File

util/throttle.lua @ 13039:9ddb344b9fab

util.human.io: Allow defining per column ellipsis function As an alternative to doing it in the mapper function. Could be useful in cases where one may want to put the ellipsis in the middle or beginning instead of the start.
author Kim Alvefur <zash@zash.se>
date Fri, 07 Apr 2023 13:00:58 +0200
parent 12975:d10957394a3c
line wrap: on
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local gettime = require "prosody.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;
};