Set last-modified header on messages

This should at least hint Google and others about how often our pages
really do change. Only set it for messages for now, since other pages
are excluded from cache anyway.

Last modified is set to the lasat modified entr in the database, we don't
make any provisions for changes in the templates or the rendering itself.
We might want to consider this in the future, maybe looking at the datestamp
of the template file and the view.py, or something along that line.

Implement simple If-Modified-Since checks, even though that's not going
to work anyway with the current version of Varnish - but hopefully it
will with the next one.

diff --git a/django/archives/mailarchives/views.py b/django/archives/mailarchives/views.py
index 78b1ef8e3eabc5f95aa820008676250f2f1d1454..213dd894d07dbe79aba7b0d921bacb646c2d0e60 100644 (file)
--- a/django/archives/mailarchives/views.py
+++ b/django/archives/mailarchives/views.py
@@ -1,7 +1,8 @@
 from django.template import RequestContext
 from django.http import HttpResponse, HttpResponseForbidden, Http404
-from django.http import HttpResponsePermanentRedirect
+from django.http import HttpResponsePermanentRedirect, HttpResponseNotModified
 from django.shortcuts import render_to_response, get_object_or_404
+from django.utils.http import http_date, parse_http_date_safe
 from django.db import connection
 from django.db.models import Q
 from django.conf import settings
@@ -252,7 +253,7 @@ SELECT id,_from,subject,date,messageid,has_attachment,parentid,datepath FROM t O
 """, {'threadid': threadid})
 
        for id,_from,subject,date,messageid,has_attachment,parentid,parentpath in curs.fetchall():
-               yield {'id':id, 'mailfrom':_from, 'subject': subject, 'printdate': date.strftime("%Y-%m-%d %H:%M:%S"), 'messageid': messageid, 'hasattachment': has_attachment, 'parentid': parentid, 'indent': " " * len(parentpath)}
+               yield {'id':id, 'mailfrom':_from, 'subject': subject, 'date': date, 'printdate': date.strftime("%Y-%m-%d %H:%M:%S"), 'messageid': messageid, 'hasattachment': has_attachment, 'parentid': parentid, 'indent': " " * len(parentpath)}
 
 
 def _get_nextprevious(listmap, dt):
@@ -305,7 +306,14 @@ def message(request, msgid):
        lists = List.objects.extra(where=["listid IN (SELECT listid FROM list_threads WHERE threadid=%s)" % m.threadid]).order_by('listname')
        listmap = dict([(l.listid, l.listname) for l in lists])
        threadstruct = list(_build_thread_structure(m.threadid))
+       newest = calendar.timegm(max(threadstruct, key=lambda x: x['date'])['date'].utctimetuple())
+       if request.META.has_key('HTTP_IF_MODIFIED_SINCE') and not settings.DEBUG:
+               ims = parse_http_date_safe(request.META.get("HTTP_IF_MODIFIED_SINCE"))
+               if ims >= newest:
+                       return HttpResponseNotModified()
+
        responses = [t for t in threadstruct if t['parentid']==m.id]
+
        if m.parentid:
                for t in threadstruct:
                        if t['id'] == m.parentid:
@@ -324,6 +332,7 @@ def message(request, msgid):
                        'nextprev': nextprev,
                        }, NavContext(request, lists[0].listid))
        r['X-pgthread'] = ":%s:" % m.threadid
+       r['Last-Modified'] = http_date(newest)
        return r
 
 @cache(hours=4)
@@ -332,14 +341,21 @@ def message_flat(request, msgid):
                msg = Message.objects.get(messageid=msgid)
        except Message.DoesNotExist:
                raise Http404('Message does not exist')
-       allmsg = Message.objects.filter(threadid=msg.threadid).order_by('date')
+       allmsg = list(Message.objects.filter(threadid=msg.threadid).order_by('date'))
        # XXX: need to get the complete list of lists!
 
+       newest = calendar.timegm(max(allmsg, key=lambda x: x.date).date.utctimetuple())
+       if request.META.has_key('HTTP_IF_MODIFIED_SINCE') and not settings.DEBUG:
+               ims = parse_http_date_safe(request.META.get('HTTP_IF_MODIFIED_SINCE'))
+               if ims >= newest:
+                       return HttpResponseNotModified()
+
        r = render_to_response('message_flat.html', {
                        'msg': msg,
                        'allmsg': allmsg,
                        }, NavContext(request))
        r['X-pgthread'] = ":%s:" % msg.threadid
+       r['Last-Modified'] = http_date(newest)
        return r
 
 @nocache