109 lines
5.0 KiB
Python
109 lines
5.0 KiB
Python
|
import sys
|
||
|
|
import os
|
||
|
|
from optparse import make_option
|
||
|
|
|
||
|
|
from django.core.management.base import BaseCommand, CommandError
|
||
|
|
from django.core.exceptions import ImproperlyConfigured
|
||
|
|
from django.utils import six
|
||
|
|
from django.db import connections, DEFAULT_DB_ALIAS, migrations
|
||
|
|
from django.db.migrations.loader import MigrationLoader, AmbiguityError
|
||
|
|
from django.db.migrations.autodetector import MigrationAutodetector, InteractiveMigrationQuestioner
|
||
|
|
from django.db.migrations.executor import MigrationExecutor
|
||
|
|
from django.db.migrations.writer import MigrationWriter
|
||
|
|
from django.db.models.loading import cache
|
||
|
|
from django.db.migrations.optimizer import MigrationOptimizer
|
||
|
|
|
||
|
|
|
||
|
|
class Command(BaseCommand):
|
||
|
|
option_list = BaseCommand.option_list + (
|
||
|
|
make_option('--no-optimize', action='store_true', dest='no_optimize', default=False,
|
||
|
|
help='Do not try to optimize the squashed operations.'),
|
||
|
|
make_option('--noinput', action='store_false', dest='interactive', default=True,
|
||
|
|
help='Tells Django to NOT prompt the user for input of any kind.'),
|
||
|
|
)
|
||
|
|
|
||
|
|
help = "Squashes an existing set of migrations (from first until specified) into a single new one."
|
||
|
|
usage_str = "Usage: ./manage.py squashmigrations app migration_name"
|
||
|
|
|
||
|
|
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." % (app_label, migration_name))
|
||
|
|
except KeyError:
|
||
|
|
raise CommandError("Cannot find a migration matching '%s' from app '%s'." % (app_label, migration_name))
|
||
|
|
|
||
|
|
# 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)))
|
||
|
|
|
||
|
|
# Make a new migration with those operations
|
||
|
|
subclass = type("Migration", (migrations.Migration, ), {
|
||
|
|
"dependencies": [],
|
||
|
|
"operations": new_operations,
|
||
|
|
"replaces": [(m.app_label, m.name) for m in migrations_to_squash],
|
||
|
|
})
|
||
|
|
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.")
|