builtin/forceloading.lua

   1 -- Prevent anyone else accessing those functions
   2 local forceload_block = minetest.forceload_block
   3 local forceload_free_block = minetest.forceload_free_block
   4 minetest.forceload_block = nil
   5 minetest.forceload_free_block = nil
   6
   7 local blocks_forceloaded
   8 local total_forceloaded = 0
   9
  10 local BLOCKSIZE = 16
  11 local function get_blockpos(pos)
  12         return {
  13                 x = math.floor(pos.x/BLOCKSIZE),
  14                 y = math.floor(pos.y/BLOCKSIZE),
  15                 z = math.floor(pos.z/BLOCKSIZE)}
  16 end
  17
  18 function minetest.forceload_block(pos)
  19         local blockpos = get_blockpos(pos)
  20         local hash = minetest.hash_node_position(blockpos)
  21         if blocks_forceloaded[hash] ~= nil then
  22                 blocks_forceloaded[hash] = blocks_forceloaded[hash] + 1
  23                 return true
  24         else
  25                 if total_forceloaded >= (tonumber(minetest.setting_get("max_forceloaded_blocks")) or 16) then
  26                         return false
  27                 end
  28                 total_forceloaded = total_forceloaded+1
  29                 blocks_forceloaded[hash] = 1
  30                 forceload_block(blockpos)
  31                 return true
  32         end
  33 end
  34
  35 function minetest.forceload_free_block(pos)
  36         local blockpos = get_blockpos(pos)
  37         local hash = minetest.hash_node_position(blockpos)
  38         if blocks_forceloaded[hash] == nil then return end
  39         if blocks_forceloaded[hash] > 1 then
  40                 blocks_forceloaded[hash] = blocks_forceloaded[hash] - 1
  41         else
  42                 total_forceloaded = total_forceloaded-1
  43                 blocks_forceloaded[hash] = nil
  44                 forceload_free_block(blockpos)
  45         end
  46 end
  47
  48 -- Keep the forceloaded areas after restart
  49 local wpath = minetest.get_worldpath()
  50 local function read_file(filename)
  51         local f = io.open(filename, "r")
  52         if f==nil then return {} end
  53         local t = f:read("*all")
  54         f:close()
  55         if t=="" or t==nil then return {} end
  56         return minetest.deserialize(t)
  57 end
  58
  59 local function write_file(filename, table)
  60         local f = io.open(filename, "w")
  61         f:write(minetest.serialize(table))
  62         f:close()
  63 end
  64
  65 blocks_forceloaded = read_file(wpath.."/force_loaded.txt")
  66 for _, __ in pairs(blocks_forceloaded) do
  67         total_forceloaded = total_forceloaded + 1
  68 end
  69
  70 minetest.after(5, function()
  71         for hash, _ in pairs(blocks_forceloaded) do
  72                 local blockpos = minetest.get_position_from_hash(hash)
  73                 forceload_block(blockpos)
  74         end
  75 end)
  76
  77 minetest.register_on_shutdown(function()
  78         write_file(wpath.."/force_loaded.txt", blocks_forceloaded)
  79 end)