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
On 12/11/06, Jeremy E. [email protected] wrote:
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:
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
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
On 12/11/06, Jeremy E. [email protected] wrote:
times faster, input of exclusively HTML characters is about 20 times
validity of the C function as well as benchmarking it
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.
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
On Dec 11, 2006, at 1:53 PM, Jeremy E. wrote:
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.
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 
Thanks-
– Ezra Z.
– Lead Rails Evangelist
– [email protected]
– Engine Y., Serious Rails Hosting
– (866) 518-YARD (9273)
On 12/12/06, Jeremy E. [email protected] wrote:
depending on the input. Input with no HTML characters is about 4
times faster, input of exclusively HTML characters is about 20 times
faster.
To use:
For example, in environment.rb
require ‘speed_up_html_escape’
I got enough requests for this that I’ve packaged it as a gem and
applied for a RubyForge project.
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