fifo

library2.4.1jsnpmunverified

Double-linked-list FIFO queue (v2.4.1, stable, low churn). O(1) push/shift/unshift/remove/move operations. Unlike array-based queues, removal of arbitrary nodes is O(1) by retaining node references. Supports iteration and bumping nodes to end. Minimal API, no dependencies. Suitable for high-performance queuing in Node.js or browser (bundled).

storage

npm install fifo

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · FIFO

fifo

storagejavascriptv2.4.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import fifo from 'fifo'

✗ const fifo = require('fifo')()

Default import is a factory function. The package ships CJS only, but ESM import works in Node 14+ with --experimental-modules or bundlers.

FIFO

✓ import fifo from 'fifo'

✗ import { FIFO } from 'fifo'

There is no named export; the default export is the constructor.

type Node

✓ import fifo from 'fifo'; const node = fifo.push('val'); // node has: value: any, prev: Node|null, next: Node|null

✗ const { Node } = require('fifo');

Node type is not exported. In TypeScript, declare interface manually or use @types/fifo.

Demonstrates basic queue operations: push, shift, first, remove, and length.

import fifo from 'fifo'; const queue = fifo(); queue.push('first'); const node = queue.push('second'); queue.push('third'); console.log(queue.shift()); // 'first' console.log(queue.first()); // 'second' queue.remove(node); console.log(queue.first()); // 'third' console.log(queue.length); // 1

Debug

Known issues

gotchaCalling fifo() multiple times creates separate instances. The default export is a factory, not a singleton.

fix

Always call fifo() to create a new instance: const q = fifo();

affects: >=2.0.0

gotchaQueue nodes have prev/next properties that should not be modified directly. Use fifo.remove() to remove nodes.

fix

Do not mutate node.prev or node.next. Use fifo.remove(node) for safe removal.

affects: >=2.0.0

gotchaCalling fifo.push() returns a node, not the value. Access value via node.value.

fix

Use const node = fifo.push('val'); const value = node.value;

affects: >=2.0.0

deprecatedThe fifo.node property is exposed but not part of the public API and may be removed in future versions.

fix

Use fifo.first() to peek at the first value, or iterate with fifo.forEach().

affects: >=2.0.0

Errors

Common errors & fixes

fifo is not a function

Forgetting to import the default export as a factory.

fix

Use const fifo = require('fifo'); const queue = fifo();

Cannot read property 'value' of undefined

Trying to access node.value on a removed node or after shift/pop returned the value.

fix

Shift returns the value directly, not a node. Use fifo.remove(node) and then node.value before removal.

TypeError: fifo.remove is not a function

Using fifo (the factory) instead of an instance.

fix

Call fifo() first: const queue = fifo(); queue.remove(node);

Upgrade

Version history

2.4.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

32 hits · last 30 days

node

Resources

githubhttps://github.com/mafintosh/fifo ↗

packagefifo ↗

homepagehttps://github.com/mafintosh/fifo ↗