Improved efficiency of startup methods.

- ShpReader will copy the input stream into memory just once rather than for every header.
- ShpReader.CopyImageData switched to use Array.Copy since that uses some unsafe magic for speed.
- In ActorInfo, cache a GetType call and prevent needless materialization in PrerequisitesOf.
- In ObjectCreator, cache type and ctor lookups since these are expensive and often repeated.
- Implement IReadOnlyDictionary<T, U> on Cache<T, U> to provide some supplementary functions.
- In TechTree.GatherOwnedPrerequisites, rearrange a Boolean 'and' expression to evaluate expensive functions later in the chain, and use ContainsKey to speed up name check.

OpenRA.Game/FileFormats/Format40.cs

@@ -12,58 +12,58 @@ namespace OpenRA.FileFormats
 {
 	public static class Format40
 	{
-		public static int DecodeInto( byte[] src, byte[] dest )
+		public static int DecodeInto(byte[] src, byte[] dest, int srcOffset)
 		{
-			var ctx = new FastByteReader(src);
+			var ctx = new FastByteReader(src, srcOffset);
 			int destIndex = 0;
 
-			while( true )
+			while (true)
 			{
 				byte i = ctx.ReadByte();
-				if( ( i & 0x80 ) == 0 )
+				if ((i & 0x80) == 0)
 				{
 					int count = i & 0x7F;
-					if( count == 0 )
+					if (count == 0)
 					{
 						// case 6
 						count = ctx.ReadByte();
 						byte value = ctx.ReadByte();
-						for( int end = destIndex + count ; destIndex < end ; destIndex++ )
+						for (int end = destIndex + count; destIndex < end; destIndex++)
-							dest[ destIndex ] ^= value;
+							dest[destIndex] ^= value;
 					}
 					else
 					{
 						// case 5
-						for( int end = destIndex + count ; destIndex < end ; destIndex++ )
+						for (int end = destIndex + count; destIndex < end; destIndex++)
 							dest[destIndex] ^= ctx.ReadByte();
 					}
 				}
 				else
 				{
 					int count = i & 0x7F;
-					if( count == 0 )
+					if (count == 0)
 					{
 						count = ctx.ReadWord();
-						if( count == 0 )
+						if (count == 0)
 							return destIndex;
 
-						if( ( count & 0x8000 ) == 0 )
+						if ((count & 0x8000) == 0)
 						{
 							// case 2
-							destIndex += ( count & 0x7FFF );
+							destIndex += (count & 0x7FFF);
 						}
-						else if( ( count & 0x4000 ) == 0 )
+						else if ((count & 0x4000) == 0)
 						{
 							// case 3
-							for( int end = destIndex + ( count & 0x3FFF ) ; destIndex < end ; destIndex++ )
+							for (int end = destIndex + (count & 0x3FFF); destIndex < end; destIndex++)
 								dest[destIndex] ^= ctx.ReadByte();
 						}
 						else
 						{
 							// case 4
 							byte value = ctx.ReadByte();
-							for( int end = destIndex + ( count & 0x3FFF ) ; destIndex < end ; destIndex++ )
+							for (int end = destIndex + (count & 0x3FFF); destIndex < end; destIndex++)
-								dest[ destIndex ] ^= value;
+								dest[destIndex] ^= value;
 						}
 					}
 					else

OpenRA.Game/FileFormats/Format80.cs

@@ -16,11 +16,12 @@ namespace OpenRA.FileFormats
 	class FastByteReader
 	{
 		readonly byte[] src;
-		int offset = 0;
+		int offset;
 
-		public FastByteReader(byte[] src)
+		public FastByteReader(byte[] src, int offset = 0)
 		{
 			this.src = src;
+			this.offset = offset;
 		}
 
 		public bool Done() { return offset >= src.Length; }
@@ -59,9 +60,9 @@ namespace OpenRA.FileFormats
 			}
 		}
 
-		public static int DecodeInto(byte[] src, byte[] dest)
+		public static int DecodeInto(byte[] src, byte[] dest, int srcOffset = 0)
 		{
-			var ctx = new FastByteReader(src);
+			var ctx = new FastByteReader(src, srcOffset);
 			var destIndex = 0;
 
 			while (true)

