net.server_epoll: Add support for systemd socket activation
Allows creating listening sockets and accepting client connections
before Prosody starts.
This is unlike normal Prosody dynamic resource management, where ports
may added and removed at any time, and the ports defined by the config.
Weird things happen if these are closed (e.g. due to reload) so here we
prevent closing and ensure sockets are reused when opened again.
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;
};