Changes between Initial Version and Version 1 of PageStatsMiddleware

Timestamp:

Aug 12, 2006, 10:39:53 PM (18 years ago)

Author:

Gary Wilson <gary.wilson@…>

Comment:

--

PageStatsMiddleware

@@ +1 @@
+= Page Stats Middleware =
+
+Display performance metrics measured during the generation of a page. Allows you to display total time, python time, database time, and number of queries for the rendered page.
+
+== The Python Code ==
+
+{{{
+#!python
+import re
+from operator import add
+from time import time
+from django.db import connection
+
+class StatsMiddleware(object):
+
+    def process_view(self, request, view_func, view_args, view_kwargs):
+
+        # turn on debugging in db backend to capture time
+        from django.conf import settings
+        debug = settings.DEBUG
+        settings.DEBUG = True
+
+        # get number of db queries before we do anything
+        n = len(connection.queries)
+
+        # time the view
+        start = time()
+        response = view_func(request, *view_args, **view_kwargs)
+        totTime = time() - start
+
+        # compute the db time for the queries just run
+        queries = len(connection.queries) - n
+        if queries:
+            dbTime = reduce(add, [float(q['time']) 
+                                  for q in connection.queries[n:]])
+        else:
+            dbTime = 0.0
+
+        # and backout python time
+        pyTime = totTime - dbTime
+
+        # restore debugging setting
+        settings.DEBUG = debug
+
+        stats = {
+            'totTime': totTime,
+            'pyTime': pyTime,
+            'dbTime': dbTime,
+            'queries': queries,
+            }
+
+        # replace the comment if found            
+        if response and response.content:
+            s = response.content
+            regexp = re.compile(r'(?P<cmt><!--\s*STATS:(?P<fmt>.*?)-->)')
+            match = regexp.search(s)
+            if match:
+                s = s[:match.start('cmt')] + \
+                    match.group('fmt') % stats + \
+                    s[match.end('cmt'):]
+                response.content = s
+
+        return response
+}}}
+
+
+== The HTML ==
+
+Put a comment in your template in this format:
+{{{
+<!-- STATS: format_string -->
+}}}
+
+Example:
+{{{
+<!-- STATS: Total: %(totTime).2f Python: %(pyTime).2f DB: %(dbTime).2f Queries: %(queries)d -->
+}}}