Fixed #8409 -- The runserver now uses conditional GET for admin media files, instead of reloading the files off disk for every request. Thanks for reporting, andylowry

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9055 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/servers/basehttp.py

@@ -11,6 +11,7 @@ from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 import mimetypes
 import os
 import re
+import stat
 import sys
 import urllib
 
@@ -648,13 +649,23 @@ class AdminMediaHandler(object):
                 headers = {'Content-type': 'text/plain'}
                 output = ['Permission denied: %s' % file_path]
             else:
-                status = '200 OK'
-                headers = {}
-                mime_type = mimetypes.guess_type(file_path)[0]
-                if mime_type:
-                    headers['Content-Type'] = mime_type
-                output = [fp.read()]
-                fp.close()
+                # This is a very simple implementation of conditional GET with
+                # the Last-Modified header. It makes media files a bit speedier
+                # because the files are only read off disk for the first
+                # request (assuming the browser/client supports conditional
+                # GET).
+                mtime = http_date(os.stat(file_path)[stat.ST_MTIME])
+                headers = {'Last-Modified': mtime}
+                if environ.get('HTTP_IF_MODIFIED_SINCE', None) == mtime:
+                    status = '304 NOT MODIFIED'
+                    output = []
+                else:
+                    status = '200 OK'
+                    mime_type = mimetypes.guess_type(file_path)[0]
+                    if mime_type:
+                        headers['Content-Type'] = mime_type
+                    output = [fp.read()]
+                    fp.close()
         start_response(status, headers.items())
         return output