Sunday, 28 September 2008

Headhunters and a dearth of trust

What is it with some headhunters?
I had a phonecall from a headhunter the other day that really rubbed my fur up the wrong way.

First, they wanted my CV in Word format. I hate that. Quite apart from having to explain that I use Linux - which frequently leads in to the "what is an OS" discussion that I find so annoying coming from an IT recruiter. Yes I can use OpenOffice to create a Word doc, but it's a preference thing. I prefer to write my CV in PDF so I have more control over the formatting - because I've found that .doc format "helps" too much, and suffers from bit-rot.

But it's not like they can't read/print-out a copy of my CV if it's in PDF. What really gets me is that there are only two reasons for wanting my CV in Word. First is so they can copy/paste my skills/experience into their mammoth database - reducing me to a set of numbers... which I really don't like.

I recognise that might be a knock to their usual system, but I really don't like being just a number in an uncharted sea of applicants. It doesn't work for me to be recruited by a company that would view me as only so important as the number (and not the quality) of the years of experience I have.

Second is that they want to remove my contact information so that they are the only point of contact between me and the employer. This view is especially reinforced by headhunters that refuse to give you the prospective employer's name, industry, size or any other potentially-identifying details (or politely change subject when I ask, as this one did). How the hell am I supposed to decide if I'm interested in working for a company I know nothing about?

I should point out - I get a phonecall a week from various recruiters. I don't have time to go to an interview a week - so I have to decide, based on what you tell me, if you are worth a morning of my time.

Word to the wise: recruiters perform a valuable service - both to employers and employees. If you are good at what you do, then nobody will be unhappy about paying you for your services! The only recruiters that need to resort to cheap tactics like hiding names are the ones that cannot build a reputation for excellence on their own... thus if you flat-out refuse, then it instantly gets my suspicions up.

Yes, I'm sure you will get ocasionally burnt by employees and employers that are unscrupulous and try to screw you out of your fee. But are those the kind of clients you want to keep anyway?

Recruiting is a people business - it is outsourced HR and builds upon long-term relationships. Trust is important, and screwing around like this ruffles that layer of trust and just feels tacky.

Please don't do it.

Thursday, 25 September 2008

Rspec mocks too much

I've recently had to learn the other side of testing - ie rspec, due to my new contract having a test suite written in "the other testing suite" * ;)

Seems fairly straightforward so far, but there's one big worry I have: Rspec has a huge reliance upon mocks.

Now I completely understand (and endorse) the benefits of using mocks. It means you can independantly test a model/controller/whatever without it mattering if something happens to have broken in some other model/module/whatever. This is a Good Thing and allows for more accurate testing due to all the benefits of loose coupling. However, I get a bit worried if everything is mocked out and there are no integration-style tests at all.

For example, if I'm testing a view, and using rspec best practice I've mocked out all model objects and don't bother with the real thing. What happens if a model changes (say a column is removed that shows up on an index list)? The view specs all rely on a mock that explicitly states what is returned, so the view specs all still pass. But the index page will be broken for a user that actually uses the site, because the real object doesn't bahave that way anymore. The mocks and the model are out of synch. :P

In an infrequently-used area of the site, this sort of error may go undetected and slip through to release.

This worries me. I know I like to rely on my test suite to catch things like this wherever possible. Sure I generally do a manual click-through, but I know that this is unreliable especially WRT edge-cases.

So, am I needlessly worrying? Have I simply missed something about how rspec is supposed to be used? What's best practice in this situation?

*Which admittedly feels a lot like having to switch from vi to emacs... Sure I know that "the other one" works for lots of people, and I meant to get around to learning it someday...

Tuesday, 23 September 2008

Getting ffmpeg to work under ubuntu

I had a fair whack of trouble getting ffmpeg to compile on ubuntu. These are the steps I took that finally got it working for me.

Firstly - I'm going to assume you've downloaded and installed the appropriate libraries (codecs?) for the various audio/video formats that you are going to use (eg lame). I'm just going to cover making ffmpeg actually compile and run.

The usual set of steps will be

  • Downloading ffmpeg: svn checkout svn:// ffmpeg
  • cd ffmpeg
  • Configuring appropriately to your build. Eg: ./configure --enable-libmp3lame --disable-vhook --disable-mmx --enable-nonfree --enable-gpl --enable-shared --enable-libamr-nb --enable-libfaad --enable-libx264 --enable-encoder=x264 --prefix=/opt/local --extra-ldflags=-L/opt/local/lib --extra-cflags=-I/opt/local/include
  • make
  • sudo make install

If that all works for you, then brilliant, but for me it fell over while trying to make, telling me it couldn't find x264. For some reason it's necessary to add --enable-pthreads to make it work on ubuntu.

The next big hurdle for me was that a bug appears in the v4l2 library for ubuntu. It doesn’t properly load some of the basic linux types. This is apparently a well-known bug in some of the older linux headers, and will stall the compilation of ffmpeg with a whole slew of bogus error messages, that essentially boil down to the __u64 and __s64 types failing to be defined appropriately.

To make a temporary fix, you can open up asm/types.h (I used find to find it) and figure out where the asm types are located on your distro (for me they’re in asm-i386/types.h).

Now, copy the two lines that define __u64 and __s64 and paste them into:
/usr/include/linux/videodev2.h just above their first use to help define v4l2_std_id

Note - this is an ugly, quick hack, but it should get the compilation going again. For a more permanent solution - I'd suggest chatting to the ubuntu people... or maybe it's time for me to get around to upgrading from feisty ;)

That will generally get you compiled and installed, but I then fell over a run-time bug that boiled down to an error message: “cannot find”. This problem had me stalled for weeks. Google returns a lot of talk about the problem, but very few solutions, but eventually I stumbled across the answer: you need to add a library path to your environment thus:
export LD_LIBRARY_PATH=/usr/local/lib/

Finally ffmpeg safely up and running on ubuntu. Yay!

Saturday, 20 September 2008

Snippet: MyModel.options_for_select

How many times have you written a quickie drop-down box to choose one instance of an associated model? Here's a quickie monkey-patch that will help. Put the following in environment.rb (or similar):

class ActiveRecord::Base
  # convenience method for selection boxes of this model
  # Assumes existance of a function "display_name" that will be a
  # displayable name for the select box.
  def self.options_for_select
    self.find(:all).map {|p| [p.display_name,] }

Make sure you have a function in your model named "display_name" that returns what you'd like to see in your drop-down, eg:

class Person < ActiveRecord::Base
  has_many :posts

  # convenience method for the person's name
  def display_name
    [first_name, last_name].compact.join(', ')
class Post < ActiveRecord::Base
  belongs_to :person

  alias :display_name :title

Then use in a view (eg as follows):

<% form_for(@person) do |f| %>
<p>Pick a post: <%= :post_id, Post.options_for_select -%><%= f.submit 'Go!' -%></p>
<% end %>

Thursday, 4 September 2008

Snippet: monkey-patching a gem

Need to make a quick monkey patch to a gem you're using? Follow the steps below:

  1. If you don't have a vendor gems directory: svn mkdir vendor/gems
  2. cd vendor/gems
  3. Unpack the gem into your vendor/gems directory with
    unpack gem <the_gem_name>
  4. Checkin the above changes so you have a clean version of the gem to start with
  5. Make your monkey patches and check them in
  6. Make sure vendor/gems is in the loadpath for gems

And you're done