Make some ZAS lists lazy (#2339)

This PR converts some lists in ZAS to be only created when needed instead of always existing and pointlessly using memory. Might lead to reduced server memory usage.

code/ZAS/ConnectionGroup.dm

@@ -127,26 +127,26 @@ Class Procs:
 
 	src.A = A
 	src.B = B
-	A.edges.Add(src)
-	B.edges.Add(src)
+	LAZYADD(A.edges, src)
+	LAZYADD(B.edges, src)
 	//id = edge_id(A,B)
 //	log_debug("New edge between [A] and [B]")
 
 
 /connection_edge/zone/add_connection(connection/c)
 	. = ..()
-	connecting_turfs.Add(c.A)
+	connecting_turfs += c.A
 
 /connection_edge/zone/remove_connection(connection/c)
-	connecting_turfs.Remove(c.A)
+	connecting_turfs -= c.A
 	. = ..()
 
 /connection_edge/zone/contains_zone(zone/Z)
 	return A == Z || B == Z
 
 /connection_edge/zone/erase()
-	A.edges.Remove(src)
-	B.edges.Remove(src)
+	LAZYREMOVE(A.edges, src)
+	LAZYREMOVE(B.edges, src)
 	. = ..()
 
 /connection_edge/zone/tick()
@@ -198,7 +198,7 @@ Class Procs:
 /connection_edge/unsimulated/New(zone/A, turf/B)
 	src.A = A
 	src.B = B
-	A.edges.Add(src)
+	LAZYADD(A.edges, src)
 	air = B.return_air()
 	//id = 52*A.id
 //	log_debug("New edge from [A] to [B].")
@@ -215,7 +215,7 @@ Class Procs:
 	. = ..()
 
 /connection_edge/unsimulated/erase()
-	A.edges.Remove(src)
+	LAZYREMOVE(A.edges, src)
 	. = ..()
 
 /connection_edge/unsimulated/contains_zone(zone/Z)

code/ZAS/Fire.dm

@@ -11,7 +11,8 @@ If it gains pressure too slowly, it may leak or just rupture instead of explodin
 #define FIRE_LIGHT_2	3
 #define FIRE_LIGHT_3	4
 
-/turf/var/obj/fire/fire = null
+/turf
+	var/tmp/obj/fire/fire = null
 
 //Some legacy definitions so fires can be started.
 atom/proc/temperature_expose(datum/gas_mixture/air, exposed_temperature, exposed_volume)
@@ -40,7 +41,7 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 	return igniting
 
 /zone/proc/process_fire()
-	var/datum/gas_mixture/burn_gas = air.remove_ratio(vsc.fire_consuption_rate, fire_tiles.len)
+	var/datum/gas_mixture/burn_gas = air.remove_ratio(vsc.fire_consuption_rate, LAZYLEN(fire_tiles))
 
 	var/firelevel = burn_gas.zburn(src, fire_tiles, force_burn = 1, no_check = 1)
 
@@ -52,21 +53,23 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 				T.fire.firelevel = firelevel
 			else
 				var/obj/effect/decal/cleanable/liquid_fuel/fuel = locate() in T
-				fire_tiles -= T
-				fuel_objs -= fuel
+				LAZYREMOVE(fire_tiles, T)
+				LAZYREMOVE(fuel_objs, fuel)
 	else
 		for(var/turf/simulated/T in fire_tiles)
 			if(istype(T.fire))
 				T.fire.RemoveFire()
 			T.fire = null
-		fire_tiles.Cut()
-		fuel_objs.Cut()
+		LAZYCLEARLIST(fire_tiles)
+		LAZYCLEARLIST(fuel_objs)
+		UNSETEMPTY(fire_tiles)
+		UNSETEMPTY(fuel_objs)
 
-	if(!fire_tiles.len)
-		SSair.active_fire_zones.Remove(src)
+	if(!LAZYLEN(fire_tiles))
+		SSair.active_fire_zones -= src
 
