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

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13898 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/utils/encoding.py

@@ -58,6 +58,11 @@ def force_unicode(s, encoding='utf-8', strings_only=False, errors='strict'):
 
     If strings_only is True, don't convert (some) non-string-like objects.
     """
+    # Handle the common case first, saves 30-40% in performance when s
+    # is an instance of unicode. This function gets called often in that
+    # setting.
+    if isinstance(s, unicode):
+        return s
     if strings_only and is_protected_type(s):
         return s
     try:

django/utils/formats.py

@@ -7,34 +7,41 @@ 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 check_for_language(lang) or settings.USE_L10N:
-    if not check_for_language(get_language()) or not settings.USE_L10N:
+        format_locations = ['django.conf.locale.%s']
-        return modules
-    locale = to_locale(get_language())
         if settings.FORMAT_MODULE_PATH:
-        format_locations = [settings.FORMAT_MODULE_PATH + '.%s']
+            format_locations.append(settings.FORMAT_MODULE_PATH + '.%s')
-    else:
+            format_locations.reverse()
-        format_locations = []
+        locale = to_locale(lang)
-    format_locations.append('django.conf.locale.%s')
+        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
+def get_format_modules(reverse=False):
-                if mod not in modules:
+    """
-                    modules.append(mod)
+    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
 
-def get_format(format_type):
+def get_format(format_type, lang=None):
     """
     For a specific format type, returns the format for the current
     language (locale), defaults to the format in the settings.
@@ -42,11 +49,20 @@ def get_format(format_type):
     """
     format_type = smart_str(format_type)
     if settings.USE_L10N:
+        if lang is None:
+            lang = get_language()
+        cache_key = (format_type, lang)
+        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):
@@ -66,12 +82,16 @@ def number_format(value, decimal_pos=None):
     """
     Formats a numeric value using localization settings
     """
+    if settings.USE_L10N:
+        lang = get_language()
+    else:
+        lang = None
     return numberformat.format(
         value,
-        get_format('DECIMAL_SEPARATOR'),
+        get_format('DECIMAL_SEPARATOR', lang),
         decimal_pos,
-        get_format('NUMBER_GROUPING'),
+        get_format('NUMBER_GROUPING', lang),
-        get_format('THOUSAND_SEPARATOR'),
+        get_format('THOUSAND_SEPARATOR', lang),
     )
 
 def localize(value):
@@ -97,7 +117,7 @@ def localize_input(value, default=None):
     """
     if isinstance(value, (decimal.Decimal, float, int)):
         return number_format(value)
-    if isinstance(value, datetime.datetime):
+    elif isinstance(value, datetime.datetime):
         value = datetime_safe.new_datetime(value)
         format = smart_str(default or get_format('DATETIME_INPUT_FORMATS')[0])
         return value.strftime(format)

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 +424,23 @@ 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):