npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

length-prefixed-json-stream

v1.0.1

Published

A length-prefixed JSON stream reader that accommodates whitespace padding

Downloads

359

Readme

length-prefixed-json-stream

A length-prefixed JSON stream reader that accommodates whitespace padding.

Length Prefixed JSON Streams

Length prefixed JSON streams are streams of JSON values, where each value is preceded by the length-in-bytes of the value. (The length is a decimal integer encoded as a string of digits.) Here's an example:

18{"message": "Hi!"}27{"message": "How are you?"}

Whitespace Padding

This module supports ASCII whitespace characters both before and after the length prefix. This has the effect of allowing literal number values to be sent without necessitating a wrapper object, by simply appending a space after the length prefix string. For example:

2 42 2 84 3 168 4 0.42

Usage

import JSONStreamIterator from 'length-prefixed-json-stream'

async function responseHandler (response) {
  const streamIterator = new JSONStreamIterator(response)

  let value
  while ((value = await streamIterator.readNextValue()) !== undefined) {
    console.log(value)
  }
}

If your JavaScript environment supports it, you can use the more readable for await…of:

async function responseHandler (response) {
  const streamIterator = new JSONStreamIterator(response)
  for await (const value of streamIterator) {
    console.log(value)
  }
}

API

import JSONStreamIterator from 'length-prefixed-json-stream'

new JSONStreamIterator(stream)

Reads values one at a time from stream.

  • stream: Node.js readable stream.

.readNextValue()

Returns a promise that resolves to the next value from the input stream. When the stream ends, the promise will resolve to undefined. If there is an error parsing the stream, or some sort of connection error, the promise will be rejected with the error.

.next()

A for await…of (async iterator) compatible method. If you are using for await…of, this is called for you, but you can also use it explicitly if you would like. It wraps the returned values according to the spec: while not complete, returns a promise that resolves to {done: false, value: …}, and when complete, returns a promise that resolves to {done: false}.

.return()

Also a part of the async iterator spec, but you can call it explicitly to end iteration early and free resources.