From f9d0231beffb3358c51cddc0187093d6917448bb Mon Sep 17 00:00:00 2001 From: Matthew Wild Date: Mon, 29 Aug 2011 13:00:33 -0400 Subject: util.throttle: Generic module by waqas to limit something over some time --- util/throttle.lua | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 util/throttle.lua diff --git a/util/throttle.lua b/util/throttle.lua new file mode 100644 index 00000000..8b62e797 --- /dev/null +++ b/util/throttle.lua @@ -0,0 +1,44 @@ + +local gettime = require "socket".gettime; + +module "throttle" + +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-self.balance); + end +end + +function create(max, period) + return setmetatable({ rate = max / period, max = max, t = 0, balance = max }, throttle_mt); +end + +return _M; -- cgit v1.2.3