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

fast-cidr-tools

v0.3.1

Published

cidr-tools but up to 20x faster

Downloads

283

Readme

fast-cidr-tools

Tools to work with IPv4 and IPv6 CIDR, but 20x faster than cidr-tools, and is not Pure ESM (publish both CommonJS and ESM).

Requires BigInt supports.

Usage

import {
  ip2bigint, // support both IPv4 and IPv6
  bigint2ip, // support both IPv4 and IPv6
  contains,
  exclude,
  expand,
  merge,
  overlap
} from 'fast-cidr-tools';

contains(['1.0.0.0/24', '2.0.0.0/24'], ['1.0.0.1']) //=> true
exclude(['::1/127'], ['::1/128']) //=> ['::/128']
expand(['2001:db8::/126']) //=> ['2001:db8::', '2001:db8::1', '2001:db8::2', '2001:db8::3']
merge(['1.0.0.0/24'], ['1.0.1.0/24']); //=> ['1.0.0.0/23']
overlap(['1.0.0.0/24'], ['1.0.0.128/25']) //=> true

Performance

fast-cidr-tools is very fast, and is specfically optimized for IPv4. In some cases, it can be 20x faster than cidr-tools. fast-cidr-tools acheive this performance by:

  • Doing less things, E.g.:
    • cidr-tools will cast input to an array if it is string (cidrTools.merge('1.0.0.0/24', '1.0.1.0/24')). fast-cidr-tools only supports array input.
    • cidr-tools sort the return value of merge and exclude by default. fast-cidr-tools's sort is opt-in.
    • And many more.
  • Use efficient calculation and avoid unnecessary string operations.
    • how cidr-tools and fast-cidr-tools calculate the "biggest power of two":
      // cidr-tools
      function biggestPowerOfTwo(num) {
        if (num === 0n) return 0n;
        return 2n ** BigInt(String(num.toString(2).length - 1));
      }
      
      // fast-cidr-tools
      // Not the actual implementation: fast-cidr-tools actually inlines the calculation
      // for better performance
      const uint64 = new BigUint64Array(1);
      const uint32 = new Uint32Array(uint64.buffer);
      function clz64(bigint: bigint) {
        uint64[0] = bigint;
        let r = Math.clz32(uint32[1]);
        if (r === 32) {
          r += Math.clz32(uint32[0]);
        }
        return r;
      }
      function biggestPowerOfTwo(num: bigint) {
        if (num === 0n) return 0n;
        const power = BigInt(64 - clz64(size) - 1);
        return 2n ** (power === -1n ? 128n : power);
      }
    • how cidr-tools and fast-cidr-tools calculate the prefix of a CIDR:
      // cidr-tools
      const zeroes = (part.end + 1n - part.start).toString(2);
      const prefix = bits[v] - (zeroes.match(/0/g) || []).length;
      
      // fast-cidr-tools
      function fast_popcnt(value: bigint | number) {
        let v = Number(value);
        v -= v >>> 1 & 0x55_55_55_55;
        v = (v & 0x33_33_33_33) + (v >>> 2 & 0x33_33_33_33);
        return BigInt((((v + (v >>> 4)) & 0x0F_0F_0F_0F) * 0x01_01_01_01) >>> 24);
      }
      const uint64_0 = new BigInt64Array(1);
      const uint32_0 = new Int32Array(uint64_0.buffer);
      function fast_popcnt64(value: bigint) {
        uint64_0[0] = value;
        return fast_popcnt(uint32_0[0]) + fast_popcnt(uint32_0[1]);
      }
      const prefix = bits[v] - (v === 4 ? fast_popcnt(end - start) : fast_popcnt64(end - start));
  • Use a more compact internal data structure. Compare how cidr-tools and fast-cidr-tools represent a CIDR internally:
    // cidr-tools
    parse('::/64'); //=> { cidr: '::/64', version: 6, prefix: '64', start: 0n, end: 18446744073709551615n }
    
    // fast-cidr-tools
    parse('::/64'); //=> [0n, 18446744073709551615n, 6]
  • Avoid repeated calculations. Notice how fast-cidr-tools pre-parse inputs instead of parsing them repeatedly:

fast-cidr-tools © Sukka, Authored and maintained by Sukka with help from contributors (list).

Personal Website · Blog · GitHub @SukkaW · Telegram Channel @SukkaChannel · Twitter @isukkaw · Keybase @sukka