+#include <stdexcept>
+#include <cstdint>
+
+namespace matador::sql {
+backend_provider::backend_provider() = default;
+// {
+  // backends_.emplace("noop", std::make_unique<noop_backend_context>());
+// }
+
+backend_provider &backend_provider::instance() {
+  static backend_provider provider;
+  return provider;
+}
+
+connection_impl *backend_provider::create_connection(const std::string &connection_type, const connection_info &info)
+{
+  auto it = backends_.find(connection_type);
+  if (it == backends_.end()) {
+    it = backends_.emplace(connection_type, std::make_unique<backend_service>(connection_type)).first;
+  }
+  return it->second->create(info);
+}
+
+void backend_provider::destroy_connection(const std::string &connection_type, connection_impl *c)
+{
+  auto it = backends_.find(connection_type);
+  if (it == backends_.end()) {
+    it = backends_.emplace(connection_type, std::make_unique<backend_service>(connection_type)).first;
+  }
+  return it->second->destroy(c);
+}
+
+const dialect &backend_provider::connection_dialect(const std::string &connection_type) {
+  auto it = backends_.find(connection_type);
+  if (it == backends_.end()) {
+    it = backends_.emplace(connection_type, std::make_unique<backend_service>(connection_type)).first;
+  }
+  return *it->second->dialect();
+}
+void backend_provider::register_backend(const std::string &connection_type, std::unique_ptr<basic_backend_service> &&service) {
+  backends_.emplace(connection_type, std::move(service));
+}
+
+backend_provider::backend_service::backend_service(const std::string &connection_type)
+{
+  if (!lib.load("matador-" + connection_type)) {
+    throw std::runtime_error("couldn't load library '" + connection_type + "'");
+  }
+
+  create_connection = reinterpret_cast<create_func>(reinterpret_cast<std::uintptr_t>(lib.function("create_database")));
+  destroy_connection = reinterpret_cast<destroy_func>(reinterpret_cast<std::uintptr_t>(lib.function("destroy_database")));
+  get_dialect = reinterpret_cast<dialect_func >(reinterpret_cast<std::uintptr_t>(lib.function("get_dialect")));
+}
+
+connection_impl *backend_provider::backend_service::create(const connection_info &info)
+{
+  return (create_connection)(info);
+}
+
+void backend_provider::backend_service::destroy(connection_impl *conn)
+{
+  (destroy_connection)(conn);
+}
+
+const dialect *backend_provider::backend_service::dialect() const
+{
+  return (get_dialect)();
+}
+
+backend_provider::backend_service::~backend_service()
+{
+  lib.unload();
+}
+
+}