def create_app_migration(self, app_label, idx, migrations):
""" Create a migration for the app which replaces the migrations """
operations = []
dependencies = set()
replaces = set()
# Create the list of migrations this one will replace
for migration in migrations:
replaces.add((migration.app_label, migration.name))
# Gather up the operations to perform and find dependencies
for migration in migrations:
# Apparently we need to reverse the operations list now
new_operations = list(migration.operations)
new_operations.reverse()
operations.extend(new_operations)
for dependency in migration.dependencies:
different_app = (dependency[0] != migration.app_label)
if different_app or dependency not in replaces:
dependencies.add(dependency)
MIGRATE_HEADING = self.style.MIGRATE_HEADING
# Reverse operations list
operations.reverse()
if self.no_optimize:
if self.verbosity > 0:
self.stdout.write(MIGRATE_HEADING(
"(Skipping optimization for '" + app_label + "'.)"))
new_operations = operations
else:
if self.verbosity > 0:
self.stdout.write(MIGRATE_HEADING(
"Optimizing '" + app_label + "'..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations))
)
# Make a new migration class with these operations
migration_class = type(str('Migration'), (Migration, ), {
'dependencies': dependencies,
'operations': new_operations,
'replaces': sorted(replaces),
})
return migration_class(idx + '_project', app_label)
def assert_optimizes_to(self, operations: List[Operation],
expected: List[Operation]):
optimized = MigrationOptimizer().optimize(operations, "tests")
deep_deconstruct = MigrationAutodetector(
ProjectState(), ProjectState()).deep_deconstruct
self.assertEqual(deep_deconstruct(optimized),
deep_deconstruct(expected))
def handle(self, app_label=None, migration_name=None, no_optimize=None, **options):
self.verbosity = int(options.get('verbosity'))
self.interactive = options.get('interactive')
if app_label is None or migration_name is None:
self.stderr.write(self.usage_str)
sys.exit(1)
# Load the current graph state, check the app and migration they asked for exists
executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
if app_label not in executor.loader.migrated_apps:
raise CommandError("App '%s' does not have migrations (so squashmigrations on it makes no sense)" % app_label)
try:
migration = executor.loader.get_migration_by_prefix(app_label, migration_name)
except AmbiguityError:
raise CommandError("More than one migration matches '%s' in app '%s'. Please be more specific." % (migration_name, app_label))
except KeyError:
raise CommandError("Cannot find a migration matching '%s' from app '%s'." % (migration_name, app_label))
# Work out the list of predecessor migrations
migrations_to_squash = [
executor.loader.get_migration(al, mn)
for al, mn in executor.loader.graph.forwards_plan((migration.app_label, migration.name))
if al == migration.app_label
]
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(self.style.MIGRATE_HEADING("Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = six.moves.input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together,
# along with collecting external dependencies and detecting
# double-squashing
operations = []
dependencies = set()
for smigration in migrations_to_squash:
if smigration.replaces:
raise CommandError("You cannot squash squashed migrations! Please transition it to a normal migration first: https://docs.djangoproject.com/en/1.7/topics/migrations/#squashing-migrations")
operations.extend(smigration.operations)
for dependency in smigration.dependencies:
if isinstance(dependency, SwappableTuple):
if settings.AUTH_USER_MODEL == dependency.setting:
dependencies.add(("__setting__", "AUTH_USER_MODEL"))
else:
dependencies.add(dependency)
elif dependency[0] != smigration.app_label:
dependencies.add(dependency)
if no_optimize:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("(Skipping optimization.)"))
new_operations = operations
else:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations))
)
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type("Migration", (migrations.Migration, ), {
"dependencies": dependencies,
"operations": new_operations,
"replaces": replaces,
})
new_migration = subclass("0001_squashed_%s" % migration.name, app_label)
# Write out the new migration file
writer = MigrationWriter(new_migration)
with open(writer.path, "wb") as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Created new squashed migration %s" % writer.path))
self.stdout.write(" You should commit this migration but leave the old ones in place;")
self.stdout.write(" the new migration will be used for new installs. Once you are sure")
self.stdout.write(" all instances of the codebase have applied the migrations you squashed,")
self.stdout.write(" you can delete them.")
