Fixed #23660 -- Moved sort_dependencies to core. (a6a8268d) · Commits · Dom Sekotill / django

django/core/management/commands/dumpdata.py

+1 −80

Original line number	Diff line number	Diff line
		@@ -138,7 +138,7 @@ class Command(BaseCommand):

		def get_objects():
		# Collate the objects to be serialized.
		for model in sort_dependencies(app_list.items()):
		for model in serializers.sort_dependencies(app_list.items()):
		if model in excluded_models:
		continue
		if not model._meta.proxy and router.allow_migrate(using, model):
		@@ -168,82 +168,3 @@ class Command(BaseCommand):
		if show_traceback:
		raise
		raise CommandError("Unable to serialize database: %s" % e)


		def sort_dependencies(app_list):
		"""Sort a list of (app_config, models) pairs into a single list of models.

		The single list of models is sorted so that any model with a natural key
		is serialized before a normal model, and any model with a natural key
		dependency has it's dependencies serialized first.
		"""
		# Process the list of models, and get the list of dependencies
		model_dependencies = []
		models = set()
		for app_config, model_list in app_list:
		if model_list is None:
		model_list = app_config.get_models()

		for model in model_list:
		models.add(model)
		# Add any explicitly defined dependencies
		if hasattr(model, 'natural_key'):
		deps = getattr(model.natural_key, 'dependencies', [])
		if deps:
		deps = [apps.get_model(dep) for dep in deps]
		else:
		deps = []

		# Now add a dependency for any FK relation with a model that
		# defines a natural key
		for field in model._meta.fields:
		if hasattr(field.rel, 'to'):
		rel_model = field.rel.to
		if hasattr(rel_model, 'natural_key') and rel_model != model:
		deps.append(rel_model)
		# Also add a dependency for any simple M2M relation with a model
		# that defines a natural key. M2M relations with explicit through
		# models don't count as dependencies.
		for field in model._meta.many_to_many:
		if field.rel.through._meta.auto_created:
		rel_model = field.rel.to
		if hasattr(rel_model, 'natural_key') and rel_model != model:
		deps.append(rel_model)
		model_dependencies.append((model, deps))

		model_dependencies.reverse()
		# Now sort the models to ensure that dependencies are met. This
		# is done by repeatedly iterating over the input list of models.
		# If all the dependencies of a given model are in the final list,
		# that model is promoted to the end of the final list. This process
		# continues until the input list is empty, or we do a full iteration
		# over the input models without promoting a model to the final list.
		# If we do a full iteration without a promotion, that means there are
		# circular dependencies in the list.
		model_list = []
		while model_dependencies:
		skipped = []
		changed = False
		while model_dependencies:
		model, deps = model_dependencies.pop()

		# If all of the models in the dependency list are either already
		# on the final model list, or not on the original serialization list,
		# then we've found another model with all it's dependencies satisfied.
		found = True
		for candidate in ((d not in models or d in model_list) for d in deps):
		if not candidate:
		found = False
		if found:
		model_list.append(model)
		changed = True
		else:
		skipped.append((model, deps))
		if not changed:
		raise CommandError("Can't resolve dependencies for %s in serialized app list." %
		', '.join('%s.%s' % (model._meta.app_label, model._meta.object_name)
		for model, deps in sorted(skipped, key=lambda obj: obj[0].__name__))
		)
		model_dependencies = skipped

		return model_list

django/core/serializers/init.py

+80 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@ To add your own serializers, use the SERIALIZATION_MODULES setting::

		import importlib

		from django.apps import apps
		from django.conf import settings
		from django.utils import six
		from django.core.serializers.base import SerializerDoesNotExist
		@@ -154,3 +155,82 @@ def _load_serializers():
		for format in settings.SERIALIZATION_MODULES:
		register_serializer(format, settings.SERIALIZATION_MODULES[format], serializers)
		_serializers = serializers


		def sort_dependencies(app_list):
		"""Sort a list of (app_config, models) pairs into a single list of models.

