PHP UK 2014 conference talk notes


Blurb

General info about the conference can be found here and a full list of talks can be found on the conference’s joindin page .

You tube videos are also available for most talks: phpuk 2014 youtube

Talks

My very scattered and hashed together notes for each of the talks I attended. Listed in no particular order.

(Re)discovering the SPL by Joshua Thijssen

  • Takeaway message: The spl is cool but comes with some GOTCHAs
  • The limititerator does not implement countable.
  • RecursiveIterators don’t recurse. They enabled recursion but need to be wrapped by the recursiveiteratoriterator (sadly this isn’t a typo). They should be called recursibleiterators.
  • Caching iterator doesn’t really cache. It should propbably be called a lookaheaditerator as it has the method hasnext(). The hasnext method is actually potentially very useful.
  • Despite a lack of documentation a lot of code actually makes useof the seekableiterator interface. If you implement an iteratable object where it’s possible to jump to specific positions implement the seekableiterator interface and you may find some unexpected free speedbost.

PHP: Under The Hood by Davey Shafik

  • Useful tool: Vulcan logic dumper. Can be used to dump the generated opcodes representing a php file.
  • Interestingly there is no difference in opcodes from calling an actual method and a call to __call() magic.

Vagrant Provisioners in a Nutshell by Erika Heidi

  • The shared folder in Vagrant can cause significant slow downs when it is being written to (example given 5s load to 25s load for symfony app). Switching file cache locations to a location not shared resolved the performance issue.
  • Useful website: phansible.com for building ansible provisioned php vagrant images. Interestingly also has config for hhvm.
  • Puppet as a provisioner has a major potential gotcha: The steps you define are not executed in the order you define them. Any dependencies in order need to be explicitly specified.

OPCache! by Julien Pauli

  • A very offhand number given was that 20% of an example php file execution time was compilation. This gives very impressive speed boosts for almost zero work.
  • The opcache is already doing compiler optimisations. I didn’t realise this and this is cool!
  • A typical symfony app stored 40mb and ~3000 files in the cache.
  • The first time a file is hit caching and optimising takes time (as expected) so it is recommended to prime the cache. It’s worth baring in mind when doing this that the cli uses a separate cache to the one apache may be using.
  • This should not be used with xdebug or any other opcode modifying extension.

Building scalable PHP applications using Google’s App Engine by Ian Barber & Mandy Waite

  • My short summary: It’s not ready for php yet. Needs more polish.
  • Built on a fork of 5.4.something. Forked so they can make a few tweaks to get it to run properly.
  • has a built in googled version of memcahce(d) that is transparent to the normal client libraries. Can either use a shared instance or pay for some dedicated memory.
  • Access to google’s cloud datastore has to be done using the rest api as they don’t have php native code yet (unlike their other language integrations).

Caching Best Practices by Eli White

  • Various levels of caching. Full page caching best left to well configured proxies.
  • Goal level of code caching is the biggest smallest reusable object. Knowledge of the code and domain is useful.
  • It can be a real benefit to have multiple levels of cache. For example APC caches on a single web server instance for a short time. Next a shared memcached pool could cache for a bit longer then a hit to the db if the cache is empty.
  • Pre-generation of cached content is a really good idea.
  • memcached can be asked to fetch data asynchronously so this could be done earlier in a script than it’s needed.
  • Interestingly when optimising Digg they did seperate queries for each user but cached each result seperately. All though this meant a far greater number of DB queries initially once the cache was warmed up it resulted in very few additional queries.

Wield AngularJS like a Pro by Nate Abele

  • Main take away point: batarang is an excellent tool for debugging/profiling angular apps in chrome.

The Seven Deadly Sins of Dependency Injection by Stephan Hochdörfer

  • Use a factory class instead of a factory method if you want to provide default dependencies for an object. This helps maintain SRP and keeps the coupling out of your non-factory code.

Facebook’s Approach to Common Web Vulnerabilities by Ben Mathews

  • Scarily facebook has a mostly single repo that is 49GB. The speaker thought this was a good thing. I disagree.
  • TODO: I have a lot of notes for this talk that need writing up properly.
comments powered by Disqus