scheduler

@library("scheduler", "0.0.0");

A cron-like task scheduler. Useful for automatic background imports or simulations.

scheduler::add

Adds a new task to the scheduler. Returns the previous task that matches the same function if any.

Note that the previous task will be lost.

scheduler::add(scheduler::PeriodicTask { fn: my_task, every: duration });

scheduler::list

Returns the current list of scheduled tasks

var current_tasks = scheduler::list();

scheduler::find

Looks for a task that matches the given function.

var found = scheduler::find(my_task);
if (found != null) {
  // use scheduler::PeriodicTask
}

scheduler::activate

Tries to find a task that matches function and activates it. Returns true if a task is found, false otherwise.

if (scheduler::activate(my_task)) {
  println("my_task successfully activated");
} else {
  println("my_task does not exist");
}

scheduler::deactivate

Tries to find a task that matches function and deactivates it. Returns true if a task is found, false otherwise.

if (scheduler::deactivate(my_task)) {
  println("my_task is not longer scheduled");
} else {
  println("my_task is not in the periodic tasks list");
}

Example

Periodically calls https://api.open-meteo.com to get the temperature in Luxembourg. The data is aggregated into a nodeGeo and a nodeTime:

var cities: nodeGeo<nodeTime<float>>;

fn main() {
  scheduler::add(
    scheduler::PeriodicTask {
      fn: fn () {
        fetch_temperature(geo { 49.612, 6.119 });
      },
      every: 30minmin,
    }
  );
}

fn fetch_temperature(location: geo) {
  var city = cities.get(location);
  if (city == null) {
    city = nodeTime<float> {};
    cities.set(location, city);
  }
  var res = Http::get(
    "https://api.open-meteo.com/v1/forecast?latitude=${location.lat()}&longitude=${location.lng()}&current=temperature_2m&timezone=UTC",
    null
  );
  var current = res.get("current");
  if (current is Map) {
    var timepoint = time::parse(current.get("time") as String, null);
    var temperature = current.get("temperature_2m") as float;
    city.setAt(timepoint, temperature);
  }
}