def build_graph(self):
"""
Build a migrations dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migrations stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
if self.connection is None:
self.applied_migrations = set()
else:
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# To start, populate the migrations graph with nodes for ALL migrations
# and their dependencies. Also make note of replacing migrations at this step.
self.graph = MigrationGraph()
self.replacements = {}
for key, migration in self.disk_migrations.items():
self.graph.add_node(key, migration)
# Replacing migrations.
if migration.replaces:
self.replacements[key] = migration
for key, migration in self.disk_migrations.items():
# Internal (same app) dependencies.
self.add_internal_dependencies(key, migration)
# Add external dependencies now that the internal ones have been resolved.
for key, migration in self.disk_migrations.items():
self.add_external_dependencies(key, migration)
# Carry out replacements where possible.
for key, migration in self.replacements.items():
# Get applied status of each of this migrations's replacement targets.
applied_statuses = [(target in self.applied_migrations)
for target in migration.replaces]
# Ensure the replacing migrations is only marked as applied if all of
# its replacement targets are.
if all(applied_statuses):
self.applied_migrations.add(key)
else:
self.applied_migrations.discard(key)
# A replacing migrations can be used if either all or none of its
# replacement targets have been applied.
if all(applied_statuses) or (not any(applied_statuses)):
self.graph.remove_replaced_nodes(key, migration.replaces)
else:
# This replacing migrations cannot be used because it is partially applied.
# Remove it from the graph and remap dependencies to it (#25945).
self.graph.remove_replacement_node(key, migration.replaces)
# Ensure the graph is consistent.
try:
self.graph.validate_consistency()
except NodeNotFoundError as exc:
# Check if the missing node could have been replaced by any squash
# migrations but wasn't because the squash migrations was partially
# applied before. In that case raise a more understandable exception
# (#23556).
# Get reverse replacements.
reverse_replacements = {}
for key, migration in self.replacements.items():
for replaced in migration.replaces:
reverse_replacements.setdefault(replaced, set()).add(key)
# Try to reraise exception with more detail.
if exc.node in reverse_replacements:
candidates = reverse_replacements.get(exc.node, set())
is_replaced = any(candidate in self.graph.nodes
for candidate in candidates)
if not is_replaced:
tries = ', '.join('%s.%s' % c for c in candidates)
raise NodeNotFoundError(
"Migration {0} depends on nonexistent node ('{1}', '{2}'). "
"Django tried to replace migrations {1}.{2} with any of [{3}] "
"but wasn't able to because some of the replaced migrations "
"are already applied.".format(exc.origin, exc.node[0],
exc.node[1], tries),
exc.node) from exc
raise exc
self.graph.ensure_not_cyclic()
def build_graph(self):
"""
Builds a migration dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migration stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
if self.connection is None:
self.applied_migrations = set()
else:
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# Do a first pass to separate out replacing and non-replacing migrations
normal = {}
replacing = {}
for key, migration in self.disk_migrations.items():
if migration.replaces:
replacing[key] = migration
else:
normal[key] = migration
# Calculate reverse dependencies - i.e., for each migration, what depends on it?
# This is just for dependency re-pointing when applying replacements,
# so we ignore run_before here.
reverse_dependencies = {}
for key, migration in normal.items():
for parent in migration.dependencies:
reverse_dependencies.setdefault(parent, set()).add(key)
# Carry out replacements if we can - that is, if all replaced migrations
# are either unapplied or missing.
for key, migration in replacing.items():
# Ensure this replacement migration is not in applied_migrations
self.applied_migrations.discard(key)
# Do the check. We can replace if all our replace targets are
# applied, or if all of them are unapplied.
applied_statuses = [(target in self.applied_migrations)
for target in migration.replaces]
can_replace = all(applied_statuses) or (not any(applied_statuses))
if not can_replace:
continue
# Alright, time to replace. Step through the replaced migrations
# and remove, repointing dependencies if needs be.
for replaced in migration.replaces:
if replaced in normal:
# We don't care if the replaced migration doesn't exist;
# the usage pattern here is to delete things after a while.
del normal[replaced]
for child_key in reverse_dependencies.get(replaced, set()):
if child_key in migration.replaces:
continue
normal[child_key].dependencies.remove(replaced)
normal[child_key].dependencies.append(key)
normal[key] = migration
# Mark the replacement as applied if all its replaced ones are
if all(applied_statuses):
self.applied_migrations.add(key)
# Finally, make a graph and load everything into it
self.graph = MigrationGraph()
for key, migration in normal.items():
self.graph.add_node(key, migration)
