GoQueue

GoQueue is a simple thread safe empty interface Queue implementation in Golang

Installation

To install GoQueue just use go get in your preferred interpreter

go get github.com/DamnWidget/goqueue

Usage

GoQueue is pretty straightforward to use, you just have to create a new Queue
and push or pop whatever element you want from or to it.

Unlimited Queues

Queues can have a maximum capacity size or be unlimited, to create an unlimited
queue just call the New method with no parameters:

// create a new unlimited Queue
q := goqueue.New()

Sized Queues

If you want to create a sized Queue, then pass the desired size of the queue as
first and only one parameter to the New function (if more than one parameter
is passed, only the first one is taken into account)

// create a new Queue with a maximum size of 1000 elements
q := goqueue.New(1000)

Queue size operations

The Queue size and capacity properties are exported via the Len and Cap
methods respectively.

q := goqueue.New(1000)
fmt.Println(q.Len())
fmt.Println(q.Cap())

Will output:

0
1000

Push elements to the end of the Queue

To push an element to the end of the Queue we just call the method Push using
the element as unique argument.

q := goqueue.New()
err := q.Push("Test")

Remember that any type of element can be pushed to the GoQueue, including your
own defined types.

type Customer struct {
    name        string
    customer_id int
}
err := q.Push(&Customer{"Test Customer", 1})

If we try to push an element beyond the size limit of the Queue the Push
method returns an error so you should always check the returned value. If
the Push is successful then, it returns nil.

Pop elements from the end of the Queue

Elements are extracted from the end of the Queue (as this Queue is a FIFO data
structure).

customer = q.Pop()

If the Queue is empty, Pop returns nil so you will always check the returned
value and use in your logic

q := goqueue.Queue()
// push things here
...

for {
    item := q.Pop()
    if item == nil {
        break
    }
    // do something useful here
}

Return all Queue elements at once

We can get all the elements from a Queue without extract them (and without
mutate the Queue) if we need to do so using the Values method.

for item := range q.Values() {
    // do something clever here with item
}

Thread Safe Operations

All the operations in the Queue are thread safe so we can share a Queue
instance safely between any number of goroutines as we need.

DamnWidget/goqueue