Commit 9b7455e9 authored by Bouke Haarsma's avatar Bouke Haarsma Committed by Baptiste Mispelon
Browse files

Fixed #21351 -- Replaced memoize with Python's lru_cache. 

Replaced the custom, untested memoize with a similar decorator from Python's
3.2 stdlib. Although some minor performance degradation (see ticket), it is
expected that in the long run lru_cache will outperform memoize once it is
implemented in C.

Thanks to EvilDMP for the report and Baptiste Mispelon for the idea of
replacing memoize with lru_cache.
parent 6c5f5b9a

django/contrib/staticfiles/finders.py

+4 −6
Original line number Diff line number Diff line
@@ -4,16 +4,14 @@ import os 
from django.conf import settings

from django.core.exceptions import ImproperlyConfigured

from django.core.files.storage import default_storage, Storage, FileSystemStorage

from django.utils.functional import empty, memoize, LazyObject

from django.utils.functional import empty, LazyObject

from django.utils.module_loading import import_by_path

from django.utils._os import safe_join

from django.utils import six

from django.utils import six, lru_cache



from django.contrib.staticfiles import utils

from django.contrib.staticfiles.storage import AppStaticStorage



_finders = OrderedDict()





class BaseFinder(object):

    """
@@ -254,7 +252,8 @@ def get_finders(): 
        yield get_finder(finder_path)





def _get_finder(import_path):

@lru_cache.lru_cache(maxsize=None)

def get_finder(import_path):

    """

    Imports the staticfiles finder class described by import_path, where

    import_path is the full Python path to the class.
@@ -264,4 +263,3 @@ def _get_finder(import_path): 
        raise ImproperlyConfigured('Finder "%s" is not a subclass of "%s"' %

                                   (Finder, BaseFinder))

    return Finder()
 
get_finder = memoize(_get_finder, _finders, 1)

django/core/management/commands/loaddata.py

+4 −5
Original line number Diff line number Diff line
@@ -14,8 +14,9 @@ from django.core.management.color import no_style 
from django.db import (connections, router, transaction, DEFAULT_DB_ALIAS,

      IntegrityError, DatabaseError)

from django.db.models import get_app_paths

from django.utils import lru_cache

from django.utils.encoding import force_text

from django.utils.functional import cached_property, memoize

from django.utils.functional import cached_property

from django.utils._os import upath

from itertools import product
@@ -164,7 +165,8 @@ class Command(BaseCommand): 
                    RuntimeWarning

                )



    def _find_fixtures(self, fixture_label):

    @lru_cache.lru_cache(maxsize=None)

    def find_fixtures(self, fixture_label):

        """

        Finds fixture files for a given label.

        """
@@ -220,9 +222,6 @@ class Command(BaseCommand): 


        return fixture_files



    _label_to_fixtures_cache = {}

    find_fixtures = memoize(_find_fixtures, _label_to_fixtures_cache, 2)



    @cached_property

    def fixture_dirs(self):

        """

django/core/urlresolvers.py

+8 −15
Original line number Diff line number Diff line
@@ -16,18 +16,14 @@ from django.http import Http404 
from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist

from django.utils.datastructures import MultiValueDict

from django.utils.encoding import force_str, force_text, iri_to_uri

from django.utils.functional import memoize, lazy

from django.utils.functional import lazy

from django.utils.http import urlquote

from django.utils.module_loading import module_has_submodule

from django.utils.regex_helper import normalize

from django.utils import six

from django.utils import six, lru_cache

from django.utils.translation import get_language





_resolver_cache = {}  # Maps URLconf modules to RegexURLResolver instances.

_ns_resolver_cache = {}  # Maps namespaces to RegexURLResolver instances.

_callable_cache = {}  # Maps view and url pattern names to their view functions.



# SCRIPT_NAME prefixes for each thread are stored here. If there's no entry for

# the current thread (which is the only one we ever access), it is assumed to

# be empty.
@@ -80,6 +76,7 @@ class NoReverseMatch(Exception): 
    pass





@lru_cache.lru_cache(maxsize=None)

def get_callable(lookup_view, can_fail=False):

    """

    Convert a string version of a function name to the callable object.
@@ -119,17 +116,17 @@ def get_callable(lookup_view, can_fail=False): 
                        "Could not import %s. View does not exist in module %s." %

                        (lookup_view, mod_name))

    return lookup_view

get_callable = memoize(get_callable, _callable_cache, 1)





@lru_cache.lru_cache(maxsize=None)

def get_resolver(urlconf):

    if urlconf is None:

        from django.conf import settings

        urlconf = settings.ROOT_URLCONF

    return RegexURLResolver(r'^/', urlconf)

get_resolver = memoize(get_resolver, _resolver_cache, 1)





@lru_cache.lru_cache(maxsize=None)

def get_ns_resolver(ns_pattern, resolver):

    # Build a namespaced resolver for the given parent urlconf pattern.

    # This makes it possible to have captured parameters in the parent
@@ -137,7 +134,6 @@ def get_ns_resolver(ns_pattern, resolver): 
    ns_resolver = RegexURLResolver(ns_pattern,

                                          resolver.url_patterns)

    return RegexURLResolver(r'^/', [ns_resolver])

get_ns_resolver = memoize(get_ns_resolver, _ns_resolver_cache, 2)





def get_mod_func(callback):
@@ -523,12 +519,9 @@ reverse_lazy = lazy(reverse, str) 




def clear_url_caches():

    global _resolver_cache

    global _ns_resolver_cache

    global _callable_cache

    _resolver_cache.clear()

    _ns_resolver_cache.clear()

    _callable_cache.clear()

    get_callable.cache_clear()

    get_resolver.cache_clear()

    get_ns_resolver.cache_clear()





def set_script_prefix(prefix):

django/test/utils.py

+1 −1
Original line number Diff line number Diff line
@@ -427,7 +427,7 @@ class TransRealMixin(object): 
        trans_real._translations = {}

        trans_real._active = local()

        trans_real._default = None

        trans_real._checked_languages = {}

        trans_real.check_for_language.cache_clear()



    def tearDown(self):

        self.flush_caches()

django/utils/functional.py

+5 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ import copy 
import operator

from functools import wraps

import sys

import warnings



from django.utils import six

from django.utils.six.moves import copyreg
@@ -24,6 +25,10 @@ def memoize(func, cache, num_args): 


    Only the first num_args are considered when creating the key.

    """

    warnings.warn(u"memoize wrapper is deprecated and will be removed in "

                  u"Django 1.9. Use django.utils.lru_cache instead.",

                  PendingDeprecationWarning, 2)



    @wraps(func)

    def wrapper(*args):

        mem_args = args[:num_args]