non-blocking iteration over large areas

asyncArea.lua

-- async iterate area
-- for when you want to execute a script on a large area, but dont want lags on your server
local defaultChunkSize = 16
local defaultDelay = 200

Area = setmetatable ({ },
	{
		__call = function (area, ...)
			return area.new (...)
		end
	}
)

Area.__index = Area
Area.__call = function (self)
	return Area.new (self)
end

function Area.new(fromPos, toPos, chunkSize, delay)
	local self = setmetatable ({ }, Area)
	self.fromPos = fromPos
	self.toPos = toPos
	self:adjustPos()
	self.chunkSize = tonumber(chunkSize) or defaultChunkSize
	self.delay = tonumber(delay) or defaultDelay
	return self
end

function Area:adjustPos()
	if self.toPos.x < self.fromPos.x then
		local tmp = self.toPos.x
		self.toPos.x = self.fromPos.x
		self.fromPos.x = tmp
	end
	
	if self.toPos.y < self.fromPos.y then
		local tmp = self.toPos.y
		self.toPos.y = self.fromPos.y
		self.fromPos.y = tmp
	end

	if self.toPos.z < self.fromPos.z then
		local tmp = self.toPos.z
		self.toPos.z = self.fromPos.z
		self.fromPos.z = tmp
	end
end

function Area:getFromPos()
	return self.fromPos
end

function Area:setFromPos(pos)
	self.fromPos = pos
	self:adjustPos()
end

function Area:getToPos()
	return self.toPos
end

function Area:setToPos(pos)
	self.toPos = pos
	self:adjustPos()
end

function Area:getChunkSize()
	return self.chunkSize
end

function Area:setChunkSize(chunkSize)
	self.chunkSize = tonumber(chunkSize) or defaultChunkSize
end

function Area:getDelay()
	return self.delay
end

function Area:setDelay(delay)
	self.delay = tonumber(delay) or defaultDelay
end

function Area:asyncIterateChunk(chunkPos, callback)
	local startPos = Position(self.fromPos.x + chunkPos.x * self.chunkSize, self.fromPos.y + chunkPos.y * self.chunkSize, self.fromPos.z + chunkPos.z)
	
	for offsetY = startPos.y, math.min(startPos.y + self.chunkSize - 1, self.toPos.y) do
	for offsetX = startPos.x, math.min(startPos.x + self.chunkSize - 1, self.toPos.x) do
		local currentPos = Position(offsetX, offsetY, startPos.z)
		callback(currentPos)
	end
	end
end

function Area:asyncIterateArea(callback)
	local chunkAmount = {
		x = math.floor((self.toPos.x - self.fromPos.x) / self.chunkSize),
		y = math.floor((self.toPos.x - self.fromPos.x) / self.chunkSize),
		z = (self.toPos.z - self.fromPos.z)
	}
	
	local n = 0
	for z = 0, chunkAmount.z do
	for y = 0, chunkAmount.y do
	for x = 0, chunkAmount.x do
		n = n + 1
		addEvent(Area.asyncIterateChunk, self.delay * n, self, {x = x, y = y, z = z}, callback)
	end
	end
	end
end

-- example code
--[[
function exampleFunction(pos, itemId)
	local tile = Tile(pos) or Game.createTile(pos)
	if tile then
		Game.createItem(itemId, 1, pos)
	end
end

function exampleCallback(pos)
	exampleFunction(pos, 1284)
end

function asyncTest()
	local area = Area(Position(160, 54, 7), Position(256, 256, 9), 32, 400)
	area:asyncIterateArea(exampleCallback)
end

addEvent(asyncTest, 4000)
]]