if writer.needs_manual_porting:
self.stdout.write(self.style.MIGRATE_HEADING("Manual porting required"))
self.stdout.write(" Your migrations contained functions that must be manually copied over,")
self.stdout.write(" as we could not safely copy their implementation.")
self.stdout.write(" See the comment at the top of the squashed migration for details.")
def handle(self, **options):
self.verbosity = options['verbosity']
self.interactive = options['interactive']
app_label = options['app_label']
start_migration_name = options['start_migration_name']
migration_name = options['migration_name']
no_optimize = options['no_optimize']
squashed_name = options['squashed_name']
include_header = options['include_header']
# Validate app_label.
try:
apps.get_app_config(app_label)
except LookupError as err:
raise CommandError(str(err))
# Load the current graph state, check the BLOG and migration they asked for exists
loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
if app_label not in loader.migrated_apps:
raise CommandError(
"App '%s' does not have migrations (so squashmigrations on "
"it makes no sense)" % app_label)
migration = self.find_migration(loader, app_label, migration_name)
# Work out the list of predecessor migrations
migrations_to_squash = [
loader.get_migration(al, mn)
for al, mn in loader.graph.forwards_plan((migration.app_label,
migration.name))
if al == migration.app_label
]
if start_migration_name:
start_migration = self.find_migration(loader, app_label,
start_migration_name)
start = loader.get_migration(start_migration.app_label,
start_migration.name)
try:
start_index = migrations_to_squash.index(start)
migrations_to_squash = migrations_to_squash[start_index:]
except ValueError:
raise CommandError(
"The migration '%s' cannot be found. Maybe it comes after "
"the migration '%s'?\n"
"Have a look at:\n"
" python manage.py showmigrations %s\n"
"to debug this issue." %
(start_migration, migration, app_label))
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(
self.style.MIGRATE_HEADING(
"Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together,
# along with collecting external dependencies and detecting
# double-squashing
operations = []
dependencies = set()
# We need to take all dependencies from the first migration in the list
# as it may be 0002 depending on 0001
first_migration = True
for smigration in migrations_to_squash:
if smigration.replaces:
raise CommandError(
"You cannot squash squashed migrations! Please transition "
"it to a normal migration first: "
"https://docs.djangoproject.com/en/%s/topics/migrations/#squashing-migrations"
% get_docs_version())
operations.extend(smigration.operations)
for dependency in smigration.dependencies:
if isinstance(dependency, SwappableTuple):
if settings.AUTH_USER_MODEL == dependency.setting:
dependencies.add(("__setting__", "AUTH_USER_MODEL"))
else:
dependencies.add(dependency)
elif dependency[0] != smigration.app_label or first_migration:
dependencies.add(dependency)
first_migration = False
if no_optimize:
if self.verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING("(Skipping optimization.)"))
new_operations = operations
else:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations,
migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations)))
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type(
"Migration", (migrations.Migration, ), {
"dependencies": dependencies,
"operations": new_operations,
"replaces": replaces,
})
if start_migration_name:
if squashed_name:
# Use the name from --squashed-name.
prefix, _ = start_migration.name.split('_', 1)
name = '%s_%s' % (prefix, squashed_name)
else:
# Generate a name.
name = '%s_squashed_%s' % (start_migration.name,
migration.name)
new_migration = subclass(name, app_label)
else:
name = '0001_%s' % (squashed_name
or 'squashed_%s' % migration.name)
new_migration = subclass(name, app_label)
new_migration.initial = True
# Write out the new migration file
writer = MigrationWriter(new_migration, include_header)
with open(writer.path, "w", encoding='utf-8') as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING(
'Created new squashed migration %s' % writer.path) + '\n'
' You should commit this migration but leave the old ones in place;\n'
' the new migration will be used for new installs. Once you are sure\n'
' all instances of the codebase have applied the migrations you squashed,\n'
' you can delete them.')
if writer.needs_manual_porting:
self.stdout.write(
self.style.MIGRATE_HEADING('Manual porting required') +
'\n'
' Your migrations contained functions that must be manually copied over,\n'
' as we could not safely copy their implementation.\n'
' See the comment at the top of the squashed migration for details.'
