#periodic #task #state #periodically #job #terminal #running

periodic_do

Run task periodically until it reaches a terminal state

1 unstable release

0.1.0 Mar 18, 2022

#5 in #periodically

23 downloads per month

MIT license

12KB
217 lines

Periodic Do

This is a library for running periodic tasks:

  • Implement the Job trait for your domain specific data type T, which represents the task to be run
  • Send instances of T via a tokio::sync::mpsc::channel to periodic_do::loop_forever
  • This library will periodically poll T for two things:
    • Is this T up to be run? If so, run it and update the job state
    • Has this T reached a terminal state? In which case it will be forgotten

Project status

Usable, but has rough edges, evaluate before using it in production.

Example Usage

use tokio;

#[tokio::main]
async fn main() -> Result<(), Error> {
  let (sender, receiver) = tokio::sync::mpsc::channel(1000);
  
  let unfinished_jobs = load_unfinished_jobs_from_database().await?;
  
  // Start the scheduler
  let capacity = periodic_do::Capacity {
      max_running_jobs: 10,
      sweep_sleep_seconds_default: 5,
      sweep_sleep_seconds_min: 1,
      sweep_sleep_seconds_max: 60,
  };
  tokio::spawn(async move {
      periodic_do::loop_forever(
          capacity, receiver, unfinished_jobs
      ).await
  });
  
  loop {
      // T implements `Job` trait
      let some_task: T = get_a_task_from_some_where().await;
      sender.send(some_task).await
  }
  
  Ok(())
}

Dependencies

~3.5–5MB
~85K SLoC