Cache (De)SerializeOptions in hot paths (#3547)

They are essentially compile time constants, so we shouldn't allocate them

Author: lolleko

engine/Sandbox.Engine/Scene/GameObject/GameObject.Network.cs

@@ -437,12 +437,14 @@ internal GameObject FindNetworkRoot()
 		return Parent.FindNetworkRoot();
 	}
 
+	private static readonly DeserializeOptions _networkRefreshDeserializeOptions = new() { IsRefreshing = true, IsNetworkRefresh = true };
+
 	/// <summary>
 	/// Update hierarchy from a network refresh.
 	/// </summary>
 	internal void NetworkRefresh( JsonObject jso )
 	{
-		Deserialize( jso, new DeserializeOptions { IsRefreshing = true, IsNetworkRefresh = true } );
+		Deserialize( jso, _networkRefreshDeserializeOptions );
 	}
 
 	/// <summary>

engine/Sandbox.Engine/Scene/GameObject/GameObject.PrefabInstanceData.cs

@@ -102,14 +102,15 @@ public void InitPatch( Json.Patch patch )
 		_patch = patch;
 	}
 
+	private static readonly SerializeOptions _serializeOptions = new();
+
 	/// <summary>
 	/// Updates the cached patch that represents differences between this instance and its source prefab.
 	/// </summary>
 	public void RefreshPatch()
 	{
-		SerializeOptions options = new SerializeOptions();
 
-		var instanceData = _instanceRoot.SerializeStandard( options );
+		var instanceData = _instanceRoot.SerializeStandard( _serializeOptions );
 
 		RemapInstanceIdsToPrefabIds( ref instanceData );
 

engine/Sandbox.Engine/Scene/GameObject/GameObject.Serialize.cs

@@ -82,6 +82,8 @@ internal bool ShouldSave( GameObject gameObject )
 		}
 	}
 
+	private static readonly SerializeOptions _defaultSerializeOptions = new();
+
 	public struct DeserializeOptions
 	{
 		/// <summary>
@@ -111,13 +113,15 @@ public struct DeserializeOptions
 		public Transform? TransformOverride { get; set; }
 	}
 
+	private static readonly DeserializeOptions _defaultDeserializeOptions = new();
+
 	/// <summary>
 	/// Returns either a full JsonObject with all the GameObjects data,
 	/// or if this GameObject is a prefab instance, it will return an object containing the patch/diff between instance and prefab.
 	/// </summary>
 	public virtual JsonObject Serialize( SerializeOptions options = null )
 	{
-		options ??= new SerializeOptions();
+		options ??= _defaultSerializeOptions;
 
 		if ( !options.ShouldSave( this ) ) return null;
 
@@ -302,8 +306,7 @@ internal virtual JsonObject SerializeStandard( SerializeOptions options )
 		return json;
 	}
 
-
-	public virtual void Deserialize( JsonObject node ) => Deserialize( node, new DeserializeOptions() );
+	public virtual void Deserialize( JsonObject node ) => Deserialize( node, _defaultDeserializeOptions );
 
 	public virtual void Deserialize( JsonObject node, DeserializeOptions options )
 	{

engine/Sandbox.Engine/Scene/Networking/NetworkObject.cs

@@ -231,6 +231,8 @@ internal void SendNetworkDestroy()
 		SceneNetworkSystem.Instance.Broadcast( msg );
 	}
 
+	private static readonly GameObject.SerializeOptions _refreshSerializeOptions = new() { SingleNetworkObject = true };
+
 	internal ObjectRefreshMsg GetRefreshMessage()
 	{
 		var system = SceneNetworkSystem.Instance;
@@ -239,23 +241,20 @@ internal ObjectRefreshMsg GetRefreshMessage()
 
 		var snapshot = ((IDeltaSnapshot)this).WriteSnapshotState();
 