)
def optimize(self, operations):
"""
Handy shortcut for getting results + number of loops
"""
optimizer = MigrationOptimizer()
return optimizer.optimize(operations), optimizer._iterations
def handle(self, **options):
self.verbosity = options.get('verbosity')
self.interactive = options.get('interactive')
app_label, migration_name = options['app_label'], options[
'migration_name']
# Load the current graph state, check the app and migration they asked for exists
executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
if app_label not in executor.loader.migrated_apps:
raise CommandError(
"App '%s' does not have migrations (so squashmigrations on it makes no sense)"
% app_label)
try:
migration = executor.loader.get_migration_by_prefix(
app_label, migration_name)
except AmbiguityError:
raise CommandError(
"More than one migration matches '%s' in app '%s'. Please be more specific."
% (migration_name, app_label))
except KeyError:
raise CommandError(
"Cannot find a migration matching '%s' from app '%s'." %
(migration_name, app_label))
# Work out the list of predecessor migrations
migrations_to_squash = [
executor.loader.get_migration(al, mn)
for al, mn in executor.loader.graph.forwards_plan((
migration.app_label, migration.name))
if al == migration.app_label
]
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(
self.style.MIGRATE_HEADING(
"Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = six.moves.input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together,
# along with collecting external dependencies and detecting
# double-squashing
operations = []
dependencies = set()
for smigration in migrations_to_squash:
if smigration.replaces:
raise CommandError(
"You cannot squash squashed migrations! Please transition it to a normal migration first: https://docs.djangoproject.com/en/1.7/topics/migrations/#squashing-migrations"
)
operations.extend(smigration.operations)
for dependency in smigration.dependencies:
if isinstance(dependency, SwappableTuple):
if settings.AUTH_USER_MODEL == dependency.setting:
dependencies.add(("__setting__", "AUTH_USER_MODEL"))
else:
dependencies.add(dependency)
elif dependency[0] != smigration.app_label:
dependencies.add(dependency)
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations)))
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type(
"Migration", (migrations.Migration, ), {
"dependencies": dependencies,
"operations": new_operations,
"replaces": replaces,
})
new_migration = subclass("0001_squashed_%s" % migration.name,
app_label)
# Write out the new migration file
writer = MigrationWriter(new_migration)
with open(writer.path, "wb") as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING(
"Created new squashed migration %s" % writer.path))
self.stdout.write(
" You should commit this migration but leave the old ones in place;"
)
self.stdout.write(
" the new migration will be used for new installs. Once you are sure"
)
self.stdout.write(
" all instances of the codebase have applied the migrations you squashed,"
)
self.stdout.write(" you can delete them.")
if writer.needs_manual_porting:
self.stdout.write(
self.style.MIGRATE_HEADING("Manual porting required"))
self.stdout.write(
" Your migrations contained functions that must be manually copied over,"
)
self.stdout.write(
" as we could not safely copy their implementation.")
self.stdout.write(
" See the comment at the top of the squashed migration for details."
)
def test_none_app_label(self):
optimizer = MigrationOptimizer()
with self.assertRaisesMessage(TypeError, 'app_label must be a str'):
optimizer.optimize([], None)
def optimize(self, operations, app_label):
"""
Handy shortcut for getting results + number of loops
"""
optimizer = MigrationOptimizer()
return optimizer.optimize(operations, app_label), optimizer._iterations
def handle(self, **options):
self.verbosity = options['verbosity']
self.interactive = options['interactive']
app_label = options['app_label']
start_migration_name = options['start_migration_name']
migration_name = options['migration_name']
no_optimize = options['no_optimize']
# Load the current graph state, check the app and migration they asked for exists
loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
if app_label not in loader.migrated_apps:
raise CommandError(
"App '%s' does not have migrations (so squashmigrations on "
"it makes no sense)" % app_label
)
migration = self.find_migration(loader, app_label, migration_name)
# Work out the list of predecessor migrations
migrations_to_squash = [
loader.get_migration(al, mn)
for al, mn in loader.graph.forwards_plan((migration.app_label, migration.name))
if al == migration.app_label
]
if start_migration_name:
start_migration = self.find_migration(loader, app_label, start_migration_name)
start = loader.get_migration(start_migration.app_label, start_migration.name)
try:
start_index = migrations_to_squash.index(start)
migrations_to_squash = migrations_to_squash[start_index:]
except ValueError:
raise CommandError(
"The migration '%s' cannot be found. Maybe it comes after "
"the migration '%s'?\n"
"Have a look at:\n"
" python manage.py showmigrations %s\n"
"to debug this issue." % (start_migration, migration, app_label)
)
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(self.style.MIGRATE_HEADING("Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = six.moves.input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together,
# along with collecting external dependencies and detecting
# double-squashing
operations = []
dependencies = set()
# We need to take all dependencies from the first migration in the list
# as it may be 0002 depending on 0001
first_migration = True
for smigration in migrations_to_squash:
if smigration.replaces:
raise CommandError(
"You cannot squash squashed migrations! Please transition "
"it to a normal migration first: "
"https://docs.djangoproject.com/en/%s/topics/migrations/#squashing-migrations" % get_docs_version()
)
operations.extend(smigration.operations)
for dependency in smigration.dependencies:
if isinstance(dependency, SwappableTuple):
if settings.AUTH_USER_MODEL == dependency.setting:
dependencies.add(("__setting__", "AUTH_USER_MODEL"))
else:
dependencies.add(dependency)
elif dependency[0] != smigration.app_label or first_migration:
dependencies.add(dependency)
first_migration = False
if no_optimize:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("(Skipping optimization.)"))
