From 38f1f1e5c2391376dea774beb0b9f9747692e5ac Mon Sep 17 00:00:00 2001
From: Vapre <vapre@hotmail.com>
Date: Sat, 4 Jul 2020 20:27:35 +0200
Subject: [PATCH] Replace TraitContainer.AllEnumerator with ApplyToAll.

As proposed in the past in #13577.

Replace TraitContainer.All() that uses the custom AllEnumerator with
TraitContainer.ApplyToAllX() that takes an action as argument.

The AllEnumerator.Current function show up in profiling reports since it is
used each tick multiple times for multiple traits. The function is 'heavy'
because it creates TraitPair<T>'s temporary objects for each actor
trait combination.

In the past about 20k ITick trait pairs were present during an average
multi player game.

Using an Apply function that takes an action avoid the need to create
these temporary objects.

To be able to still use 'DoTimed' somewhat efficiently the measurement
was moved to inside the trait container method.

Results in a 25% performance improvement in accessing all traits of
a certain type.

Apply function could be used for other TraitContainer functions as well
for further improvements.

Test result for calling on a dummy trait on 20k actors a 1000 times:
  1315 ms traitcontainer.AllEnumerator (current)
   989 ms traitcontainer.Apply (this commit)
---
 OpenRA.Game/TraitDictionary.cs | 38 ++++++++++++++++++++++++++++++++++
 OpenRA.Game/World.cs           |  9 ++++++--
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/OpenRA.Game/TraitDictionary.cs b/OpenRA.Game/TraitDictionary.cs
index 774563c27c..4d91bba30d 100644
--- a/OpenRA.Game/TraitDictionary.cs
+++ b/OpenRA.Game/TraitDictionary.cs
@@ -11,8 +11,10 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using OpenRA.Primitives;
+using OpenRA.Support;
 
 namespace OpenRA
 {
@@ -122,6 +124,16 @@ namespace OpenRA
 				t.Value.RemoveActor(a.ActorID);
 		}
 
+		public void ApplyToActorsWithTrait<T>(Action<Actor, T> action)
+		{
+			InnerGet<T>().ApplyToAll(action);
+		}
+
+		public void ApplyToActorsWithTraitTimed<T>(Action<Actor, T> action, string text)
+		{
+			InnerGet<T>().ApplyToAllTimed(action, text);
+		}
+
 		interface ITraitContainer
 		{
 			void Add(Actor actor, object trait);
@@ -277,6 +289,32 @@ namespace OpenRA
 				actors.RemoveRange(startIndex, count);
 				traits.RemoveRange(startIndex, count);
 			}
+
+			public void ApplyToAll(Action<Actor, T> action)
+			{
+				for (var i = 0; i < actors.Count; i++)
+					action(actors[i], traits[i]);
+			}
+
+			public void ApplyToAllTimed(Action<Actor, T> action, string text)
+			{
+				var longTickThresholdInStopwatchTicks = PerfTimer.LongTickThresholdInStopwatchTicks;
+				var start = Stopwatch.GetTimestamp();
+				for (var i = 0; i < actors.Count; i++)
+				{
+					var actor = actors[i];
+					var trait = traits[i];
+					action(actor, trait);
+					var current = Stopwatch.GetTimestamp();
+					if (current - start > longTickThresholdInStopwatchTicks)
+					{
+						PerfTimer.LogLongTick(start, current, text, trait);
+						start = Stopwatch.GetTimestamp();
+					}
+					else
+						start = current;
+				}
+			}
 		}
 	}
 }
diff --git a/OpenRA.Game/World.cs b/OpenRA.Game/World.cs
index d29aec8aef..59a0e536f6 100644
--- a/OpenRA.Game/World.cs
+++ b/OpenRA.Game/World.cs
@@ -465,7 +465,7 @@ namespace OpenRA
 					foreach (var a in actors.Values)
 						a.Tick();
 
-				ActorsWithTrait<ITick>().DoTimed(x => x.Trait.Tick(x.Actor), "Trait");
+				ApplyToActorsWithTraitTimed<ITick>((Actor actor, ITick trait) => trait.Tick(actor), "Trait");
 
 				effects.DoTimed(e => e.Tick(this), "Effect");
 			}
@@ -477,7 +477,7 @@ namespace OpenRA
 		// For things that want to update their render state once per tick, ignoring pause state
 		public void TickRender(WorldRenderer wr)
 		{
-			ActorsWithTrait<ITickRender>().DoTimed(x => x.Trait.TickRender(wr, x.Actor), "Render");
+			ApplyToActorsWithTraitTimed<ITickRender>((Actor actor, ITickRender trait) => trait.TickRender(wr, actor), "Render");
 			ScreenMap.TickRender();
 		}
 
@@ -536,6 +536,11 @@ namespace OpenRA
 			return TraitDict.ActorsWithTrait<T>();
 		}
 
+		public void ApplyToActorsWithTraitTimed<T>(Action<Actor, T> action, string text)
+		{
+			TraitDict.ApplyToActorsWithTraitTimed<T>(action, text);
+		}
+
 		public IEnumerable<Actor> ActorsHavingTrait<T>()
 		{
 			return TraitDict.ActorsHavingTrait<T>();