Spits out the positions of every unit, every frame into a file, and can read it back for validation. Use /startlogging [filename] and /startvalidating [fielname]

dbg_desync_helper.lua

function widget:GetInfo()
	return {
		name = "Desync Helper",
		desc = "Spits out the positions of every unit, every frame into a file, and can read it back for validation. Use /startlogging [filename] and /startvalidating [fielname]",
		author = "Beherith",
		date = "2022.09.09",
		license = "GNU GPL, v2 or later",
		layer = -math.huge,
		enabled = true,
	}
end
-- IMPORTANT HEADLESS INFO: to enable this widget in headless mode, make the order of it non-zero in /luaui/config/byar.lua

-- back of napkin:
-- if there are 1000 units for 30*60*30 frames,
-- and each unitpos takes about 16 bytes, then what do we do?
-- file size will be ~ 1gb, that is fine.

-- each line of the file will be a lua table, where 
-- [GAMEFRAME] = {unitID = {x= y= z= }}
-- things to check will be existence checks and 
-- floored positions

-- need two commands, startlogging, and validatelog

local writelog = false
local validatelog = false
local loglines = nil
local padzeros = 7

local writelogfile 
local validatelogfile

local gameFrame = 0
local frame = 0
local floor = math.floor
local format = string.format

local continuouslogging = false
local circularbuffer = {}
local circularbuffersize = 600

local writeprojectiles = false
local projectilefile

local myPlayerID = Spring.GetMyPlayerID()
local myPlayerName = Spring.GetPlayerInfo(myPlayerID,false)

local function StrPosition(unitID)
	local x,y,z = Spring.GetUnitPosition(unitID)
	if x then 
		return string.format('%f %f %f %s',x,y,z,UnitDefs[Spring.GetUnitDefID(unitID)].name)
	else
		return "0 0 0 nil"
	end
end

local function StrProjPosition(projectileID)
	local x,y,z = Spring.GetProjectilePosition(projectileID)
	if x then 
		return string.format('%f %f %f %s',x,y,z,tostring(Spring.GetProjectileName(projectileID)))
	else
		return "0 0 0 nil"
	end
end

local function ValidateUnit(unitID, posstr)
	local ps
	if Spring.ValidUnitID(unitID) then 
		ps = StrPosition(unitID)
		if ps == posstr then 
			return true
		end
	end
	local px, py, pz = Spring.GetUnitPosition(unitID)
	Spring.SendCommands({"pause 1"})
	Spring.MarkerAddPoint(px, py, pz, "INVALID:" .. tostring(unitID) )
	Spring.Echo("Validation check failed for unitID", unitID)
	Spring.Echo("Expected Position", posstr)
	Spring.Echo("Ingame position:", ps)
	return false
end

local function CreateDebugLine(allunits) 
	local segmentedtable = {}
	for i,unitID in ipairs(allunits) do 
		local ps= StrPosition(unitID)
		segmentedtable[i] = string.format("[%d] = \"%s\"", unitID, ps)
	end
	return table.concat(segmentedtable,', ')
end

local function CreateDebugLineProjectiles(allprojeciles) 
	local segmentedtable = {}
	for i,projectileID in ipairs(allprojeciles) do 
		local ps= StrProjPosition(projectileID)
		segmentedtable[i] = string.format("[%d] = \"%s\"", projectileID, ps)
	end
	return table.concat(segmentedtable,', ')
end

local syncerrorkey = "Sync error for "
local syncerrorlen = string.len(syncerrorkey)


local function dumpCircularBuffer()
	local logf = io.open(string.format("SyncErrorLog_%d_%s.txt",gameFrame,myPlayerName),'w')
	for i=gameFrame - 59, gameFrame do 
		logf:write(string.format("%07d return { %s }\n",i, circularbuffer[i % circularbuffersize]) )
	end		
	logf:close()
	Spring.Echo("dumpCircularBuffer: First sync error encountered, writing file")
end

function widget:AddConsoleLine(line, priority)
	-- [t=00:20:24.273043][f=0033531] Sync error for [teh]Beherith in frame 33528 (got bfe67f8e, correct is 6ccb53e5)
	if not continuouslogging then return end 
	if string.sub(line, 1, syncerrorlen) == syncerrorkey then 
		continuouslogging = false
		dumpCircularBuffer()
	end
end

