def run_select_for_update(self, status, nowait=False): """ Utility method that runs a SELECT FOR UPDATE against all Person instances. After the select_for_update, it attempts to update the name of the only record, save, and commit. This function expects to run in a separate thread. """ status.append('started') try: # We need to enter transaction management again, as this is done on # per-thread basis transaction.enter_transaction_management(True) transaction.managed(True) people = list( Person.objects.all().select_for_update(nowait=nowait) ) people[0].name = 'Fred' people[0].save() transaction.commit() except DatabaseError as e: status.append(e) finally: # This method is run in a separate thread. It uses its own # database connection. Close it without waiting for the GC. connection.close()
def process_response(self, request, response): """Commits and leaves transaction management.""" if transaction.is_managed(): if transaction.is_dirty(): transaction.commit() transaction.leave_transaction_management() return response
def work(): mod = Mod.objects.create(fld=1) pk = mod.pk sid = transaction.savepoint() mod1 = Mod.objects.filter(pk=pk).update(fld=20) transaction.savepoint_rollback(sid) mod2 = Mod.objects.get(pk=pk) transaction.commit() self.assertEqual(mod2.fld, 1)
def test_manually_managed(self): """ You can manually manage transactions if you really want to, but you have to remember to commit/rollback. """ with transaction.commit_manually(): Reporter.objects.create(first_name="Libby", last_name="Holtzman") transaction.commit() self.assertEqual(Reporter.objects.count(), 1)
def ticket_11101(self): management.call_command( 'loaddata', 'thingy.json', verbosity=0, commit=False ) self.assertEqual(Thingy.objects.count(), 1) transaction.rollback() self.assertEqual(Thingy.objects.count(), 0) transaction.commit()
def decorated(self, *args, **kwargs): if not transaction.is_managed(using=self.using): transaction.enter_transaction_management(using=self.using) forced_managed = True else: forced_managed = False try: func(self, *args, **kwargs) if forced_managed: transaction.commit(using=self.using) else: transaction.commit_unless_managed(using=self.using) finally: if forced_managed: transaction.leave_transaction_management(using=self.using)
def test_block(self): """ Check that a thread running a select_for_update that accesses rows being touched by a similar operation on another connection blocks correctly. """ # First, let's start the transaction in our thread. self.start_blocking_transaction() # Now, try it again using the ORM's select_for_update # facility. Do this in a separate thread. status = [] thread = threading.Thread( target=self.run_select_for_update, args=(status,) ) # The thread should immediately block, but we'll sleep # for a bit to make sure. thread.start() sanity_count = 0 while len(status) != 1 and sanity_count < 10: sanity_count += 1 time.sleep(1) if sanity_count >= 10: raise ValueError('Thread did not run and block') # Check the person hasn't been updated. Since this isn't # using FOR UPDATE, it won't block. p = Person.objects.get(pk=self.person.pk) self.assertEqual('Reinhardt', p.name) # When we end our blocking transaction, our thread should # be able to continue. self.end_blocking_transaction() thread.join(5.0) # Check the thread has finished. Assuming it has, we should # find that it has updated the person's name. self.assertFalse(thread.isAlive()) # We must commit the transaction to ensure that MySQL gets a fresh read, # since by default it runs in REPEATABLE READ mode transaction.commit() p = Person.objects.get(pk=self.person.pk) self.assertEqual('Fred', p.name)
def setUp(self): transaction.enter_transaction_management(True) transaction.managed(True) self.person = Person.objects.create(name='Reinhardt') # We have to commit here so that code in run_select_for_update can # see this data. transaction.commit() # We need another database connection to test that one connection # issuing a SELECT ... FOR UPDATE will block. new_connections = ConnectionHandler(settings.DATABASES) self.new_connection = new_connections[DEFAULT_DB_ALIAS] self.new_connection.enter_transaction_management() self.new_connection.managed(True) # We need to set settings.DEBUG to True so we can capture # the output SQL to examine. self._old_debug = settings.DEBUG settings.DEBUG = True