 /zone/proc/remove_liquidfuel(var/used_liquid_fuel, var/remove_fire=0)
-	if(!fuel_objs.len)
+	if(!LAZYLEN(fuel_objs))
 		return
 
 	//As a simplification, we remove fuel equally from all fuel sources. It might be that some fuel sources have more fuel,
@@ -77,12 +80,12 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 	for(var/O in fuel_objs)
 		var/obj/effect/decal/cleanable/liquid_fuel/fuel = O
 		if(!istype(fuel))
-			fuel_objs -= fuel
+			LAZYREMOVE(fuel_objs, fuel)
 			continue
 
 		fuel.amount -= fuel_to_remove
 		if(fuel.amount <= 0)
-			fuel_objs -= fuel
+			LAZYREMOVE(fuel_objs, fuel)
 			if(remove_fire)
 				var/turf/T = fuel.loc
 				if(istype(T) && T.fire) qdel(T.fire)
@@ -103,8 +106,10 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 	SSair.active_fire_zones |= zone
 
 	var/obj/effect/decal/cleanable/liquid_fuel/fuel = locate() in src
+	LAZYINITLIST(zone.fire_tiles)
 	zone.fire_tiles |= src
-	if(fuel) zone.fuel_objs += fuel
+	if(fuel) 
+		LAZYADD(zone.fuel_objs, fuel)
 
 	return 0
 
@@ -180,8 +185,11 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 			else
 				enemy_tile.adjacent_fire_act(loc, air_contents, air_contents.temperature, air_contents.volume)
 
-	animate(src, color = fire_color(air_contents.temperature), 5)
 	set_light(l_color = color)
+	var/list/animate_targets = get_above_oo() + src
+	for (var/thing in animate_targets)
+		var/atom/movable/AM = thing
+		animate(AM, color = fire_color(air_contents.temperature), 5)
 
 /obj/fire/New(newLoc,fl)
 	..()
@@ -197,7 +205,7 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 	set_light(3, 1, color)
 
 	firelevel = fl
-	SSair.active_hotspots.Add(src)
+	SSair.active_hotspots += src
 
 /obj/fire/proc/fire_color(var/env_temperature)
 	var/temperature = max(4000*sqrt(firelevel/vsc.fire_firelevel_multiplier), env_temperature)
@@ -215,11 +223,14 @@ turf/proc/hotspot_expose(exposed_temperature, exposed_volume, soh = 0)
 
 		T.fire = null
 		loc = null
-	SSair.active_hotspots.Remove(src)
+	SSair.active_hotspots -= src
 
+/turf/simulated
+	var/tmp/fire_protection = 0 //Protects newly extinguished tiles from being overrun again.
 
-/turf/simulated/var/fire_protection = 0 //Protects newly extinguished tiles from being overrun again.
 /turf/proc/apply_fire_protection()
+	return
+
 /turf/simulated/apply_fire_protection()
 	fire_protection = world.time
 

code/ZAS/Zone.dm

@@ -44,17 +44,17 @@ Class Procs:
 	var/name
 	var/invalid = 0
 	var/list/contents = list()
-	var/list/fire_tiles = list()
-	var/list/fuel_objs = list()
+	var/list/fire_tiles
+	var/list/fuel_objs
 
 	var/needs_update = 0
 
-	var/list/edges = list()
+	var/list/edges
 
 	var/datum/gas_mixture/air = new
 
-	var/list/graphic_add = list()
-	var/list/graphic_remove = list()
+	var/list/graphic_add
+	var/list/graphic_remove
 
 /zone/New()
 	SSair.add_zone(src)
@@ -74,9 +74,10 @@ Class Procs:
 	contents += T
 	if(T.fire)
 		var/obj/effect/decal/cleanable/liquid_fuel/fuel = locate() in T
-		fire_tiles.Add(T)
+		LAZYADD(fire_tiles, T)
 		SSair.active_fire_zones |= src
-		if(fuel) fuel_objs += fuel
+		if (fuel)
+			LAZYADD(fuel_objs, fuel)
 	T.update_graphic(air.graphic)
 