new_operations = operations
else:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations))
)
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type("Migration", (migrations.Migration, ), {
"dependencies": dependencies,
"operations": new_operations,
"replaces": replaces,
})
if start_migration_name:
new_migration = subclass("%s_squashed_%s" % (start_migration.name, migration.name), app_label)
else:
new_migration = subclass("0001_squashed_%s" % migration.name, app_label)
new_migration.initial = True
# Write out the new migration file
writer = MigrationWriter(new_migration)
with open(writer.path, "wb") as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Created new squashed migration %s" % writer.path))
self.stdout.write(" You should commit this migration but leave the old ones in place;")
self.stdout.write(" the new migration will be used for new installs. Once you are sure")
self.stdout.write(" all instances of the codebase have applied the migrations you squashed,")
self.stdout.write(" you can delete them.")
if writer.needs_manual_porting:
self.stdout.write(self.style.MIGRATE_HEADING("Manual porting required"))
self.stdout.write(" Your migrations contained functions that must be manually copied over,")
self.stdout.write(" as we could not safely copy their implementation.")
self.stdout.write(" See the comment at the top of the squashed migration for details.")
def handle(self, app_label=None, migration_name=None, **options):
self.verbosity = int(options.get('verbosity'))
self.interactive = options.get('interactive')
if app_label is None or migration_name is None:
self.stderr.write(self.usage_str)
sys.exit(1)
# Load the current graph state, check the app and migration they asked for exists
executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
if app_label not in executor.loader.migrated_apps:
raise CommandError(
"App '%s' does not have migrations (so squashmigrations on it makes no sense)"
% app_label)
try:
migration = executor.loader.get_migration_by_prefix(
app_label, migration_name)
except AmbiguityError:
raise CommandError(
"More than one migration matches '%s' in app '%s'. Please be more specific."
% (migration_name, app_label))
except KeyError:
raise CommandError(
"Cannot find a migration matching '%s' from app '%s'." %
(migration_name, app_label))
# Work out the list of predecessor migrations
migrations_to_squash = [
executor.loader.get_migration(al, mn)
for al, mn in executor.loader.graph.forwards_plan((
migration.app_label, migration.name))
if al == migration.app_label
]
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(
self.style.MIGRATE_HEADING(
"Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = six.moves.input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together
operations = []
for smigration in migrations_to_squash:
operations.extend(smigration.operations)
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations)))
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type(
"Migration", (migrations.Migration, ), {
"dependencies": [],
"operations": new_operations,
"replaces": replaces,
})
new_migration = subclass("0001_squashed_%s" % migration.name,
app_label)
# Write out the new migration file
writer = MigrationWriter(new_migration)
with open(writer.path, "wb") as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING(
"Created new squashed migration %s" % writer.path))
self.stdout.write(
" You should commit this migration but leave the old ones in place;"
)
self.stdout.write(
" the new migration will be used for new installs. Once you are sure"
)
self.stdout.write(
" all instances of the codebase have applied the migrations you squashed,"
)
self.stdout.write(" you can delete them.")
