rooster

Rooster is a job scheduler that runs in multiple queues with jobs being executed in parallel.

How to use

import "github.com/arkadyb/rooster"

Create new rooster

To create new rooster item use NewRooster function that takes two arguments - selector and queues where selector is function of type QueueSelectorFunc that describes a way next execution queue is selected for a new scheduled job.

You may define your own QueueSelectorFunc to select queue depending on content of your job or scheduler. A simple Round Robin selector may look like

roundRobinSelector:=func() rooster.QueueSelectorFunc {
    selectedQueueIndex := 0
    return func(queues []*rooster.Queue) *rooster.Queue {
        q := queues[selectedQueueIndex]

        selectedQueueIndex++
        if selectedQueueIndex >= len(queues) {
            selectedQueueIndex = 0
        }

        return q
    }
}

Queues are the workload chains that store and execute jobs. User rooster.NewQueue() function to create new queue.

scheduler:=rooster.NewRooster(roundRobinSelector, []*rooster.Queue{rooster.NewQueue(), rooster.NewQueue()})

Here rooster would be created with two execution queues with one being selected to run scheduled job in round robin style.

Schedule job

Rooster exposes Enqueue function to schedule new job and Dequeue to remove job before its being executed. Use rooster.NewJob() function to create a new job. Function takes two arguments - time when job should be executed and JobFunc.

scheduler.Enqueue(NewJob(time.Now().Add(5 * time.Second), func(j *Job){
    fmt.Printf("Job %s has been executed\n", j.GetID())
}))

Middleware

Interceptors may be included into execution chain for given Queue. Specify interceptor functions when creating new queue

NewQueue(func(job Job){
    fmt.Printf("First interceptor run for job %s\n", job.GetID())
}, func(job Job){
    fmt.Printf("Second interceptor run for job %s\n", job.GetID())
})

License

The MIT License (MIT)