File

util/watchdog.lua @ 12795:87424cbedc55

util.hashring: Support associating arbitrary data with nodes In this API, a 'node' is always a simple text string. Sometimes the caller may have a more complex structure representing a node, but the hash ring is really only concerned with the node's name. This API change allows :add_nodes() to take a table of `node_name = value` pairs, as well as the simple array of node names previously accepted. The 'value' of the selected node is returned as a new second result from :get_node(). If no value is passed when a node is added, it defaults to `true` (as before, but this was never previously exposed).
author Matthew Wild <mwild1@gmail.com>
date Fri, 02 Dec 2022 20:32:36 +0000
parent 12547:e79c64b2dfed
child 12975:d10957394a3c
line wrap: on
line source

local timer = require "util.timer";
local setmetatable = setmetatable;

local _ENV = nil;
-- luacheck: std none

local watchdog_methods = {};
local watchdog_mt = { __index = watchdog_methods };

local function new(timeout, callback)
	local watchdog = setmetatable({
		timeout = timeout;
		callback = callback;
		timer_id = nil;
	}, watchdog_mt);

	watchdog:reset(); -- Kick things off

	return watchdog;
end

function watchdog_methods:reset(new_timeout)
	if new_timeout then
		self.timeout = new_timeout;
	end
	if self.timer_id then
		timer.reschedule(self.timer_id, self.timeout+1);
	else
		self.timer_id = timer.add_task(self.timeout+1, function ()
			return self:callback();
		end);
	end
end

function watchdog_methods:cancel()
	if self.timer_id then
		timer.stop(self.timer_id);
		self.timer_id = nil;
	end
end

return {
	new = new;
};