def handle(self, **options):
self.verbosity = options.get('verbosity')
self.interactive = options.get('interactive')
app_label, migration_name = options['app_label'], options['migration_name']
# Load the current graph state, check the app and migration they asked for exists
executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
if app_label not in executor.loader.migrated_apps:
raise CommandError("App '%s' does not have migrations (so squashmigrations on it makes no sense)" % app_label)
try:
migration = executor.loader.get_migration_by_prefix(app_label, migration_name)
except AmbiguityError:
raise CommandError("More than one migration matches '%s' in app '%s'. Please be more specific." % (migration_name, app_label))
except KeyError:
raise CommandError("Cannot find a migration matching '%s' from app '%s'." % (migration_name, app_label))
# Work out the list of predecessor migrations
migrations_to_squash = [
executor.loader.get_migration(al, mn)
for al, mn in executor.loader.graph.forwards_plan((migration.app_label, migration.name))
if al == migration.app_label
]
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(self.style.MIGRATE_HEADING("Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = six.moves.input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together
operations = []
for smigration in migrations_to_squash:
operations.extend(smigration.operations)
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(" Optimized from %s operations to %s operations." % (len(operations), len(new_operations)))
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type("Migration", (migrations.Migration, ), {
"dependencies": [],
"operations": new_operations,
"replaces": replaces,
})
new_migration = subclass("0001_squashed_%s" % migration.name, app_label)
# Write out the new migration file
writer = MigrationWriter(new_migration)
with open(writer.path, "wb") as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Created new squashed migration %s" % writer.path))
self.stdout.write(" You should commit this migration but leave the old ones in place;")
self.stdout.write(" the new migration will be used for new installs. Once you are sure")
self.stdout.write(" all instances of the codebase have applied the migrations you squashed,")
self.stdout.write(" you can delete them.")
def write_to_last_migration_files(self, changes):
loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
new_changes = {}
update_previous_migration_paths = {}
for app_label, app_migrations in changes.items():
# Find last migration.
leaf_migration_nodes = loader.graph.leaf_nodes(app=app_label)
if len(leaf_migration_nodes) == 0:
raise CommandError(
f"App {app_label} has no migration, cannot update last migration."
)
leaf_migration_node = leaf_migration_nodes[0]
# Multiple leaf nodes have already been checked earlier in command.
leaf_migration = loader.graph.nodes[leaf_migration_node]
# Updated migration cannot be a squash migration, a dependency of
# another migration, and cannot be already applied.
if leaf_migration.replaces:
raise CommandError(
f"Cannot update squash migration '{leaf_migration}'."
)
if leaf_migration_node in loader.applied_migrations:
raise CommandError(
f"Cannot update applied migration '{leaf_migration}'."
)
depending_migrations = [
migration
for migration in loader.disk_migrations.values()
if leaf_migration_node in migration.dependencies
]
if depending_migrations:
formatted_migrations = ", ".join(
[f"'{migration}'" for migration in depending_migrations]
)
raise CommandError(
f"Cannot update migration '{leaf_migration}' that migrations "
f"{formatted_migrations} depend on."
)
# Build new migration.
for migration in app_migrations:
leaf_migration.operations.extend(migration.operations)
for dependency in migration.dependencies:
if isinstance(dependency, SwappableTuple):
if settings.AUTH_USER_MODEL == dependency.setting:
leaf_migration.dependencies.append(
("__setting__", "AUTH_USER_MODEL")
)
else:
leaf_migration.dependencies.append(dependency)
elif dependency[0] != migration.app_label:
leaf_migration.dependencies.append(dependency)
# Optimize migration.
optimizer = MigrationOptimizer()
leaf_migration.operations = optimizer.optimize(
leaf_migration.operations, app_label
)
# Update name.
previous_migration_path = MigrationWriter(leaf_migration).path
suggested_name = (
leaf_migration.name[:4] + "_" + leaf_migration.suggest_name()
)
if leaf_migration.name == suggested_name:
new_name = leaf_migration.name + "_updated"
else:
new_name = suggested_name
leaf_migration.name = new_name
# Register overridden migration.
new_changes[app_label] = [leaf_migration]
update_previous_migration_paths[app_label] = previous_migration_path
self.write_migration_files(new_changes, update_previous_migration_paths)
def _detect_changes(self, convert_apps=None):
"""
Returns a dict of migration plans which will achieve the
change from from_state to to_state. The dict has app labels
as keys and a list of migrations as values.
The resulting migrations aren't specially named, but the names
do matter for dependencies inside the set.
