fix typo

to give old, deferrred blocks a chance to time-out.  Needed
because if players aren't currently creating new terrain,
old blocks would never get processed, causing the block log
to only grow rather than eventually run dry (which could result
in very long shutdown times).

init.lua

@@ -4,12 +4,28 @@
 -- Splizard's snow mod.
 --
 
+biome_lib = {}
+
+-- Boilerplate to support localized strings if intllib mod is installed.
+local S
+if minetest.global_exists("intllib") then
+	if intllib.make_gettext_pair then
+		S = intllib.make_gettext_pair()
+	else
+		S = intllib.Getter()
+	end
+else
+	S = function(s) return s end
+end
+biome_lib.intllib = S
+
 -- Various settings - most of these probably won't need to be changed
 
-biome_lib = {}
 biome_lib.air = {name = "air"}
 
 biome_lib.block_log = {}
+biome_lib.block_recheck_list = {}
+biome_lib.run_block_recheck_list = false
 
 biome_lib.actionslist_aircheck = {}
 biome_lib.actionslist_no_aircheck = {}
@@ -54,28 +70,22 @@ biome_lib.default_wet_surfaces = c3 and tableize(c3) or {"default:dirt", "defaul
 biome_lib.default_ground_nodes = c4 and tableize(c4) or {"default:dirt_with_grass"}
 biome_lib.default_grow_nodes =   c5 and tableize(c5) or {"default:dirt_with_grass"}
 
--- Boilerplate to support localized strings if intllib mod is installed.
-local S
-if minetest.global_exists("intllib") then
-	if intllib.make_gettext_pair then
-		S = intllib.make_gettext_pair()
-	else
-		S = intllib.Getter()
-	end
-else
-	S = function(s) return s end
-end
-biome_lib.intllib = S
+biome_lib.debug_log_level = tonumber(minetest.settings:get("biome_lib_debug_log_level")) or 0
 
-local DEBUG_LEVEL = tonumber(minetest.settings:get("biome_lib_debug")) or 0
+local rr = tonumber(minetest.settings:get("biome_lib_queue_run_ratio")) or -100
+biome_lib.queue_run_ratio = 100 - rr
+biome_lib.entries_per_step = math.max(-rr, 1)
 
-function biome_lib.dbg(msg, level)
-	local l = tonumber(level) or 0
-	if DEBUG_LEVEL >= l then
-		print("[Biome Lib] "..msg)
-		minetest.log("verbose", "[Biome Lib] "..msg)
-	end
-end
+-- the timer that manages the block timeout is in microseconds, but the timer
+-- that manages the queue wakeup call has to be in seconds, and works best if
+-- it takes a little longer than the block timeout interval.
+
+local t = tonumber(minetest.settings:get("biome_lib_block_timeout")) or 300
+
+biome_lib.block_timeout = t * 1000000
+biome_lib.block_queue_wakeup_time = t * 1.1
+
+local time_speed = tonumber(minetest.settings:get("time_speed"))
 
 biome_lib.plantlife_seed_diff = 329 -- needs to be global so other mods can see it
 
@@ -94,7 +104,6 @@ local humidity_persistence = 0.5
 local humidity_scale = 250
 
 local time_scale = 1
-local time_speed = tonumber(minetest.settings:get("time_speed"))
 
 if time_speed and time_speed > 0 then
 	time_scale = 72 / time_speed
@@ -107,6 +116,14 @@ biome_lib.perlin_humidity = PerlinNoise(humidity_seeddiff, humidity_octaves, hum
 
 -- Local functions
 
+function biome_lib.dbg(msg, level)
+	local l = tonumber(level) or 0
+	if biome_lib.debug_log_level >= l then
+		print("[Biome Lib] "..msg)
+		minetest.log("verbose", "[Biome Lib] "..msg)
+	end
+end
+
 local function get_biome_data(pos, perlin_fertile)
 	local fertility = perlin_fertile:get_2d({x=pos.x, y=pos.z})
 
@@ -440,9 +457,6 @@ local function confirm_block_surroundings(p)
 	return true
 end
 
-biome_lib.block_recheck_list = {}
-biome_lib.run_block_recheck_list = false
-
 function biome_lib.generate_block(shutting_down)
 
 	if shutting_down then
@@ -472,11 +486,13 @@ function biome_lib.generate_block(shutting_down)
 	local pos_hash = 	minetest.hash_node_position(minp)
 
 	if not biome_lib.pos_hash then -- we need to read the maplock and get the surfaces list
+		local now = minetest.get_us_time()
 		biome_lib.pos_hash = {}
 		minetest.load_area(minp)
 		if not confirm_block_surroundings(minp)
-		  and not shutting_down then -- if any neighbors appear not to be loaded, skip this block for now
-
+		  and not shutting_down
+		  and (blocklog[1][4] + biome_lib.block_timeout) > now then -- if any neighbors appear not to be loaded and the block hasn't expired yet, defer it
+			blocklog[1][4] = now -- reset the timer, give this block more time to "cook"
 			if biome_lib.run_block_recheck_list then
 				biome_lib.block_log[#biome_lib.block_log + 1] = table.copy(biome_lib.block_recheck_list[1])
 				table.remove(biome_lib.block_recheck_list, 1)
@@ -537,11 +553,6 @@ end
 
