lakelezz / white_rabbit

Rust task scheduler.

“I'm late! I'm late! For a very important date!”

by “The White Rabbit” 『Alice's Adventures in Wonderland』

About

white_rabbit schedules your tasks and can repeat them!

One funny use case are chat bots, e.g. a remind me-command that might be repeated after a user-specified time.

We are using chrono's DateTime<Utc>, enabling you to serialise and thus backup currently running tasks, in case you want to shutdown/restart your application, constructing a new scheduler is doable. However, please make sure your internal clock is synced.

Everyone is welcome to contribute, check out the CONTRIBUTING.md for further guidance.

Example

Let's have a look at a code-example:

use white_rabbit::{DateResult, Duration, Scheduler};

fn main() {
    let mut scheduler = Scheduler::new(4);

    scheduler.add_task_duration(Duration::seconds(5), |_| {
        println!("I'm here!");

        DateResult::Done
    });
}

Precision

The scheduler sleeps when unneeded. Due to preemption or different implementations across operating systems, it may occur that the scheduler will sleep longer than intended.

Be aware, an incorrect system clock may lead to tasks being run earlier or later.

Installation

Add this to your Cargo.toml:

[dependencies]
white_rabbit = "0.1.0"

white_rabbit's Issues

Make Context time accessible

Tasks are handed a Context reference on execution. I would like to access the context's time to schedule a follow-up task based on it. The field is private though and there is no accessor method. (I know that I could just call now() to get the current time, which should be almost equal to the time stored in the context. But then the task might be delayed slightly each time it is rescheduled).

Delete scheduled Tasks

Deleting scheduled tasks is a feature I would like to add.
It will require to change the underlying data-structure.