Fixed #18556 -- Allowed RelatedManager.add() to execute 1 query where possible.

Thanks Loic Bistuer for review.
This commit is contained in:
Tim Graham 2015-03-14 21:25:33 -04:00 committed by Loïc Bistuer
parent c2e70f0265
commit adc0c4fbac
8 changed files with 151 additions and 28 deletions

View File

@ -501,15 +501,38 @@ def create_generic_related_manager(superclass, rel):
False,
self.prefetch_cache_name)
def add(self, *objs):
def add(self, *objs, **kwargs):
bulk = kwargs.pop('bulk', True)
db = router.db_for_write(self.model, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
def check_and_update_obj(obj):
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected, got %r" % (
self.model._meta.object_name, obj
))
setattr(obj, self.content_type_field_name, self.content_type)
setattr(obj, self.object_id_field_name, self.pk_val)
if bulk:
pks = []
for obj in objs:
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected" % self.model._meta.object_name)
setattr(obj, self.content_type_field_name, self.content_type)
setattr(obj, self.object_id_field_name, self.pk_val)
obj.save()
if obj._state.adding or obj._state.db != db:
raise ValueError(
"%r instance isn't saved. Use bulk=False or save "
"the object first. but must be." % obj
)
check_and_update_obj(obj)
pks.append(obj.pk)
self.model._base_manager.using(db).filter(pk__in=pks).update(**{
self.content_type_field_name: self.content_type,
self.object_id_field_name: self.pk_val,
})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in objs:
check_and_update_obj(obj)
obj.save()
add.alters_data = True
def remove(self, *objs, **kwargs):
@ -542,13 +565,14 @@ def create_generic_related_manager(superclass, rel):
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
bulk = kwargs.pop('bulk', True)
clear = kwargs.pop('clear', False)
db = router.db_for_write(self.model, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear()
self.add(*objs)
self.add(*objs, bulk=bulk)
else:
old_objs = set(self.using(db).all())
new_objs = []
@ -559,7 +583,7 @@ def create_generic_related_manager(superclass, rel):
new_objs.append(obj)
self.remove(*old_objs)
self.add(*new_objs)
self.add(*new_objs, bulk=bulk)
set.alters_data = True
def create(self, **kwargs):

View File

@ -765,16 +765,36 @@ def create_foreign_related_manager(superclass, rel):
cache_name = self.field.related_query_name()
return queryset, rel_obj_attr, instance_attr, False, cache_name
def add(self, *objs):
def add(self, *objs, **kwargs):
bulk = kwargs.pop('bulk', True)
objs = list(objs)
db = router.db_for_write(self.model, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
def check_and_update_obj(obj):
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected, got %r" % (
self.model._meta.object_name, obj,
))
setattr(obj, self.field.name, self.instance)
if bulk:
pks = []
for obj in objs:
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected, got %r" %
(self.model._meta.object_name, obj))
setattr(obj, self.field.name, self.instance)
obj.save()
check_and_update_obj(obj)
if obj._state.adding or obj._state.db != db:
raise ValueError(
"%r instance isn't saved. Use bulk=False or save "
"the object first." % obj
)
pks.append(obj.pk)
self.model._base_manager.using(db).filter(pk__in=pks).update(**{
self.field.name: self.instance,
})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in objs:
check_and_update_obj(obj)
obj.save()
add.alters_data = True
def create(self, **kwargs):
@ -835,6 +855,7 @@ def create_foreign_related_manager(superclass, rel):
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
bulk = kwargs.pop('bulk', True)
clear = kwargs.pop('clear', False)
if self.field.null:
@ -842,7 +863,7 @@ def create_foreign_related_manager(superclass, rel):
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear()
self.add(*objs)
self.add(*objs, bulk=bulk)
else:
old_objs = set(self.using(db).all())
new_objs = []
@ -852,10 +873,10 @@ def create_foreign_related_manager(superclass, rel):
else:
new_objs.append(obj)
self.remove(*old_objs)
self.add(*new_objs)
self.remove(*old_objs, bulk=bulk)
self.add(*new_objs, bulk=bulk)
else:
self.add(*objs)
self.add(*objs, bulk=bulk)
set.alters_data = True
return RelatedManager