"""
# The first phase is generating all the operations for each app
# and gathering them into a big per-app list.
# We'll then go through that list later and order it and split
# into migrations to resolve dependencies caused by M2Ms and FKs.
self.generated_operations = {}
# Prepare some old/new state and model lists, ignoring
# proxy models and unmigrated apps.
self.old_apps = self.from_state.render(ignore_swappable=True)
self.new_apps = self.to_state.render()
self.old_model_keys = []
for al, mn in sorted(self.from_state.models.keys()):
model = self.old_apps.get_model(al, mn)
if not model._meta.proxy and model._meta.managed and al not in self.from_state.real_apps:
self.old_model_keys.append((al, mn))
self.new_model_keys = []
for al, mn in sorted(self.to_state.models.keys()):
model = self.new_apps.get_model(al, mn)
if not model._meta.proxy and model._meta.managed and (
al not in self.from_state.real_apps or
(convert_apps and al in convert_apps)):
self.new_model_keys.append((al, mn))
# Renames have to come first
self.generate_renamed_models()
# Prepare field lists, and prepare a list of the fields that used
# through models in the old state so we can make dependencies
# from the through model deletion to the field that uses it.
self.kept_model_keys = set(self.old_model_keys).intersection(
self.new_model_keys)
self.through_users = {}
self.old_field_keys = set()
self.new_field_keys = set()
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name),
model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
self.old_field_keys.update(
(app_label, model_name, x) for x, y in old_model_state.fields)
self.new_field_keys.update(
(app_label, model_name, x) for x, y in new_model_state.fields)
# Through model stuff
for field_name, field in old_model_state.fields:
old_field = self.old_apps.get_model(
app_label,
old_model_name)._meta.get_field_by_name(field_name)[0]
if hasattr(old_field, "rel") and hasattr(
old_field.rel, "through"
) and not old_field.rel.through._meta.auto_created:
through_key = (
old_field.rel.through._meta.app_label,
old_field.rel.through._meta.object_name.lower(),
)
self.through_users[through_key] = (app_label,
old_model_name,
field_name)
# Generate non-rename model operations
self.generate_created_models()
self.generate_deleted_models()
# Generate field operations
self.generate_added_fields()
self.generate_removed_fields()
self.generate_altered_fields()
self.generate_altered_unique_together()
self.generate_altered_index_together()
# Now, reordering to make things possible. The order we have already
# isn't bad, but we need to pull a few things around so FKs work nicely
# inside the same app
for app_label, ops in sorted(self.generated_operations.items()):
for i in range(10000):
found = False
for i, op in enumerate(ops):
for dep in op._auto_deps:
if dep[0] == app_label:
# Alright, there's a dependency on the same app.
for j, op2 in enumerate(ops):
if self.check_dependency(op2, dep) and j > i:
ops = ops[:i] + ops[i + 1:j +
1] + [op] + ops[j + 1:]
found = True
break
if found:
break
if found:
break
if not found:
break
else:
raise ValueError(
"Infinite loop caught in operation dependency resolution")
self.generated_operations[app_label] = ops
# Now, we need to chop the lists of operations up into migrations with
# dependencies on each other.
# We do this by stepping up an app's list of operations until we
# find one that has an outgoing dependency that isn't in another app's
# migration yet (hasn't been chopped off its list). We then chop off the
# operations before it into a migration and move onto the next app.
# If we loop back around without doing anything, there's a circular
# dependency (which _should_ be impossible as the operations are all
# split at this point so they can't depend and be depended on)
self.migrations = {}
num_ops = sum(len(x) for x in self.generated_operations.values())
chop_mode = False
while num_ops:
