[keel] Split out Nostalgia Foundation and Pack lib into Keel

src/keel/assetmanager.hpp

@@ -0,0 +1,302 @@
+/*
+ * Copyright 2016 - 2023 Gary Talent (gary@drinkingtea.net). All rights reserved.
+ */
+
+#pragma once
+
+#include <ox/event/signal.hpp>
+#include <ox/fs/fs.hpp>
+#include <ox/model/typenamecatcher.hpp>
+#include <ox/std/hashmap.hpp>
+#include <ox/std/utility.hpp>
+
+namespace keel {
+
+class AssetManager;
+
+template<typename T>
+class AssetRef;
+
+#ifndef OX_BARE_METAL
+template<typename T>
+class AssetContainer {
+
+	friend AssetManager;
+	friend AssetRef<T>;
+
+	protected:
+		ox::Signal<ox::Error()> updated;
+
+	private:
+		T m_obj;
+		mutable int m_references = 0;
+
+	public:
+		template<class... Args>
+		explicit constexpr AssetContainer(Args&&... args): m_obj(ox::forward<Args>(args)...) {
+		}
+
+		AssetContainer(AssetContainer&) = delete;
+		AssetContainer(AssetContainer&&) = delete;
+		AssetContainer& operator=(AssetContainer&) = delete;
+		AssetContainer& operator=(AssetContainer&&) = delete;
+
+		[[nodiscard]]
+		constexpr T *get() noexcept {
+			return &m_obj;
+		}
+
+		[[nodiscard]]
+		constexpr const T *get() const noexcept {
+			 return &m_obj;
+		}
+
+		constexpr void set(T &&val) {
+			m_obj = std::move(val);
+		}
+
+		constexpr void set(const T &val) {
+			m_obj = val;
+		}
+
+	protected:
+		constexpr void incRefs() const noexcept {
+			++m_references;
+		}
+
+		constexpr void decRefs() const noexcept {
+			--m_references;
+		}
+
+		[[nodiscard]]
+		constexpr int references() const noexcept {
+			return m_references;
+		}
+
+};
+
+template<typename T>
+class AssetRef: public ox::SignalHandler {
+	private:
+		const AssetContainer<T> *m_ctr = nullptr;
+
+	public:
+		ox::Signal<ox::Error()> updated;
+
+		explicit constexpr AssetRef(const AssetContainer<T> *c = nullptr) noexcept;
+
+		constexpr AssetRef(const AssetRef &h) noexcept;
+
+		constexpr AssetRef(AssetRef &&h) noexcept;
+
+		~AssetRef() noexcept override {
+			if (m_ctr) {
+				m_ctr->decRefs();
+			}
+		}
+
+		[[nodiscard]]
+		constexpr const T *get() const noexcept {
+			if (m_ctr) {
+				return m_ctr->get();
+			}
+			return nullptr;
+		}
+
+		constexpr const T &operator*() const & noexcept {
+			return *m_ctr->get();
+		}
+
+		constexpr const T &&operator*() const && noexcept {
+			return *m_ctr->get();
+		}
+
+		constexpr const T *operator->() const noexcept {
+			return m_ctr->get();
+		}
+
+		AssetRef &operator=(const AssetRef &h) noexcept {
+			if (this == &h) {
+				return *this;
+			}
+			if (m_ctr) {
+				m_ctr->decRefs();
+				oxIgnoreError(m_ctr->updated.disconnectObject(this));
+			}
+			m_ctr = h.m_ctr;
+			m_ctr->updated.connect(&updated, &ox::Signal<ox::Error()>::emitCheckError);
+			if (m_ctr) {
+				m_ctr->incRefs();
+			}
+			return *this;
+		}
+
+		AssetRef &operator=(AssetRef &&h) noexcept {
+			if (this == &h) {
+				return *this;
+			}
+			if (m_ctr) {
+				m_ctr->decRefs();
+				oxIgnoreError(m_ctr->updated.disconnectObject(this));
+			}
+			m_ctr = h.m_ctr;
+			m_ctr->updated.connect(this, &AssetRef::emitUpdated);
+			h.m_ctr = nullptr;
+			return *this;
+		}
+
+		explicit constexpr operator bool() const noexcept {
+			return m_ctr;
+		}
+
+	private:
+		constexpr ox::Error emitUpdated() const noexcept {
+			updated.emit();
+			return OxError(0);
+		}
+};
+
+template<typename T>
+constexpr AssetRef<T>::AssetRef(const AssetContainer<T> *c) noexcept: m_ctr(c) {
+	if (c) {