		The single list of models is sorted so that any model with a natural key
		is serialized before a normal model, and any model with a natural key
		dependency has it's dependencies serialized first.
		"""
		# Process the list of models, and get the list of dependencies
		model_dependencies = []
		models = set()
		for app_config, model_list in app_list:
		if model_list is None:
		model_list = app_config.get_models()

		for model in model_list:
		models.add(model)
		# Add any explicitly defined dependencies
		if hasattr(model, 'natural_key'):
		deps = getattr(model.natural_key, 'dependencies', [])
		if deps:
		deps = [apps.get_model(dep) for dep in deps]
		else:
		deps = []

		# Now add a dependency for any FK relation with a model that
		# defines a natural key
		for field in model._meta.fields:
		if hasattr(field.rel, 'to'):
		rel_model = field.rel.to
		if hasattr(rel_model, 'natural_key') and rel_model != model:
		deps.append(rel_model)
		# Also add a dependency for any simple M2M relation with a model
		# that defines a natural key. M2M relations with explicit through
		# models don't count as dependencies.
		for field in model._meta.many_to_many:
		if field.rel.through._meta.auto_created:
		rel_model = field.rel.to
		if hasattr(rel_model, 'natural_key') and rel_model != model:
		deps.append(rel_model)
		model_dependencies.append((model, deps))

		model_dependencies.reverse()
		# Now sort the models to ensure that dependencies are met. This
		# is done by repeatedly iterating over the input list of models.
		# If all the dependencies of a given model are in the final list,
		# that model is promoted to the end of the final list. This process
		# continues until the input list is empty, or we do a full iteration
		# over the input models without promoting a model to the final list.
		# If we do a full iteration without a promotion, that means there are
		# circular dependencies in the list.
		model_list = []
		while model_dependencies:
		skipped = []
		changed = False
		while model_dependencies:
		model, deps = model_dependencies.pop()

		# If all of the models in the dependency list are either already
		# on the final model list, or not on the original serialization list,
		# then we've found another model with all it's dependencies satisfied.
		found = True
		for candidate in ((d not in models or d in model_list) for d in deps):
		if not candidate:
		found = False
		if found:
		model_list.append(model)
		changed = True
		else:
		skipped.append((model, deps))
		if not changed:
		raise RuntimeError("Can't resolve dependencies for %s in serialized app list." %
		', '.join('%s.%s' % (model._meta.app_label, model._meta.object_name)
		for model, deps in sorted(skipped, key=lambda obj: obj[0].__name__))
		)
		model_dependencies = skipped

		return model_list

django/db/backends/creation.py

+1 −2

Original line number	Diff line number	Diff line
		@@ -8,7 +8,6 @@ from django.utils.encoding import force_bytes
		from django.utils.functional import cached_property
		from django.utils.six.moves import input
		from django.utils.six import StringIO
		from django.core.management.commands.dumpdata import sort_dependencies
		from django.db import router
		from django.apps import apps
		from django.core import serializers
		@@ -425,7 +424,7 @@ class BaseDatabaseCreation(object):

		# Make a function to iteratively return every object
		def get_objects():
		for model in sort_dependencies(app_list):
		for model in serializers.sort_dependencies(app_list):
		if (not model._meta.proxy and model._meta.managed and
		router.allow_migrate(self.connection.alias, model)):
		queryset = model._default_manager.using(self.connection.alias).order_by(model._meta.pk.name)

tests/fixtures_regress/tests.py

+22 −23

Original line number	Diff line number	Diff line
		@@ -11,7 +11,6 @@ from django.core import serializers
		from django.core.serializers.base import DeserializationError
		from django.core import management
		from django.core.management.base import CommandError
		from django.core.management.commands.dumpdata import sort_dependencies
		from django.db import transaction, IntegrityError
		from django.db.models import signals
		from django.test import (TestCase, TransactionTestCase, skipIfDBFeature,
		@@ -579,7 +578,7 @@ class NaturalKeyFixtureTests(TestCase):
		Store must be serialized before then Person, and both
		must be serialized before Book.
		"""
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Book, Person, Store])]
		)
		self.assertEqual(
		@@ -588,7 +587,7 @@ class NaturalKeyFixtureTests(TestCase):
		)

		def test_dependency_sorting_2(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Book, Store, Person])]
		)
		self.assertEqual(
		@@ -597,7 +596,7 @@ class NaturalKeyFixtureTests(TestCase):
		)

		def test_dependency_sorting_3(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Store, Book, Person])]
		)
		self.assertEqual(
		@@ -606,7 +605,7 @@ class NaturalKeyFixtureTests(TestCase):
		)

		def test_dependency_sorting_4(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Store, Person, Book])]
		)
		self.assertEqual(
		@@ -615,7 +614,7 @@ class NaturalKeyFixtureTests(TestCase):
		)