 -- "Play" them back, populating them with new stuff in the process
 
-local rr = tonumber(minetest.settings:get("biome_lib_queue_run_ratio")) or -100
-
-biome_lib.queue_run_ratio = 100 - rr
-biome_lib.entries_per_step = math.max(-rr, 1)
-
 minetest.register_globalstep(function(dtime)
 	if not biome_lib.block_log[1] then return end -- the block log is empty
 
@@ -551,6 +562,25 @@ minetest.register_globalstep(function(dtime)
 	end
 end)
 
+-- Periodically wake-up the queue to give old blocks a chance to time-out
+-- if the player isn't currently exploring (i.e. they're just playing in one area)
+
+function biome_lib.wake_up_queue()
+	if #biome_lib.block_recheck_list > 0
+	  and #biome_lib.block_log == 0 then
+		-- we move the second element and not the first because we can't be
+		-- sure if the recheck list's first item is the one currently acted upon
+		-- (else it'd be the first item in the main block log)
+		biome_lib.block_log = table.copy(biome_lib.block_recheck_list)
+		biome_lib.block_recheck_list = {}
+		biome_lib.queue_idle_flag = false
+		biome_lib.dbg("Woke-up the map queue to give old blocks a chance to time-out.", 3)
+	end
+	minetest.after(biome_lib.block_queue_wakeup_time, biome_lib.wake_up_queue)
+end
+
+biome_lib.wake_up_queue()
+
 -- Play out the entire log all at once on shutdown
 -- to prevent unpopulated map areas
 
@@ -763,17 +793,23 @@ function biome_lib:get_nodedef_field(nodename, fieldname)
 	return minetest.registered_nodes[nodename][fieldname]
 end
 
-if DEBUG_LEVEL >= 3 then
+if biome_lib.debug_log_level >= 3 then
 	biome_lib.last_count = 0
 
 	function biome_lib.show_pending_block_count()
 		if biome_lib.last_count ~= #biome_lib.block_log then
-			biome_lib.dbg("Pending block count: "..(#biome_lib.block_log + #biome_lib.block_recheck_list), 3)
+			biome_lib.dbg(string.format("Pending block counts - ready to process: %-8icurrently deferred: %i",
+				#biome_lib.block_log, #biome_lib.block_recheck_list), 3)
 			biome_lib.last_count = #biome_lib.block_log
 			biome_lib.queue_idle_flag = false
 		elseif not biome_lib.queue_idle_flag then
+			if #biome_lib.block_recheck_list > 0 then
 				biome_lib.dbg("Mapblock queue only contains blocks that can't yet be processed.",  3)
-			biome_lib.dbg("Idling the queue until new mapblocks show up.",  3)
+				biome_lib.dbg("Idling the queue until new blocks arrive or the next wake-up call occurs.",  3)
+			else
+				biome_lib.dbg("Mapblock queue has run dry.",  3)
+				biome_lib.dbg("Idling the queue until new blocks arrive.",  3)
+			end
 			biome_lib.queue_idle_flag = true
 		end
 		minetest.after(1, biome_lib.show_pending_block_count)

search_functions.lua

@@ -56,6 +56,7 @@ end
 -- split into individual mapblocks to reduce lag
 
 minetest.register_on_generated(function(minp, maxp, blockseed)
+	local timestamp = minetest.get_us_time()
 	for x = 0, 4 do
 		local minx = minp.x + x*16
 		for y = 0, 4 do
@@ -65,8 +66,8 @@ minetest.register_on_generated(function(minp, maxp, blockseed)
 
 				local bmin = {x=minx, y=miny, z=minz}
 				local bmax = {x=minx + 15, y=miny + 15, z=minz + 15}
-				biome_lib.block_log[#biome_lib.block_log + 1] = { bmin, bmax, true }
-				biome_lib.block_log[#biome_lib.block_log + 1] = { bmin, bmax, false }
+				biome_lib.block_log[#biome_lib.block_log + 1] = { bmin, bmax, true, timestamp }
+				biome_lib.block_log[#biome_lib.block_log + 1] = { bmin, bmax, false, timestamp }
 			end
 		end
 	end