OpenRA.Game/FileFormats/ShpReader.cs

@@ -67,6 +67,9 @@ namespace OpenRA.FileFormats
 		int recurseDepth = 0;
 		readonly int imageCount;
 
+		readonly long shpBytesFileOffset;
+		readonly byte[] shpBytes;
+
 		public ShpReader(Stream stream)
 		{
 			imageCount = stream.ReadUInt16();
@@ -93,22 +96,16 @@ namespace OpenRA.FileFormats
 					throw new InvalidDataException("Reference doesnt point to image data {0}->{1}".F(h.FileOffset, h.RefOffset));
 			}
 
+			shpBytesFileOffset = stream.Position;
+			shpBytes = stream.ReadBytes((int)(stream.Length - stream.Position));
+
 			foreach (var h in headers)
-				Decompress(stream, h);
+				Decompress(h);
 
 			spriteFrames = Exts.Lazy(() => headers.Cast<ISpriteFrame>());
 		}
 
-		static byte[] ReadCompressedData(Stream stream, ImageHeader h)
+		void Decompress(ImageHeader h)
-		{
-			stream.Position = h.FileOffset;
-
-			// Actually, far too big. There's no length field with the correct length though :(
-			var compressedLength = (int)(stream.Length - stream.Position);
-			return stream.ReadBytes(compressedLength);
-		}
-
-		void Decompress(Stream stream, ImageHeader h)
 		{
 			// No extra work is required for empty frames
 			if (h.Size.Width == 0 || h.Size.Height == 0)
@@ -125,19 +122,19 @@ namespace OpenRA.FileFormats
 					if (h.RefImage.Data == null)
 					{
 						++recurseDepth;
-						Decompress(stream, h.RefImage);
+						Decompress(h.RefImage);
 						--recurseDepth;
 					}
 
 					h.Data = CopyImageData(h.RefImage.Data);
-					Format40.DecodeInto(ReadCompressedData(stream, h), h.Data);
+					Format40.DecodeInto(shpBytes, h.Data, (int)(h.FileOffset - shpBytesFileOffset));
 					break;
 				}
 
 				case Format.Format80:
 				{
 					var imageBytes = new byte[Size.Width * Size.Height];
-					Format80.DecodeInto(ReadCompressedData(stream, h), imageBytes);
+					Format80.DecodeInto(shpBytes, imageBytes, (int)(h.FileOffset - shpBytesFileOffset));
 					h.Data = imageBytes;
 					break;
 				}
@@ -150,9 +147,7 @@ namespace OpenRA.FileFormats
 		byte[] CopyImageData(byte[] baseImage)
 		{
 			var imageData = new byte[Size.Width * Size.Height];
-			for (var i = 0; i < Size.Width * Size.Height; i++)
+			Array.Copy(baseImage, imageData, imageData.Length);
-				imageData[i] = baseImage[i];
-
 			return imageData;
 		}
 

OpenRA.Game/GameRules/ActorInfo.cs

@@ -94,7 +94,11 @@ namespace OpenRA
 			while (t.Count != 0)
 			{
 				var prereqs = PrerequisitesOf(t[index]);
-				var unsatisfied = prereqs.Where(n => !ret.Any(x => x.GetType() == n || n.IsAssignableFrom(x.GetType())));
+				var unsatisfied = prereqs.Where(n => !ret.Any(x =>
+				{
+					var type = x.GetType();
+					return type == n || n.IsAssignableFrom(type);
+				}));
 				if (!unsatisfied.Any())
 				{
 					ret.Add(t[index]);
@@ -111,14 +115,13 @@ namespace OpenRA
 			return ret;
 		}
 
-		static List<Type> PrerequisitesOf(ITraitInfo info)
+		static IEnumerable<Type> PrerequisitesOf(ITraitInfo info)
 		{
 			return info
 				.GetType()
 				.GetInterfaces()
-				.Where( t => t.IsGenericType && t.GetGenericTypeDefinition() == typeof( Requires<> ) )
+				.Where(t => t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Requires<>))
-				.Select( t => t.GetGenericArguments()[ 0 ] )
+				.Select(t => t.GetGenericArguments()[0]);
-				.ToList();
 		}
 
 		public IEnumerable<Pair<string, Type>> GetInitKeys()

