1 files changed, 118 insertions, 0 deletions
diff --git a/mesecons/mesecons/actionqueue.lua b/mesecons/mesecons/actionqueue.lua
new file mode 100644
index 0000000..fa4079f
--- /dev/null
+++ b/mesecons/mesecons/actionqueue.lua
@@ -0,0 +1,118 @@
+mesecon.queue.actions={} -- contains all ActionQueue actions
+
+function mesecon.queue:add_function(name, func)
+	mesecon.queue.funcs[name] = func
+end
+
+-- If add_action with twice the same overwritecheck and same position are called, the first one is overwritten
+-- use overwritecheck nil to never overwrite, but just add the event to the queue
+-- priority specifies the order actions are executed within one globalstep, highest first
+-- should be between 0 and 1
+function mesecon.queue:add_action(pos, func, params, time, overwritecheck, priority)
+	-- Create Action Table:
+	time = time or 0 -- time <= 0 --> execute, time > 0 --> wait time until execution
+	priority = priority or 1
+	local action = {	pos=mesecon.tablecopy(pos),
+				func=func,
+				params=mesecon.tablecopy(params or {}),
+				time=time,
+				owcheck=(overwritecheck and mesecon.tablecopy(overwritecheck)) or nil,
+				priority=priority}
+
+	local toremove = nil
+	-- Otherwise, add the action to the queue
+	if overwritecheck then -- check if old action has to be overwritten / removed:
+		for i, ac in ipairs(mesecon.queue.actions) do
+			if(mesecon.cmpPos(pos, ac.pos)
+			and mesecon.cmpAny(overwritecheck, ac.owcheck)) then
+				toremove = i
+				break
+			end
+		end
+	end
+
+	if (toremove ~= nil) then
+		table.remove(mesecon.queue.actions, toremove)
+	end
+
+	table.insert(mesecon.queue.actions, action)
+end
+
+-- execute the stored functions on a globalstep
+-- if however, the pos of a function is not loaded (get_node_or_nil == nil), do NOT execute the function
+-- this makes sure that resuming mesecons circuits when restarting minetest works fine
+-- However, even that does not work in some cases, that's why we delay the time the globalsteps
+-- start to be execute by 5 seconds
+local get_highest_priority = function (actions)
+	local highestp = -1
+	local highesti
+	for i, ac in ipairs(actions) do
+		if ac.priority > highestp then
+			highestp = ac.priority
+			highesti = i
+		end
+	end
+
+	return highesti
+end
+
+local m_time = 0
+local resumetime = mesecon.setting("resumetime", 4)
+minetest.register_globalstep(function (dtime)
+	m_time = m_time + dtime
+	-- don't even try if server has not been running for XY seconds; resumetime = time to wait
+	-- after starting the server before processing the ActionQueue, don't set this too low
+	if (m_time < resumetime) then return end
+	local actions = mesecon.tablecopy(mesecon.queue.actions)
+	local actions_now={}
+
+	mesecon.queue.actions = {}
+
+	-- sort actions into two categories:
+	-- those toexecute now (actions_now) and those to execute later (mesecon.queue.actions)
+	for i, ac in ipairs(actions) do
+		if ac.time > 0 then
+			ac.time = ac.time - dtime -- executed later
+			table.insert(mesecon.queue.actions, ac)
+		else
+			table.insert(actions_now, ac)
+		end
+	end
+
+	while(#actions_now > 0) do -- execute highest priorities first, until all are executed
+		local hp = get_highest_priority(actions_now)
+		mesecon.queue:execute(actions_now[hp])
+		table.remove(actions_now, hp)
+	end
+end)
+
+function mesecon.queue:execute(action)
+	mesecon.queue.funcs[action.func](action.pos, unpack(action.params))
+end
+
+
+-- Store and read the ActionQueue to / from a file
+-- so that upcoming actions are remembered when the game
+-- is restarted
+
+local wpath = minetest.get_worldpath()
+local function file2table(filename)
+	local f = io.open(filename, "r")
+	if f==nil then return {} end
+	local t = f:read("*all")
+	f:close()
+	if t=="" or t==nil then return {} end
+	return minetest.deserialize(t)
+end
+
+local function table2file(filename, table)
+	local f = io.open(filename, "w")
+	f:write(minetest.serialize(table))
+	f:close()
+end
+
+mesecon.queue.actions = file2table(wpath.."/mesecon_actionqueue")
+
+minetest.register_on_shutdown(function()
+	mesecon.queue.actions = table2file(wpath.."/mesecon_actionqueue", mesecon.queue.actions)
+end)