Remove allocations when enumerating sync hashes on an actor.

Exposing Actor.SyncHashes as an array allows allocation free enumeration, we just need to adjust the SyncHash type to run the hash function.

OpenRA.Game/Actor.cs

@@ -28,8 +28,9 @@ namespace OpenRA
 		internal struct SyncHash
 		{
 			public readonly ISync Trait;
-			public readonly int Hash;
-			public SyncHash(ISync trait, int hash) { Trait = trait; Hash = hash; }
+			readonly Func<object, int> hashFunction;
+			public SyncHash(ISync trait) { Trait = trait; hashFunction = Sync.GetHashFunction(trait); }
+			public int Hash() { return hashFunction(Trait); }
 		}
 
 		public readonly ActorInfo Info;
@@ -70,7 +71,7 @@ namespace OpenRA
 			}
 		}
 
-		internal IEnumerable<SyncHash> SyncHashes { get; private set; }
+		internal SyncHash[] SyncHashes { get; private set; }
 
 		readonly IFacing facing;
 		readonly IHealth health;
@@ -129,11 +130,7 @@ namespace OpenRA
 			defaultVisibility = Trait<IDefaultVisibility>();
 			Targetables = TraitsImplementing<ITargetable>().ToArray();
 
-			SyncHashes =
-				TraitsImplementing<ISync>()
-				.Select(sync => Pair.New(sync, Sync.GetHashFunction(sync)))
-				.ToArray()
-				.Select(pair => new SyncHash(pair.First, pair.Second(pair.First)));
+			SyncHashes = TraitsImplementing<ISync>().Select(sync => new SyncHash(sync)).ToArray();
 		}
 
 		Rectangle DetermineRenderBounds()

OpenRA.Game/Network/SyncReport.cs

@@ -68,22 +68,30 @@ namespace OpenRA.Network
 			report.Effects.Clear();
 
 			foreach (var actor in orderManager.World.ActorsHavingTrait<ISync>())
+			{
 				foreach (var syncHash in actor.SyncHashes)
-					if (syncHash.Hash != 0)
+				{
+					var hash = syncHash.Hash();
+					if (hash != 0)
+					{
 						report.Traits.Add(new TraitReport()
 						{
 							ActorID = actor.ActorID,
 							Type = actor.Info.Name,
 							Owner = (actor.Owner == null) ? "null" : actor.Owner.PlayerName,
 							Trait = syncHash.Trait.GetType().Name,
-							Hash = syncHash.Hash,
+							Hash = hash,
 							NamesValues = DumpSyncTrait(syncHash.Trait)
 						});
+					}
+				}
+			}
 
 			foreach (var sync in orderManager.World.SyncedEffects)
 			{
 				var hash = Sync.Hash(sync);
 				if (hash != 0)
+				{
 					report.Effects.Add(new EffectReport()
 					{
 						Name = sync.GetType().Name,
@@ -92,6 +100,7 @@ namespace OpenRA.Network
 					});
 				}
 			}
+		}
 
 		internal void DumpSyncReport(int frame, IEnumerable<FrameData.ClientOrder> orders)
 		{

OpenRA.Game/World.cs

@@ -404,7 +404,7 @@ namespace OpenRA
 				// Hash fields marked with the ISync interface.
 				foreach (var actor in ActorsHavingTrait<ISync>())
 					foreach (var syncHash in actor.SyncHashes)
-						ret += n++ * (int)(1 + actor.ActorID) * syncHash.Hash;
+						ret += n++ * (int)(1 + actor.ActorID) * syncHash.Hash();
 
 				// Hash game state relevant effects such as projectiles.
 				foreach (var sync in SyncedEffects)