mods/ITEMS/REDSTONE/mesecons/actionqueue.lua

   1 mesecon.queue.actions={} -- contains all ActionQueue actions
   2
   3 function mesecon.queue:add_function(name, func)
   4         mesecon.queue.funcs[name] = func
   5 end
   6
   7 -- If add_action with twice the same overwritecheck and same position are called, the first one is overwritten
   8 -- use overwritecheck nil to never overwrite, but just add the event to the queue
   9 -- priority specifies the order actions are executed within one globalstep, highest first
  10 -- should be between 0 and 1
  11 function mesecon.queue:add_action(pos, func, params, time, overwritecheck, priority)
  12         -- Create Action Table:
  13         time = time or 0 -- time <= 0 --> execute, time > 0 --> wait time until execution
  14         priority = priority or 1
  15         local action = {        pos=mesecon.tablecopy(pos),
  16                                 func=func,
  17                                 params=mesecon.tablecopy(params or {}),
  18                                 time=time,
  19                                 owcheck=(overwritecheck and mesecon.tablecopy(overwritecheck)) or nil,
  20                                 priority=priority}
  21
  22         local toremove = nil
  23         -- Otherwise, add the action to the queue
  24         if overwritecheck then -- check if old action has to be overwritten / removed:
  25                 for i, ac in ipairs(mesecon.queue.actions) do
  26                         if(vector.equals(pos, ac.pos)
  27                         and mesecon.cmpAny(overwritecheck, ac.owcheck)) then
  28                                 toremove = i
  29                                 break
  30                         end
  31                 end
  32         end
  33
  34         if (toremove ~= nil) then
  35                 table.remove(mesecon.queue.actions, toremove)
  36         end
  37
  38         table.insert(mesecon.queue.actions, action)
  39 end
  40
  41 -- execute the stored functions on a globalstep
  42 -- if however, the pos of a function is not loaded (get_node_or_nil == nil), do NOT execute the function
  43 -- this makes sure that resuming mesecons circuits when restarting minetest works fine
  44 -- However, even that does not work in some cases, that's why we delay the time the globalsteps
  45 -- start to be execute by 5 seconds
  46 local get_highest_priority = function (actions)
  47         local highestp = -1
  48         local highesti
  49         for i, ac in ipairs(actions) do
  50                 if ac.priority > highestp then
  51                         highestp = ac.priority
  52                         highesti = i
  53                 end
  54         end
  55
  56         return highesti
  57 end
  58
  59 local m_time = 0
  60 local resumetime = mesecon.setting("resumetime", 4)
  61 minetest.register_globalstep(function (dtime)
  62         m_time = m_time + dtime
  63         -- don't even try if server has not been running for XY seconds; resumetime = time to wait
  64         -- after starting the server before processing the ActionQueue, don't set this too low
  65         if (m_time < resumetime) then return end
  66         local actions = mesecon.tablecopy(mesecon.queue.actions)
  67         local actions_now={}
  68
  69         mesecon.queue.actions = {}
  70
  71         -- sort actions into two categories:
  72         -- those toexecute now (actions_now) and those to execute later (mesecon.queue.actions)
  73         for i, ac in ipairs(actions) do
  74                 if ac.time > 0 then
  75                         ac.time = ac.time - dtime -- executed later
  76                         table.insert(mesecon.queue.actions, ac)
  77                 else
  78                         table.insert(actions_now, ac)
  79                 end
  80         end
  81
  82         while(#actions_now > 0) do -- execute highest priorities first, until all are executed
  83                 local hp = get_highest_priority(actions_now)
  84                 mesecon.queue:execute(actions_now[hp])
  85                 table.remove(actions_now, hp)
  86         end
  87 end)
  88
  89 function mesecon.queue:execute(action)
  90         -- ignore if action queue function name doesn't exist,
  91         -- (e.g. in case the action queue savegame was written by an old mesecons version)
  92         if mesecon.queue.funcs[action.func] then
  93                 mesecon.queue.funcs[action.func](action.pos, unpack(action.params))
  94         end
  95 end
  96
  97
  98 -- Store and read the ActionQueue to / from a file
  99 -- so that upcoming actions are remembered when the game
 100 -- is restarted
 101 mesecon.queue.actions = mesecon.file2table("mesecon_actionqueue")
 102
 103 minetest.register_on_shutdown(function()
 104         mesecon.table2file("mesecon_actionqueue", mesecon.queue.actions)
 105 end)