[FEATURE REQUEST] Is there any way to do some specific action before periodic task enqueue?

[ChihSeanHsu]

Is your feature request related to a problem? Please describe.
As title, I'm wondering is there any option or handler before periodic task enqueue?

Describe the solution you'd like
Maybe, we can solve this case just like error-handling

Additional context
IMO, we can implement this function in Enqueue part, not only for periodic task.

[hibiken]

@ChihSeanHsu thank you for creating a feature request.

What kind of action do you need to perform before enqueueing a task? I want to understand the motivation.

[ChihSeanHsu]

@hibiken Thanks for your prompt response.
We want to have a metrics to monitor the periodic enqueue count or some other actions (Currently, I have no another idea).
Although, we can just make this metrics by processing task part, but I just wonder is there any pre-action way not post-action.

[hibiken]

I see. Actually, now that I'm thinking about it, maybe it makes sense to allow users to provide callbacks before and after enqueue happens on Scheduler.

Something like:

type SchedulerOpts struct {
    // PreEnqueueFunc, if provided, is called before a task gets enqueued by Scheduler.
    // The callback function should return quickly to not block the current thread.
    PreEnqueueFunc func(task *Task, opts []Option)

    // PostEnqueueFunc, if provided, is called after a task gets enqueued by Scheduler.
    // The callback function should return quickly to not block the current thread.
    PostEnqueueFunc func(info *TaskInfo, err error)

   // ... other options

   // Deprecated: Use PostEnqueueFunc instead
   ErrorHandlerFunc func(task *Task, opts []Option, err error)
}

[ChihSeanHsu]

@hibiken Great.
Thanks for your help!
What will the road map be about this small feature?
Or can I just submit a PR about it?

[hibiken]

@ChihSeanHsu Feel free to open a PR if you have bandwidth to work on it. Thanks :)

[ChihSeanHsu]

Hi @hibiken
Here is the PR, and feel free to review it thanks.

[hibiken]

Closed via #476. This feature will be included in the next release. Thank you @ChihSeanHsu !