Check packet size before using unreliable remote

src/ReplicatedFirst/Packages/Chickynoid/Shared/Vendor/RemotePacketSizeCounter.lua

@@ -0,0 +1,200 @@
+--!strict
+-- https://github.com/Pyseph/RemotePacketSizeCounter
+local BASE_REMOTE_OVERHEAD = 9
+local REMOTEFUNCTION_OVERHEAD = 2
+local CLIENT_TO_SERVER_OVERHEAD = 5
+
+local TYPE_OVERHEAD = 1
+
+-- Byte sizes of different types of values
+local Float64 = 8
+local Float32 = 4
+local Float16 = 2
+local Int32 = 4
+local Int16 = 2
+local Int8 = 1
+
+-- Vector3's are stored as 3 Float32s, which equates to 12 bytes. They have a 1-byte overhead
+-- for what's presumably type differentiation, so the informal calculation for datatypes is:
+-- num_types*num_bytes_in_type + TYPE_OVERHEAD
+-- Example:
+-- Vector3: 3 float32s, 1 byte overhead: 3*4 + 1 = 13 bytes
+-- The structs of datatypes can be found below:
+-- https://dom.rojo.space/binary.html
+-- !! It should still be benchmarked to see if the bytes are correctly calculated !!
+
+local COLOR3_BYTES = 3*Float32
+local VECTOR3_BYTES = 3*Float32
+
+local TypeByteSizes: {[string]: number} = {
+	["nil"] = 0,
+	EnumItem = Int32,
+	boolean = 1,
+	number = Float64,
+	UDim = Float32 + Int32,
+	UDim2 = 2*(Float32 + Int32),
+	Ray = 6*Float32,
+	Faces = 6,
+	Axes = 6,
+	BrickColor = Int32,
+	Color3 = COLOR3_BYTES,
+	Vector2 = 2*Float32,
+	Vector3 = VECTOR3_BYTES,
+	-- It's unclear how instances are sent, but in binary-storage format they're stored with
+	-- 'Referents', which can be found in the binary-storage documentation above.
+	-- Benchmarks also show that they take up 4 bytes, excluding byte overhead.
+	Instance = Int32,
+	Vector2int16 = 2*Int16,
+	Vector3int16 = 3*Int16,
+	NumberSequenceKeypoint = 3*Float32,
+	ColorSequenceKeypoint = 4*Float32,
+	NumberRange = 2*Float32,
+	Rect = 2*(2*Float32),
+	PhysicalProperties = 5*Float32,
+	Color3uint8 = 3*Int8,
+}
+
+-- https://dom.rojo.space/binary.html#cframe
+local CFrameSpecialCases = {
+	[CFrame.Angles(0, 0, 0)] 							= true, 	[CFrame.Angles(0, math.rad(180), math.rad(0))] 				= true,
+	[CFrame.Angles(math.rad(90), 0, 0)] 				= true, 	[CFrame.Angles(math.rad(-90), math.rad(-180), math.rad(0))] = true,
+	[CFrame.Angles(0, math.rad(180), math.rad(180))] 	= true,		[CFrame.Angles(0, math.rad(0), math.rad(180))] 				= true,
+	[CFrame.Angles(math.rad(-90), 0, 0)] 				= true,		[CFrame.Angles(math.rad(90), math.rad(180), math.rad(0))] 	= true,
+	[CFrame.Angles(0, math.rad(180), math.rad(90))] 	= true,		[CFrame.Angles(0, math.rad(0), math.rad(-90))] 				= true,
+	[CFrame.Angles(0, math.rad(90), math.rad(90))] 		= true,		[CFrame.Angles(0, math.rad(-90), math.rad(-90))]			= true,
+	[CFrame.Angles(0, 0, math.rad(90))] 				= true,		[CFrame.Angles(0, math.rad(-180), math.rad(-90))] 			= true,
+	[CFrame.Angles(0, math.rad(-90), math.rad(90))] 	= true,		[CFrame.Angles(0, math.rad(90), math.rad(-90))] 			= true,
+	[CFrame.Angles(math.rad(-90), math.rad(-90), 0)] 	= true,		[CFrame.Angles(math.rad(90), math.rad(90), 0)] 				= true,
+	[CFrame.Angles(0, math.rad(-90), 0)] 				= true,		[CFrame.Angles(0, math.rad(90), 0)] 						= true,
+	[CFrame.Angles(math.rad(90), math.rad(-90), 0)] 	= true,		[CFrame.Angles(math.rad(-90), math.rad(90), 0)] 			= true,
+	[CFrame.Angles(0, math.rad(90), math.rad(180))] 	= true,		[CFrame.Angles(0, math.rad(-90), math.rad(180))] 			= true,
+}
+
+-- https://en.wikipedia.org/wiki/Variable-length_quantity
+local function GetVLQSize(InitialSize: number, Length: number)
+	return math.max(math.ceil(math.log(Length + InitialSize, 128)), InitialSize)
+end
+
+local function GetDataByteSize(Data: any, AlreadyTraversed: {[{[any]: any}]: boolean})
+	local DataType = typeof(Data)
+	if TypeByteSizes[DataType] then
+		return TypeByteSizes[DataType]
+	elseif DataType == "string" or DataType == "buffer" then
+		-- https://data-oriented-house.github.io/Squash/docs/binary/#strings
+		local Length = DataType == "string" and #Data or buffer.len(Data)
+		return GetVLQSize(1, Length) + Length
+	elseif DataType == "table" then
