Slides from a lightning talk presented at Aberdeen PHP User Group on Wednesday 3rd of August 2016.

1. PHP Aberdeen
Quick optimisation
of PHP with
Webgrind
Andy Gaskell - @AndyGasman / @SSOFB

2. Webgrind
“Webgrind is a Xdebug profiling web frontend in PHP.
It implements a subset of the features of kcachegrind
and installs in seconds and works on all platforms. For
quick'n'dirty optimizations it does the job.”
https://github.com/jokkedk/webgrind

3. Introduction
Webgrind - why?
● Characterise to optimise
● No point in optimising code without characterising
● Look inside libraries
● Find the slow bits
● Understand the platforms you work on

4. Install xdebug
You probably don’t need to.
php 5
sudo apt-get install php5-xdebug
php 7
sudo apt-get install php-xdebug

5. ...and maybe graphviz too
Just for the graphs really
sudo apt-get install graphviz

6. Enable xdebug everywhere
php 5
/etc/php5/apache2/php.ini
php 7
/etc/php/7.0/apache2/php.ini

7. Enable xdebug per thing
Pop it in your .ini or .htaccess like...
xdebug.profiler_enable=1
...great for a quick debug/profile of system
characterisation.

8. Just copy the files to
Easiest bit :)
● Download from github
● Put them in a folder under your web root
● Change the config.php if the xdebug isn’t outputting to
/tmp

9. Use cases?
● How can I make this bat-shit fast?
● Why is this server / system slower than the other one?
● What’s holding this up?
● How does the performance differ between library X
and Y?

10. Just hit it up in your browser
Just go to wherever you put the files, ie
http://localhost/webgrind or
http://dev.stuff.com/webgrind

11. Looking at results
Loads of info, have a tinker…
● Tweak the settings, to remove some noise
● Change the sorts
● Browse the call graph
● Compare costs

16. Practical example
● API experiences large slow-down with growth in data
size
● Characterised with Webgrind

17. Before...
Average time:
0.442942536816s
Slowest time:
13.3827910423s
After...
Average time:
0.335654691152s
Slowest time:
0.815340042114s

18. Tricks and tips - running
● Sometimes it can take a couple of minutes to generate
the report
● Sometimes it can crash your system if it’s doing big
stuff
● You can see the files being created to gauge size /
complexity, ie “ls -lha /tmp/cachegrind*”
● If it’s taking crazy-long, set the “show” value lower

19. Tricks and tips - analysing
● Call graphs are colour coded
● If you don’t like svg call graphs, you can set
“graphImageType” to “png” in webgrind/config.php

20. Other options
● Do it in your IDE, via xdebug remote profiler
○ PHP Storm
○ Eclipse
○ NotePad++
● Use KCachegrind / Callgrind, a Linux (KDE) profiling
App

21. Read more
● Webgrind website (just github)
https://github.com/jokkedk/webgrind
● Google your platform for WAMP, MAMP or NGINX
info

22. Any questions?
Andy Gaskell - @AndyGasman / @SSOFB

23. Thanks :)
Andy Gaskell - @AndyGasman / @SSOFB