Improve lookups of nodes by key in MiniYaml.

OpenRA.Game/ExternalMods.cs

@@ -94,17 +94,17 @@ void LoadMod(MiniYaml yaml, string path = null, bool forceRegistration = false)
 
 			if (sheetBuilder != null)
 			{
-				var iconNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon");
+				var iconNode = yaml.NodeWithKeyOrDefault("Icon");
 				if (iconNode != null && !string.IsNullOrEmpty(iconNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(iconNode.Value.Value)))
 						mod.Icon = sheetBuilder.Add(new Png(stream));
 
-				var icon2xNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon2x");
+				var icon2xNode = yaml.NodeWithKeyOrDefault("Icon2x");
 				if (icon2xNode != null && !string.IsNullOrEmpty(icon2xNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(icon2xNode.Value.Value)))
 						mod.Icon2x = sheetBuilder.Add(new Png(stream), 1f / 2);
 
-				var icon3xNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon3x");
+				var icon3xNode = yaml.NodeWithKeyOrDefault("Icon3x");
 				if (icon3xNode != null && !string.IsNullOrEmpty(icon3xNode.Value.Value))
 					using (var stream = new MemoryStream(Convert.FromBase64String(icon3xNode.Value.Value)))
 						mod.Icon3x = sheetBuilder.Add(new Png(stream), 1f / 3);

OpenRA.Game/GameRules/SoundInfo.cs

@@ -40,16 +40,16 @@ public SoundInfo(MiniYaml y)
 		static Dictionary<string, SoundPool> ParseSoundPool(MiniYaml y, string key)
 		{
 			var ret = new Dictionary<string, SoundPool>();
-			var classifiction = y.Nodes.First(x => x.Key == key);
+			var classifiction = y.NodeWithKey(key);
 			foreach (var t in classifiction.Value.Nodes)
 			{
 				var volumeModifier = 1f;
-				var volumeModifierNode = t.Value.Nodes.FirstOrDefault(x => x.Key == nameof(SoundPool.VolumeModifier));
+				var volumeModifierNode = t.Value.NodeWithKeyOrDefault(nameof(SoundPool.VolumeModifier));
 				if (volumeModifierNode != null)
 					volumeModifier = FieldLoader.GetValue<float>(volumeModifierNode.Key, volumeModifierNode.Value.Value);
 
 				var interruptType = SoundPool.DefaultInterruptType;
-				var interruptTypeNode = t.Value.Nodes.FirstOrDefault(x => x.Key == nameof(SoundPool.InterruptType));
+				var interruptTypeNode = t.Value.NodeWithKeyOrDefault(nameof(SoundPool.InterruptType));
 				if (interruptTypeNode != null)
 					interruptType = FieldLoader.GetValue<SoundPool.InterruptType>(interruptTypeNode.Key, interruptTypeNode.Value.Value);
 

OpenRA.Game/GameRules/WeaponInfo.cs

@@ -145,7 +145,8 @@ public WeaponInfo(MiniYaml content)
 
 		static object LoadProjectile(MiniYaml yaml)
 		{
-			if (!yaml.ToDictionary().TryGetValue("Projectile", out var proj))
+			var proj = yaml.NodeWithKeyOrDefault("Projectile")?.Value;
+			if (proj == null)
 				return null;
 
 			var ret = Game.CreateObject<IProjectileInfo>(proj.Value + "Info");

OpenRA.Game/GameSpeed.cs

@@ -10,7 +10,6 @@
 #endregion
 
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenRA
 {
@@ -38,7 +37,7 @@ public class GameSpeeds : IGlobalModData
 		static object LoadSpeeds(MiniYaml y)
 		{
 			var ret = new Dictionary<string, GameSpeed>();
-			var speedsNode = y.Nodes.FirstOrDefault(n => n.Key == "Speeds");
+			var speedsNode = y.NodeWithKeyOrDefault("Speeds");
 			if (speedsNode == null)
 				throw new YamlException("Error parsing GameSpeeds: Missing Speeds node!");
 

