File

plugins/mod_cron.lua @ 12446:e54b8a5e35ad 0.12

util.random: Test whether util.crand works before using it (fix #1734) util.crand can be configured at compile time to use the Linux getrandom() system call, available from Linux 3.17, but it is still possible to load it with an older kernel lacking that system call, where attempting to use it throws an ENOSYS error. By testing for this on load we can fall back to /dev/urandom in this case.
author Kim Alvefur <zash@zash.se>
date Sat, 02 Apr 2022 16:33:27 +0200
parent 12186:7f25ac9d8f0d
child 12489:8b42575738f0
line wrap: on
line source

module:set_global();

local async = require("util.async");
local datetime = require("util.datetime");

local periods = { hourly = 3600; daily = 86400; weekly = 7 * 86400 }

local active_hosts = {}

function module.add_host(host_module)

	local last_run_times = host_module:open_store("cron", "map");
	active_hosts[host_module.host] = true;

	local function save_task(task, started_at) last_run_times:set(nil, task.id, started_at); end

	local function task_added(event)
		local task = event.item;
		if task.name == nil then task.name = task.when; end
		if task.id == nil then task.id = event.source.name .. "/" .. task.name:gsub("%W", "_"):lower(); end
		if task.last == nil then task.last = last_run_times:get(nil, task.id); end
		task.save = save_task;
		module:log("debug", "%s task %s added, last run %s", task.when, task.id,
			task.last and datetime.datetime(task.last) or "never");
		if task.last == nil then
			local now = os.time();
			task.last = now - now % periods[task.when];
		end
		return true
	end

	local function task_removed(event)
		local task = event.item;
		host_module:log("debug", "Task %s removed", task.id);
		return true
	end

	host_module:handle_items("task", task_added, task_removed, true);

	function host_module.unload() active_hosts[host_module.host] = nil; end
end

local function should_run(when, last) return not last or last + periods[when] * 0.995 <= os.time() end

local function run_task(task)
	local started_at = os.time();
	task:run(started_at);
	task:save(started_at);
end

local task_runner = async.runner(run_task);
scheduled = module:add_timer(1, function()
	module:log("info", "Running periodic tasks");
	local delay = 3600;
	for host in pairs(active_hosts) do
		module:log("debug", "Running periodic tasks for host %s", host);
		for _, task in ipairs(module:context(host):get_host_items("task")) do
			module:log("debug", "Considering %s task %s (%s)", task.when, task.id, task.run);
			if should_run(task.when, task.last) then task_runner:run(task); end
		end
	end
	module:log("debug", "Wait %ds", delay);
	return delay
end);