Question

Some time ago I wrote a question regarding the use of temporary files within a rails app. On thar particular case, I decided to use tempfile

This causes a problem if I also want to use the x-sendfile directive (as a parameter in Rails 2, or as a configuration option in Rails 3) so that the file sending is handled by my web server directly, not my rails app.

So I thought about doing something like this:

require 'tempfile'

def foo()
  # creates a temporary file in tmp/
  Tempfile.open('prefix', "#{Rails.root}/tmp") do |f|
    f.print('a temp message')
    f.flush
    send_file(f.path, :x_sendfile => true) # send_file f.path in rails 3
  end
end

This setup has one issue: the file is deleted before being sent!

On one hand, tempfile will delete the file as soon as the Tempfile.open block is over. On the other, x-sendfile makes the send_file call asynchronous – it returns very quickly, so the server hardly has time to send the file.

My best possible solution right now involves using non-temporary files (File instead of Tempfile), and then a cron task that erases the temp folder periodically. This is a bit inelegant since:

• I have to use my own tempfile naming scheme
• Files stay on the tmp folder longer than they are needed.

Is there a better setup? Or, is there at least a “success” callback on the asynchronous send_file, so I can erase f when it’s done?

Thanks a lot.

Answer 1

Given that Rails3 uses x-sendfile when it is available, and there is no way to deactivate it, you just can’t use send_file with a library such as TempFile. The best option is the one I mentioned in the question: use a regular File, and have a cron task that removes old temp files periodically.

EDIT: The removal of unused files has now been easier to deal with with the maid gem:

https://github.com/benjaminoakes/maid