OpenRA.Game/Graphics/CursorProvider.cs

@@ -27,22 +27,22 @@ public CursorProvider(ModData modData)
 			var sequenceYaml = MiniYaml.Merge(modData.Manifest.Cursors.Select(
 				s => MiniYaml.FromStream(fileSystem.Open(s), s)));
 
-			var nodesDict = new MiniYaml(null, sequenceYaml).ToDictionary();
+			var cursorsYaml = new MiniYaml(null, sequenceYaml).NodeWithKey("Cursors").Value;
 
 			// Overwrite previous definitions if there are duplicates
 			var pals = new Dictionary<string, IProvidesCursorPaletteInfo>();
 			foreach (var p in modData.DefaultRules.Actors[SystemActors.World].TraitInfos<IProvidesCursorPaletteInfo>())
 				if (p.Palette != null)
 					pals[p.Palette] = p;
 
-			Palettes = nodesDict["Cursors"].Nodes.Select(n => n.Value.Value)
+			Palettes = cursorsYaml.Nodes.Select(n => n.Value.Value)
 				.Where(p => p != null)
 				.Distinct()
 				.ToDictionary(p => p, p => pals[p].ReadPalette(modData.DefaultFileSystem));
 
 			var frameCache = new FrameCache(fileSystem, modData.SpriteLoaders);
 			var cursors = new Dictionary<string, CursorSequence>();
-			foreach (var s in nodesDict["Cursors"].Nodes)
+			foreach (var s in cursorsYaml.Nodes)
 				foreach (var sequence in s.Value.Nodes)
 					cursors.Add(sequence.Key, new CursorSequence(frameCache, sequence.Key, s.Key, s.Value.Value, sequence.Value));
 

OpenRA.Game/HotkeyDefinition.cs

@@ -10,7 +10,6 @@
 #endregion
 
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenRA
 {
@@ -31,29 +30,26 @@ public HotkeyDefinition(string name, MiniYaml node)
 			if (!string.IsNullOrEmpty(node.Value))
 				Default = FieldLoader.GetValue<Hotkey>("value", node.Value);
 
-			var descriptionNode = node.Nodes.FirstOrDefault(n => n.Key == "Description");
-			if (descriptionNode != null)
-				Description = descriptionNode.Value.Value;
+			var nodeDict = node.ToDictionary();
 
-			var typesNode = node.Nodes.FirstOrDefault(n => n.Key == "Types");
-			if (typesNode != null)
-				Types = FieldLoader.GetValue<HashSet<string>>("Types", typesNode.Value.Value);
+			if (nodeDict.TryGetValue("Description", out var descriptionYaml))
+				Description = descriptionYaml.Value;
 
-			var contextsNode = node.Nodes.FirstOrDefault(n => n.Key == "Contexts");
-			if (contextsNode != null)
-				Contexts = FieldLoader.GetValue<HashSet<string>>("Contexts", contextsNode.Value.Value);
+			if (nodeDict.TryGetValue("Types", out var typesYaml))
+				Types = FieldLoader.GetValue<HashSet<string>>("Types", typesYaml.Value);
 
-			var platformNode = node.Nodes.FirstOrDefault(n => n.Key == "Platform");
-			if (platformNode != null)
+			if (nodeDict.TryGetValue("Contexts", out var contextYaml))
+				Contexts = FieldLoader.GetValue<HashSet<string>>("Contexts", contextYaml.Value);
+
+			if (nodeDict.TryGetValue("Platform", out var platformYaml))
 			{
-				var platformOverride = platformNode.Value.Nodes.FirstOrDefault(n => n.Key == Platform.CurrentPlatform.ToString());
+				var platformOverride = platformYaml.NodeWithKeyOrDefault(Platform.CurrentPlatform.ToString());
 				if (platformOverride != null)
 					Default = FieldLoader.GetValue<Hotkey>("value", platformOverride.Value.Value);
 			}
 
