From 370e8cfbf55f1abc74943f75e2af9545d7c0d246 Mon Sep 17 00:00:00 2001 From: Grant Mathews Date: Thu, 1 Oct 2015 14:45:02 -0700 Subject: [PATCH] Cache results from regex_util.normalize This should speed up applications that lean heavily on urlresolvers.reverse. --- django/utils/regex_helper.py | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/django/utils/regex_helper.py b/django/utils/regex_helper.py index 4a697b2..4424ba0 100644 --- a/django/utils/regex_helper.py +++ b/django/utils/regex_helper.py @@ -7,6 +7,8 @@ should be good enough for a large class of URLS, however. """ from __future__ import unicode_literals +from threading import local + from django.utils import six from django.utils.six.moves import zip @@ -46,6 +48,8 @@ class NonCapture(list): Used to represent a non-capturing group in the pattern string. """ +_normalized = local() +_normalized.results = {} def normalize(pattern): """ @@ -69,6 +73,13 @@ def normalize(pattern): resolving can be done using positional args when keyword args are specified, the two cannot be mixed in the same reverse() call. """ + if pattern not in _normalized.results: + _normalized.results[pattern] = _normalize(pattern) + + # Return a copy of the list to avoid corrupting the cache + return list(_normalized.results[pattern]) + +def _normalize(pattern): # Do a linear scan to work out the special features of this pattern. The # idea is that we scan once here and collect all the information we need to # make future decisions. -- 2.2.1