block-queue

library0.0.2jsnpmunverified

A minimal Node.js in-process blocking FIFO queue implementation. Version 0.0.2 is the latest stable release. Provides a simple concurrency-limited task queue with a reducer pattern. Unlike async.queue, this library blocks on push when the internal buffer is full, enforcing backpressure. Suitable for simple in-process task orchestration where flow control is needed.

devops

npm install block-queue

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · BLOCK-QUEUE

block-queue

devopsjavascriptv0.0.2

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

✓ const queue = require('block-queue');

✗ import queue from 'block-queue';

This package is CommonJS only and does not support ESM import syntax.

queue

✓ const q = queue(1, reducer);

✗ const q = new queue(1, reducer);

queue is a factory function, not a constructor. Do not use 'new'.

queue.push

✓ q.push('task');

✗ q.push('task', callback);

push only accepts a single task argument. No callback or options.

Creates a blocking queue with concurrency 2, pushes three tasks. The reducer processes tasks sequentially per slot.

const queue = require('block-queue'); const q = queue(2, (task, done) => { console.log('Processing:', task); setTimeout(done, 1000); }); q.push('task1'); q.push('task2'); q.push('task3'); // output after ~2 seconds: // Processing: task1 // Processing: task2 // Processing: task3

Debug

Known issues

gotchaThe 'blocking' behavior: queue.push will block if all slots are occupied. This can cause deadlocks if the reducer never calls done.

fix

Ensure the reducer always calls the done callback, even on error.

affects: >=0.0.1

deprecatedPackage has not been updated since 2013 and may have compatibility issues with modern Node.js versions.

fix

Consider using more modern libraries like async.queue or p-limit with promise support.

affects: >=0.0.1

gotchaNo support for error handling: errors thrown in the reducer are not caught.

fix

Wrap reducer body in try-catch and handle errors manually.

affects: >=0.0.1

gotchaqueue.clear() does not cancel in-flight tasks; it only empties pending tasks.

fix

Be aware that currently executing tasks will continue.

affects: >=0.0.1

Errors

Common errors & fixes

Error: done is not a function

Reducer expects a function but something else was passed.

fix

Pass a proper function: function(task, done) { ... }

TypeError: queue is not a constructor

Using 'new' on the queue factory function.

fix

Use queue() without new: const q = queue(1, reducer);

block-queue: task is undefined

Push called without arguments.

fix

Provide a task: q.push('myTask');

Upgrade

Version history

0.0.2latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

9 hits · last 30 days

node

Resources

githubgit://github.com/hit9/node-block-queue ↗

packageblock-queue ↗

homepagehttps://github.com/hit9/node-block-queue ↗