Caching and mongrel


I have turned on caching and am using the action controller directive caches_page for an action that returns an image file (used in the HTML img src attribute). The first time I visit the page which contains those img tags, all looks great and a bunch of pages are created in the location where the cache is being stored (defaults to RAILS_ROOT + "/public"). However, on the second visit, the page is missing some images and when looking at the files in the cache directory, I notice that the images which displayed correctly on the second visit contain simply a binary image file. However, the files that did not work contain some text like:

#<Proc:0x03dff400@C:/ruby/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/streaming.rb:68>

Does anyone know what is going on there? Is this a mongrel cache problem?

I found out what was going on and thought you should know. The action which was being cached used the send_file action controller method. However, (this was a pain to diagnose) when using default options the :stream => true option will cause the data to be generated AFTER the cache copy is taken hence the stuff in the cache is actually the instruction to stream the file. So, the fix is to say :stream => false in the send_file method and VOILA! I guess that's why I was the only poor soul seeing this cause probably no one caches requests generated by send_file.