function widget:Initialize()
	gameFrame = Spring.GetGameFrame()
end

local startlogging = 'startlogging'
local startvalidating = 'startvalidating'

function widget:TextCommand(command)
	if string.sub(command,1, string.len(startlogging)) == startlogging then
		writelog = true
		Spring.Echo("Starting desync logging:", command) 
		writelogfile = io.open(string.sub(command,string.len(startlogging) + 2),'w')
	end
	if string.sub(command,1, string.len(startvalidating)) == startvalidating then
		validatelog = true
		Spring.Echo("Starting validation", command)
		validatelogfile = io.open(string.sub(command,string.len(startvalidating) + 2),'r')
		--loglines = validatelogfile:lines()
		frame = 0
		while true do
			local nextline = validatelogfile:read("*l")
			if nextline then -- try to fast-forward
				frame = tonumber(string.sub(nextline,1,padzeros))
				if frame and frame >= gameFrame  then 
					Spring.Echo("Fastforward", frame, string.sub(nextline,1,padzeros))
					break
				end
			else
				Spring.Echo("reached end of file",command, frame)
				break
			end
			if frame % 1000 == 1 then 
				collectgarbage("collect")
				collectgarbage("collect")
			end
		end
		Spring.Echo("Fast-forwaded log to frame",frame)
	end
	
	if string.sub(command,1, string.len("dumpcircularbuffer")) == "dumpcircularbuffer" then
		dumpCircularBuffer()
	end
	
	if string.sub(command,1, string.len("dumpprojectileids")) == "dumpprojectileids" then 
		Spring.Echo("Starting projectile logging")
		projectilefile = io.open("dumpprojectileids.txt",'w')
		writeprojectiles = true
	end
end

local numchecks = 0
function widget:GameFrame()
	gameFrame = Spring.GetGameFrame()
	if writelog or continuouslogging then 
		local allunits = Spring.GetAllUnits()
		local line = CreateDebugLine(allunits)
		if continuouslogging then 
			circularbuffer[gameFrame % circularbuffersize] = nil
			circularbuffer[gameFrame % circularbuffersize] = line
		end
		if writelog then 
			writelogfile:write(string.format("%07d return { %s }\n",gameFrame, line) )
		end
	end
	
	if writeprojectiles then 
		-- Spring.GetProjectilesInRectangle ( number xmin, number zmin, number xmax, number zmax [, bool excludeWeaponProjectiles [, bool excludePieceProjectiles ]] ) 
		local projectiles = Spring.GetProjectilesInRectangle( - Game.mapSizeX, -Game.mapSizeZ, 2* Game.mapSizeX, 2* Game.mapSizeZ, false, false) 
		--Spring.Echo(#projectiles)
		local line = CreateDebugLineProjectiles(projectiles)
		projectilefile:write(string.format("%07d return { %s }\n",gameFrame, line) )
	end
	if validatelog and validatelogfile then 
		local line = validatelogfile:read("*l")
		if line then 
			local frame =  tonumber(string.sub(line,1,padzeros))
			if frame ~= gameFrame then
				Spring.Echo("Validation log frames are off by", frame, gameFrame)
			end
			local tfunc = assert(loadstring(string.sub(line,padzeros+1)))
			local unittable = tfunc()
			for unitID, postable in pairs(unittable) do 
				ValidateUnit(unitID, postable)
				numchecks = numchecks + 1
			end
		else
			Spring.Echo("Reached end of line while reading validation log")
			validatelog = false
		end
		if gameFrame % 120 == 0 then 
			Spring.Echo("Position checks performed = ", numchecks)
			numchecks = 0
		end
	end
	
	if (writelog or validatelog or continuouslogging) and gameFrame % (20*30) == 0 then 
		collectgarbage("collect")
		collectgarbage("collect")
	end
	
end

function widget:Shutdown()
	if validatelogfile then validatelogfile:close() end 
	if writelogfile then writelogfile:close() end 
	if projectilefile then projectilefile:close() end 
end