# Add all internal dependencies first to ensure __first__ dependencies
# find the correct root node.
for key, migration in normal.items():
for parent in migration.dependencies:
if parent[0] != key[0] or parent[1] == '__first__':
# Ignore __first__ references to the same app (#22325)
continue
self.graph.add_dependency(key, parent)
for key, migration in normal.items():
for parent in migration.dependencies:
if parent[0] == key[0]:
# Internal dependencies already added.
continue
parent = self.check_key(parent, key[0])
if parent is not None:
self.graph.add_dependency(key, parent)
for child in migration.run_before:
child = self.check_key(child, key[0])
if child is not None:
self.graph.add_dependency(child, key)
def build_graph(self):
"""
Builds a migration dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migration stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
if self.connection is None:
self.applied_migrations = set()
else:
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# Do a first pass to separate out replacing and non-replacing migrations
normal = {}
replacing = {}
for key, migration in self.disk_migrations.items():
if migration.replaces:
replacing[key] = migration
else:
normal[key] = migration
# Calculate reverse dependencies - i.e., for each migration, what depends on it?
# This is just for dependency re-pointing when applying replacements,
# so we ignore run_before here.
reverse_dependencies = {}
for key, migration in normal.items():
for parent in migration.dependencies:
reverse_dependencies.setdefault(parent, set()).add(key)
# Remember the possible replacements to generate more meaningful error
# messages
reverse_replacements = {}
for key, migration in replacing.items():
for replaced in migration.replaces:
reverse_replacements.setdefault(replaced, set()).add(key)
# Carry out replacements if we can - that is, if all replaced migrations
# are either unapplied or missing.
for key, migration in replacing.items():
# Ensure this replacement migration is not in applied_migrations
self.applied_migrations.discard(key)
# Do the check. We can replace if all our replace targets are
# applied, or if all of them are unapplied.
applied_statuses = [(target in self.applied_migrations) for target in migration.replaces]
can_replace = all(applied_statuses) or (not any(applied_statuses))
if not can_replace:
continue
# Alright, time to replace. Step through the replaced migrations
# and remove, repointing dependencies if needs be.
for replaced in migration.replaces:
if replaced in normal:
# We don't care if the replaced migration doesn't exist;
# the usage pattern here is to delete things after a while.
del normal[replaced]
for child_key in reverse_dependencies.get(replaced, set()):
if child_key in migration.replaces:
continue
# child_key may appear in a replacement
if child_key in reverse_replacements:
for replaced_child_key in reverse_replacements[child_key]:
if replaced in replacing[replaced_child_key].dependencies:
replacing[replaced_child_key].dependencies.remove(replaced)
replacing[replaced_child_key].dependencies.append(key)
else:
normal[child_key].dependencies.remove(replaced)
normal[child_key].dependencies.append(key)
normal[key] = migration
# Mark the replacement as applied if all its replaced ones are
if all(applied_statuses):
self.applied_migrations.add(key)
# Finally, make a graph and load everything into it
self.graph = MigrationGraph()
for key, migration in normal.items():
self.graph.add_node(key, migration)
def _reraise_missing_dependency(migration, missing, exc):
"""
Checks if ``missing`` could have been replaced by any squash
migration but wasn't because the the squash migration was partially
applied before. In that case raise a more understandable exception.
#23556
"""
if missing in reverse_replacements:
candidates = reverse_replacements.get(missing, set())
is_replaced = any(candidate in self.graph.nodes for candidate in candidates)
if not is_replaced:
tries = ', '.join('%s.%s' % c for c in candidates)
exc_value = NodeNotFoundError(
"Migration {0} depends on nonexistent node ('{1}', '{2}'). "
"Django tried to replace migration {1}.{2} with any of [{3}] "
"but wasn't able to because some of the replaced migrations "
"are already applied.".format(
migration, missing[0], missing[1], tries
),
missing)
exc_value.__cause__ = exc
six.reraise(NodeNotFoundError, exc_value, sys.exc_info()[2])
