ramblings of a hikikomori - Rails, Firefox, Anime, Mac
Seen in the Rails source - Orcl nds shrt indx nmsJanuary 18th, 2008
Hah.
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Comments and TrackBacks (2) | Category: Ruby on Rails Living on the Edge (of Rails) #3 - X-Sendfile and many other sexy enhancementsJanuary 16th, 2008
Edge Rails saw a barrage of refinements and enhancements this week and there’s even talk about Rails 2.1 being just a little around the corner. There’s also been a flurry of contributions to making Rails more thread-safe and performance optimizations (all still work in progress at the moment) - it’s really nice to see how the Rails community is looking seriously at performance post-Rails 2.0 (not that they weren’t serious about performance before Rails 2.0!).
This week’s report covers changes from 7 Jan 2008 to the day the corresponding Rails Envy podcast was recorded (13 Jan 2008).
If you only have a vague idea of what it is (like, X-Sendfile is that thing that lets you send files, right?), you’d do well to read this helpful explanation. (In short, X-Sendfile allows you to send static files directly and more performantly to HTTP clients and bypassing your app server process.) You don’t have to set those headers yourself or install the plugin mentioned in that article though, since edge Rails has an augmented send_file helper that does all the legwork for you.
All you have to do now is to this:
send_file '/path/to.png', :x_sendfile => true, :type => 'image/png'Rails will set the X-Sendfile header for you (i.e. response.headers['X-Sendfile'] = '/path/to.png') and sends a HEAD response (empty response body) with the file path, allowing your web server (Apache, Lighttpd) to serve the static file and not involve your Rails processes (such as your precious, perpertually resource-starved mongrels).
This is really nice if you are serving lots of static files (downloadable images and documents come to mind) and are not already using X-Sendfile or doing it the “long” way (by setting the response header and then render :nothing => true).
Related changeset: http://dev.rubyonrails.org/changeset/8628
Rails 2.0.2 allowed you to set ActionController::Base.asset_host to a proc that took a single source argument (as detailed in my earlier post). People were still running into problems with asset hosting though, particularly while trying to serve assets from an SSL-protected page (i.e. HTTPS requests). When serving SSL-protected pages, you’d need to either have an SSL certificate for each asset host(!) or live with a mixed media warning (which browsers report when you have SSL and non-SSL content on the same page).
The asset_host proc now takes the entire controller request instance as an optional second argument. This allows you to either use a single asset host or to disable asset hosting for SSL requests. For example, this proc below practically disables asset hosting:
ActionController::Base.asset_host = Proc.new { |source, request|
if request.ssl?
"#{request.protocol}#{request.host_with_port}" # Disable asset hosting.
else
"#{request.protocol}assets.example.com" # Use asset host.
end
}Related changeset: http://dev.rubyonrails.org/changeset/8578
There’s now a nicer way to access headers - instead of request.env["HTTP_CONTENT_TYPE"] you can now do request.headers["Content-Type"] (or request.headers["content-type"] (note all lowercase) or even good old request.headers["HTTP_CONTENT_TYPE"]. How convenient - I often worry about getting the casing right (was it ‘Content-Type’ or ‘Content-type’?) and now I can be sure it doesn’t matter!
Related changeset: http://dev.rubyonrails.org/changeset/8625
ActiveSupport::TestCase (and the ActionController::TestCase and ActionMailer::TestCase subclasses) now support declarative setup and teardown callbacks that are called before setup/after teardown. For example,
class FooTestCase < ActiveSupport::TestCase
setup :run_this_first, :then_run_this do
# Run this last.
end
teardown :remove_tmp_files, :undef_constants
def run_this_first
end
def then_run_this
end
def remove_tmp_files
end
def undef_constants
end
endwill run run_this_first, then_run_this, and finally the stuff that’s in the given block to ’setup’ before running the actual setup method. The teardown callbacks are done in reverse order, meaning undef_constants is called, and then remove_tmp_files (and then the actual teardown method).
Related changeset: http://dev.rubyonrails.org/changeset/8570
The bundled TMail library (that ActionMailer uses) has been updated from 1.1.0 to 1.2.1. This new version currently maintained by Mikel Lindsaar promises bugfixes and greater test coverage. For more details, see https://rubyforge.org/frs/shownotes.php?group_id=4512&release_id=18049.
Mikel has been working with Rails core to get Tmail Ruby 1.9-compatible. Good work Mikel!
Related changeset: http://dev.rubyonrails.org/changeset/8620
ActionController::UrlWriter respects the relative_url_root. For those of you who don’t know, the ActionController::UrlWriter module is a convenient mixin that allows you to use url_for and your named routes in arbitrary classes (such as in your mailers or in a BackgrounDRb worker).
class SitemapWorker < BackgrounDRb::MetaWorker
include ActionController::UrlWriter
# Access your named routes and the url_for helper.
url = page_url(:permalink => ‘foo’)
end And now it respects your relative_url_root instead of blissfully ignoring it.
Related changeset: http://dev.rubyonrails.org/changeset/8616
render :text => nil and render :text => false work properly now instead of inexplicably trying to render a file. This was a big gotcha when using render :text => some_variable where some_variable could potentially be false or nil in some cases - Obie Fernandez has a writeup on this long-standing bug. Related changeset: http://dev.rubyonrails.org/changeset/8577
There’re significant performance improvements for classic fixtures with HABTM data, due to some slightly clever caching model classes, and instantiating fixtures from the model class, instead of expensive constant lookups from the name of the class.
Related changesets: http://dev.rubyonrails.org/changeset/8560 and http://dev.rubyonrails.org/changeset/8561
Permalink | Comments and TrackBacks (3) | Category: Open Source, Ruby, Ruby on Rails Retrying code blocks in Ruby (on exceptions, whatever)January 14th, 2008
I am not certain whether the ability to retry a code block when encountering exceptions was a feature available in Ruby, but I certainly couldn’t find anything on that topic (what I did find were mostly about the retry keyword for iterator loops).
