Add player iteration methods to builtin, optimization of many mods

builtin/game/register.lua

@@ -556,6 +556,99 @@ core.registered_on_protection_violation, core.register_on_protection_violation =
 core.registered_on_item_eats, core.register_on_item_eat = make_registration()
 core.registered_on_punchplayers, core.register_on_punchplayer = make_registration()
 
+-- Player step iterration
+
+players_per_step = core.settings:get("players_per_globalstep")
+players_per_step = players_per_step and tonumber(players_per_step) or 20
+
+local player_iter = nil
+local player_iter_forced = nil
+local playerstep_iter = nil
+local playerstep_funcs = {}
+local playerstep_funcs_forced = {}
+local playernames = {}
+local playernames_forced = {}
+
+core.register_playerstep = function(func, force)
+	local funcs = force and playerstep_funcs_forced or playerstep_funcs
+	funcs[#funcs + 1] = func
+end
+
+local function table_iter(t)
+	local i = 0
+	local n = table.getn(t)
+	return function ()
+		i = i + 1
+		if i <= n then
+			return t[i]
+		end
+	end
+end
+
+function core.get_player_iter()
+	local names = {}
+	for player in table_iter(core.get_connected_players()) do
+		local name = player:get_player_name()
+		if name then
+			names[#names + 1] = name
+		end
+	end
+	return table_iter(names)
+end
+
+local function get_playerstep_func()
+	if playerstep_iter == nil then
+		playerstep_iter = table_iter(playerstep_funcs)
+		playernames = {}
+		for _ = 1, players_per_step do
+			if player_iter == nil then
+				player_iter = core.get_player_iter()
+			end
+			local name = player_iter()
+			if not name then
+				player_iter = nil
+				break
+			end
+			playernames[#playernames + 1] = name
+		end
+	end
+	local func = playerstep_iter()
+	playerstep_iter = func and playerstep_iter
+	return func or get_playerstep_func()
+end
+
+-- Run playerstep callbacks
+
+core.register_globalstep(function(dtime)
+	-- Run forced callbacks
+	if #playerstep_funcs_forced ~= 0 then
+		playernames_forced = {}
+		for _ = 1, players_per_step do
+			if player_iter_forced == nil then
+				player_iter_forced = core.get_player_iter()
+			end
+			local name = player_iter_forced()
+			if not name then
+				player_iter_forced = nil
+				break
+			end
+			playernames_forced[#playernames_forced + 1] = name
+		end
+		for func in table_iter(playerstep_funcs_forced) do
+			if type(func) == "function" then
+				func(dtime, playernames_forced)
+			end
+		end
+	end
+	if #playerstep_funcs ~= 0 then
+		-- Run single step callbacks
+		local func = get_playerstep_func()
+		if type(func) == "function" then
+			func(dtime, playernames)
+		end
+	end
+end)
+
 --
 -- Compatibility for on_mapgen_init()
 --

builtin/game/statbars.lua

@@ -185,16 +185,9 @@ core.register_on_joinplayer(function(player)
 	initialize_builtin_statbars(player)
 end)
 
-
-local time = 0
-local update_time = 1
-core.register_globalstep(function(dtime)
-	time = time + dtime
-	if time > update_time then
-	
-	local players = core.get_connected_players()
-	for i = 1, #players do
-		local player = players[i]
+minetest.register_playerstep(function(dtime, playernames)
+	for _, name in pairs(playernames) do
+		local player = minetest.get_player_by_name(name)
 		local player_name = player:get_player_name()
 
 		local wielded_item = player:get_wielded_item()
@@ -224,6 +217,4 @@ core.register_globalstep(function(dtime)
 			hud.change_item(player, "itemname", {text = description})
 		end
 	end
-	time = 0
-	end
-end)
+end, minetest.is_singleplayer()) -- Force step in singlplayer mode only

doc/lua_api.txt

@@ -2363,6 +2363,17 @@ Call these functions only at load time!
 
 * `minetest.register_globalstep(func(dtime))`
     * Called every server step, usually interval of 0.1s
+* `minetest.register_playerstep(function(dtime, playernames), force)`
+	* Called one registration per step, see `force`
+	* `dtime` : Delta time since last callback, see `dedicated_server_step` setting
+	* `playernames` : Table of player names, see `players_per_globalstep` setting
+	* `force` : Boolean value (optional)
+		* Force this callback to run on every server step, default: `false`
+	* Note: This callback should not be rate limited or players may be missed!
+		* See the [fire] mod for an example of how this may be done reliably
+* `minetest.get_player_iter()`
+	* Returns a player name iterrator, as used by `minetest.register_playerstep`
+	* See `builtin/game/register.lua` for example usage
 * `minetest.register_on_shutdown(func())`
     * Called before server shutdown
     * **Warning**: If the server terminates abnormally (i.e. crashes), the registered

multicraft.conf.example

@@ -1115,6 +1115,10 @@
 #    type: float
 # dedicated_server_step = 0.1
 
+#    Maxumim number of players to process per step, see `minetest.register_playerstep`
+#    type: int
+# players_per_globalstep = 20
+
 #    Time in between active block management cycles
 #    type: float
 # active_block_mgmt_interval = 2.0