+		c->updated.connect(this, &AssetRef::emitUpdated);
+	}
+}
+
+template<typename T>
+constexpr AssetRef<T>::AssetRef(const AssetRef &h) noexcept {
+	m_ctr = h.m_ctr;
+	if (m_ctr) {
+		m_ctr->updated.connect(this, &AssetRef::emitUpdated);
+		m_ctr->incRefs();
+	}
+}
+
+template<typename T>
+constexpr AssetRef<T>::AssetRef(AssetRef &&h) noexcept {
+	m_ctr = h.m_ctr;
+	m_ctr->updated.connect(this, &AssetRef::emitUpdated);
+	h.m_ctr = nullptr;
+}
+
+class AssetManager {
+	private:
+		class AssetTypeManagerBase {
+			public:
+				virtual ~AssetTypeManagerBase() = default;
+
+				virtual void gc() noexcept = 0;
+		};
+
+		template<typename T>
+		class AssetTypeManager: public AssetTypeManagerBase {
+			private:
+				ox::HashMap<ox::String, ox::UniquePtr<AssetContainer<T>>> m_cache;
+
+			public:
+				ox::Result<AssetRef<T>> getAsset(const ox::String &assetId) const noexcept {
+					auto out = m_cache.at(assetId);
+					oxReturnError(out);
+					return AssetRef<T>(out.value->get());
+				}
+
+				ox::Result<AssetRef<T>> setAsset(const ox::String &assetId, const T &obj) noexcept {
+					auto &p = m_cache[assetId];
+					if (!p) {
+						p = ox::make_unique<AssetContainer<T>>(obj);
+					} else {
+						p->set(obj);
+						p->updated.emit();
+					}
+					return AssetRef<T>(p.get());
+				}
+
+				ox::Result<AssetRef<T>> setAsset(const ox::String &assetId, T &&obj) noexcept {
+					auto &p = m_cache[assetId];
+					if (!p) {
+						p = ox::make_unique<AssetContainer<T>>(obj);
+					} else {
+						p->set(std::move(obj));
+						p->updated.emit();
+					}
+					return AssetRef<T>(p.get());
+				}
+
+				void gc() noexcept final {
+					for (const auto &ack : m_cache.keys()) {
+						auto &ac = m_cache[ack];
+						if (!ac->references()) {
+							m_cache.erase(ack);
+						}
+					}
+				}
+		};
+
+		ox::HashMap<ox::String, ox::UniquePtr<AssetTypeManagerBase>> m_assetTypeManagers;
+
+		template<typename T>
+		AssetTypeManager<T> *getTypeManager() noexcept {
+			constexpr auto typeName = ox::requireModelTypeName<T>();
+			static_assert(ox_strcmp(typeName, "") != 0, "Types must have TypeName to use AssetManager");
+			auto &am = m_assetTypeManagers[typeName];
+			if (!am) {
+				am = ox::make_unique<AssetTypeManager<T>>();
+			}
+			return dynamic_cast<AssetTypeManager<T>*>(am.get());
+		}
+
+	public:
+		template<typename T>
+		ox::Result<AssetRef<T>> getAsset(const ox::String &assetId) noexcept {
+			auto m = getTypeManager<T>();
+			return m->getAsset(assetId);
+		}
+
+		template<typename T>
+		ox::Result<AssetRef<T>> setAsset(const ox::String &assetId, const T &obj) noexcept {
+			auto m = getTypeManager<T>();
+			return m->setAsset(assetId, obj);
+		}
+
+		void gc() noexcept {
+			for (const auto &amk : m_assetTypeManagers.keys()) {
+				auto &am = m_assetTypeManagers[amk];
+				am->gc();
+			}
+		}
+};
+#else
+template<typename T>
+class AssetRef {
+	private:
+		const T *m_obj = nullptr;
+
+	public:
+		constexpr AssetRef() noexcept = default;
+
+		explicit constexpr AssetRef(const T *obj) noexcept: m_obj(obj) {
+		}
+
+		constexpr const T *get() const noexcept {
+			return m_obj;
+		}
+
+		constexpr const T &operator*() const & noexcept {
+			return *m_obj;
+		}
+
+		constexpr const T &&operator*() const && noexcept {
+			return *m_obj;
+		}
+
+		constexpr const T *operator->() const noexcept {
+			return m_obj;
+		}
+
+		explicit constexpr operator bool() const noexcept {
+			return m_obj;
+		}
+};
+#endif
+
+}