# On every iteration, we step through all the apps and see if there
# is a completed set of operations.
# If we find that a subset of the operations are complete we can
# try to chop it off from the rest and continue, but we only
# do this if we've already been through the list once before
# without any chopping and nothing has changed.
for app_label in sorted(self.generated_operations.keys()):
chopped = []
dependencies = set()
for operation in list(self.generated_operations[app_label]):
deps_satisfied = True
operation_dependencies = set()
for dep in operation._auto_deps:
if dep[0] == "__setting__":
operation_dependencies.add((dep[0], dep[1]))
elif dep[0] != app_label:
# External app dependency. See if it's not yet
# satisfied.
for other_operation in self.generated_operations[
dep[0]]:
if self.check_dependency(other_operation, dep):
deps_satisfied = False
break
if not deps_satisfied:
break
else:
if self.migrations.get(dep[0], None):
operation_dependencies.add(
(dep[0],
self.migrations[dep[0]][-1].name))
else:
operation_dependencies.add(
(dep[0], "__latest__"))
if deps_satisfied:
chopped.append(operation)
dependencies.update(operation_dependencies)
self.generated_operations[
app_label] = self.generated_operations[app_label][
1:]
else:
break
# Make a migration! Well, only if there's stuff to put in it
if dependencies or chopped:
if not self.generated_operations[app_label] or chop_mode:
subclass = type(str("Migration"), (Migration, ), {
"operations": [],
"dependencies": []
})
instance = subclass(
"auto_%i" %
(len(self.migrations.get(app_label, [])) + 1),
app_label)
instance.dependencies = list(dependencies)
instance.operations = chopped
self.migrations.setdefault(app_label,
[]).append(instance)
chop_mode = False
else:
self.generated_operations[
app_label] = chopped + self.generated_operations[
app_label]
new_num_ops = sum(
len(x) for x in self.generated_operations.values())
if new_num_ops == num_ops:
if not chop_mode:
chop_mode = True
else:
raise ValueError("Cannot resolve operation dependencies")
num_ops = new_num_ops
# OK, add in internal dependencies among the migrations
for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name))
# De-dupe dependencies
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.dependencies = list(set(migration.dependencies))
# Optimize migrations
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.operations = MigrationOptimizer().optimize(
migration.operations, app_label=app_label)
return self.migrations
def handle(self, *args, **options):
verbosity = options["verbosity"]
app_label = options["app_label"]
migration_name = options["migration_name"]
check = options["check"]
# Validate app_label.
try:
apps.get_app_config(app_label)
except LookupError as err:
raise CommandError(str(err))
# Load the current graph state.
loader = MigrationLoader(None)
if app_label not in loader.migrated_apps:
raise CommandError(f"App '{app_label}' does not have migrations.")
# Find a migration.
try:
migration = loader.get_migration_by_prefix(app_label, migration_name)
except AmbiguityError:
raise CommandError(
f"More than one migration matches '{migration_name}' in app "
f"'{app_label}'. Please be more specific."
)
except KeyError:
raise CommandError(
f"Cannot find a migration matching '{migration_name}' from app "
f"'{app_label}'."
)
# Optimize the migration.
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(migration.operations, migration.app_label)
if len(migration.operations) == len(new_operations):
if verbosity > 0:
self.stdout.write("No optimizations possible.")
return
else:
if verbosity > 0:
self.stdout.write(
"Optimizing from %d operations to %d operations."
% (len(migration.operations), len(new_operations))
)
if check:
sys.exit(1)
# Set the new migration optimizations.
migration.operations = new_operations
# Write out the optimized migration file.
writer = MigrationWriter(migration)
migration_file_string = writer.as_string()
if writer.needs_manual_porting:
if migration.replaces:
raise CommandError(
"Migration will require manual porting but is already a squashed "
"migration.\nTransition to a normal migration first: "
"https://docs.djangoproject.com/en/%s/topics/migrations/"
"#squashing-migrations" % get_docs_version()
)
# Make a new migration with those operations.
subclass = type(
"Migration",
(migrations.Migration,),
{
"dependencies": migration.dependencies,
"operations": new_operations,
"replaces": [(migration.app_label, migration.name)],
},
)
optimized_migration_name = "%s_optimized" % migration.name
optimized_migration = subclass(optimized_migration_name, app_label)
writer = MigrationWriter(optimized_migration)
migration_file_string = writer.as_string()
if verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING("Manual porting required") + "\n"
" Your migrations contained functions that must be manually "
"copied over,\n"
" as we could not safely copy their implementation.\n"
" See the comment at the top of the optimized migration for "
"details."
)
if shutil.which("black"):
self.stdout.write(
self.style.WARNING(
"Optimized migration couldn't be formatted using the "
'"black" command. You can call it manually.'
)
)
with open(writer.path, "w", encoding="utf-8") as fh:
fh.write(migration_file_string)
run_formatters([writer.path])
if verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING(f"Optimized migration {writer.path}")
)