View File

@ -36,7 +36,7 @@ Related objects reference
In this example, the methods below will be available both on
``topping.pizza_set`` and on ``pizza.toppings``.
.. method:: add(*objs)
.. method:: add(*objs, bulk=True)
Adds the specified model objects to the related object set.
@ -48,7 +48,13 @@ Related objects reference
In the example above, in the case of a
:class:`~django.db.models.ForeignKey` relationship,
``e.save()`` is called by the related manager to perform the update.
:meth:`QuerySet.update() <django.db.models.query.QuerySet.update>`
is used to perform the update. This requires the objects to already be
saved.
You can use the ``bulk=False`` argument to instead have the related
manager perform the update by calling ``e.save()``.
Using ``add()`` with a many-to-many relationship, however, will not
call any ``save()`` methods, but rather create the relationships
using :meth:`QuerySet.bulk_create()
@ -56,6 +62,12 @@ Related objects reference
some custom logic when a relationship is created, listen to the
:data:`~django.db.models.signals.m2m_changed` signal.
.. versionchanged:: 1.9
The ``bulk`` parameter was added. In order versions, foreign key
updates were always done using ``save()``. Use ``bulk=False`` if
you require the old behavior.
.. method:: create(**kwargs)
Creates a new object, saves it and puts it in the related object set.
@ -135,7 +147,7 @@ Related objects reference
:class:`~django.db.models.ForeignKey`\s where ``null=True`` and it also
accepts the ``bulk`` keyword argument.
.. method:: set(objs, clear=False)
.. method:: set(objs, bulk=True, clear=False)
.. versionadded:: 1.9
@ -150,6 +162,8 @@ Related objects reference
If ``clear=True``, the ``clear()`` method is called instead and the
whole set is added at once.
The ``bulk`` argument is passed on to :meth:`add`.
Note that since ``set()`` is a compound operation, it is subject to
race conditions. For instance, new objects may be added to the database
in between the call to ``clear()`` and the call to ``add()``.

View File

@ -400,6 +400,11 @@ Models
managers created by ``ForeignKey``, ``GenericForeignKey``, and
``ManyToManyField``.
* The :meth:`~django.db.models.fields.related.RelatedManager.add` method on
a reverse foreign key now has a ``bulk`` parameter to allow executing one
query regardless of the number of objects being added rather than one query
per object.
* Added the ``keep_parents`` parameter to :meth:`Model.delete()
<django.db.models.Model.delete>` to allow deleting only a child's data in a
model that uses multi-table inheritance.
@ -669,6 +674,15 @@ Dropped support for PostgreSQL 9.0
Upstream support for PostgreSQL 9.0 ended in September 2015. As a consequence,
Django 1.9 sets 9.1 as the minimum PostgreSQL version it officially supports.
Bulk behavior of ``add()`` method of related managers
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To improve performance, the ``add()`` methods of the related managers created
by ``ForeignKey`` and ``GenericForeignKey`` changed from a series of
``Model.save()`` calls to a single ``QuerySet.update()`` call. The change means
that ``pre_save`` and ``post_save`` signals aren't sent anymore. You can use
the ``bulk=False`` keyword argument to revert to the previous behavior.
Template ``LoaderOrigin`` and ``StringOrigin`` are removed
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