def test_concurrent_delete(self): "Deletes on concurrent transactions don't collide and lock the database. Regression for #9479" # Create some dummy data b1 = Book(id=1, pagecount=100) b2 = Book(id=2, pagecount=200) b3 = Book(id=3, pagecount=300) b1.save() b2.save() b3.save() transaction.commit() self.assertEqual(3, Book.objects.count()) # Delete something using connection 2. cursor2 = self.conn2.cursor() cursor2.execute('DELETE from delete_regress_book WHERE id=1') self.conn2._commit() # Now perform a queryset delete that covers the object # deleted in connection 2. This causes an infinite loop # under MySQL InnoDB unless we keep track of already # deleted objects. Book.objects.filter(pagecount__lt=250).delete() transaction.commit() self.assertEqual(1, Book.objects.count()) transaction.commit()
def test_forward_refs(self): """ Tests that objects ids can be referenced before they are defined in the serialization data. """ # The deserialization process needs to be contained # within a transaction in order to test forward reference # handling. transaction.enter_transaction_management() transaction.managed(True) objs = serializers.deserialize(self.serializer_name, self.fwd_ref_str) with connection.constraint_checks_disabled(): for obj in objs: obj.save() transaction.commit() transaction.leave_transaction_management() for model_cls in (Category, Author, Article): self.assertEqual(model_cls.objects.all().count(), 1) art_obj = Article.objects.all()[0] self.assertEqual(art_obj.categories.all().count(), 1) self.assertEqual(art_obj.author.name, "Agnes")
def fake_committer(): "Query, commit, then query again, leaving with a pending transaction" _ = Mod.objects.count() transaction.commit() _ = Mod.objects.count()
def committer(): """ Perform a database query, then commit the transaction """ _ = Mod.objects.count() transaction.commit()
def handle(self, *fixture_labels, **options): using = options.get('database') connection = connections[using] if not len(fixture_labels): raise CommandError( "No database fixture specified. Please provide the path of at " "least one fixture in the command line." ) verbosity = int(options.get('verbosity')) show_traceback = options.get('traceback') # commit is a stealth option - it isn't really useful as # a command line option, but it can be useful when invoking # loaddata from within another script. # If commit=True, loaddata will use its own transaction; # if commit=False, the data load SQL will become part of # the transaction in place when loaddata was invoked. commit = options.get('commit', True) # Keep a count of the installed objects and fixtures fixture_count = 0 loaded_object_count = 0 fixture_object_count = 0 models = set() humanize = lambda dirname: "'%s'" % dirname if dirname else 'absolute path' # Get a cursor (even though we don't need one yet). This has # the side effect of initializing the test database (if # it isn't already initialized). cursor = connection.cursor() # Start transaction management. All fixtures are installed in a # single transaction to ensure that all references are resolved. if commit: transaction.commit_unless_managed(using=using) transaction.enter_transaction_management(using=using) transaction.managed(True, using=using) class SingleZipReader(zipfile.ZipFile): def __init__(self, *args, **kwargs): zipfile.ZipFile.__init__(self, *args, **kwargs) if settings.DEBUG: assert len(self.namelist()) == 1, "Zip-compressed fixtures must contain only one file." def read(self): return zipfile.ZipFile.read(self, self.namelist()[0]) compression_types = { None: open, 'gz': gzip.GzipFile, 'zip': SingleZipReader } if has_bz2: compression_types['bz2'] = bz2.BZ2File app_module_paths = [] for app in get_apps(): if hasattr(app, '__path__'): # It's a 'models/' subpackage for path in app.__path__: app_module_paths.append(path) else: # It's a models.py module app_module_paths.append(app.__file__) app_fixtures = [os.path.join(os.path.dirname(path), 'fixtures') for path in app_module_paths] try: with connection.constraint_checks_disabled(): for fixture_label in fixture_labels: parts = fixture_label.split('.') if len(parts) > 1 and parts[-1] in compression_types: compression_formats = [parts[-1]] parts = parts[:-1] else: compression_formats = compression_types.keys() if len(parts) == 1: fixture_name = parts[0] formats = serializers.get_public_serializer_formats() else: fixture_name, format = '.'