Today I was working on some revisions to Twitter’s Protected User stack { or Project: PrivateParts as I like to refer to it in my head }, when I had to make some string changes to emails being sent to users. Offhandedly, I ran across this bug report on RubyForge.

HOLY HELL IN A HANDBASKET!

The Ruby GetText 1.90.0 gem uses an instance of a Class Object as a key to a hash! Steven Rusitschka noticed this and noted that “the memory Mongrel used increased by 1 MB with each request it served …”

To avoid any possibility of a reader absentmindedly skipping over that last quote from Steven, I present it for you again in vibrant color and with extra bold.

“the memory Mongrel used increased by 1 MB with each request it served …”

Okay. Deep breaths. Before everyone goes around MonkeyPatching GetText, there’s a new release out, 1.91.0. Let’s look and see if a fix has been put into place.

Old: 1.90.0

def bound_target(klass = self) # :nodoc:
  if cached?
    if @@__cache_bound_target[klass] # <---- Yowza!
      return @@__cache_bound_target[klass]
    end
  end

  ret = nil
  if klass.kind_of? Class or klass.kind_of? Module
    ret = klass
  else
    ret = klass.class
  end
  ret = GetText if ret.name =~ /^\#<|^$/
  @@__cache_bound_target[klass] = ret
  ret
end

New: 1.91.0

def bound_target(klass = self) # :nodoc:
  id = klass.object_id
  if cached?
   tgt = @@__cache_bound_target[id] # <---- Ahhh, much better.
   return tgt if tgt
  end

  ret = (klass.kind_of? Module) ? klass : klass.class
  if ret.name =~ /^\#<|^$/ or ret == GetText
     #GC for dead object_ids.
     ret = Object
     if @@__cache_bound_target.size > CACHE_BOUND_TARGET_MAX_SIZE
        @@__cache_bound_target.clear
     end
  end
  @@__cache_bound_target[id] = ret
  ret
end

The GetText gem is now using the object_id as the cache key. To say the least, this has made a huge difference in the memory profile of Twitter’s Mongrels. Not much more to say here. If you’re running GetText with Rails and are find yourself a bit leaky, check your gem version. You may be due for an upgrade!