Create a separate FrameCache for caching sprite frames.

We split the caching SpriteLoader into a SpriteCache and FrameCache. SpriteLoader instead becomes a holder for static loading methods.

Only a few classes loaded sprite frames, and they all use it with a transient cache. By moving this method into a new class, we can lose the now redundant frame cache, saving on memory significantly since the frame data array can be reclaimed by the GC. This saves ~58 MiB on frames and ~4 MiB on the caching dictionary in simple tests.

OpenRA.Editor/TileSetRenderer.cs

@@ -50,10 +50,10 @@ namespace OpenRA.Editor
 			this.TileSize = Math.Min(tileSize.Width, tileSize.Height);
 
 			templates = new Dictionary<ushort, byte[][]>();
-			var spriteLoader = new SpriteLoader(Game.modData.SpriteLoaders, tileset.Extensions, null);
+			var frameCache = new FrameCache(Game.modData.SpriteLoaders, tileset.Extensions);
 			foreach (var t in tileset.Templates)
 			{
-				var allFrames = spriteLoader.LoadAllFrames(t.Value.Image);
+				var allFrames = frameCache[t.Value.Image];
 				var frames = t.Value.Frames != null ? t.Value.Frames.Select(f => allFrames[f]).ToArray() : allFrames;
 				templates.Add(t.Value.Id, frames.Select(f => ExtractSquareTile(f)).ToArray());
 			}

OpenRA.Game/Graphics/CursorProvider.cs

@@ -45,10 +45,10 @@ namespace OpenRA.Graphics
 			foreach (var p in nodesDict["Palettes"].Nodes)
 				palette.AddPalette(p.Key, new ImmutablePalette(GlobalFileSystem.Open(p.Value.Value), shadowIndex), false);
 
-			var spriteLoader = new SpriteLoader(modData.SpriteLoaders, new string[0], new SheetBuilder(SheetType.Indexed));
+			var spriteCache = new SpriteCache(modData.SpriteLoaders, new string[0], new SheetBuilder(SheetType.Indexed));
 			foreach (var s in nodesDict["Cursors"].Nodes)
-				LoadSequencesForCursor(spriteLoader, s.Key, s.Value);
+				LoadSequencesForCursor(spriteCache, s.Key, s.Value);
-			spriteLoader.SheetBuilder.Current.ReleaseBuffer();
+			spriteCache.SheetBuilder.Current.ReleaseBuffer();
 
 			palette.Initialize();
 		}
@@ -59,10 +59,10 @@ namespace OpenRA.Graphics
 			return new PaletteReference(name, palette.GetPaletteIndex(name), pal);
 		}
 
-		void LoadSequencesForCursor(SpriteLoader loader, string cursorSrc, MiniYaml cursor)
+		void LoadSequencesForCursor(SpriteCache cache, string cursorSrc, MiniYaml cursor)
 		{
 			foreach (var sequence in cursor.Nodes)
-				cursors.Add(sequence.Key, new CursorSequence(loader, cursorSrc, cursor.Value, sequence.Value));
+				cursors.Add(sequence.Key, new CursorSequence(cache, cursorSrc, cursor.Value, sequence.Value));
 		}
 
 		public bool HasCursorSequence(string cursor)

OpenRA.Game/Graphics/CursorSequence.cs

@@ -23,9 +23,9 @@ namespace OpenRA.Graphics
 
 		Sprite[] sprites;
 
-		public CursorSequence(SpriteLoader loader, string cursorSrc, string palette, MiniYaml info)
+		public CursorSequence(SpriteCache cache, string cursorSrc, string palette, MiniYaml info)
 		{
-			sprites = loader.LoadAllSprites(cursorSrc);
+			sprites = cache[cursorSrc];
 			var d = info.ToDictionary();
 
 			start = Exts.ParseIntegerInvariant(d["start"].Value);

OpenRA.Game/Graphics/Sequence.cs

@@ -29,7 +29,7 @@ namespace OpenRA.Graphics
 		public readonly int ShadowZOffset;
 		public readonly int[] Frames;
 
