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()