.join(parts[:-1]), parts[-1] if format in serializers.get_public_serializer_formats(): formats = [format] else: formats = [] if formats: if verbosity >= 2: self.stdout.write("Loading '%s' fixtures..." % fixture_name) else: raise CommandError( "Problem installing fixture '%s': %s is not a known serialization format." % (fixture_name, format)) if os.path.isabs(fixture_name): fixture_dirs = [fixture_name] else: fixture_dirs = app_fixtures + list(settings.FIXTURE_DIRS) + [''] for fixture_dir in fixture_dirs: if verbosity >= 2: self.stdout.write("Checking %s for fixtures..." % humanize(fixture_dir)) label_found = False for combo in product([using, None], formats, compression_formats): database, format, compression_format = combo file_name = '.'.join( p for p in [ fixture_name, database, format, compression_format ] if p ) if verbosity >= 3: self.stdout.write("Trying %s for %s fixture '%s'..." % \ (humanize(fixture_dir), file_name, fixture_name)) full_path = os.path.join(fixture_dir, file_name) open_method = compression_types[compression_format] try: fixture = open_method(full_path, 'r') except IOError: if verbosity >= 2: self.stdout.write("No %s fixture '%s' in %s." % \ (format, fixture_name, humanize(fixture_dir))) else: try: if label_found: raise CommandError("Multiple fixtures named '%s' in %s. Aborting." % (fixture_name, humanize(fixture_dir))) fixture_count += 1 objects_in_fixture = 0 loaded_objects_in_fixture = 0 if verbosity >= 2: self.stdout.write("Installing %s fixture '%s' from %s." % \ (format, fixture_name, humanize(fixture_dir))) objects = serializers.deserialize(format, fixture, using=using) for obj in objects: objects_in_fixture += 1 if router.allow_syncdb(using, obj.object.__class__): loaded_objects_in_fixture += 1 models.add(obj.object.__class__) try: obj.save(using=using) except (DatabaseError, IntegrityError) as e: e.args = ("Could not load %(app_label)s.%(object_name)s(pk=%(pk)s): %(error_msg)s" % { 'app_label': obj.object._meta.app_label, 'object_name': obj.object._meta.object_name, 'pk': obj.object.pk, 'error_msg': force_text(e) },) raise loaded_object_count += loaded_objects_in_fixture fixture_object_count += objects_in_fixture label_found = True except Exception as e: if not isinstance(e, CommandError): e.args = ("Problem installing fixture '%s': %s" % (full_path, e),) raise finally: fixture.close() # If the fixture we loaded contains 0 objects, assume that an # error was encountered during fixture loading. if objects_in_fixture == 0: raise CommandError( "No fixture data found for '%s'. (File format may be invalid.)" % (fixture_name)) # Since we disabled constraint checks, we must manually check for # any invalid keys that might have been added table_names = [model._meta.db_table for model in models] try: connection.check_constraints(table_names=table_names) except Exception as e: e.args = ("Problem installing fixtures: %s" % e,) raise except (SystemExit, KeyboardInterrupt): raise except Exception as e: if commit: transaction.rollback(using=using) transaction.leave_transaction_management(using=using) raise # If we found even one object in a fixture, we need to reset the # database sequences. if loaded_object_count > 0: sequence_sql = connection.ops.sequence_reset_sql(no_style(), models) if sequence_sql: if verbosity >= 2: self.stdout.write("Resetting sequences\n") for line in sequence_sql: cursor.execute(line) if commit: transaction.commit(using=using) transaction.leave_transaction_management(using=using) if verbosity >= 1: if fixture_object_count == loaded_object_count: self.stdout.write("Installed %d object(s) from %d fixture(s)" % ( loaded_object_count, fixture_count)) else: self.stdout.write("Installed %d object(s) (of %d) from %d fixture(s)" % ( loaded_object_count, fixture_object_count, fixture_count)) # Close the DB connection. This is required as a workaround for an # edge case in MySQL: if the same connection is used to # create tables, load data, and query, the query can return # incorrect results. See Django #7572, MySQL #37735. if commit: connection.close()
def manually_managed(self): r = Reporter(first_name="Dirk", last_name="Gently") r.save() transaction.commit()