Commit 7628f87e authored by Patryk Zawadzki's avatar Patryk Zawadzki Committed by Tim Graham
Browse files

Fixed #25750 -- Made Options._expire_cache() faster 

Avoided unnecessary list operations and delattr() calls that result
in an exception being raised as it causes call frame reconstruction
which is very costly, especially so in a function that is called
millions of times.
parent 6c01010d

django/db/models/options.py

+9 −13
Original line number Diff line number Diff line
@@ -65,9 +65,9 @@ def make_immutable_fields_list(name, data): 


@python_2_unicode_compatible

class Options(object):

    FORWARD_PROPERTIES = ('fields', 'many_to_many', 'concrete_fields',

                          'local_concrete_fields', '_forward_fields_map')

    REVERSE_PROPERTIES = ('related_objects', 'fields_map', '_relation_tree')

    FORWARD_PROPERTIES = {'fields', 'many_to_many', 'concrete_fields',

                          'local_concrete_fields', '_forward_fields_map'}

    REVERSE_PROPERTIES = {'related_objects', 'fields_map', '_relation_tree'}



    def __init__(self, meta, app_label=None):

        self._get_fields_cache = {}
@@ -586,18 +586,14 @@ class Options(object): 
    def _expire_cache(self, forward=True, reverse=True):

        # This method is usually called by apps.cache_clear(), when the

        # registry is finalized, or when a new field is added.

        properties_to_expire = []

        if forward:

            properties_to_expire.extend(self.FORWARD_PROPERTIES)

            for cache_key in self.FORWARD_PROPERTIES:

                if cache_key in self.__dict__:

                    delattr(self, cache_key)

        if reverse and not self.abstract:

            properties_to_expire.extend(self.REVERSE_PROPERTIES)



        for cache_key in properties_to_expire:

            try:

            for cache_key in self.REVERSE_PROPERTIES:

                if cache_key in self.__dict__:

                    delattr(self, cache_key)

            except AttributeError:

                pass



        self._get_fields_cache = {}



    def get_fields(self, include_parents=True, include_hidden=False):