Initial commit

builtin/common/after.lua

@@ -0,0 +1,50 @@
+local jobs = {}
+local time = 0.0
+local time_next = math.huge
+
+core.register_globalstep(function(dtime)
+	time = time + dtime
+
+	if time < time_next then
+		return
+	end
+
+	time_next = math.huge
+
+	-- Iterate backwards so that we miss any new timers added by
+	-- a timer callback.
+	for i = #jobs, 1, -1 do
+		local job = jobs[i]
+		if time >= job.expire then
+			core.set_last_run_mod(job.mod_origin)
+			job.func(unpack(job.arg))
+			local jobs_l = #jobs
+			jobs[i] = jobs[jobs_l]
+			jobs[jobs_l] = nil
+		elseif job.expire < time_next then
+			time_next = job.expire
+		end
+	end
+end)
+
+function core.after(after, func, ...)
+	assert(tonumber(after) and type(func) == "function",
+		"Invalid minetest.after invocation")
+	local expire = time + after
+	local new_job = {
+		func = func,
+		expire = expire,
+		arg = {...},
+		mod_origin = core.get_last_run_mod(),
+	}
+
+	jobs[#jobs + 1] = new_job
+	time_next = math.min(time_next, expire)
+
+	return {
+		cancel = function()
+			new_job.func = function() end
+			new_job.args = {}
+		end
+	}
+end