Codechange: Move std::unique_ptr out of LRUCache implementation.

This is an implementation detail of how OpenGLSprites are stored.

src/misc/lrucache.hpp

@@ -16,12 +16,12 @@
 /**
  * Size limited cache with a least recently used eviction strategy.
  * @tparam Tkey Type of the cache key.
- * @tparam Tdata Type of the cache item. The cache will store a pointer of this type.
+ * @tparam Tdata Type of the cache item.
  */
 template <class Tkey, class Tdata>
 class LRUCache {
 private:
-	typedef std::pair<Tkey, std::unique_ptr<Tdata>> Tpair;
+	typedef std::pair<Tkey, Tdata> Tpair;
 	typedef typename std::list<Tpair>::iterator Titer;
 
 	std::list<Tpair> data; ///< Ordered list of all items.
@@ -51,7 +51,7 @@ public:
 	 * @param key Key under which the item should be stored.
 	 * @param item Item to insert.
 	 */
-	void Insert(const Tkey key, std::unique_ptr<Tdata> &&item)
+	void Insert(const Tkey key, Tdata &&item)
 	{
 		if (this->Contains(key)) {
 			/* Replace old value. */
@@ -85,13 +85,14 @@ public:
 	 * @return The item value.
 	 * @note Throws if item not found.
 	 */
-	inline Tdata *Get(const Tkey key)
+	inline const Tdata &Get(const Tkey key)
 	{
-		if (this->lookup.find(key) == this->lookup.end()) throw std::out_of_range("item not found");
+		auto it = this->lookup.find(key);
+		if (it == this->lookup.end()) throw std::out_of_range("item not found");
 		/* Move to front if needed. */
-		this->data.splice(this->data.begin(), this->data, this->lookup[key]);
+		this->data.splice(this->data.begin(), this->data, it->second);
 
-		return this->data.front().second.get();
+		return this->data.front().second;
 	}
 };
 

src/video/opengl.cpp

@@ -1077,7 +1077,7 @@ void OpenGLBackend::DrawMouseCursor()
 	for (const auto &cs : this->cursor_sprites) {
 		/* Sprites are cached by PopulateCursorCache(). */
 		if (this->cursor_cache.Contains(cs.image.sprite)) {
-			OpenGLSprite *spr = this->cursor_cache.Get(cs.image.sprite);
+			const OpenGLSprite *spr = this->cursor_cache.Get(cs.image.sprite).get();
 
 			this->RenderOglSprite(spr, cs.image.pal,
 					this->cursor_pos.x + cs.pos.x + UnScaleByZoom(spr->x_offs, ZOOM_LVL_GUI),
@@ -1089,10 +1089,10 @@ void OpenGLBackend::DrawMouseCursor()
 
 class OpenGLSpriteAllocator : public SpriteAllocator {
 public:
-	LRUCache<SpriteID, OpenGLSprite> &lru;
+	OpenGLSpriteLRUCache &lru;
 	SpriteID sprite;
 
-	OpenGLSpriteAllocator(LRUCache<SpriteID, OpenGLSprite> &lru, SpriteID sprite) : lru(lru), sprite(sprite) {}
+	OpenGLSpriteAllocator(OpenGLSpriteLRUCache &lru, SpriteID sprite) : lru(lru), sprite(sprite) {}
 protected:
 	void *AllocatePtr(size_t) override { NOT_REACHED(); }
 };
@@ -1274,7 +1274,7 @@ void OpenGLBackend::ReleaseAnimBuffer(const Rect &update_rect)
  * @param y Y position of the sprite.
  * @param zoom Zoom level to use.
  */
-void OpenGLBackend::RenderOglSprite(OpenGLSprite *gl_sprite, PaletteID pal, int x, int y, ZoomLevel zoom)
+void OpenGLBackend::RenderOglSprite(const OpenGLSprite *gl_sprite, PaletteID pal, int x, int y, ZoomLevel zoom)
 {
 	/* Set textures. */
 	bool rgb = gl_sprite->BindTextures();
@@ -1518,7 +1518,7 @@ inline Dimension OpenGLSprite::GetSize(ZoomLevel level) const
  * Bind textures for rendering this sprite.
  * @return True if the sprite has RGBA data.
  */
-bool OpenGLSprite::BindTextures()
+bool OpenGLSprite::BindTextures() const
 {
 	_glActiveTexture(GL_TEXTURE0);
 	_glBindTexture(GL_TEXTURE_2D, this->tex[TEX_RGBA] != 0 ? this->tex[TEX_RGBA] : OpenGLSprite::dummy_tex[TEX_RGBA]);

src/video/opengl.h

@@ -23,6 +23,8 @@ bool HasStringInExtensionList(std::string_view string, std::string_view substrin
 
 class OpenGLSprite;
 
+using OpenGLSpriteLRUCache = LRUCache<SpriteID, std::unique_ptr<OpenGLSprite>>;
+
 /** Platform-independent back-end class for OpenGL video drivers. */
 class OpenGLBackend : public SpriteEncoder {
 private:
@@ -58,7 +60,7 @@ private:
 	GLint  sprite_rgb_loc = 0; ///< Uniform location for RGB mode flag.
 	GLint  sprite_crash_loc = 0; ///< Uniform location for crash remap mode flag.
 
-	LRUCache<SpriteID, OpenGLSprite> cursor_cache; ///< Cache of encoded cursor sprites.
+	OpenGLSpriteLRUCache cursor_cache; ///< Cache of encoded cursor sprites.
 	PaletteID last_sprite_pal = (PaletteID)-1; ///< Last uploaded remap palette.
 	bool clear_cursor_cache = false; ///< A clear of the cursor cache is pending.
 
@@ -74,7 +76,7 @@ private:
 
 	void InternalClearCursorCache();
 
-	void RenderOglSprite(OpenGLSprite *gl_sprite, PaletteID pal, int x, int y, ZoomLevel zoom);
+	void RenderOglSprite(const OpenGLSprite *gl_sprite, PaletteID pal, int x, int y, ZoomLevel zoom);
 
 public:
 	/** Get singleton instance of this class. */
@@ -134,7 +136,7 @@ private:
 	static bool Create();
 	static void Destroy();
 
-	bool BindTextures();
+	bool BindTextures() const;
 
 public:
 	OpenGLSprite(SpriteType sprite_type, const SpriteLoader::SpriteCollection &sprite);