From dd2ae9fe5e4506f2f2f94572d66d5b63f55dd826 Mon Sep 17 00:00:00 2001
From: RoosterDragon <RoosterDragon@outlook.com>
Date: Fri, 15 Dec 2017 19:26:09 +0000
Subject: [PATCH] Avoid LINQ in some Tick methods.

As Tick is called often, avoiding allocation overhead in these methods is useful.
---
 OpenRA.Game/Traits/Player/PlayerResources.cs  |  8 ++++---
 .../Player/ConquestVictoryConditions.cs       | 16 +++++++++----
 OpenRA.Mods.Common/Traits/Player/TechTree.cs  | 23 ++++++++++++++++---
 3 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/OpenRA.Game/Traits/Player/PlayerResources.cs b/OpenRA.Game/Traits/Player/PlayerResources.cs
index eb92af6214..06f3b91249 100644
--- a/OpenRA.Game/Traits/Player/PlayerResources.cs
+++ b/OpenRA.Game/Traits/Player/PlayerResources.cs
@@ -172,9 +172,11 @@ namespace OpenRA.Traits
 
 		void ITick.Tick(Actor self)
 		{
-			ResourceCapacity = self.World.ActorsWithTrait<IStoreResources>()
-				.Where(a => a.Actor.Owner == owner)
-				.Sum(a => a.Trait.Capacity);
+			// PERF: Avoid LINQ.
+			ResourceCapacity = 0;
+			foreach (var tp in self.World.ActorsWithTrait<IStoreResources>())
+				if (tp.Actor.Owner == owner)
+					ResourceCapacity += tp.Trait.Capacity;
 
 			if (Resources > ResourceCapacity)
 				Resources = ResourceCapacity;
diff --git a/OpenRA.Mods.Common/Traits/Player/ConquestVictoryConditions.cs b/OpenRA.Mods.Common/Traits/Player/ConquestVictoryConditions.cs
index 973f5a0958..5e83e51e3a 100644
--- a/OpenRA.Mods.Common/Traits/Player/ConquestVictoryConditions.cs
+++ b/OpenRA.Mods.Common/Traits/Player/ConquestVictoryConditions.cs
@@ -33,6 +33,7 @@ namespace OpenRA.Mods.Common.Traits
 	{
 		readonly ConquestVictoryConditionsInfo info;
 		readonly MissionObjectives mo;
+		Player[] otherPlayers;
 		int objectiveID = -1;
 
 		public ConquestVictoryConditions(Actor self, ConquestVictoryConditionsInfo cvcInfo)
@@ -51,13 +52,18 @@ namespace OpenRA.Mods.Common.Traits
 			if (!self.Owner.NonCombatant && self.Owner.HasNoRequiredUnits())
 				mo.MarkFailed(self.Owner, objectiveID);
 
-			var others = self.World.Players.Where(p => !p.NonCombatant
-				&& !p.IsAlliedWith(self.Owner));
+			// Players, NonCombatants, and IsAlliedWith are all fixed once the game starts, so we can cache the result.
+			if (otherPlayers == null)
+				otherPlayers = self.World.Players.Where(p => !p.NonCombatant && !p.IsAlliedWith(self.Owner)).ToArray();
 
-			if (!others.Any()) return;
+			if (otherPlayers.Length == 0) return;
 
-			if (others.All(p => p.WinState == WinState.Lost))
-				mo.MarkCompleted(self.Owner, objectiveID);
+			// PERF: Avoid LINQ.
+			foreach (var otherPlayer in otherPlayers)
+				if (otherPlayer.WinState != WinState.Lost)
+					return;
+
+			mo.MarkCompleted(self.Owner, objectiveID);
 		}
 
 		public void OnPlayerLost(Player player)
diff --git a/OpenRA.Mods.Common/Traits/Player/TechTree.cs b/OpenRA.Mods.Common/Traits/Player/TechTree.cs
index fc15e076ce..a95830432a 100644
--- a/OpenRA.Mods.Common/Traits/Player/TechTree.cs
+++ b/OpenRA.Mods.Common/Traits/Player/TechTree.cs
@@ -130,13 +130,30 @@ namespace OpenRA.Mods.Common.Traits
 
 			bool HasPrerequisites(Cache<string, List<Actor>> ownedPrerequisites)
 			{
-				return prerequisites.All(p => !(p.Replace("~", "").StartsWith("!") ^ !ownedPrerequisites.ContainsKey(p.Replace("!", "").Replace("~", ""))));
+				// PERF: Avoid LINQ.
+				foreach (var prereq in prerequisites)
+				{
+					var withoutTilde = prereq.Replace("~", "");
+					if (withoutTilde.StartsWith("!") ^ !ownedPrerequisites.ContainsKey(withoutTilde.Replace("!", "")))
+						return false;
+				}
+
+				return true;
 			}
 
 			bool IsHidden(Cache<string, List<Actor>> ownedPrerequisites)
 			{
-				return prerequisites.Any(prereq => prereq.StartsWith("~") &&
-					(prereq.Replace("~", "").StartsWith("!") ^ !ownedPrerequisites.ContainsKey(prereq.Replace("~", "").Replace("!", ""))));
+				// PERF: Avoid LINQ.
+				foreach (var prereq in prerequisites)
+				{
+					if (!prereq.StartsWith("~"))
+						continue;
+					var withoutTilde = prereq.Replace("~", "");
+					if (withoutTilde.StartsWith("!") ^ !ownedPrerequisites.ContainsKey(withoutTilde.Replace("!", "")))
+						return true;
+				}
+
+				return false;
 			}
 
 			public void Update(Cache<string, List<Actor>> ownedPrerequisites)