mirror of
https://github.com/kikito/cron.lua.git
synced 2024-12-19 18:34:20 +00:00
94 lines
2.9 KiB
Markdown
94 lines
2.9 KiB
Markdown
cron.lua
|
|
========
|
|
|
|
[](https://travis-ci.org/kikito/cron.lua)
|
|
|
|
`cron.lua` are a set of functions for executing actions at a certain time interval.
|
|
|
|
API
|
|
===
|
|
|
|
`local clock = cron.after(time, callback, ...)`.
|
|
Creates a clock that will execute `callback` after `time` passes. If additional params were provided, they are passed to `callback`.
|
|
|
|
`local clock = cron.every(time, callback, ...)`.
|
|
Creates a clock that will execute `callback` every `time`, periodically. Additional parameters are passed to the `callback` too.
|
|
|
|
|
|
Clock methods:
|
|
|
|
`local expired = clock:update(dt)`.
|
|
Increases the internal timer in the clock by `dt`.
|
|
|
|
* On one-time clocks, if the internal timer surpasses the clock's `time`, then the clock's `callback` is invoked.
|
|
* On periodic clocks, the `callback` is executed 0 or more times, depending on how big `dt` is and the clock's internal timer.
|
|
* `expired` will be true for one-time clocks whose time has passed, so their function has been invoked.
|
|
|
|
`clock:reset([running])`
|
|
Changes the internal timer manually to `running`, or to 0 if nothing is specified. It never invokes `callback`.
|
|
|
|
|
|
Examples
|
|
========
|
|
|
|
```lua
|
|
local cron = require 'cron'
|
|
|
|
local function printMessage()
|
|
print('Hello')
|
|
end
|
|
|
|
-- the following calls are equivalent:
|
|
local c1 = cron.after(5, printMessage)
|
|
local c2 = cron.after(5, print, 'Hello')
|
|
|
|
c1:update(2) -- will print nothing, the action is not done yet
|
|
c1:update(5) -- will print 'Hello' once
|
|
|
|
c1:reset() -- reset the counter to 0
|
|
|
|
-- prints 'hey' 5 times and then prints 'hello'
|
|
while not c1:update(1) do
|
|
print('hey')
|
|
end
|
|
|
|
-- Create a periodical clock:
|
|
local c3 = cron.every(10, printMessage)
|
|
|
|
c3:update(5) -- nothing (total time: 5)
|
|
c3:update(4) -- nothing (total time: 9)
|
|
c3:update(12) -- prints 'Hello' twice (total time is now 21)
|
|
```
|
|
|
|
Gotchas / Warnings
|
|
==================
|
|
|
|
* `cron.lua` does *not* implement any hardware or software clock; you will have to provide it with the access to the hardware timers, in the form of periodic calls to `cron.update`
|
|
* `cron` does not have any defined time units (seconds, milliseconds, etc). You define the units it uses by passing it a `dt` on `cron.update`. If `dt` is in seconds, then `cron` will work in seconds. If `dt` is in milliseconds, then `cron` will work in milliseconds.
|
|
|
|
Installation
|
|
============
|
|
|
|
|
|
Just copy the cron.lua file somewhere in your projects (maybe inside a /lib/ folder) and require it accordingly.
|
|
|
|
Remember to store the value returned by require somewhere! (I suggest a local variable named `cron`)
|
|
|
|
```lua
|
|
local cron = require 'cron'
|
|
```
|
|
|
|
Also, make sure to read the license file; the text of that license file must appear somewhere in your projects' files.
|
|
|
|
Specs
|
|
=====
|
|
|
|
This project uses [busted](https://olivinelabs.com/busted) for its specs. If you want to run the specs, you will have to install it first. Then run:
|
|
|
|
```bash
|
|
cd path/where/the/spec/folder/is
|
|
busted
|
|
```
|
|
|
|
|