Before you ask why I need this, the motivation for this was because I was getting intermittent HTTP errors (503s mostly) trying to connect to a web service. Turns out it’s really easy in Ruby to implement a retryable method that does something like this:
retryable(:tries => 5, :on => OpenURI::HTTPError) do
open('http://example.com/flaky_api')
# Code that mashes up stuff for your "social networking" site.
endHere are the Kernel#retryable specs (pastie).
And the code:
# Options:
# * :tries - Number of retries to perform. Defaults to 1.
# * :on - The Exception on which a retry will be performed. Defaults to Exception, which retries on any Exception.
#
# Example
# =======
# retryable(:tries => 1, :on => OpenURI::HTTPError) do
# # your code here
# end
#
def retryable(options = {}, &block)
opts = { :tries => 1, :on => Exception }.merge(options)
retry_exception, retries = opts[:on], opts[:tries]
begin
return yield
rescue retry_exception
retry if (retries -= 1) > 0
end
yield
endIt’s not hard to implement the same for checking return values as well, i.e.
retryable_deluxe(:tries => 5, :on => { :return => nil }) { puts "working..." }
retryable_deluxe(:on => { :exception => StandardError, :return => nil }) do
# your code here
endRuby is nice.
Permalink | Comments and TrackBacks (9) | Category: Ruby My very own X of the Year 2007January 9th, 2008
It’s about 9 days too late, but I figure it’d be fun to just throw these out and see if anyone else enjoyed the same things I did in 2007.
This has definitely got to go to Call of Duty 4: Modern Warfare. The single-player campaign was short but visually impressive and amazingly realistic. It was like watching a movie in most parts. And really, sneaking by Spetsnaz just a few metres away in sniper ghillie suits and was totally pimp. Multiplayer is real good fun too, I’m still playing it now (usually on GamingSA.com servers as ‘konata’).
Special mention: World of Warcraft (yes, I quit it ages ago, but it’s still good for the early part of 2007 when I was still playing casually).
Yes, I got a PSP just this year. And yes, Jeanne d’Arc is the best game I’ve played and completed in a while. For those who don’t know, Jeanne d’Arc is a very accessible Strategy RPG (SRPG) that is very loosely based on Joan of Arc. It’s much easier to play than Final Fantasy: Tactics or Disgaea: Hour of Darkness and doesn’t leave you constantly wondering about missing out on secrets. Highly recommended if you’re looking for an RPG-like game on the PSP.
I haven’t had the chance to play many other PSP games, but look forward to getting deeper into Disgaea: Hour of Darkness (and highly anticipating Final Fantasy VII: Crisis Core in March 2008).
2007 is the year I switched my anime tastes from mostly shonen anime (like Naruto and Bleach) to the seinen genre.
My favorite anime for 2007 (this is a tough one) has to go to Lucky Star. I even went through a prolonged Konata-ism phase and even had a printout of Konata saying “Relax” pasted right above where I sit in the office.
It’s therapeutic :)
2007 was a good anime year. Tekkon Kinkreet had an edgy, surreal drawing style but had a fantastic plot. I highly recommend it if you’ve missed it - it’s about 10 times better than your run-of-the-mill Princess Mononoke or Spirited Away type anime movies, in my humble opinion.
Potemayo’s moeblobs were just too funny to watch. Gochuko (below) had me LOL when she went around using tape to fix everything she sliced with her big scythe. At first appearances Potemayo may look like a kid’s anime but it’s really a work of comic genius for adults.
Genshiken 2 picks up where the 1st season left off and while the ending left quite a bit to be desired, on the whole it was enjoyable watching otakus cope with life (who knew it was so tough to get a job in Japan).
What did you enjoy in the last year and more importantly, do you have any recommendations for an ani-otaku like me?
Permalink | Comments and TrackBacks (2) | Category: Anime, Personal Living on the Edge (of Rails) - 1st week of the year editionJanuary 9th, 2008
Yup, it’s time for your weekly dose of the changes on edge Rails, more or less covered in the latest Rails Envy podcast. Using edge Rails is neither arcane nor terrifying, and hopefully weekly reports like these will allow you to take control of your own release schedule with your Rails apps.
This week’s report covers changes from 31 Dec 2007 to the day the podcast was recorded (6 Jan 2007).
Looks like most of the changes from the 2.1 caching branch have been
merged into the trunk. Some key points:
ActiveSupport::Cache::*).ActiveRecord::Base.cache_key to make it easier to cache Active Records in combination with the ActiveSupport cache libraries introduced in this changeset.ActionController::Base.fragment_cache_store is now ActionController::Base.cache_storeYup, you couldn’t do fragment caching in non-erb views before - now you can.
If you’re using edge Rails and use the rails:freeze:edge rake task, you probably usually forget to run (or maybe you’re not even aware of) rake rails:update to update your Rails app with the latest config/, scripts/ and javascript files from the version of Rails you just froze to. On edge Rails, the rake rails:freeze:edge task runs the rails:update task for you. +1 for convenience!
I prefer to use Piston so I’m gonna have to keep remembering to run my rake rails:update now and then!
Check out the related changeset.
Only 1 optimization in the past week worth talking about: the ActiveRecord::Base#exists? method is faster. It now uses ActiveRecord::Base#select_all instead of a more expensive ActiveRecord::Base#find that unnecessarily instantiates AR objects. (Check out the related changeset.)
atom_feed_helper to comply with the Atom specifications. Permalink | Comments and TrackBacks (1) | Category: Open Source, Personal, Ruby, Ruby on Rails 
