fast-fifo

A fast fifo implementation similar to the one powering nextTick in Node.js core

npm install fast-fifo

Uses a linked list of growing fixed sized arrays to implement the FIFO to avoid allocating a wrapper object for each item.

Usage

const FIFO = require('fast-fifo')

const q = new FIFO()

q.push('hello')
q.push('world')

q.shift() // returns hello
q.shift() // returns world

API

q = new FIFO()

Create a new FIFO.

q.push(value)

Push a value to the FIFO. value can be anything other than undefined.

value = q.shift()

Return the oldest value from the FIFO.

q.clear()

Remove all values from the FIFO.

bool = q.isEmpty()

Returns true if the FIFO is empty and false otherwise.

value = q.peek()

Return the oldest value from the FIFO without shifting it out.

len = q.length

Get the number of entries remaining in the FIFO.

Benchmarks

Included in bench.js is a simple benchmark that benchmarks this against a simple linked list based FIFO.

On my machine the benchmark looks like this:

fifo bulk push and shift: 2881.508ms
fifo individual push and shift: 3248.437ms
fast-fifo bulk push and shift: 1606.972ms
fast-fifo individual push and shift: 1328.064ms
fifo bulk push and shift: 3266.902ms
fifo individual push and shift: 3320.944ms
fast-fifo bulk push and shift: 1858.307ms
fast-fifo individual push and shift: 1516.983ms

YMMV

License

MIT