Crate crony

Crony: a simple cron runner

Use the Job trait to create your cron job struct, pass it to the Runner and then start it via run() method. Runner will spawn new thread where it will start looping through the jobs and will run their handle method once the scheduled time is reached.

If your OS has enough threads to spare each job will get its own thread to execute, if not it will be executed in the same thread as the loop but will hold the loop until the job is finished.

Please look at the Job trait documentation for more information.

Example

use crony::{Job, Runner, Schedule};
use std::thread;
use std::time::Duration;

struct ExampleJob;
impl Job for ExampleJob {
    fn schedule(&self) -> Schedule {
        "1/5 * * * * *".parse().unwrap()
    }
    fn handle(&self) {
        println!("Hello, I am a cron job running at: {}", self.now());
    }
}

fn run() {
    let mut runner = Runner::new();

    println!("Adding ExampleJob to the Runner");
    runner = runner.add(Box::new(ExampleJob));

    println!("Starting the Runner for 20 seconds");
    runner = runner.run();
    thread::sleep(Duration::from_millis(20 * 1000));

    println!("Stopping the Runner");
    runner.stop();
}

fn main() {
    run();
}

Output:

Adding ExampleJob to the Runner
Starting the Runner for 20 seconds
Hello, I am a cron job running at: 2021-01-31 03:06:25.908475 UTC
Hello, I am a cron job running at: 2021-01-31 03:06:30.912637 UTC
Hello, I am a cron job running at: 2021-01-31 03:06:35.926938 UTC
Hello, I am a cron job running at: 2021-01-31 03:06:40.962138 UTC
Stopping the Runner

Structs

• Runner
  Runner that will hold all the jobs and will start up the execution and eventually will stop it.
• Schedule
  Re-export of (cron)[https://crates.io/crates/cron] crate struct for setting the cron schedule time. Read its documentation for more information and options.
• TRACKER
  Singleton instance of a tracker that won’t allow same job to run again while its already running unless you specificly allow the job to run in parallel with itself
• Tracker
  Struct for marking jobs running

Traits

• Job