raise exc
# Add all internal dependencies first to ensure __first__ dependencies
# find the correct root node.
for key, migration in normal.items():
for parent in migration.dependencies:
if parent[0] != key[0] or parent[1] == '__first__':
# Ignore __first__ references to the same app (#22325)
continue
try:
self.graph.add_dependency(migration, key, parent)
except NodeNotFoundError as e:
# Since we added "key" to the nodes before this implies
# "parent" is not in there. To make the raised exception
# more understandable we check if parent could have been
# replaced but hasn't (eg partially applied squashed
# migration)
_reraise_missing_dependency(migration, parent, e)
for key, migration in normal.items():
for parent in migration.dependencies:
if parent[0] == key[0]:
# Internal dependencies already added.
continue
parent = self.check_key(parent, key[0])
if parent is not None:
try:
self.graph.add_dependency(migration, key, parent)
except NodeNotFoundError as e:
# Since we added "key" to the nodes before this implies
# "parent" is not in there.
_reraise_missing_dependency(migration, parent, e)
for child in migration.run_before:
child = self.check_key(child, key[0])
if child is not None:
try:
self.graph.add_dependency(migration, child, key)
except NodeNotFoundError as e:
# Since we added "key" to the nodes before this implies
# "child" is not in there.
_reraise_missing_dependency(migration, child, e)
def test_loading_squashed_ref_squashed(self):
"Tests loading a squashed migration with a new migration referencing it"
r"""
The sample migrations are structured like this:
app_1 1 --> 2 ---------------------*--> 3 *--> 4
\ / /
*-------------------*----/--> 2_sq_3 --*
\ / /
=============== \ ============= / == / ======================
app_2 *--> 1_sq_2 --* /
\ /
*--> 1 --> 2 --*
Where 2_sq_3 is a replacing migration for 2 and 3 in app_1,
as 1_sq_2 is a replacing migration for 1 and 2 in app_2.
"""
loader = MigrationLoader(connection)
recorder = MigrationRecorder(connection)
self.addCleanup(recorder.flush)
# Load with nothing applied: both migrations squashed.
loader.build_graph()
plan = set(loader.graph.forwards_plan(('app1', '4_auto')))
plan = plan - loader.applied_migrations.keys()
expected_plan = {
('app1', '1_auto'),
('app2', '1_squashed_2'),
('app1', '2_squashed_3'),
('app1', '4_auto'),
}
self.assertEqual(plan, expected_plan)
# Load with nothing applied and migrate to a replaced migration.
# Not possible if loader.replace_migrations is True (default).
loader.build_graph()
msg = "Node ('app1', '3_auto') not a valid node"
with self.assertRaisesMessage(NodeNotFoundError, msg):
loader.graph.forwards_plan(('app1', '3_auto'))
# Possible if loader.replace_migrations is False.
loader.replace_migrations = False
loader.build_graph()
plan = set(loader.graph.forwards_plan(('app1', '3_auto')))
plan = plan - loader.applied_migrations.keys()
expected_plan = {
('app1', '1_auto'),
('app2', '1_auto'),
('app2', '2_auto'),
('app1', '2_auto'),
('app1', '3_auto'),
}
self.assertEqual(plan, expected_plan)
loader.replace_migrations = True
# Fake-apply a few from app1: unsquashes migration in app1.
self.record_applied(recorder, 'app1', '1_auto')
self.record_applied(recorder, 'app1', '2_auto')
loader.build_graph()
plan = set(loader.graph.forwards_plan(('app1', '4_auto')))
plan = plan - loader.applied_migrations.keys()
expected_plan = {
('app2', '1_squashed_2'),
('app1', '3_auto'),
('app1', '4_auto'),
}
self.assertEqual(plan, expected_plan)
# Fake-apply one from app2: unsquashes migration in app2 too.
self.record_applied(recorder, 'app2', '1_auto')
loader.build_graph()
plan = set(loader.graph.forwards_plan(('app1', '4_auto')))
plan = plan - loader.applied_migrations.keys()
expected_plan = {
('app2', '2_auto'),
('app1', '3_auto'),
('app1', '4_auto'),
}
self.assertEqual(plan, expected_plan)
def tearDown(self):
