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import os
import re
from importlib import import_module
from types import ModuleType
import mock
import peewee as pw
from cached_property import cached_property
from peewee_migrate import LOGGER, MigrateHistory
from peewee_migrate.auto import diff_many, NEWLINE
from peewee_migrate.compat import string_types, exec_in
from peewee_migrate.migrator import Migrator
CLEAN_RE = re.compile(r'\s+$', re.M)
MIGRATE_DIR = os.path.join(os.getcwd(), 'migrations')
VOID = lambda m, d: None # noqa
with open(os.path.join(os.path.abspath(os.path.dirname(__file__)), 'template.txt')) as t:
MIGRATE_TEMPLATE = t.read()
class BaseRouter(object):
"""Abstract base class for router."""
def __init__(self, database, migrate_table='migratehistory', logger=LOGGER):
self.database = database
self.migrate_table = migrate_table
self.logger = logger
if not isinstance(self.database, (pw.Database, pw.Proxy)):
raise RuntimeError('Invalid database: %s' % database)
@cached_property
def model(self):
"""Ensure that migrations has prepared to run."""
# Initialize MigrationHistory model
MigrateHistory._meta.database = self.database
MigrateHistory._meta.db_table = self.migrate_table
MigrateHistory.create_table(True)
return MigrateHistory
@property
def todo(self):
raise NotImplementedError
def create(self, name='auto', auto=False):
"""Create a migration."""
migrate = rollback = ''
if auto:
if isinstance(auto, string_types):
try:
auto = import_module(auto)
except ImportError:
return self.logger.error("Can't import models module: %s", auto)
if isinstance(auto, ModuleType):
auto = list(filter(
lambda m: isinstance(m, type) and issubclass(m, pw.Model),
(getattr(auto, model) for model in dir(auto)))) # noqa
for migration in self.diff:
self.run_one(migration, self.migrator)
models1 = auto
models2 = list(self.migrator.orm.values())
migrate = diff_many(models1, models2, migrator=self.migrator)
if not migrate:
return self.logger.warn('No changes found.')
migrate = NEWLINE + NEWLINE.join('\n\n'.join(migrate).split('\n'))
migrate = CLEAN_RE.sub('\n', migrate)
rollback = diff_many(models2, models1, migrator=self.migrator, reverse=True)
rollback = NEWLINE + NEWLINE.join('\n\n'.join(rollback).split('\n'))
rollback = CLEAN_RE.sub('\n', rollback)
self.logger.info('Creating migration "%s"', name)
path = self._create(name, migrate, rollback)
self.logger.info('Migration created %s', path)
return path
def _create(self, name, migrate='', rollback=''):
raise NotImplementedError
def read(self, name):
raise NotImplementedError
@property
def done(self):
"""Scan migrations in database."""
return [mm.name for mm in self.model.select()]
@property
def diff(self):
"""Calculate difference between fs and db."""
done = set(self.done)
return [name for name in self.todo if name not in done]
@cached_property
def migrator(self):
"""Create migrator and setup it with fake migrations."""
migrator = Migrator(self.database)
for name in self.done:
self.run_one(name, migrator)
return migrator
def run_one(self, name, migrator, fake=True, downgrade=False, force=False):
"""Run a migration."""
try:
migrate, rollback = self.read(name)
if fake:
with mock.patch('peewee.Model.select'):
with mock.patch('peewee.Query._execute'):
migrate(migrator, self.database, fake=fake)
if force:
self.model.create(name=name)
self.logger.info('Done %s', name)
migrator.clean()
return migrator
self.logger.info('Running "%s"', name)
with self.database.transaction():
if not downgrade:
migrate(migrator, self.database, fake=fake)
migrator.run()
self.model.create(name=name)
self.logger.info('Done %s', name)
else:
self.logger.info('Rolling back %s', name)
rollback(migrator, self.database, fake=fake)
migrator.run()
self.model.delete().where(self.model.name == name).execute()
self.logger.info('Rolled back %s', name)
except Exception as exc:
self.database.rollback()
self.logger.exception('Migration failed: %s', name)
raise
def run(self, name=None, fake=False):
"""Run migrations."""
self.logger.info('Starting migrations')
done = []
diff = self.diff
if not diff:
self.logger.info('There is nothing to migrate')
return done
migrator = self.migrator
for mname in diff:
self.run_one(mname, migrator, fake=fake, force=fake)
done.append(mname)
if name and name == mname:
break
return done
def rollback(self, name):
name = name.strip()
done = self.done
if not done:
raise RuntimeError('No migrations are found.')
if name != done[-1]:
raise RuntimeError('Only last migration can be canceled.')
migrator = self.migrator
self.run_one(name, migrator, False, True)
self.logger.warn('Downgraded migration: %s', name)
class Router(BaseRouter):
filemask = re.compile(r"[\d]{3}_[^\.]+\.py$")
def __init__(self, database, migrate_dir=MIGRATE_DIR, **kwargs):
super(Router, self).__init__(database, **kwargs)
self.migrate_dir = migrate_dir
@property
def todo(self):
"""Scan migrations in file system."""
if not os.path.exists(self.migrate_dir):
self.logger.warn('Migration directory: %s does not exist.', self.migrate_dir)
os.makedirs(self.migrate_dir)
return sorted(
''.join(f[:-3]) for f in os.listdir(self.migrate_dir) if self.filemask.match(f))
def _create(self, name, migrate='', rollback=''):
"""Create a migration."""
num = len(self.todo)
prefix = '{:03}_'.format(num + 1)
name = prefix + name + '.py'
path = os.path.join(self.migrate_dir, name)
with open(path, 'w') as f:
f.write(MIGRATE_TEMPLATE.format(migrate=migrate, rollback=rollback))
return path
def read(self, name):
"""Read migration from file."""
with open(os.path.join(self.migrate_dir, name + '.py')) as f:
code = f.read()
scope = {}
exec_in(code, scope)
return scope.get('migrate', VOID), scope.get('rollback', VOID)
class ModuleRouter(BaseRouter):
def __init__(self, database, migrate_module='migrations', **kwargs):
super(ModuleRouter, self).__init__(database, **kwargs)
if isinstance(migrate_module, string_types):
migrate_module = import_module(migrate_module)
self.migrate_module = migrate_module
def read(self, name):
mod = getattr(self.migrate_module, name)
return getattr(mod, 'migrate', VOID), getattr(mod, 'rollback', VOID)
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