+		if AlreadyTraversed[Data] then
+			return 0
+		end
+		AlreadyTraversed[Data] = true
+
+		local KeyTotal = 0
+		local ValueTotal = 0
+
+		local NumKeys = 1
+		local IsArray = Data[1] ~= nil
+ 		for Key, Value in next, Data do
+			NumKeys += 1
+
+			if not IsArray then
+				KeyTotal += GetDataByteSize(Key, AlreadyTraversed) + TYPE_OVERHEAD
+			end
+			ValueTotal += GetDataByteSize(Value, AlreadyTraversed) + TYPE_OVERHEAD
+		end
+
+		if IsArray then
+			return GetVLQSize(1, NumKeys) + ValueTotal
+		else
+			return GetVLQSize(1, NumKeys) + KeyTotal + ValueTotal
+		end
+	elseif DataType == "CFrame" then
+		local IsSpecialCase = false
+		for SpecialCase in next, CFrameSpecialCases do
+			if SpecialCase == Data.Rotation then
+				IsSpecialCase = true
+				break
+			end
+		end
+
+		if IsSpecialCase then
+			-- Axis-aligned CFrames skip sending rotation and are encoded as only 13 bytes
+			return 1 + VECTOR3_BYTES
+		else
+			-- 1 byte for the ID, 12 bytes for the position vector, and 6 bytes for the quaternion representation
+			--                         I'm assuming they send x,y,z quaternions and reconstruct w from `x*x + y*y + z*z + w*w = 1`.
+			return 1 + VECTOR3_BYTES + 3*Float16
+		end
+	elseif DataType == "NumberSequence" or DataType == "ColorSequence" then
+		local Total = 4
+		for _, Keypoint in next, Data.Keypoints do
+			Total += GetDataByteSize(Keypoint, AlreadyTraversed)
+		end
+
+		return Total
+	else
+		warn("[PacketSizeCounter]: Unsupported data type: " .. DataType)
+		return 0
+	end
+end
+
+--- @class PacketSizeCounter
+--- The main class for calculating the size of packets.
+local PacketSizeCounter = {}
+
+--- @prop BaseRemoteOverhead number
+--- @within PacketSizeCounter
+--- @readonly
+--- The byte overhead of a remote event, in bytes.
+PacketSizeCounter.BaseRemoteOverhead = BASE_REMOTE_OVERHEAD
+
+
+--- @prop RemoteFunctionOverhead number
+--- @within PacketSizeCounter
+--- @readonly
+--- The additional byte overhead of a remote function, in bytes.
+PacketSizeCounter.RemoteFunctionOverhead = REMOTEFUNCTION_OVERHEAD
+
+
+--- @prop ClientToServerOverhead number
+--- @within PacketSizeCounter
+--- @readonly
+--- The additional byte overhead of a client-to-server remote, in bytes.
+PacketSizeCounter.ClientToServerOverhead = CLIENT_TO_SERVER_OVERHEAD
+
+
+--- @prop TypeOverhead number
+--- @within PacketSizeCounter
+--- @readonly
+--- The byte overhead of a type, in bytes.
+PacketSizeCounter.TypeOverhead = TYPE_OVERHEAD
+
+--- Returns the byte size of a packet from the given data. Remote overhead is automatically added, and is different based on the remote type and run context.
+function PacketSizeCounter.GetPacketSize(CounterData: {
+	RunContext: "Server" | "Client",
+	RemoteType: "RemoteEvent" | "RemoteFunction",
+	PacketData: {any}
+}): number
+	local Total = BASE_REMOTE_OVERHEAD
+	if CounterData.RemoteType == "RemoteFunction" then
+		Total += REMOTEFUNCTION_OVERHEAD
+	end
+	if CounterData.RunContext == "Client" then
+		Total += CLIENT_TO_SERVER_OVERHEAD
+	end
+
+	local AlreadyTraversed = {}
+
+	for _, Data in ipairs(CounterData.PacketData) do
+		Total += GetDataByteSize(Data, AlreadyTraversed) + TYPE_OVERHEAD
+	end
+
+	return Total
+end
+--- Returns the byte size of a single data object type. Supports most types.
+function PacketSizeCounter.GetDataByteSize(Data: any): number
+	return GetDataByteSize(Data, {}) + TYPE_OVERHEAD
+end
+
+table.freeze(PacketSizeCounter)
+return PacketSizeCounter

src/ServerScriptService/Packages/Chickynoid/Server/ServerModule.lua

@@ -23,6 +23,8 @@ local WeaponsModule = require(script.Parent.WeaponsServer)
 local CollisionModule = require(path.Shared.Simulation.CollisionModule)
 local Antilag = require(script.Parent.Antilag)
 local FastSignal = require(path.Shared.Vendor.FastSignal)
+local RemotePacketSizeCounter = require(path.Shared.Vendor.RemotePacketSizeCounter)
+
 local ServerMods = require(script.Parent.ServerMods)
 local Animations = require(path.Shared.Simulation.Animations)
 
