github.com/mcfly722/gopackages/scheduler

scheduler

This scheduler collects objects to queue according it's deadline time. Checking the first one deadline element in this queue, you can understand is there other deadlines in this queue occurs or not.

Usage

1. Create scheduler:

scheduler := NewScheduler()

2. Insert some elements with it deadline times:

now := time.Now()
scheduler.RegisterNewTimer(now.Add(2*time.Second), object2)
scheduler.RegisterNewTimer(now.Add(3*time.Second), object3)
scheduler.RegisterNewTimer(now.Add(3*time.Second), object3)
scheduler.RegisterNewTimer(now.Add(1*time.Second), object1)

3. Check the first one deadline.

If it reached, method scheduler.TakeFirstOutdated() returns object, otherwise it returns nil.

object := scheduler.TakeFirstOutdatedOrNil()
if object != nil {
  // timer for this object is outdated, object pulled from scheduler queue, now make some work with it
}

4. You can cancel particular object from queue

scheduler := scheduler.NewScheduler()
scheduler.RegisterNewTimer(time.Now(), 1)
scheduler.RegisterNewTimer(time.Now(), 1)
scheduler.RegisterNewTimer(time.Now(), 2)
scheduler.RegisterNewTimer(time.Now(), 1)
scheduler.RegisterNewTimer(time.Now(), 2)
scheduler.RegisterNewTimer(time.Now(), 2)
scheduler.CancelTimerFor(1)
scheduler.CancelTimerFor(2)

Several same objects in queue supported

5. Or cancel all scheduler timers

scheduler.CancelAllTimers()

Limitations and specific

• Currently insertion of new deadline works for O(n) time (n - is the average size of deadlines queue)
  For large schedulers which have more than 1000 timers, it would be nice to use more optimized insertion algorithm with O(log(n)) time.
  
• All operations with scheduler are thread safe.