A simple Go FIFO queue.

Queue is a FIFO queue implementation, to create it simply call New().

q := qfifo.New(nil)
q.Push(1)
q.Push(2)
....

Under the hood, Queue uses slice with default capacity of 10, to increase the capacity use QueueOptions.

q = qfifo.New(&QueueOptions{
		InitialSize: 20,
	})
q.Push(1)
q.Push(2)
....

To add an element, use Push() and to pull an element out use Pop(). All method has internal lock so they are safe to be used in multiple go routine.

Publisher uses Queue and periodically pull element to be passed into a publish function. Common scenario to use Publisher such as logging, we want to buffer the logs and periodically write buffered logs to persistence media such as text file or database. In this case, we can do that inside the publish function and let logging methods to push logs to queue while publish function writes the logs into text file.

To create a publisher:

p, err = qfifo.NewPublisher(PublisherArgs{
		PublishFunc: func(p *Publisher, v interface{}) {
            // v is the pulled element
            fmt.Println(v.(int)) // assuming the queued elements are integers
        },
	})
if err != nil {
    return err
}
defer p.Close()  // make sure to call this

p.Push(1)
p.Push(2)
..........

PublishFunc is non-blocking because will be called by internal go routine. If it is unset then NewPublisher() returns ErrPublishFunctionUnset.