@@ -90,6 +92,7 @@ ServerModule.flags.DEBUG_BOT_BANDWIDTH = false
 ]=]
 function ServerModule:Setup()
     self.worldRoot = self:GetDoNotReplicate()
+    -- self.worldRoot = workspace
 
     Players.PlayerAdded:Connect(function(player)
         self:PlayerConnected(player)
@@ -182,7 +185,7 @@ function ServerModule:AssignSlot(playerRecord)
     return false
 end
 
-function ServerModule:AddConnection(userId, player)
+function ServerModule:AddConnection(userId, player, characterMod)
     if self.playerRecords[userId] ~= nil or self.loadingPlayerRecords[userId] ~= nil then
         warn("Player was already connected.", userId)
         self:PlayerDisconnected(userId)
@@ -210,7 +213,7 @@ function ServerModule:AddConnection(userId, player)
 	playerRecord.OnBeforePlayerSpawn = FastSignal.new()
 	playerRecord.visHistoryList = {}
 
-    playerRecord.characterMod = "HumanoidChickynoid"
+    playerRecord.characterMod = characterMod or "HumanoidChickynoid"
 
 	playerRecord.lastConfirmedSnapshotServerFrame = nil --Stays nil til a player confirms they've seen a whole snapshot, for delta compression purposes
 
@@ -324,6 +327,8 @@ function ServerModule:AddConnection(userId, player)
         self.chickynoid = chickynoid
         chickynoid.playerRecord = self
 
+		-- This can be really inefficient when you have a ton of parts! Consider
+		-- changing this spawn behavior, maybe CollectionService or something.
         local list = {}
         for _, obj: SpawnLocation in pairs(workspace:GetDescendants()) do
             if obj:IsA("SpawnLocation") and obj.Enabled == true then
@@ -666,7 +671,13 @@ function ServerModule:UpdatePlayerStatesToPlayers()
 			event.serverFrame = self.serverTotalFrames
 			event.playerStateDelta, event.playerStateDeltaFrame = playerRecord.chickynoid:ConstructPlayerStateDelta(self.serverTotalFrames)
 
-			playerRecord:SendUnreliableEventToClient(event)
+			-- // CHECK PACKET SIZE, PROBABLY HUGE FOR A BIG STATE
+			local s = RemotePacketSizeCounter.GetDataByteSize(event.playerStateDelta)
+			if s > 700 then
+				playerRecord:SendEventToClient(event)
+			else
+				playerRecord:SendUnreliableEventToClient(event)
+			end
 
 			--Clear the error state flag 
 			playerRecord.chickynoid.errorState = Enums.NetworkProblemState.None
@@ -718,7 +729,7 @@ function ServerModule:UpdatePlayerThinks(deltaTime)
 		if playerRecord.chickynoid then
 			playerRecord.chickynoid:Think(self, self.serverSimulationTime, deltaTime)
 
-			if playerRecord.chickynoid.simulation.state.pos.y < -2000 then
+			if playerRecord.chickynoid.simulation.state.position.y < -2000 then
 				playerRecord:Despawn()
 			end
 		end

src/ServerScriptService/Packages/Chickynoid/Server/ServerSnapshotGen.lua

@@ -8,6 +8,7 @@ local Profiler = require(path.Shared.Vendor.Profiler)
 local CharacterData = require(path.Shared.Simulation.CharacterData)
 
 local DeltaTable = require(path.Shared.Vendor.DeltaTable)
+local RemotePacketSizeCounter = require(path.Shared.Vendor.RemotePacketSizeCounter)
 local Enums = require(path.Shared.Enums)
 local EventType = Enums.EventType
 local absoluteMaxSizeOfBuffer = 4096
@@ -219,7 +220,12 @@ function module:DoWork(playerRecords, serverTotalFrames, serverSimulationTime, d
 			for _,snapshot in queue do
 				snapshot.m = #queue
 
-				playerRecord:SendUnreliableEventToClient(snapshot)
+				local s = RemotePacketSizeCounter.GetDataByteSize(snapshot.playerStateDelta)
+				if s > 700 then
+					playerRecord:SendEventToClient(snapshot)
+				else
+					playerRecord:SendUnreliableEventToClient(snapshot)
+				end
 			end
 		end
 	end