Mike, Thank you very much for explaining it to me. I had no idea that the cache middleware wouldn't read the file and cache it along with the response. I figured caching the file itself as well would be redundant, which could be costly depending on the size of these files I am storing in memory. But now that I know the file isn't getting cached, it makes sense. If it is a bug, that's no big deal because I will do what you said and read the file into memory so it does get cached. But I can definitely understand why it wouldn't be a bug, since loading the files into memory without the programmer doing it purposefully could be bad too, and very costly in memory (if I am understanding the issue correctly).
I will definitely go about caching the files the non-lazy way from now on :) Thanks, Brandon On Mar 27, 5:45 pm, Mike Axiak <[EMAIL PROTECTED]> wrote: > 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/... > 2:http://www.djangoproject.com/documentation/cache/#controlling-cache-u... > > 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_fileon 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/Idon'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 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