-			var readonlyNode = node.Nodes.FirstOrDefault(n => n.Key == "Readonly");
-			if (readonlyNode != null)
-				Readonly = FieldLoader.GetValue<bool>("Readonly", readonlyNode.Value.Value);
+			if (nodeDict.TryGetValue("Readonly", out var readonlyYaml))
+				Readonly = FieldLoader.GetValue<bool>("Readonly", readonlyYaml.Value);
 		}
 	}
 }

OpenRA.Game/Manifest.cs

@@ -214,7 +214,7 @@ static string[] YamlList(Dictionary<string, MiniYaml> yaml, string key)
 			if (!yaml.ContainsKey(key))
 				return Array.Empty<string>();
 
-			return yaml[key].ToDictionary().Keys.ToArray();
+			return yaml[key].Nodes.Select(n => n.Key).ToArray();
 		}
 
 		static IReadOnlyDictionary<string, string> YamlDictionary(Dictionary<string, MiniYaml> yaml, string key)

OpenRA.Game/Map/Map.cs

@@ -95,9 +95,9 @@ public MapField(string key, string fieldName = null, bool required = true, strin
 				t == typeof(MiniYaml) ? Type.MiniYaml : Type.Normal;
 		}
 
-		public void Deserialize(Map map, ImmutableArray<MiniYamlNode> nodes)
+		public void Deserialize(Map map, MiniYaml yaml)
 		{
-			var node = nodes.FirstOrDefault(n => n.Key == key);
+			var node = yaml.NodeWithKeyOrDefault(key);
 			if (node == null)
 			{
 				if (required)
@@ -363,13 +363,13 @@ public Map(ModData modData, IReadOnlyPackage package)
 
 			var yaml = new MiniYaml(null, MiniYaml.FromStream(Package.GetStream("map.yaml"), package.Name));
 			foreach (var field in YamlFields)
-				field.Deserialize(this, yaml.Nodes);
+				field.Deserialize(this, yaml);
 
 			if (MapFormat < SupportedMapFormat)
 				throw new InvalidDataException($"Map format {MapFormat} is not supported.\n File: {package.Name}");
 
-			PlayerDefinitions = MiniYaml.NodesOrEmpty(yaml, "Players");
-			ActorDefinitions = MiniYaml.NodesOrEmpty(yaml, "Actors");
+			PlayerDefinitions = yaml.NodeWithKeyOrDefault("Players")?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
+			ActorDefinitions = yaml.NodeWithKeyOrDefault("Actors")?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
 
 			Grid = modData.Manifest.Get<MapGrid>();
 

OpenRA.Game/MiniYaml.cs

@@ -141,6 +141,34 @@ public MiniYaml WithNodesAppended(IEnumerable<MiniYamlNode> nodes)
 			return new MiniYaml(Value, newNodes);
 		}
 
+		public MiniYamlNode NodeWithKey(string key)
+		{
+			var result = NodeWithKeyOrDefault(key);
+			if (result == null)
+				throw new InvalidDataException($"No node with key '{key}'");
+			return result;
+		}
+
+		public MiniYamlNode NodeWithKeyOrDefault(string key)
+		{
+			// PERF: Avoid LINQ.
+			var first = true;
+			MiniYamlNode result = null;
+			foreach (var node in Nodes)
+			{
+				if (node.Key != key)
+					continue;
+
+				if (!first)
+					throw new InvalidDataException($"Duplicate key '{node.Key}' in {node.Location}");
+
+				first = false;
+				result = node;
+			}
+
+			return result;
+		}
+
 		public Dictionary<string, MiniYaml> ToDictionary()
 		{
 			return ToDictionary(MiniYamlIdentity);
@@ -175,11 +203,6 @@ public MiniYaml(string value, IEnumerable<MiniYamlNode> nodes)
 			Nodes = ImmutableArray.CreateRange(nodes);
 		}
 
