Moves existing_station_areas to SSmapping, to prevent midround lag

code/controllers/subsystem/mapping.dm

@@ -10,6 +10,8 @@ SUBSYSTEM_DEF(mapping)
 	var/list/teleportlocs
 	/// List of all areas that can be accessed via IC and OOC means
 	var/list/ghostteleportlocs
+	///List of areas that exist on the station this shift
+	var/list/existing_station_areas
 
 // This has to be here because world/New() uses [station_name()], which looks this datum up
 /datum/controller/subsystem/mapping/PreInit()
@@ -89,6 +91,13 @@ SUBSYSTEM_DEF(mapping)
 
 	ghostteleportlocs = sortAssoc(ghostteleportlocs)
 
+	// Now we make a list of areas that exist on the station. Good for if you don't want to select areas that exist for one station but not others. Directly references
+	existing_station_areas = list()
+	for(var/area/AR in world)
+		var/turf/picked = safepick(get_area_turfs(AR.type))
+		if(picked && is_station_level(picked.z))
+			existing_station_areas += AR
+
 	// World name
 	if(GLOB.configuration.general.server_name)
 		world.name = "[GLOB.configuration.general.server_name]: [station_name()]"

code/modules/events/anomaly.dm

@@ -5,13 +5,6 @@
 
 /datum/event/anomaly/proc/findEventArea()
 	var/static/list/allowed_areas
-	var/static/list/existing_areas
-	if(!existing_areas)
-		existing_areas = list()
-		for(var/area/AR in world)
-			var/turf/picked = safepick(get_area_turfs(AR.type))
-			if(picked && is_station_level(picked.z))
-				existing_areas += AR
 	if(!allowed_areas)
 		//Places that shouldn't explode
 		var/list/safe_area_types = typecacheof(list(
@@ -36,7 +29,7 @@
 		))
 
 		allowed_areas = typecacheof(GLOB.the_station_areas) - safe_area_types + unsafe_area_subtypes
-	var/list/possible_areas = typecache_filter_list(existing_areas, allowed_areas)
+	var/list/possible_areas = typecache_filter_list(SSmapping.existing_station_areas, allowed_areas)
 	if(length(possible_areas))
 		return pick(possible_areas)