def schedule_changed(self):
try:
# If MySQL is running with transaction isolation level
# REPEATABLE-READ (default), then we won't see changes done by
# other transactions until the current transaction is
# committed (Issue #41).
try:
transaction.commit()
except transaction.TransactionManagementError:
pass # not in transaction management.
last, ts = self._last_timestamp, self.Changes.last_change()
except DatabaseError as exc:
logger.exception('Database gave error: %r', exc)
return False
try:
if ts and ts > (last if last else ts):
return True
finally:
self._last_timestamp = ts
return False
python类TransactionManagementError()的实例源码
def validate_in_transaction(connection):
"""Ensure that `connection` is within a transaction.
This only enquires as to Django's perspective on the situation. It does
not actually check that the database agrees with Django.
:raise TransactionManagementError: If no transaction is in progress.
"""
if not in_transaction(connection):
raise TransactionManagementError(
# XXX: GavinPanella 2015-08-07 bug=1482563: This error message is
# specific to lobjects, but this lives in a general utils module.
"PostgreSQL's large object support demands that all interactions "
"are done in a transaction. Further, lobject() has been known to "
"segfault when used outside of a transaction. This assertion has "
"prevented the use of lobject() outside of a transaction. Please "
"investigate.")
def test_on_signal__no_transaction(self, partial, on_commit):
# test with signal_honor_transaction and not in transaction
event = self.mock_event('x.y', sender_field=None)
event.signal_honors_transaction = True
event._on_signal = Mock(name='_on_signal')
instance = self.Model()
on_commit.side_effect = TransactionManagementError()
assert django.TransactionManagementError is TransactionManagementError
event.on_signal(instance, kw=1)
partial.assert_called_once_with(event._on_signal, instance, {'kw': 1})
on_commit.assert_called_once_with(partial())
partial.return_value.assert_called_once_with()
def on_commit(self, fun, *args, **kwargs):
if args or kwargs:
fun = partial(fun, *args, **kwargs)
if on_commit is not None:
try:
return on_commit(fun)
except TransactionManagementError:
pass # not in transaction management, execute now.
return fun()
def get_rollback(self):
"""
Get the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
return self.needs_rollback
def set_rollback(self, rollback):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
self.needs_rollback = rollback
def validate_no_atomic_block(self):
"""
Raise an error if an atomic block is active.
"""
if self.in_atomic_block:
raise TransactionManagementError(
"This is forbidden when an 'atomic' block is active.")
def validate_no_broken_transaction(self):
if self.needs_rollback:
raise TransactionManagementError(
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block.")
# ##### Foreign key constraints checks handling #####
def on_commit(self, func):
if self.in_atomic_block:
# Transaction in progress; save for execution on commit.
self.run_on_commit.append((set(self.savepoint_ids), func))
elif not self.get_autocommit():
raise TransactionManagementError('on_commit() cannot be used in manual transaction management')
else:
# No transaction in progress and in autocommit mode; execute
# immediately.
func()
def release_lock(name):
"""
Release a lock for all. Note that the lock will be released even if it was
never acquired.
"""
# Note that in unit tests, and in case the wrapped code raises an
# IntegrityError, releasing the cache will result in a
# TransactionManagementError. This is because unit tests run inside atomic
# blocks. We cannot execute queries inside an atomic block if a transaction
# needs to be rollbacked.
try:
cache.delete(name)
except TransactionManagementError:
logger.error("Could not release lock %s", name)
def get_rollback(self):
"""
Get the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
return self.needs_rollback
def set_rollback(self, rollback):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
self.needs_rollback = rollback
def validate_no_atomic_block(self):
"""
Raise an error if an atomic block is active.
"""
if self.in_atomic_block:
raise TransactionManagementError(
"This is forbidden when an 'atomic' block is active.")
def validate_no_broken_transaction(self):
if self.needs_rollback:
raise TransactionManagementError(
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block.")
# ##### Foreign key constraints checks handling #####
def get_rollback(self):
"""
Get the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
return self.needs_rollback
def set_rollback(self, rollback):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
self.needs_rollback = rollback
def validate_no_atomic_block(self):
"""
Raise an error if an atomic block is active.
"""
if self.in_atomic_block:
raise TransactionManagementError(
"This is forbidden when an 'atomic' block is active.")
def validate_no_broken_transaction(self):
if self.needs_rollback:
raise TransactionManagementError(
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block.")
# ##### Foreign key constraints checks handling #####
def on_commit(self, func):
if self.in_atomic_block:
# Transaction in progress; save for execution on commit.
self.run_on_commit.append((set(self.savepoint_ids), func))
elif not self.get_autocommit():
raise TransactionManagementError('on_commit() cannot be used in manual transaction management')
else:
# No transaction in progress and in autocommit mode; execute
# immediately.
func()
def get_rollback(self):
"""
Get the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
return self.needs_rollback
def set_rollback(self, rollback):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
self.needs_rollback = rollback
def validate_no_atomic_block(self):
"""
Raise an error if an atomic block is active.
"""
if self.in_atomic_block:
raise TransactionManagementError(
"This is forbidden when an 'atomic' block is active.")
def validate_no_broken_transaction(self):
if self.needs_rollback:
raise TransactionManagementError(
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block.")
# ##### Foreign key constraints checks handling #####
def on_commit(self, func):
if self.in_atomic_block:
# Transaction in progress; save for execution on commit.
self.run_on_commit.append((set(self.savepoint_ids), func))
elif not self.get_autocommit():
raise TransactionManagementError('on_commit() cannot be used in manual transaction management')
else:
# No transaction in progress and in autocommit mode; execute
# immediately.
func()
def get_rollback(self):
"""
Get the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
return self.needs_rollback
def set_rollback(self, rollback):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
self.needs_rollback = rollback
def validate_no_atomic_block(self):
"""
Raise an error if an atomic block is active.
"""
if self.in_atomic_block:
raise TransactionManagementError(
"This is forbidden when an 'atomic' block is active.")
def validate_no_broken_transaction(self):
if self.needs_rollback:
raise TransactionManagementError(
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block.")
# ##### Foreign key constraints checks handling #####
def on_commit(self, func):
if self.in_atomic_block:
# Transaction in progress; save for execution on commit.
self.run_on_commit.append((set(self.savepoint_ids), func))
elif not self.get_autocommit():
raise TransactionManagementError('on_commit() cannot be used in manual transaction management')
else:
# No transaction in progress and in autocommit mode; execute
# immediately.
func()
def atomic_save(model):
try:
with transaction.atomic():
model.save()
except transaction.TransactionManagementError:
# sqlite isn't happy
model.save()
