trie-uaparser

Yet another user agent parser

As of time of writing (3rd june 2018), the fastest user agent parser.

$ node benchmark/benchmark-parse.js
   trie-uaparser v1.0.5 x 106,078 ops/sec ±0.82% (92 runs sampled)
       useragent v2.3.0 x 9,442 ops/sec ±1.10% (88 runs sampled)
useragent_parser v1.0.0 x 59,402 ops/sec ±0.98% (91 runs sampled)
useragent-parser v0.1.1 x 21,017 ops/sec ±1.39% (87 runs sampled)
       ua-parser v0.3.5 x 41,224 ops/sec ±1.33% (89 runs sampled)
Fastest is trie-uaparser v1.0.5

Examples

const {parse} = require("trie-uaparser");

const ua = "Mozilla/5.0 (Linux; U; Android 4.1.2; fr-fr; G740-L00 Build/HuaweiG740-L00) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30";
expect(parse(ua)).to.equal("Android Browser");

const match = parse(ua, {
    match: true
});

expect(match).not.to.equal(false);
expect(match.family).to.equal("Android Browser");
expect(match.version).to.equal("4.0");
expect(match.os).not.to.equal(null);
expect(typeof match.os).to.equal("object");
expect(match.os.family).to.equal("Android");
expect(match.os.version).to.equal("4.1.2");

Differences with existing user agent parsers

Most of the user agents parser use multiple regular expressions, each of them associated to a particular software/os.

This library instead, split the user agent into tokens and determines the software/os using a trie data structure.

It leads to:

Speed

Search using trie data structure will always be faster than looping through regexes execution. And if you have lots of data to analyse, speed is not only a nice thing to have.

Evolution

Adding a new pattern does not conflict with existing patterns.

In regexes based parsers, to detect Edge in "Mozilla/5.0 (Windows NT 10.0; Win64; x64; ServiceUI 11) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 Edge/16.16299", /edge/ has to be tested before /chrome/ to detect Safari without conflicting with Edge, /safari/ has to be between /chrome/ and /edge/

The more patterns you add, the harder it is to make it play well with existing patterns.

More over, adding a new pattern has a small impact on speed because it is similar to add an entry in a hashmap which is not the case for regexes based parsers.