File

util/throttle.lua @ 10688:83668e16b9a3

MUC: Switch to new storage format by default Changing the default setting of `new_muc_storage_format` from false to true. The code supports reading both formats since 0.11, but servers with MUCs stored using the new format will not be able to downgrade to 0.10 or earlier. The new format is clearer (less nesting for the most commonly-accessed data), and combined with the new map-store methods, allows for some operations to become more efficient (such as finding out which MUCs on a service a given user is affiliated with).
author Matthew Wild <mwild1@gmail.com>
date Thu, 12 Mar 2020 16:10:44 +0000
parent 8555:4f0f5b49bb03
child 12975:d10957394a3c
line wrap: on
line source


local gettime = require "util.time".now
local setmetatable = setmetatable;

local _ENV = nil;
-- luacheck: std none

local throttle = {};
local throttle_mt = { __index = throttle };

function throttle:update()
	local newt = gettime();
	local elapsed = newt - self.t;
	self.t = newt;
	local balance = (self.rate * elapsed) + self.balance;
	if balance > self.max then
		self.balance = self.max;
	else
		self.balance = balance;
	end
	return self.balance;
end

function throttle:peek(cost)
	cost = cost or 1;
	return self.balance >= cost or self:update() >= cost;
end

function throttle:poll(cost, split)
	if self:peek(cost) then
		self.balance = self.balance - cost;
		return true;
	else
		local balance = self.balance;
		if split then
			self.balance = 0;
		end
		return false, balance, (cost-balance);
	end
end

local function create(max, period)
	return setmetatable({ rate = max / period, max = max, t = gettime(), balance = max }, throttle_mt);
end

return {
	create = create;
};