OpenRA.Game/ObjectCreator.cs

@@ -19,10 +19,15 @@ namespace OpenRA
 {
 	public class ObjectCreator
 	{
-		Pair<Assembly, string>[] assemblies;
+		readonly Cache<string, Type> typeCache;
+		readonly Cache<Type, ConstructorInfo> ctorCache;
+		readonly Pair<Assembly, string>[] assemblies;
 
 		public ObjectCreator(Manifest manifest)
 		{
+			typeCache = new Cache<string, Type>(FindType);
+			ctorCache = new Cache<Type, ConstructorInfo>(GetCtor);
+
 			// All the core namespaces
 			var asms = typeof(Game).Assembly.GetNamespaces() // Game
 				.Select(c => Pair.New(typeof(Game).Assembly, c))
@@ -48,23 +53,18 @@ namespace OpenRA
 
 		public T CreateObject<T>(string className, Dictionary<string, object> args)
 		{
-			var type = FindType(className);
+			var type = typeCache[className];
 			if (type == null)
 			{
 				MissingTypeAction(className);
 				return default(T);
 			}
 
-			var flags = BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance;
+			var ctor = ctorCache[type];
-			var ctors = type.GetConstructors(flags)
+			if (ctor == null)
-				.Where(x => x.HasAttribute<UseCtorAttribute>()).ToList();
-
-			if (ctors.Count == 0)
 				return (T)CreateBasic(type);
-			else if (ctors.Count == 1)
-				return (T)CreateUsingArgs(ctors[0], args);
 			else
-				throw new InvalidOperationException("ObjectCreator: UseCtor on multiple constructors; invalid.");
+				return (T)CreateUsingArgs(ctor, args);
 		}
 
 		public Type FindType(string className)
@@ -74,6 +74,21 @@ namespace OpenRA
 				.FirstOrDefault(t => t != null);
 		}
 
+		public ConstructorInfo GetCtor(Type type)
+		{
+			var flags = BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance;
+			var ctors = type.GetConstructors(flags).Where(x => x.HasAttribute<UseCtorAttribute>());
+			using (var e = ctors.GetEnumerator())
+			{
+				if (!e.MoveNext())
+					return null;
+				var ctor = e.Current;
+				if (!e.MoveNext())
+					return ctor;
+			}
+			throw new InvalidOperationException("ObjectCreator: UseCtor on multiple constructors; invalid.");
+		}
+
 		public object CreateBasic(Type type)
 		{
 			return type.GetConstructor(new Type[0]).Invoke(new object[0]);

OpenRA.Game/Primitives/Cache.cs

@@ -14,18 +14,17 @@ using System.Collections.Generic;
 
 namespace OpenRA.Primitives
 {
-	public class Cache<T, U> : IEnumerable<KeyValuePair<T, U>>
+	public class Cache<T, U> : IReadOnlyDictionary<T, U>
 	{
-		Dictionary<T, U> hax;
+		readonly Dictionary<T, U> cache;
-		Func<T,U> loader;
+		readonly Func<T, U> loader;
 
-		public Cache(Func<T,U> loader, IEqualityComparer<T> c)
+		public Cache(Func<T, U> loader, IEqualityComparer<T> c)
 		{
-			hax = new Dictionary<T, U>(c);
 			if (loader == null)
 				throw new ArgumentNullException("loader");
-
 			this.loader = loader;
+			cache = new Dictionary<T, U>(c);
 		}
 
 		public Cache(Func<T, U> loader)
@@ -36,18 +35,17 @@ namespace OpenRA.Primitives
 			get
 			{
 				U result;
-				if (!hax.TryGetValue(key, out result))
+				if (!cache.TryGetValue(key, out result))
-					hax.Add(key, result = loader(key));
+					cache.Add(key, result = loader(key));
-
 				return result;
 			}
 		}
-
+		public bool ContainsKey(T key) { return cache.ContainsKey(key); }
-		public IEnumerator<KeyValuePair<T, U>> GetEnumerator() { return hax.GetEnumerator(); }
+		public bool TryGetValue(T key, out U value) { return cache.TryGetValue(key, out value); }
-
+		public int Count { get { return cache.Count; } }
+		public ICollection<T> Keys { get { return cache.Keys; } }
+		public ICollection<U> Values { get { return cache.Values; } }
+		public IEnumerator<KeyValuePair<T, U>> GetEnumerator() { return cache.GetEnumerator(); }
 		IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); }
-
-		public IEnumerable<T> Keys { get { return hax.Keys; } }
-		public IEnumerable<U> Values { get { return hax.Values; } }
 	}
 }

