Index: venv/Lib/site-packages/django/middleware/http.py |
=================================================================== |
new file mode 100644 |
--- /dev/null |
+++ b/venv/Lib/site-packages/django/middleware/http.py |
@@ -0,0 +1,45 @@ |
+from django.utils.cache import ( |
+ cc_delim_re, get_conditional_response, set_response_etag, |
+) |
+from django.utils.deprecation import MiddlewareMixin |
+from django.utils.http import parse_http_date_safe |
+ |
+ |
+class ConditionalGetMiddleware(MiddlewareMixin): |
+ """ |
+ Handles conditional GET operations. If the response has an ETag or |
+ Last-Modified header, and the request has If-None-Match or |
+ If-Modified-Since, the response is replaced by an HttpNotModified. An ETag |
+ header is added if needed. |
+ """ |
+ def process_response(self, request, response): |
+ # It's too late to prevent an unsafe request with a 412 response, and |
+ # for a HEAD request, the response body is always empty so computing |
+ # an accurate ETag isn't possible. |
+ if request.method != 'GET': |
+ return response |
+ |
+ if self.needs_etag(response) and not response.has_header('ETag'): |
+ set_response_etag(response) |
+ |
+ etag = response.get('ETag') |
+ last_modified = response.get('Last-Modified') |
+ if last_modified: |
+ last_modified = parse_http_date_safe(last_modified) |
+ |
+ if etag or last_modified: |
+ return get_conditional_response( |
+ request, |
+ etag=etag, |
+ last_modified=last_modified, |
+ response=response, |
+ ) |
+ |
+ return response |
+ |
+ def needs_etag(self, response): |
+ """ |
+ Return True if an ETag header should be added to response. |
+ """ |
+ cache_control_headers = cc_delim_re.split(response.get('Cache-Control', '')) |
+ return all(header.lower() != 'no-store' for header in cache_control_headers) |