-		public Sequence(SpriteLoader loader, string unit, string name, MiniYaml info)
+		public Sequence(SpriteCache cache, string unit, string name, MiniYaml info)
 		{
 			var srcOverride = info.Value;
 			Name = name;
@@ -50,7 +50,7 @@ namespace OpenRA.Graphics
 
 				// Apply offset to each sprite in the sequence
 				// Different sequences may apply different offsets to the same frame
-				sprites = loader.LoadAllSprites(srcOverride ?? unit).Select(
+				sprites = cache[srcOverride ?? unit].Select(
 					s => new Sprite(s.sheet, s.bounds, s.offset + offset, s.channel, blendMode)).ToArray();
 
 				if (!d.ContainsKey("Length"))

OpenRA.Game/Graphics/SequenceProvider.cs

@@ -21,12 +21,12 @@ namespace OpenRA.Graphics
 	public class SequenceProvider
 	{
 		readonly Lazy<Sequences> sequences;
-		public readonly SpriteLoader SpriteLoader;
+		public readonly SpriteCache SpriteCache;
 
 		public SequenceProvider(SequenceCache cache, Map map)
 		{
 			this.sequences = Exts.Lazy(() => cache.LoadSequences(map));
-			this.SpriteLoader = cache.SpriteLoader;
+			this.SpriteCache = cache.SpriteCache;
 		}
 
 		public Sequence GetSequence(string unitName, string sequenceName)
@@ -70,8 +70,8 @@ namespace OpenRA.Graphics
 	public class SequenceCache
 	{
 		readonly ModData modData;
-		readonly Lazy<SpriteLoader> spriteLoader;
+		readonly Lazy<SpriteCache> spriteCache;
-		public SpriteLoader SpriteLoader { get { return spriteLoader.Value; } }
+		public SpriteCache SpriteCache { get { return spriteCache.Value; } }
 
 		readonly Dictionary<string, UnitSequences> sequenceCache = new Dictionary<string, UnitSequences>();
 
@@ -79,7 +79,7 @@ namespace OpenRA.Graphics
 		{
 			this.modData = modData;
 
-			spriteLoader = Exts.Lazy(() => new SpriteLoader(modData.SpriteLoaders, tileSet.Extensions, new SheetBuilder(SheetType.Indexed)));
+			spriteCache = Exts.Lazy(() => new SpriteCache(modData.SpriteLoaders, tileSet.Extensions, new SheetBuilder(SheetType.Indexed)));
 		}
 
 		public Sequences LoadSequences(Map map)
@@ -128,7 +128,7 @@ namespace OpenRA.Graphics
 				{
 					try
 					{
-						unitSequences.Add(kvp.Key, new Sequence(spriteLoader.Value, node.Key, kvp.Key, kvp.Value));
+						unitSequences.Add(kvp.Key, new Sequence(spriteCache.Value, node.Key, kvp.Key, kvp.Value));
 					}
 					catch (FileNotFoundException ex)
 					{

OpenRA.Game/Graphics/SpriteLoader.cs

@@ -30,32 +30,42 @@ namespace OpenRA.Graphics
 		bool DisableExportPadding { get; }
 	}
 
-	public class SpriteLoader
+	public class SpriteCache
 	{
 		public readonly SheetBuilder SheetBuilder;
-		readonly ISpriteLoader[] loaders;
 		readonly Cache<string, Sprite[]> sprites;
-		readonly Cache<string, ISpriteFrame[]> frames;
-		readonly string[] exts;
 
-		public SpriteLoader(ISpriteLoader[] loaders, string[] exts, SheetBuilder sheetBuilder)
+		public SpriteCache(ISpriteLoader[] loaders, string[] exts, SheetBuilder sheetBuilder)
 		{
-			this.loaders = loaders;
 			SheetBuilder = sheetBuilder;
-
 			// Include extension-less version
-			this.exts = exts.Append("").ToArray();
+			exts = exts.Append("").ToArray();
-			sprites = new Cache<string, Sprite[]>(CacheSprites);
+			sprites = new Cache<string, Sprite[]>(filename => SpriteLoader.GetSprites(filename, exts, loaders, sheetBuilder));
-			frames = new Cache<string, ISpriteFrame[]>(CacheFrames);
 		}
 
