Initial commit

src/loader/component_interface.hpp

@@ -0,0 +1,35 @@
+#pragma once
+
+class component_interface
+{
+public:
+	virtual ~component_interface()
+	{
+	}
+
+	virtual void post_start()
+	{
+	}
+
+	virtual void post_load()
+	{
+	}
+
+	virtual void pre_destroy()
+	{
+	}
+
+	virtual void post_unpack()
+	{
+	}
+
+	virtual void* load_import([[maybe_unused]] const std::string& library, [[maybe_unused]] const std::string& function)
+	{
+		return nullptr;
+	}
+
+	virtual bool is_supported()
+	{
+		return true;
+	}
+};

src/loader/component_loader.cpp

@@ -0,0 +1,127 @@
+#include <stdinc.hpp>
+#include "component_loader.hpp"
+
+void component_loader::register_component(std::unique_ptr<component_interface>&& component_)
+{
+	get_components().push_back(std::move(component_));
+}
+
+bool component_loader::post_start()
+{
+	static auto handled = false;
+	if (handled) return true;
+	handled = true;
+
+	try
+	{
+		for (const auto& component_ : get_components())
+		{
+			component_->post_start();
+		}
+	}
+	catch (premature_shutdown_trigger&)
+	{
+		return false;
+	}
+
+	return true;
+}
+
+bool component_loader::post_load()
+{
+	static auto handled = false;
+	if (handled) return true;
+	handled = true;
+
+	clean();
+
+	try
+	{
+		for (const auto& component_ : get_components())
+		{
+			component_->post_load();
+		}
+	}
+	catch (premature_shutdown_trigger&)
+	{
+		return false;
+	}
+
+	return true;
+}
+
+void component_loader::post_unpack()
+{
+	static auto handled = false;
+	if (handled) return;
+	handled = true;
+
+	for (const auto& component_ : get_components())
+	{
+		component_->post_unpack();
+	}
+}
+
+void component_loader::pre_destroy()
+{
+	static auto handled = false;
+	if (handled) return;
+	handled = true;
+
+	for (const auto& component_ : get_components())
+	{
+		component_->pre_destroy();
+	}
+}
+
+void component_loader::clean()
+{
+	auto& components = get_components();
+	for (auto i = components.begin(); i != components.end();)
+	{
+		if (!(*i)->is_supported())
+		{
+			(*i)->pre_destroy();
+			i = components.erase(i);
+		}
+		else
+		{
+			++i;
+		}
+	}
+}
+
+void* component_loader::load_import(const std::string& library, const std::string& function)
+{
+	void* function_ptr = nullptr;
+
+	for (const auto& component_ : get_components())
+	{
+		auto* const component_function_ptr = component_->load_import(library, function);
+		if (component_function_ptr)
+		{
+			function_ptr = component_function_ptr;
+		}
+	}
+
+	return function_ptr;
+}
+
+void component_loader::trigger_premature_shutdown()
+{
+	throw premature_shutdown_trigger();
+}
+
+std::vector<std::unique_ptr<component_interface>>& component_loader::get_components()
+{
+	using component_vector = std::vector<std::unique_ptr<component_interface>>;
+	using component_vector_container = std::unique_ptr<component_vector, std::function<void(component_vector*)>>;
+
+	static component_vector_container components(new component_vector, [](component_vector* component_vector)
+	{
+		pre_destroy();
+		delete component_vector;
+	});
+
+	return *components;
+}

src/loader/component_loader.hpp

@@ -0,0 +1,61 @@
+#pragma once
+#include "component_interface.hpp"
+
+class component_loader final
+{
+public:
+	class premature_shutdown_trigger final : public std::exception
+	{
+		[[nodiscard]] const char* what() const noexcept override
+		{
+			return "Premature shutdown requested";
+		}
+	};
+
+	template <typename T>
+	class installer final
+	{
+		static_assert(std::is_base_of<component_interface, T>::value, "component has invalid base class");
+
+	public:
+		installer()
+		{
+			register_component(std::make_unique<T>());
+		}
+	};
+
+	template <typename T>
+	static T* get()
+	{
+		for (const auto& component_ : get_components())
+		{
+			if (typeid(*component_.get()) == typeid(T))
+			{
+				return reinterpret_cast<T*>(component_.get());
+			}
+		}
+
+		return nullptr;
+	}
+
+	static void register_component(std::unique_ptr<component_interface>&& component);
+
+	static bool post_start();
+	static bool post_load();
+	static void post_unpack();
+	static void pre_destroy();
+	static void clean();
+
+	static void* load_import(const std::string& library, const std::string& function);
+
+	static void trigger_premature_shutdown();
+
+private:
+	static std::vector<std::unique_ptr<component_interface>>& get_components();
+};
+
+#define REGISTER_COMPONENT(name)                       \
+namespace                                           \
+{                                                   \
+	static component_loader::installer<name> __component; \
+}