-		public static ImmutableArray<MiniYamlNode> NodesOrEmpty(MiniYaml y, string s)
-		{
-			return y.Nodes.FirstOrDefault(n => n.Key == s)?.Value.Nodes ?? ImmutableArray<MiniYamlNode>.Empty;
-		}
-
 		static List<MiniYamlNode> FromLines(IEnumerable<ReadOnlyMemory<char>> lines, string filename, bool discardCommentsAndWhitespace, Dictionary<string, string> stringPool)
 		{
 			stringPool ??= new Dictionary<string, string>();
@@ -668,6 +691,11 @@ yield return (hasKey ? key + ":" : "")
 				foreach (var line in Nodes.ToLines())
 					yield return "\t" + line;
 		}
+
+		public MiniYamlNodeBuilder NodeWithKeyOrDefault(string key)
+		{
+			return Nodes.SingleOrDefault(n => n.Key == key);
+		}
 	}
 
 	[Serializable]

OpenRA.Game/Network/GameServer.cs

@@ -140,7 +140,7 @@ public class GameServer
 		static object LoadClients(MiniYaml yaml)
 		{
 			var clients = new List<GameClient>();
-			var clientsNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Clients");
+			var clientsNode = yaml.NodeWithKeyOrDefault("Clients");
 			if (clientsNode != null)
 			{
 				var regex = new Regex(@"Client@\d+");
@@ -159,7 +159,7 @@ public GameServer(MiniYaml yaml)
 			// Games advertised using the old API used a single Mods field
 			if (Mod == null || Version == null)
 			{
-				var modsNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Mods");
+				var modsNode = yaml.NodeWithKeyOrDefault("Mods");
 				if (modsNode != null)
 				{
 					var modVersion = modsNode.Value.Value.Split('@');

OpenRA.Game/Network/LocalizedMessage.cs

@@ -60,7 +60,7 @@ public class LocalizedMessage
 		static object LoadArguments(MiniYaml yaml)
 		{
 			var arguments = new Dictionary<string, object>();
-			var argumentsNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Arguments");
+			var argumentsNode = yaml.NodeWithKeyOrDefault("Arguments");
 			if (argumentsNode != null)
 			{
 				foreach (var argumentNode in argumentsNode.Value.Nodes)

OpenRA.Game/Network/Session.cs

@@ -227,7 +227,7 @@ public static Global Deserialize(MiniYaml data)
 			{
 				var gs = FieldLoader.Load<Global>(data);
 
-				var optionsNode = data.Nodes.FirstOrDefault(n => n.Key == "Options");
+				var optionsNode = data.NodeWithKeyOrDefault("Options");
 				if (optionsNode != null)
 					foreach (var n in optionsNode.Value.Nodes)
 						gs.LobbyOptions[n.Key] = FieldLoader.Load<LobbyOptionState>(n.Value);

OpenRA.Game/PlayerDatabase.cs

@@ -9,7 +9,6 @@
  */
 #endregion
 
-using System.Linq;
 using System.Threading.Tasks;
 using OpenRA.FileFormats;
 using OpenRA.Graphics;
@@ -94,10 +93,10 @@ public PlayerBadge LoadBadge(MiniYaml yaml)
 				});
 			}
 
-			var labelNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Label");
-			var icon24Node = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon24");
-			var icon48Node = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon48");
-			var icon72Node = yaml.Nodes.FirstOrDefault(n => n.Key == "Icon72");
+			var labelNode = yaml.NodeWithKeyOrDefault("Label");
+			var icon24Node = yaml.NodeWithKeyOrDefault("Icon24");
+			var icon48Node = yaml.NodeWithKeyOrDefault("Icon48");
+			var icon72Node = yaml.NodeWithKeyOrDefault("Icon72");
 			if (labelNode == null)
 				return null;
 

OpenRA.Game/PlayerProfile.cs

@@ -10,7 +10,6 @@
 #endregion
 
 using System.Collections.Generic;
-using System.Linq;
 
 namespace OpenRA
 {
@@ -31,7 +30,7 @@ static object LoadBadges(MiniYaml yaml)
 		{
 			var badges = new List<PlayerBadge>();
 
-			var badgesNode = yaml.Nodes.FirstOrDefault(n => n.Key == "Badges");
+			var badgesNode = yaml.NodeWithKeyOrDefault("Badges");
 			if (badgesNode != null)
 			{
 				var playerDatabase = Game.ModData.Manifest.Get<PlayerDatabase>();