-		Sprite[] CacheSprites(string filename)
+		public Sprite[] this[string filename] { get { return sprites[filename]; } }
+	}
+
+	public class FrameCache
 	{
-			return frames[filename].Select(a => SheetBuilder.Add(a))
+		readonly Cache<string, ISpriteFrame[]> frames;
-				.ToArray();
+
+		public FrameCache(ISpriteLoader[] loaders, string[] exts)
+		{
+			frames = new Cache<string, ISpriteFrame[]>(filename => SpriteLoader.GetFrames(filename, exts, loaders));
 		}
 
-		ISpriteFrame[] CacheFrames(string filename)
+		public ISpriteFrame[] this[string filename] { get { return frames[filename]; } }
+	}
+
+	public static class SpriteLoader
+	{
+		public static Sprite[] GetSprites(string filename, string[] exts, ISpriteLoader[] loaders, SheetBuilder sheetBuilder)
+		{
+			return GetFrames(filename, exts, loaders).Select(a => sheetBuilder.Add(a)).ToArray();
+		}
+
+		public static ISpriteFrame[] GetFrames(string filename, string[] exts, ISpriteLoader[] loaders)
 		{
 			using (var stream = GlobalFileSystem.OpenWithExts(filename, exts))
 			{
@@ -67,8 +77,5 @@ namespace OpenRA.Graphics
 				throw new InvalidDataException(filename + " is not a valid sprite file");
 			}
 		}
-
-		public Sprite[] LoadAllSprites(string filename) { return sprites[filename]; }
-		public ISpriteFrame[] LoadAllFrames(string filename) { return frames[filename]; }
 	}
 }

OpenRA.Game/Graphics/Theater.cs

@@ -37,11 +37,10 @@ namespace OpenRA.Graphics
 			sheetBuilder = new SheetBuilder(SheetType.Indexed, allocate);
 			templates = new Dictionary<ushort, Sprite[]>();
 
-			// We manage the SheetBuilder ourselves, to avoid loading all of the tileset images
+			var frameCache = new FrameCache(Game.modData.SpriteLoaders, tileset.Extensions);
-			var spriteLoader = new SpriteLoader(Game.modData.SpriteLoaders, tileset.Extensions, null);
 			foreach (var t in tileset.Templates)
 			{
-				var allFrames = spriteLoader.LoadAllFrames(t.Value.Image);
+				var allFrames = frameCache[t.Value.Image];
 				var frames = t.Value.Frames != null ? t.Value.Frames.Select(f => allFrames[f]).ToArray() : allFrames;
 				templates.Add(t.Value.Id, frames.Select(f => sheetBuilder.Add(f)).ToArray());
 			}

OpenRA.Mods.Common/UtilityCommands/ConvertSpriteToPngCommand.cs

@@ -41,8 +41,7 @@ namespace OpenRA.Mods.Common.UtilityCommands
 
 			var palette = new ImmutablePalette(args[2], shadowIndex);
 
-			var frames = new SpriteLoader(modData.SpriteLoaders, new string[0], null)
+			var frames = SpriteLoader.GetFrames(src, new string[0], modData.SpriteLoaders);
-				.LoadAllFrames(src);
 
 			var usePadding = !args.Contains("--nopadding");
 			var count = 0;

OpenRA.Mods.Common/Widgets/Logic/AssetBrowserLogic.cs

@@ -308,7 +308,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			else
 			{
 				currentFilename = filename;
-				currentSprites = world.Map.SequenceProvider.SpriteLoader.LoadAllSprites(filename);
+				currentSprites = world.Map.SequenceProvider.SpriteCache[filename];
 				currentFrame = 0;
 				frameSlider.MaximumValue = (float)currentSprites.Length - 1;
 				frameSlider.Ticks = currentSprites.Length;