Brandon,
It appears that the Cache Middleware does not read the content from
the file before caching the response [1]. I'm not sure if this is a
bug or not...though I'd probably lean towards it being a bug. (Do we
not cache middleware to *always* evaluate a file object before caching
the response?)
Anyway, until that behavior gets changed, there's no reason you can't
read (via .read()) your files to just send your content.
If you expect Django to cache all your data, then you have to read the
entire file into memory at *some* point. So I see two options:
1. Read all the file contents into memory by calling
file_object.read() before putting it into the HttpResponse object.
2. Disabling cache middleware for that view. To do this, you can
use the cache_control decorator [2]. E.g.:
@cache_control(max_age=0)
dev view(request): ...
As it is your kind of giving Django conflicting requests since you're
saying "Don't load the file into memory, load it lazily" while also
saying "load the entire response into the cache".
Regards,
Mike
1: http://code.djangoproject.com/browser/django/trunk/django/middleware/cache.py
2:
http://www.djangoproject.com/documentation/cache/#controlling-cache-using-other-headers
On Mar 27, 6:13 pm, bfrederi <[EMAIL PROTECTED]> wrote:
> I appreciate the help Rajesh,
>
> I haven't added any special settings for the cachemiddleware, I just
> placed 'django.middleware.cache.CacheMiddleware' in my middleware
> classes and that's it. As far as the low-level caching that I have
> written into my code using the "from django.core.cache import cache",
> all of that is working fine. It's just the middleware that is the
> issue. As soon as I set the cache middleware in my middleware classes
> setting, that's when I start having problems.
>
> Here is an example view, where I try to open a file and it gives me a
> "ValueError: I/O operation on closed file":
> view (the line it actually executes is line 24):http://dpaste.com/41671/
> function it calls (open_system_file):http://dpaste.com/41672/
>
> Every part of that view works fine except for when I go to open that
> file on line 24. And it works fine in my tests.py, I get the exact
> data that I am supposed to from the file (the specific test is on line
> 22):http://dpaste.com/41678/(open_system_file on line 23 is defined
> in system_methods on line 3)
>
> And as far as stack traces go, I have my mod python error I just gave
> you. Here is the apache2 error log (I blocked out my ip out of
> paranoia):http://dpaste.com/41682/I don't know what else to give you
> that would help as far as problems within the stack. I'm not doing
> anything db related, so if there is something else you need me to
> post, please mention it by name specifically, in case there is
> something I'm not thinking of.
>
> Thanks for the help,
> Brandon
>
> On Mar 27, 4:01 pm, Rajesh Dhawan <[EMAIL PROTECTED]> wrote:
>
> > Hi Brandon,
>
> > > I would paste in some code examples, but this project is several
> > > hundred lines long, and there are several incidences where I open
> > > files that is conflicting with the cache middleware.
>
> > Not knowing how you have your cache setup (anonymous, all views, low-
> > level), it's hard to tell what's causing this problem. You haven't
> > included full stack traces either. So, I would suggest including at
> > least this:
>
> > - A snippet of a view that fails...include at least one file opening
> > command.
> > - Full stacktraces of the two errors you mentioned along with the
> > snippets of your application code that the stack traces point to.
>
> > -Rajesh D
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