@tadej told me a few days ago at the Firefox 3 launch party that he had issues with the way caching is handled in Firefox 3. I didn’t have such issues myself but it reminded me that I didn’t change the caching behavior when I installed it. So yesterday I opened the preferences and found the caching options under Advanced / Network. I was not really surprised that the options for how the cache works were missing — you really don’t want your everyday Joe to change this stuff since it may affect the perceived speed of the browser.
Since this was probably just left out of the interface I opened about:config and filtered with cache which gave me a few entries. The most interesting one was browser.cache.check_doc_frequency. Unfortunately it has a numeric value with a hidden meaning. And I had no idea what that meaning is.
I googled the thing and found a mozillaZine article about it. It explains how it works — the property defines how often the browser checks for a new version of a specific file. The possible values are as follows:
- 0
- once per session
- 1
- everytime
- 2
- never
- 3
- when out of date (default)
The default is 3 which is not very good for development purposes when you want changes to take effect immediately. What you want is 1 which means that every request will go to the server every time. You’ll get many 304s but you’ll also get a 200 as soon as a file changes on the server. So I changed the value to 1 and now I’m a happy developer.
