[1.2.X] Fixed #14290 -- Made format localization faster by caching the format modules. Thanks, Teemu Kurppa and Anssi Kääriäinen for the report and initial patches.

Backport from trunk (r13898).

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13903 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/utils/formats.py

@@ -7,29 +7,36 @@ from django.utils.importlib import import_module
 from django.utils.encoding import smart_str
 from django.utils import dateformat, numberformat, datetime_safe
 
-def get_format_modules(reverse=False):
+# format_cache is a mapping from (format_type, lang) to the format string.
+# By using the cache, it is possible to avoid running get_format_modules
+# repeatedly.
+_format_cache = {}
+_format_modules_cache = {}
+
+def iter_format_modules(lang):
     """
-    Returns an iterator over the format modules found in the project and Django
+    Does the heavy lifting of finding format modules.
     """
-    modules = []
-    if not check_for_language(get_language()) or not settings.USE_L10N:
-        return modules
-    locale = to_locale(get_language())
+    if check_for_language(lang) or settings.USE_L10N:
+        format_locations = ['django.conf.locale.%s']
         if settings.FORMAT_MODULE_PATH:
-        format_locations = [settings.FORMAT_MODULE_PATH + '.%s']
-    else:
-        format_locations = []
-    format_locations.append('django.conf.locale.%s')
+            format_locations.append(settings.FORMAT_MODULE_PATH + '.%s')
+            format_locations.reverse()
+        locale = to_locale(lang)
+        locales = set((locale, locale.split('_')[0]))
         for location in format_locations:
-        for l in (locale, locale.split('_')[0]):
+            for loc in locales:
                 try:
-                mod = import_module('.formats', location % l)
+                    yield import_module('.formats', location % loc)
                 except ImportError:
                     pass
-            else:
-                # Don't return duplicates
-                if mod not in modules:
-                    modules.append(mod)
+
+def get_format_modules(reverse=False):
+    """
+    Returns an iterator over the format modules found
+    """
+    lang = get_language()
+    modules = _format_modules_cache.setdefault(lang, list(iter_format_modules(lang)))
     if reverse:
         modules.reverse()
     return modules
@@ -42,11 +49,18 @@ def get_format(format_type):
     """
     format_type = smart_str(format_type)
     if settings.USE_L10N:
+        cache_key = (format_type, get_language())
+        try:
+            return _format_cache[cache_key] or getattr(settings, format_type)
+        except KeyError:
             for module in get_format_modules():
                 try:
-                return getattr(module, format_type)
+                    val = getattr(module, format_type)
+                    _format_cache[cache_key] = val
+                    return val
                 except AttributeError:
                     pass
+            _format_cache[cache_key] = None
     return getattr(settings, format_type)
 
 def date_format(value, format=None):

django/utils/numberformat.py

@@ -1,4 +1,6 @@
 from django.conf import settings
+from django.utils.safestring import mark_safe
+
 
 def format(number, decimal_sep, decimal_pos, grouping=0, thousand_sep=''):
     """
@@ -11,15 +13,20 @@ def format(number, decimal_sep, decimal_pos, grouping=0, thousand_sep=''):
     * thousand_sep: Thousand separator symbol (for example ",")
 
     """
+    use_grouping = settings.USE_L10N and \
+        settings.USE_THOUSAND_SEPARATOR and grouping
+    # Make the common case fast:
+    if isinstance(number, int) and not use_grouping and not decimal_pos:
+        return mark_safe(unicode(number))
     # sign
     if float(number) < 0:
         sign = '-'
     else:
         sign = ''
-    # decimal part
     str_number = unicode(number)
     if str_number[0] == '-':
         str_number = str_number[1:]
+    # decimal part
     if '.' in str_number:
         int_part, dec_part = str_number.split('.')
         if decimal_pos:
@@ -30,13 +37,12 @@ def format(number, decimal_sep, decimal_pos, grouping=0, thousand_sep=''):
         dec_part = dec_part + ('0' * (decimal_pos - len(dec_part)))
     if dec_part: dec_part = decimal_sep + dec_part
     # grouping
-    if settings.USE_L10N and settings.USE_THOUSAND_SEPARATOR and grouping:
+    if use_grouping:
         int_part_gd = ''
         for cnt, digit in enumerate(int_part[::-1]):
             if cnt and not cnt % grouping:
                 int_part_gd += thousand_sep
             int_part_gd += digit
         int_part = int_part_gd[::-1]
-
     return sign + int_part + dec_part
 

tests/regressiontests/i18n/tests.py

@@ -8,10 +8,11 @@ import pickle
 from django.conf import settings
 from django.template import Template, Context
 from django.test import TestCase
-from django.utils.formats import get_format, date_format, time_format, localize, localize_input
+from django.utils.formats import get_format, date_format, time_format, localize, localize_input, iter_format_modules
 from django.utils.numberformat import format as nformat
 from django.utils.safestring import mark_safe, SafeString, SafeUnicode
 from django.utils.translation import ugettext, ugettext_lazy, activate, deactivate, gettext_lazy, to_locale
+from django.utils.importlib import import_module
 
 
 from forms import I18nForm, SelectDateForm, SelectDateWidget, CompanyForm
@@ -423,6 +424,24 @@ class FormattingTests(TestCase):
         finally:
             deactivate()
 
+    def test_iter_format_modules(self):
+        """
+        Tests the iter_format_modules function.
+        """
+        activate('de-at')
+        old_format_module_path = settings.FORMAT_MODULE_PATH
+        try:
+            settings.USE_L10N = True
+            de_format_mod = import_module('django.conf.locale.de.formats')
+            self.assertEqual(list(iter_format_modules('de')), [de_format_mod])
+            settings.FORMAT_MODULE_PATH = 'regressiontests.i18n.other.locale'
+            test_de_format_mod = import_module('regressiontests.i18n.other.locale.de.formats')
+            self.assertEqual(list(iter_format_modules('de')), [test_de_format_mod, de_format_mod])
+        finally:
+            settings.FORMAT_MODULE_PATH = old_format_module_path
+            deactivate()
+
+
 class MiscTests(TestCase):
 
     def test_parse_spec_http_header(self):