# Reset applied-migrations state.
for db in self.databases:
recorder = MigrationRecorder(connections[db])
recorder.migration_qs.filter(app='migrations').delete()
# -*- coding: utf-8 -*-
from django.db import models, migrations, DEFAULT_DB_ALIAS, connections
from django.db.migrations.recorder import MigrationRecorder
import django.db.models.deletion
from django.conf import settings
connection = connections[DEFAULT_DB_ALIAS]
recorder = MigrationRecorder(connection)
linaro_django_xmlrpc_applied = False
lava_scheduler_app_applied = False
for app, name in recorder.applied_migrations():
if app == "linaro_django_xmlrpc" and name == "0001_initial":
linaro_django_xmlrpc_applied = True
if app == "lava_scheduler_app" and name == "0001_initial":
lava_scheduler_app_applied = True
if not linaro_django_xmlrpc_applied and lava_scheduler_app_applied:
recorder.record_applied("linaro_django_xmlrpc", "0001_initial")
class Migration(migrations.Migration):
dependencies = [
("auth", "0001_initial"),
migrations.swappable_dependency(settings.AUTH_USER_MODEL),
("linaro_django_xmlrpc", "__first__"),
("dashboard_app", "__first__"),
]
operations = [
migrations.CreateModel(
name="DefaultDeviceOwner",
def tearDown(self):
super(TestTenantSchemaOperations, self).tearDown()
# Make sure all migrations are considered unapplied.
MigrationRecorder(connection).flush()
def build_graph(self, ignore_unmigrated=False):
"""
Builds a migration dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migration stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# Do a first pass to separate out replacing and non-replacing migrations
normal = {}
replacing = {}
for key, migration in self.disk_migrations.items():
if migration.replaces:
replacing[key] = migration
else:
normal[key] = migration
# Calculate reverse dependencies - i.e., for each migration, what depends on it?
# This is just for dependency re-pointing when applying replacements,
# so we ignore run_before here.
reverse_dependencies = {}
for key, migration in normal.items():
for parent in migration.dependencies:
reverse_dependencies.setdefault(parent, set()).add(key)
# Carry out replacements if we can - that is, if all replaced migrations
# are either unapplied or missing.
for key, migration in replacing.items():
# Ensure this replacement migration is not in applied_migrations
self.applied_migrations.discard(key)
# Do the check. We can replace if all our replace targets are
# applied, or if all of them are unapplied.
applied_statuses = [(target in self.applied_migrations)
for target in migration.replaces]
can_replace = all(applied_statuses) or (not any(applied_statuses))
if not can_replace:
continue
# Alright, time to replace. Step through the replaced migrations
# and remove, repointing dependencies if needs be.
for replaced in migration.replaces:
if replaced in normal:
# We don't care if the replaced migration doesn't exist;
# the usage pattern here is to delete things after a while.
del normal[replaced]
for child_key in reverse_dependencies.get(replaced, set()):
if child_key in migration.replaces:
continue
normal[child_key].dependencies.remove(replaced)
normal[child_key].dependencies.append(key)
normal[key] = migration
# Mark the replacement as applied if all its replaced ones are
if all(applied_statuses):
self.applied_migrations.add(key)
# Finally, make a graph and load everything into it
self.graph = MigrationGraph()
for key, migration in normal.items():
self.graph.add_node(key, migration)
for key, migration in normal.items():
for parent in migration.dependencies:
# Special-case __first__, which means "the first migration" for
# migrated apps, and is ignored for unmigrated apps. It allows
# makemigrations to declare dependencies on apps before they
# even have migrations.
if parent[1] == "__first__" and parent not in self.graph:
if parent[0] in self.unmigrated_apps:
if ignore_unmigrated:
migration.dependencies.remove(parent)
parent = None
else:
# This app isn't migrated, but something depends on it.
# We'll add a fake initial migration for it into the
# graph.
app_config = apps.get_app_config(parent[0])
ops = []
for model in app_config.get_models():
model_state = ModelState.from_model(model)
ops.append(
operations.CreateModel(
name=model_state.name,
fields=model_state.fields,
options=model_state.options,
bases=model_state.bases,
))
new_migration = type(
"FakeInitialMigration",
(Migration, ),
{"operations": ops},
)(parent[1], parent[0])
self.graph.add_node(parent, new_migration)
self.applied_migrations.add(parent)
elif parent[0] in self.migrated_apps:
parent = list(self.graph.root_nodes(parent[0]))[0]
else:
raise ValueError("Dependency on unknown app %s" %
parent[0])
if parent is not None:
self.graph.add_dependency(key, parent)
def tearDown(self):
# Reset applied-migrations state.
for db in connections:
MigrationRecorder(connections[db])
def fake_initial_users_migrations():
recorder = MigrationRecorder(connection)
recorder.record_applied("users", "0001_initial")