OpenRA.Game/Settings.cs

@@ -385,7 +385,7 @@ public void Save()
 					else
 					{
 						// Update or add the custom value
-						var fieldYaml = sectionYaml.Value.Nodes.FirstOrDefault(n => n.Key == fli.YamlName);
+						var fieldYaml = sectionYaml.Value.NodeWithKeyOrDefault(fli.YamlName);
 						if (fieldYaml != null)
 							fieldYaml.Value.Value = serialized;
 						else

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -11,7 +11,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Collections.ObjectModel;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
@@ -350,7 +349,7 @@ public interface INotifyGameSaved { void GameSaved(World w); }
 	public interface IGameSaveTraitData
 	{
 		List<MiniYamlNode> IssueTraitData(Actor self);
-		void ResolveTraitData(Actor self, ImmutableArray<MiniYamlNode> data);
+		void ResolveTraitData(Actor self, MiniYaml data);
 	}
 
 	[RequireExplicitImplementation]

OpenRA.Game/Widgets/WidgetLoader.cs

@@ -66,7 +66,7 @@ public Widget LoadWidget(WidgetArgs args, Widget parent, MiniYamlNode node)
 					foreach (var c in child.Value.Nodes)
 						LoadWidget(args, widget, c);
 
-			var logicNode = node.Value.Nodes.FirstOrDefault(n => n.Key == "Logic");
+			var logicNode = node.Value.NodeWithKeyOrDefault("Logic");
 			var logic = logicNode?.Value.ToDictionary();
 			args.Add("logicArgs", logic);
 

OpenRA.Game/World.cs

@@ -423,7 +423,7 @@ public void Tick()
 					if (tp.Actor == null)
 						break;
 
-					tp.Trait.ResolveTraitData(tp.Actor, kv.Value.Nodes);
+					tp.Trait.ResolveTraitData(tp.Actor, kv.Value);
 				}
 
 				gameSaveTraitData.Clear();

OpenRA.Mods.Cnc/Graphics/ClassicTilesetSpecificSpriteSequence.cs

@@ -10,7 +10,6 @@
 #endregion
 
 using System.Collections.Generic;
-using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Graphics;
 
@@ -39,10 +38,10 @@ public ClassicTilesetSpecificSpriteSequence(SpriteCache cache, ISpriteSequenceLo
 
 		protected override IEnumerable<ReservationInfo> ParseFilenames(ModData modData, string tileset, int[] frames, MiniYaml data, MiniYaml defaults)
 		{
-			var node = data.Nodes.FirstOrDefault(n => n.Key == TilesetFilenames.Key) ?? defaults.Nodes.FirstOrDefault(n => n.Key == TilesetFilenames.Key);
+			var node = data.NodeWithKeyOrDefault(TilesetFilenames.Key) ?? defaults.NodeWithKeyOrDefault(TilesetFilenames.Key);
 			if (node != null)
 			{
-				var tilesetNode = node.Value.Nodes.FirstOrDefault(n => n.Key == tileset);
+				var tilesetNode = node.Value.NodeWithKeyOrDefault(tileset);
 				if (tilesetNode != null)
 				{
 					var loadFrames = CalculateFrameIndices(start, length, stride ?? length ?? 0, facings, frames, transpose, reverseFacings, shadowStart);
@@ -55,10 +54,10 @@ protected override IEnumerable<ReservationInfo> ParseFilenames(ModData modData,
 
 		protected override IEnumerable<ReservationInfo> ParseCombineFilenames(ModData modData, string tileset, int[] frames, MiniYaml data)
 		{
-			var node = data.Nodes.FirstOrDefault(n => n.Key == TilesetFilenames.Key);
+			var node = data.NodeWithKeyOrDefault(TilesetFilenames.Key);
 			if (node != null)
 			{
-				var tilesetNode = node.Value.Nodes.FirstOrDefault(n => n.Key == tileset);
+				var tilesetNode = node.Value.NodeWithKeyOrDefault(tileset);
 				if (tilesetNode != null)
 				{
 					if (frames == null)