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https://github.com/serpapi/nokolexbor
High-performance HTML5 parser for Ruby based on Lexbor, with support for both CSS selectors and XPath.
https://github.com/serpapi/nokolexbor
c-extension css html5 parser ruby serpapi web-scraping xpath
Last synced: 6 days ago
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High-performance HTML5 parser for Ruby based on Lexbor, with support for both CSS selectors and XPath.
- Host: GitHub
- URL: https://github.com/serpapi/nokolexbor
- Owner: serpapi
- Created: 2022-11-28T23:05:38.000Z (almost 2 years ago)
- Default Branch: master
- Last Pushed: 2024-04-22T09:43:09.000Z (7 months ago)
- Last Synced: 2024-05-02T21:57:29.907Z (6 months ago)
- Topics: c-extension, css, html5, parser, ruby, serpapi, web-scraping, xpath
- Language: C
- Homepage:
- Size: 631 KB
- Stars: 154
- Watchers: 12
- Forks: 3
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Nokolexbor
[](https://github.com/serpapi/nokolexbor/actions/workflows/ci.yml)
Nokolexbor is a drop-in replacement for Nokogiri. It's 5.2x faster at parsing HTML and up to 997x faster at CSS selectors.
It's a performance-focused HTML5 parser for Ruby based on [Lexbor](https://github.com/lexbor/lexbor/). It supports both CSS selectors and XPath. Nokolexbor's API is designed to be 1:1 compatible as much as possible with [Nokogiri's API](https://github.com/sparklemotion/nokogiri).
## Requirements
Nokolexbor is shipped with pre-compiled gems on most common platforms:
* Linux: `x86_64`, with glibc >= 2.17
* macOS: `x86_64` and `arm64`
* Windows: `ucrt64`, `mingw32` and `mingw64`
If you are on a supported platform, just jump to the [Installation](#installation) section. Otherwise, you need to install CMake to compile C extensions:
### macOS
```
brew install cmake
```
### Linux (Debian, Ubuntu, etc.)
```
sudo apt-get install cmake
```
## Installation
Add to your Gemfile:
```ruby
gem 'nokolexbor'
```
Then, run `bundle install`.
Or, install the gem directly:
```
gem install nokolexbor
```
## Quick start
```ruby
require 'nokolexbor'
require 'open-uri'
# Parse HTML document
doc = Nokolexbor::HTML(URI.open('https://github.com/serpapi/nokolexbor'))
# Search for nodes by css
doc.css('#readme h1', 'article h2', 'p[dir=auto]').each do |node|
puts node.content
end
# Search for text nodes by css
doc.css('#readme p > ::text').each do |text|
puts text.content
end
# Search for nodes by xpath
doc.xpath('//div[@id="readme"]//h1', '//article//h2').each do |node|
puts node.content
end
```
## Features
* Nokogiri-compatible APIs.
* High performance HTML parsing, DOM manipulation and CSS selectors engine.
* XPath search engine (ported from libxml2).
* Text nodes CSS selector support: `::text`.
## Searching methods overview
* `css` and `at_css`
* Based on Lexbor.
* Only accepts CSS selectors, doesn't support mixed syntax like `div#abc /text()`.
* To select text nodes, use pseudo element `::text`. e.g. `div#abc > ::text`.
* Performance is much higher than libxml2 based methods.
* `xpath` and `at_xpath`
* Based on libxml2.
* Only accepts XPath syntax.
* Works in the same way as Nokogiri's `xpath` and `at_xpath`.
* `nokogiri_css` and `nokogiri_at_css` (requires Nokogiri installed)
* Based on libxml2.
* Accept mixed syntax like `div#abc /text()`.
* Works in the same way as Nokogiri's `css` and `at_css`.
## Different behaviors from Nokogiri
* For selector `:nth-of-type(n)`, `n` is not affected by prior filter. For example, if we want to select the 3rd `div` excluding class `a` and class `b`, which will be the last `div` in the following HTML:
```
```
In Nokogiri, the selector should be `div:not(.a):not(.b):nth-of-type(3)`
In Nokolexbor, `:not` does affect the place of the last `div` (same in browsers), the selector should be `div:not(.a):not(.b):nth-of-type(5)`, but this losts the purpose of filtering though.
## Benchmarks
Benchmark parsing google result page (368 KB) and selecting nodes using CSS and XPath. Run on MacBook Pro (2019) 2.3 GHz 8-Core Intel Core i9.
Run with: `ruby bench/bench.rb`
| | Nokolexbor (iters/s) | Nokogiri (iters/s) | Diff |
| ---------- | ------------- | ----------- | -------------- |
| parsing | 487.6 | 93.5 | 5.22x faster |
| at_css | 50798.8 | 50.9 | 997.87x faster |
| css | 7437.6 | 52.3 | 142.11x faster |
| at_xpath | 57.077 | 53.176 | same-ish |
| xpath | 51.523 | 58.438 | same-ish |
Raw data
```
Warming up --------------------------------------
Nokolexbor parse 56.000 i/100ms
Nokogiri parse 8.000 i/100ms
Calculating -------------------------------------
Nokolexbor parse 487.564 (±10.9%) i/s - 9.688k in 20.117173s
Nokogiri parse 93.470 (±21.4%) i/s - 1.736k in 20.024163s
Comparison:
Nokolexbor parse: 487.6 i/s
Nokogiri parse: 93.5 i/s - 5.22x (± 0.00) slower
Warming up --------------------------------------
Nokolexbor at_css 5.548k i/100ms
Nokogiri at_css 6.000 i/100ms
Calculating -------------------------------------
Nokolexbor at_css 50.799k (±13.8%) i/s - 987.544k in 20.018481s
Nokogiri at_css 50.907 (±35.4%) i/s - 828.000 in 20.666258s
Comparison:
Nokolexbor at_css: 50798.8 i/s
Nokogiri at_css: 50.9 i/s - 997.87x (± 0.00) slower
Warming up --------------------------------------
Nokolexbor css 709.000 i/100ms
Nokogiri css 4.000 i/100ms
Calculating -------------------------------------
Nokolexbor css 7.438k (±14.7%) i/s - 145.345k in 20.083833s
Nokogiri css 52.338 (±36.3%) i/s - 816.000 in 20.042053s
Comparison:
Nokolexbor css: 7437.6 i/s
Nokogiri css: 52.3 i/s - 142.11x (± 0.00) slower
Warming up --------------------------------------
Nokolexbor at_xpath 2.000 i/100ms
Nokogiri at_xpath 4.000 i/100ms
Calculating -------------------------------------
Nokolexbor at_xpath 57.077 (±31.5%) i/s - 920.000 in 20.156393s
Nokogiri at_xpath 53.176 (±35.7%) i/s - 876.000 in 20.036717s
Comparison:
Nokolexbor at_xpath: 57.1 i/s
Nokogiri at_xpath: 53.2 i/s - same-ish: difference falls within error
Warming up --------------------------------------
Nokolexbor xpath 3.000 i/100ms
Nokogiri xpath 3.000 i/100ms
Calculating -------------------------------------
Nokolexbor xpath 51.523 (±31.1%) i/s - 903.000 in 20.102568s
Nokogiri xpath 58.438 (±35.9%) i/s - 852.000 in 20.001408s
Comparison:
Nokogiri xpath: 58.4 i/s
Nokolexbor xpath: 51.5 i/s - same-ish: difference falls within error
```