X-Git-Url: http://git.ithinksw.org/philo.git/blobdiff_plain/1324f9b1e4d57c5ab50bc264507f7adc3207eb99..677e193e0d79c7370e01df25e67f0498dc3a947b:/philo/utils/entities.py?ds=inline diff --git a/philo/utils/entities.py b/philo/utils/entities.py index 05e41fc..830276e 100644 --- a/philo/utils/entities.py +++ b/philo/utils/entities.py @@ -1,8 +1,11 @@ +from functools import partial from UserDict import DictMixin from django.db import models from django.contrib.contenttypes.models import ContentType +from philo.utils.lazycompat import SimpleLazyObject + ### AttributeMappers @@ -20,8 +23,8 @@ class AttributeMapper(object, DictMixin): def __getitem__(self, key): """Returns the ultimate python value of the :class:`~philo.models.base.Attribute` with the given ``key`` from the cache, populating the cache if necessary.""" - if not self._cache_populated: - self._populate_cache() + if not self._cache_filled: + self._fill_cache() return self._cache[key] def __setitem__(self, key, value): @@ -53,63 +56,70 @@ class AttributeMapper(object, DictMixin): def get_attribute(self, key, default=None): """Returns the :class:`~philo.models.base.Attribute` instance with the given ``key`` from the cache, populating the cache if necessary, or ``default`` if no such attribute is found.""" - if not self._cache_populated: - self._populate_cache() + if not self._cache_filled: + self._fill_cache() return self._attributes_cache.get(key, default) def keys(self): """Returns the keys from the cache, first populating the cache if necessary.""" - if not self._cache_populated: - self._populate_cache() + if not self._cache_filled: + self._fill_cache() return self._cache.keys() def items(self): """Returns the items from the cache, first populating the cache if necessary.""" - if not self._cache_populated: - self._populate_cache() + if not self._cache_filled: + self._fill_cache() return self._cache.items() def values(self): """Returns the values from the cache, first populating the cache if necessary.""" - if not self._cache_populated: - self._populate_cache() + if not self._cache_filled: + self._fill_cache() return self._cache.values() - def _populate_cache(self): - if self._cache_populated: + def _fill_cache(self): + if self._cache_filled: return attributes = self.get_attributes() value_lookups = {} for a in attributes: - value_lookups.setdefault(a.value_content_type, []).append(a.value_object_id) + value_lookups.setdefault(a.value_content_type_id, []).append(a.value_object_id) self._attributes_cache[a.key] = a - values_bulk = {} + values_bulk = dict(((ct_pk, SimpleLazyObject(partial(ContentType.objects.get_for_id(ct_pk).model_class().objects.in_bulk, pks))) for ct_pk, pks in value_lookups.items())) + + cache = {} - for ct, pks in value_lookups.items(): - values_bulk[ct] = ct.model_class().objects.in_bulk(pks) + for a in attributes: + cache[a.key] = SimpleLazyObject(partial(self._lazy_value_from_bulk, values_bulk, a)) + a._value_cache = cache[a.key] - self._cache.update(dict([(a.key, getattr(values_bulk[a.value_content_type].get(a.value_object_id), 'value', None)) for a in attributes])) - self._cache_populated = True + self._cache.update(cache) + self._cache_filled = True + + def _lazy_value_from_bulk(self, bulk, attribute): + v = bulk[attribute.value_content_type_id].get(attribute.value_object_id) + return getattr(v, 'value', None) def clear_cache(self): """Clears the cache.""" self._cache = {} self._attributes_cache = {} - self._cache_populated = False + self._cache_filled = False class LazyAttributeMapperMixin(object): """In some cases, it may be that only one attribute value needs to be fetched. In this case, it is more efficient to avoid populating the cache whenever possible. This mixin overrides the :meth:`__getitem__` and :meth:`get_attribute` methods to prevent their populating the cache. If the cache has been populated (i.e. through :meth:`keys`, :meth:`values`, etc.), then the value or attribute will simply be returned from the cache.""" def __getitem__(self, key): - if key not in self._cache and not self._cache_populated: + if key not in self._cache and not self._cache_filled: self._add_to_cache(key) return self._cache[key] def get_attribute(self, key, default=None): - if key not in self._attributes_cache and not self._cache_populated: + if key not in self._attributes_cache and not self._cache_filled: self._add_to_cache(key) return self._attributes_cache.get(key, default) @@ -175,16 +185,16 @@ class PassthroughAttributeMapper(AttributeMapper): self._attributes = [e.attributes for e in entities] super(PassthroughAttributeMapper, self).__init__(self._attributes[0].entity) - def _populate_cache(self): - if self._cache_populated: + def _fill_cache(self): + if self._cache_filled: return for a in reversed(self._attributes): - a._populate_cache() + a._fill_cache() self._attributes_cache.update(a._attributes_cache) self._cache.update(a._cache) - self._cache_populated = True + self._cache_filled = True def get_attributes(self): raise NotImplementedError