FasterHTMLEscape, an h replacement

rubyonrails-talk
1

h is a function commonly used in .rhtml templates to escape HTML data (e.g. "<%=h html %>"). It is defined in ERB::Util#html_escape (h is an alias). It's implementation is relatively unoptimized, requiring a separate gsub for each of <, >, &, and ". Ruby's implementation of String#gsub (str_gsub, written in C), converts all string arguments to regular expressions before scanning the input, further slowing things down.

I have rewritten html_escape in C, speeding it up by a factor of 4-20 depending on the input. Input with no HTML characters is about 4 times faster, input of exclusively HTML characters is about 20 times faster.

Attached is a tarball, which includes:

extconf.rb - for creating the makefile to compile the extension faster_html_escape.c - The C version of html_escape (which is created inside the FasterHTMLEscape module) speed_up_html_escape.rb - This replaces the ERB::Util version of html_escape and h, as well as CGI.escapeHTML, with the C version test_faster_html_escape.rb - Small test script for checking the validity of the C function as well as benchmarking it test_faster_html_escape.sh - Uses test_faster_html_escape.rb to check and benchmark the C function with various inputs

To install (assuming Unix conventions):

  tar zxf faster_html_escape.tar.gz   cd faster_html_escape   ruby extconf.rb   make   ./test_faster_html_escape.sh   sudo make install

To use:

  # For example, in environment.rb   require 'speed_up_html_escape'

If there is interest in this, I can look into packaging it as a gem.

Please try it out and give me feedback.

Thanks, Jeremy

faster_html_escape.tar.gz (2.44 KB)

2

Great idea Jeremy! Considering that this is used so often in rendering html, this is a simple way to improve rendering performance especially for files that have large amounts of html_escaped content.

Have you considered creating a gem for this?

Ideally I’d like to see this replace the built-in ruby html_escape once adequate testing and analysis has been done on the module, but in the meantime it would be great to have it as a gem to lower the barrier of entry for users (especially windoze users which often don’t have compilers).

Blessings,

Jeff

3

Anything that can reliably improve speed should be greeted with much enthusiasm. So, I definitely think there will be interest in this and the gem idea is a good one.

thanks, andy

4

Hey Jeremy-

  This is definitely cool. I would definitely use this as a gem if you make it into one. If you don't I might vendor it in merb :wink:

Thanks-

-- Ezra Zygmuntowicz-- Lead Rails Evangelist -- ez@engineyard.com -- Engine Yard, Serious Rails Hosting -- (866) 518-YARD (9273)

5

I got enough requests for this that I've packaged it as a gem and applied for a RubyForge project. I'll post again after the project has been approved and the gem is available via gem install. I don't anticipate having a Win32 version, but if you running Rails on Win32, you probably don't care too much about performance.

Thanks, Jeremy

6

I got enough requests for this that I've packaged it as a gem and applied for a RubyForge project. I'll post again after the project has been approved and the gem is available via gem install.

Very nice

  I don't anticipate having a Win32 version, but if you running Rails on Win32, you probably don't care too much about performance.   

lol

Thanks,

matthi

7

The gem is now available via "gem install faster_html_escape". After installing it, add "require 'speed_up_html_escape'" to environment.rb to speed your h up.

If you want to use it outside of Rails:

  require 'rubygems'   require_gem 'faster_html_escape'   require 'speed_up_html_escape'

Please direct any questions/comments to the RubyForge site: http://rubyforge.org/projects/fasterh/.

Thanks, Jeremy