-		var o = new GameObject.SerializeOptions
-		{
-			SingleNetworkObject = true
-		};
-
 		var msg = new ObjectRefreshMsg
 		{
 			Guid = GameObject.Id,
 			Parent = GameObject.Parent.Id,
-			JsonData = GameObject.Serialize( o ).ToJsonString(),
+			JsonData = GameObject.Serialize( _refreshSerializeOptions ).ToJsonString(),
 			TableData = WriteReliableData(),
 			Snapshot = system.DeltaSnapshots.GetFullSnapshotData( snapshot )
 		};
 
 		return msg;
 	}
 
+	private static readonly GameObject.SerializeOptions _refreshDescendantSerializeOptions = new() { IgnoreChildren = true };
+
 	internal void SendNetworkRefresh( GameObject go )
 	{
 		var system = SceneNetworkSystem.Instance;
@@ -288,17 +287,11 @@ internal void SendNetworkRefresh( GameObject go )
 		{
 			var snapshot = ((IDeltaSnapshot)this).WriteSnapshotState();
 
-			// Only this one object...
-			var options = new GameObject.SerializeOptions
-			{
-				IgnoreChildren = true
-			};
-
 			var msg = new ObjectRefreshDescendantMsg
 			{
 				GameObjectId = GameObject.Id,
 				ParentId = go.Parent.Id,
-				JsonData = go.Serialize( options ).ToJsonString(),
+				JsonData = go.Serialize( _refreshDescendantSerializeOptions ).ToJsonString(),
 				TableData = WriteReliableData(),
 				Snapshot = system.DeltaSnapshots.GetFullSnapshotData( snapshot )
 			};
@@ -579,16 +572,16 @@ internal void TransmitStateChanged()
 		LocalSnapshotState.ClearConnections();
 	}
 
+	private static readonly GameObject.SerializeOptions _createSerializeOptions = new() { SingleNetworkObject = true };
+
 	internal ObjectCreateMsg GetCreateMessage()
 	{
-		var o = new GameObject.SerializeOptions { SingleNetworkObject = true };
-
 		if ( GameObject.Parent is null )
 		{
 			throw new( $"GameObject {GameObject.Id} ({GameObject.Name} has invalid parent" );
 		}
 
-		var jsonData = GameObject.Serialize( o );
+		var jsonData = GameObject.Serialize( _createSerializeOptions );
 		if ( jsonData is null )
 		{
 			throw new( $"Unable to serialize {GameObject.Id} ({GameObject.Name})" );

engine/Sandbox.Engine/Scene/Networking/SceneNetworkSystem.cs

@@ -281,6 +281,8 @@ public override async Task MountVPKs( Connection source, MountedVPKsResponse msg
 		MountedVPKs = await MountMaps( msg.MountedVPKs );
 	}
 
+	private static readonly GameObject.SerializeOptions _snapshotSerializeOptions = new() { SceneForNetwork = true };
+
 	/// <summary>
 	/// A client has joined and wants a snapshot of the world.
 	/// </summary>
@@ -291,16 +293,11 @@ public override void GetSnapshot( Connection source, ref SnapshotMsg msg )
 
 		msg.Time = Time.Now;
 
-		var o = new GameObject.SerializeOptions
-		{
-			SceneForNetwork = true
-		};
-
 		var analytic = new Api.Events.EventRecord( "SceneNetworkSystem.GetSnapshot" );
 
 		using ( analytic.ScopeTimer( "SceneTime" ) )
 		{
-			msg.SceneData = Game.ActiveScene.Serialize( o ).ToJsonString();
+			msg.SceneData = Game.ActiveScene.Serialize( _snapshotSerializeOptions ).ToJsonString();
 		}
 
 		using ( analytic.ScopeTimer( "NetworkObjectTime" ) )

engine/Sandbox.Engine/Scene/Scene/Scene.LoadSave.cs

@@ -217,8 +217,6 @@ public override void Deserialize( JsonObject node, DeserializeOptions option )
 		}
 	}
 
-	public override void Deserialize( JsonObject node ) => Deserialize( node, new DeserializeOptions() );
-
 	internal JsonObject SerializeProperties()
 	{
 		var jso = new JsonObject();