OpenRA.Game/Primitives/ReadOnlyDictionary.cs

@@ -25,8 +25,8 @@ namespace OpenRA
 	{
 		int Count { get; }
 		TValue this[TKey key] { get; }
-		IEnumerable<TKey> Keys { get; }
+		ICollection<TKey> Keys { get; }
-		IEnumerable<TValue> Values { get; }
+		ICollection<TValue> Values { get; }
 
 		bool ContainsKey(TKey key);
 		bool TryGetValue(TKey key, out TValue value);
@@ -68,9 +68,9 @@ namespace OpenRA
 
 		public TValue this[TKey key] { get { return dict[key]; } }
 
-		public IEnumerable<TKey> Keys { get { return dict.Keys; } }
+		public ICollection<TKey> Keys { get { return dict.Keys; } }
 
-		public IEnumerable<TValue> Values { get { return dict.Values; } }
+		public ICollection<TValue> Values { get { return dict.Values; } }
 		#endregion
 
 		#region IEnumerable implementation

OpenRA.Mods.RA/Player/TechTree.cs

@@ -80,9 +80,13 @@ namespace OpenRA.Mods.RA
 
 			// Add buildables that have a build limit set and are not already in the list
 			player.World.ActorsWithTrait<Buildable>()
-				  .Where(a => a.Actor.Info.Traits.Get<BuildableInfo>().BuildLimit > 0 && !a.Actor.IsDead() && a.Actor.IsInWorld && a.Actor.Owner == player && ret.Keys.All(k => k != a.Actor.Info.Name))
+				  .Where(a =>
-				  .ToList()
+					  a.Actor.Owner == player &&
-				  .ForEach(b => ret[b.Actor.Info.Name].Add(b.Actor));
+					  a.Actor.IsInWorld &&
+					  !a.Actor.IsDead() &&
+					  !ret.ContainsKey(a.Actor.Info.Name) &&
+					  a.Actor.Info.Traits.Get<BuildableInfo>().BuildLimit > 0)
+				  .Do(b => ret[b.Actor.Info.Name].Add(b.Actor));
 
 			return ret;
 		}
@@ -111,17 +115,17 @@ namespace OpenRA.Mods.RA
 
 			bool HasPrerequisites(Cache<string, List<Actor>> ownedPrerequisites)
 			{
-				return prerequisites.All(p => !(p.Replace("~", "").StartsWith("!") ^ !ownedPrerequisites.Keys.Contains(p.Replace("!", "").Replace("~", ""))));
+				return prerequisites.All(p => !(p.Replace("~", "").StartsWith("!") ^ !ownedPrerequisites.ContainsKey(p.Replace("!", "").Replace("~", ""))));
 			}
 
 			bool IsHidden(Cache<string, List<Actor>> ownedPrerequisites)
 			{
-				return prerequisites.Any(prereq => prereq.StartsWith("~") && (prereq.Replace("~", "").StartsWith("!") ^ !ownedPrerequisites.Keys.Contains(prereq.Replace("~", "").Replace("!", ""))));
+				return prerequisites.Any(prereq => prereq.StartsWith("~") && (prereq.Replace("~", "").StartsWith("!") ^ !ownedPrerequisites.ContainsKey(prereq.Replace("~", "").Replace("!", ""))));
 			}
 
 			public void Update(Cache<string, List<Actor>> ownedPrerequisites)
 			{
-				var hasReachedLimit = limit > 0 && ownedPrerequisites.Keys.Contains(Key) && ownedPrerequisites[Key].Count >= limit;
+				var hasReachedLimit = limit > 0 && ownedPrerequisites.ContainsKey(Key) && ownedPrerequisites[Key].Count >= limit;
 				// The '!' annotation inverts prerequisites: "I'm buildable if this prerequisite *isn't* met"
 				var nowHasPrerequisites = HasPrerequisites(ownedPrerequisites) && !hasReachedLimit;
 				var nowHidden = IsHidden(ownedPrerequisites);