burst-queue

burst-queue

A simple queue that takes functions and executes those functions on a specified interval. Optionally a maximum number of functions to execute per interval can be specified when creating a burst-queue.

Objects

Queue(period, [callsPerPeriod])
Returns a burst-queue that will execute passed-in functions every period (milliseconds). The optional callsPerPeriod value denotes a maximum number of functions to be executed at each interval.

var Queue = require('burst-queue');
// Call the oldest 20 functions every minute
var queue = new Queue(60*1000, 20);

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Methods

add(fn) / add([fn1, fn2, ...])
Adds functions to the queue. The add method takes either a single function or an array of functions. Returns the queue's internal id(s) of the passed in functions. The internal ids can be later used to remove items from the queue. If an array of functions is passed to add, an array of ids is returned in the same order as the functions that were passed in.

var hello = function() { console.log("hello") };
var comma = function() { console.log(",") };
var space = function() { console.log(" ") };
var is_it_me = function() { console.log("is it me") };
var youre_looking_for = function() { console.log("you're looking for") };

queue.add(hello);
queue.add([ comma, space, is_it_me, space, youre_looking_for ]);

//>hello, is it me you're looking for

clear()
Clears the queue of all functions.

var queue = new Queue(60*1000, 2);
queue.add([ hello, comma, comma, space );
// the first 2 functions are called instantly since we must first
// reach the calls per period limit before enqueueing functions
console.log(queue.enqueued());
//> 2
queue.clear();
console.log(queue.enqueued());
//> 0

enqueued()
Returns the current count of items in the queue.

remove(id)
Takes an id returned from an add call and removes that function from the queue, if it is still in the queue. Returns a bool that designates whether the remove call successfully found and removed the function from the queue. If a function no longer exists in the queue when remove is called on its id, remove returns false.

var tryRemove = function(id) {
    if (queue.remove(id)) {
        console.log("success!");
    } else {
        console.log("fail!");
    }
}

var helloId = queue.add(hello);
tryRemove(helloId);
//> success!
tryRemove(helloId);
//> fail!

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Properties

counter
Returns the current value of the counter used for generating the queue's internal ids for functions. This value increments by one each time a function is added to the queue.

availableCalls
Only valid when callsPerPeriod is defined. Returns the number of calls available in the current period. Any function added to the queue in when availableCalls returns a value greater than 0 will be executed immediately.