 /zone/proc/remove(turf/simulated/T)
@@ -87,10 +88,10 @@ Class Procs:
 	soft_assert(T in contents, "Lists are weird broseph")
 #endif
 	contents -= T
-	fire_tiles -= T
+	LAZYREMOVE(fire_tiles, T)
 	if(T.fire)
 		var/obj/effect/decal/cleanable/liquid_fuel/fuel = locate() in T
-		fuel_objs -= fuel
+		LAZYREMOVE(fuel_objs, fuel)
 	T.zone = null
 	T.update_graphic(graphic_remove = air.graphic)
 	if(contents.len)
@@ -154,11 +155,16 @@ Class Procs:
 		if(istype(T))
 			T.create_fire(vsc.fire_firelevel_multiplier)
 
+	LAZYINITLIST(graphic_add)
+	LAZYINITLIST(graphic_remove)
 	if(air.check_tile_graphic(graphic_add, graphic_remove))
 		for(var/turf/simulated/T in contents)
 			T.update_graphic(graphic_add, graphic_remove)
-		graphic_add.len = 0
-		graphic_remove.len = 0
+
+		LAZYCLEARLIST(graphic_add)
+		LAZYCLEARLIST(graphic_remove)
+		UNSETEMPTY(graphic_add)
+		UNSETEMPTY(graphic_remove)
 
 	for(var/connection_edge/E in edges)
 		if(E.sleeping)
@@ -172,7 +178,7 @@ Class Procs:
 	M << "O2 per N2: [(air.gas["nitrogen"] ? air.gas["oxygen"]/air.gas["nitrogen"] : "N/A")] Moles: [air.total_moles]"
 	M << "Simulated: [contents.len] ([air.group_multiplier])"
 	//M << "Unsimulated: [unsimulated_contents.len]"
-	//M << "Edges: [edges.len]"
+	//M << "Edges: [LAZYLEN(edges)]"
 	if(invalid) M << "Invalid!"
 	var/zone_edges = 0
 	var/space_edges = 0

code/modules/xgm/xgm_gas_mixture.dm

@@ -13,7 +13,7 @@
 	var/group_multiplier = 1
 
 	//List of active tile overlays for this gas_mixture.  Updated by check_tile_graphic()
-	var/list/graphic = list()
+	var/list/graphic
 
 /datum/gas_mixture/New(_volume = CELL_VOLUME, _temperature = 0, _group_multiplier = 1)
 	volume = _volume
@@ -349,7 +349,7 @@
 //Two lists can be passed by reference if you need know specifically which graphics were added and removed.
 /datum/gas_mixture/proc/check_tile_graphic(list/graphic_add = null, list/graphic_remove = null)
 	for(var/g in gas_data.overlay_limit)
-		if (graphic[gas_data.tile_overlay[g]])
+		if (graphic && graphic[gas_data.tile_overlay[g]])
 			//Overlay is already applied for this gas, check if it's still valid.
 			if(gas[g] <= gas_data.overlay_limit[g])
 				LAZYADD(graphic_remove, gas_data.tile_overlay[g])
@@ -361,6 +361,7 @@
 	. = 0
 	//Apply changes
 	if(LAZYLEN(graphic_add))
+		LAZYINITLIST(graphic)
 		for (var/entry in graphic_add)
 			graphic[entry] = TRUE	// This is an assoc list to make checking it a bit faster.
 		. = 1
@@ -368,6 +369,8 @@
 		graphic -= graphic_remove
 		. = 1
 
+	UNSETEMPTY(graphic)
+
 //Simpler version of merge(), adjusts gas amounts directly and doesn't account for temperature or group_multiplier.
 /datum/gas_mixture/proc/add(datum/gas_mixture/right_side)
 	for(var/g in right_side.gas)