		def test_dependency_sorting_5(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Person, Book, Store])]
		)
		self.assertEqual(
		@@ -624,7 +623,7 @@ class NaturalKeyFixtureTests(TestCase):
		)

		def test_dependency_sorting_6(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Person, Store, Book])]
		)
		self.assertEqual(
		@@ -633,7 +632,7 @@ class NaturalKeyFixtureTests(TestCase):
		)

		def test_dependency_sorting_dangling(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Person, Circle1, Store, Book])]
		)
		self.assertEqual(
		@@ -643,38 +642,38 @@ class NaturalKeyFixtureTests(TestCase):

		def test_dependency_sorting_tight_circular(self):
		self.assertRaisesMessage(
		CommandError,
		RuntimeError,
		"""Can't resolve dependencies for fixtures_regress.Circle1, fixtures_regress.Circle2 in serialized app list.""",
		sort_dependencies,
		serializers.sort_dependencies,
		[('fixtures_regress', [Person, Circle2, Circle1, Store, Book])],
		)

		def test_dependency_sorting_tight_circular_2(self):
		self.assertRaisesMessage(
		CommandError,
		RuntimeError,
		"""Can't resolve dependencies for fixtures_regress.Circle1, fixtures_regress.Circle2 in serialized app list.""",
		sort_dependencies,
		serializers.sort_dependencies,
		[('fixtures_regress', [Circle1, Book, Circle2])],
		)

		def test_dependency_self_referential(self):
		self.assertRaisesMessage(
		CommandError,
		RuntimeError,
		"""Can't resolve dependencies for fixtures_regress.Circle3 in serialized app list.""",
		sort_dependencies,
		serializers.sort_dependencies,
		[('fixtures_regress', [Book, Circle3])],
		)

		def test_dependency_sorting_long(self):
		self.assertRaisesMessage(
		CommandError,
		RuntimeError,
		"""Can't resolve dependencies for fixtures_regress.Circle1, fixtures_regress.Circle2, fixtures_regress.Circle3 in serialized app list.""",
		sort_dependencies,
		serializers.sort_dependencies,
		[('fixtures_regress', [Person, Circle2, Circle1, Circle3, Store, Book])],
		)

		def test_dependency_sorting_normal(self):
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [Person, ExternalDependency, Book])]
		)
		self.assertEqual(
		@@ -720,7 +719,7 @@ class M2MNaturalKeyFixtureTests(TestCase):
		#14226, namely if M2M checks are removed from sort_dependencies
		altogether.
		"""
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [M2MSimpleA, M2MSimpleB])]
		)
		self.assertEqual(sorted_deps, [M2MSimpleB, M2MSimpleA])
		@@ -731,10 +730,10 @@ class M2MNaturalKeyFixtureTests(TestCase):
		fail loudly
		"""
		self.assertRaisesMessage(
		CommandError,
		RuntimeError,
		"Can't resolve dependencies for fixtures_regress.M2MSimpleCircularA, "
		"fixtures_regress.M2MSimpleCircularB in serialized app list.",
		sort_dependencies,
		serializers.sort_dependencies,
		[('fixtures_regress', [M2MSimpleCircularA, M2MSimpleCircularB])]
		)

		@@ -743,7 +742,7 @@ class M2MNaturalKeyFixtureTests(TestCase):
		M2M relations with explicit through models should NOT count as
		dependencies. The through model itself will have dependencies, though.
		"""
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [M2MComplexA, M2MComplexB, M2MThroughAB])]
		)
		# Order between M2MComplexA and M2MComplexB doesn't matter. The through
		@@ -758,7 +757,7 @@ class M2MNaturalKeyFixtureTests(TestCase):
		M2MComplexCircular1C, M2MCircular1ThroughAB,
		M2MCircular1ThroughBC, M2MCircular1ThroughCA)
		try:
		sorted_deps = sort_dependencies(
		sorted_deps = serializers.sort_dependencies(
		[('fixtures_regress', [A, B, C, AtoB, BtoC, CtoA])]
		)
		except CommandError:
		@@ -778,7 +777,7 @@ class M2MNaturalKeyFixtureTests(TestCase):
		This test tests the circularity with explicit natural_key.dependencies
		"""
		try:
		sorted_deps = sort_dependencies([
		sorted_deps = serializers.sort_dependencies([
		('fixtures_regress', [
		M2MComplexCircular2A,
		M2MComplexCircular2B,