View File

@ -247,6 +247,32 @@ class GenericRelationsTests(TestCase):
self.comp_func
)
def test_add_bulk(self):
bacon = Vegetable.objects.create(name="Bacon", is_yucky=False)
t1 = TaggedItem.objects.create(content_object=self.quartz, tag="shiny")
t2 = TaggedItem.objects.create(content_object=self.quartz, tag="clearish")
# One update() query.
with self.assertNumQueries(1):
bacon.tags.add(t1, t2)
self.assertEqual(t1.content_object, bacon)
self.assertEqual(t2.content_object, bacon)
def test_add_bulk_false(self):
bacon = Vegetable.objects.create(name="Bacon", is_yucky=False)
t1 = TaggedItem.objects.create(content_object=self.quartz, tag="shiny")
t2 = TaggedItem.objects.create(content_object=self.quartz, tag="clearish")
# One save() for each object.
with self.assertNumQueries(2):
bacon.tags.add(t1, t2, bulk=False)
self.assertEqual(t1.content_object, bacon)
self.assertEqual(t2.content_object, bacon)
def test_add_rejects_unsaved_objects(self):
t1 = TaggedItem(content_object=self.quartz, tag="shiny")
msg = "<TaggedItem: shiny> instance isn't saved. Use bulk=False or save the object first."
with self.assertRaisesMessage(ValueError, msg):
self.bacon.tags.add(t1)
def test_set(self):
bacon = Vegetable.objects.create(name="Bacon", is_yucky=False)
fatty = bacon.tags.create(tag="fatty")
@ -266,13 +292,13 @@ class GenericRelationsTests(TestCase):
bacon.tags.set([])
self.assertQuerysetEqual(bacon.tags.all(), [])
bacon.tags.set([fatty, salty], clear=True)
bacon.tags.set([fatty, salty], bulk=False, clear=True)
self.assertQuerysetEqual(bacon.tags.all(), [
"<TaggedItem: fatty>",
"<TaggedItem: salty>",
])
bacon.tags.set([fatty], clear=True)
bacon.tags.set([fatty], bulk=False, clear=True)
self.assertQuerysetEqual(bacon.tags.all(), [
"<TaggedItem: fatty>",
])

View File

@ -57,7 +57,11 @@ class ManyToOneTests(TestCase):
# Create a new article, and add it to the article set.
new_article2 = Article(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))
self.r.article_set.add(new_article2)
msg = "<Article: Paul's story> instance isn't saved. Use bulk=False or save the object first."
with self.assertRaisesMessage(ValueError, msg):
self.r.article_set.add(new_article2)
self.r.article_set.add(new_article2, bulk=False)
self.assertEqual(new_article2.reporter.id, self.r.id)
self.assertQuerysetEqual(self.r.article_set.all(),
[

View File

@ -115,6 +115,15 @@ class ManyToOneNullTests(TestCase):
self.assertEqual(1, self.r2.article_set.count())
self.assertEqual(1, qs.count())
def test_add_efficiency(self):
r = Reporter.objects.create()
articles = []
for _ in range(3):
articles.append(Article.objects.create())
with self.assertNumQueries(1):
r.article_set.add(*articles)
self.assertEqual(r.article_set.count(), 3)
def test_clear_efficiency(self):
r = Reporter.objects.create()
for _ in range(3):

View File

@ -1043,6 +1043,17 @@ class RouterTestCase(TestCase):
self.assertEqual(Book.objects.using('default').count(), 1)
self.assertEqual(Book.objects.using('other').count(), 1)
def test_invalid_set_foreign_key_assignment(self):
marty = Person.objects.using('default').create(name="Marty Alchin")
dive = Book.objects.using('other').create(
title="Dive into Python",
published=datetime.date(2009, 5, 4),
)
# Set a foreign key set with an object from a different database
msg = "<Book: Dive into Python> instance isn't saved. Use bulk=False or save the object first."
with self.assertRaisesMessage(ValueError, msg):
marty.edited.set([dive])
def test_foreign_key_cross_database_protection(self):
"Foreign keys can cross databases if they two databases have a common source"
# Create a book and author on the default database
@ -1085,7 +1096,7 @@ class RouterTestCase(TestCase):
# Set a foreign key set with an object from a different database
try:
marty.edited = [pro, dive]
marty.edited.set([pro, dive], bulk=False)
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")
@ -1107,7 +1118,7 @@ class RouterTestCase(TestCase):
# Add to a foreign key set with an object from a different database
try:
marty.edited.add(dive)
marty.edited.add(dive, bulk=False)
except ValueError:
self.fail("Assignment across primary/replica databases with a common source should be ok")