ringbuffer.js

A simple ring buffer data structure for Node.js.

Installation

$ npm install ringbufferjs

Example

var RingBuffer = require('ringbufferjs');

var ring = new RingBuffer(2);

ring.enq(10);
ring.enq(5);
ring.enq(1); // 10 will be discarded
ring.size(); // 2
ring.peek(); // 5
ring.deq(); // 5
ring.size(); // 1

API

RingBuffer()

Initializes a new empty RingBuffer with the default capacity (50).

RingBuffer(capacity)

Initializes a new empty RingBuffer with the given capacity.

RingBuffer(capacity, evictedCb)

Initializes a new empty RingBuffer with the given capacity which will execute the provided evictedCb when an element is evicted.

RingBuffer#capacity()

Returns the capacity of the ring buffer.

RingBuffer#deq()

Dequeues the top element of the ring buffer. Throws an Error when the buffer is empty.

RingBuffer#deqN(count)

Dequeues count elements from the top of the ring buffer and returns them. Throws an Error if there are not enough elements in the buffer.

RingBuffer#enq(element)

Enqueues the element at the end of the ring buffer and returns its new size. When the buffer is full the oldest element is discarded.

RingBuffer#isEmpty()

Returns whether the ring buffer is empty or not.

RingBuffer#isFull()

Returns whether the ring buffer is full or not.

RingBuffer#peek()

Peeks at the top element of the ring buffer. Throws an Error when the buffer is empty.

RingBuffer#peekN(count)

Returns count elements from the top of the ring buffer. Throws an Error if there are not enough elements in the buffer.

RingBuffer#size()

Returns the size of the ring buffer.

Testing

$ npm install
$ npm test

Licence

MIT

2.0.0 / 2020-05-07

• Stop supporting component and browser builds.

1.1.0 / 2017-09-11

• Add #peekN(count) to peek N elements and #deqN(count) to dequeue N elements. Thank you @bfirsh!

1.0.0 / 2017-05-04

• Add eviction callback. Thank you @rektide!

0.0.1 / 2013-03-04

• First version with #capacity(), #deq(), #enq(), #isEmpty(), #isFull(), #peek(), and #size().