def commit_on_success_unless_managed(using=None, savepoint=False, connection=None):
"""
Transitory API to preserve backwards-compatibility while refactoring.
Once the legacy transaction management is fully deprecated, this should
simply be replaced by atomic. Until then, it's necessary to guarantee that
a commit occurs on exit, which atomic doesn't do when it's nested.
Unlike atomic, savepoint defaults to False because that's closer to the
legacy behavior.
"""
if not connection:
assert not using_gevent()
connection = connection or get_connection(using)
if connection.get_autocommit() or connection.in_atomic_block:
return atomic(using, savepoint, connection=connection)
else:
def entering(using, connection=None):
pass
def exiting(exc_type, using, connection):
set_dirty(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def _transaction_func(entering, exiting, using, connection=None):
"""
Takes 3 things, an entering function (what to do to start this block of
transaction management), an exiting function (what to do to end it, on both
success and failure, and using which can be: None, indicating using is
DEFAULT_DB_ALIAS, a callable, indicating that using is DEFAULT_DB_ALIAS and
to return the function already wrapped.
Returns either a Transaction objects, which is both a decorator and a
context manager, or a wrapped function, if using is a callable.
"""
# Note that although the first argument is *called* `using`, it
# may actually be a function; @autocommit and @autocommit('foo')
# are both allowed forms.
# TODO:
if not connection:
assert not using_gevent()
if using is None:
using = DEFAULT_DB_ALIAS
if callable(using):
return Transaction(entering,
exiting,
DEFAULT_DB_ALIAS,
connection=connection)(using)
return Transaction(entering, exiting, using, connection=connection)
def commit_on_success(using=None, connection=None):
"""
This decorator activates commit on response. This way, if the view function
runs successfully, a commit is made; if the viewfunc produces an exception,
a rollback is made. This is one of the most common ways to do transaction
control in Web apps.
"""
warnings.warn("commit_on_success is deprecated in favor of atomic.",
RemovedInDjango18Warning,
stacklevel=2)
if not connection:
assert not using_gevent()
def entering(using, connection=None):
enter_transaction_management(using=using, connection=connection)
def exiting(exc_type, using, connection=None):
try:
if exc_type is not None:
if is_dirty(using=using, connection=connection):
rollback(using=using, connection=connection)
else:
if is_dirty(using=using, connection=connection):
try:
commit(using=using, connection=connection)
except:
rollback(using=using, connection=connection)
raise
finally:
leave_transaction_management(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def commit_on_success_unless_managed(using=None,
savepoint=False,
connection=None):
"""
Transitory API to preserve backwards-compatibility while refactoring.
Once the legacy transaction management is fully deprecated, this should
simply be replaced by atomic. Until then, it's necessary to guarantee that
a commit occurs on exit, which atomic doesn't do when it's nested.
Unlike atomic, savepoint defaults to False because that's closer to the
legacy behavior.
"""
if not connection:
assert not using_gevent()
connection = connection or get_connection(using)
if connection.get_autocommit() or connection.in_atomic_block:
return atomic(using, savepoint, connection=connection)
else:
def entering(using, connection=None):
pass
def exiting(exc_type, using, connection):
set_dirty(using=using, connection=connection)
return _transaction_func(entering,
exiting,
using,
connection=connection)
def commit_on_success(using=None, connection=None):
"""
This decorator activates commit on response. This way, if the view function
runs successfully, a commit is made; if the viewfunc produces an exception,
a rollback is made. This is one of the most common ways to do transaction
control in Web apps.
"""
warnings.warn("commit_on_success is deprecated in favor of atomic.", RemovedInDjango18Warning, stacklevel=2)
if not connection:
assert not using_gevent()
def entering(using, connection=None):
enter_transaction_management(using=using, connection=connection)
def exiting(exc_type, using, connection=None):
try:
if exc_type is not None:
if is_dirty(using=using, connection=connection):
rollback(using=using, connection=connection)
else:
if is_dirty(using=using, connection=connection):
try:
commit(using=using, connection=connection)
except:
rollback(using=using, connection=connection)
raise
finally:
leave_transaction_management(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def get_autocommit(using=None, connection=None):
"""
Get the autocommit status of the connection.
"""
if connection:
connection.get_autocommit()
else:
assert not using_gevent()
return get_connection(using).get_autocommit()
def rollback(using=None, connection=None):
"""
Rolls back a transaction and resets the dirty flag.
"""
if connection:
connection.rollback()
else:
assert not using_gevent()
get_connection(using).rollback()
def clean_savepoints(using=None, connection=None):
"""
Resets the counter used to generate unique savepoint ids in this thread.
"""
if connection:
connection.clean_savepoints()
else:
assert not using_gevent()
get_connection(using).clean_savepoints()
def get_rollback(using=None, connection=None):
"""
Gets the "needs rollback" flag -- for *advanced use* only.
"""
if connection:
connection.get_rollback()
else:
assert not using_gevent()
return get_connection(using).get_rollback()
def clean_savepoints(using=None, connection=None):
"""
Resets the counter used to generate unique savepoint ids in this thread.
"""
if connection:
connection.clean_savepoints()
else:
assert not using_gevent()
get_connection(using).clean_savepoints()
def get_rollback(using=None, connection=None):
"""
Gets the "needs rollback" flag -- for *advanced use* only.
"""
if connection:
connection.get_rollback()
else:
assert not using_gevent()
return get_connection(using).get_rollback()
def rollback(using=None, connection=None):
"""
Rolls back a transaction and resets the dirty flag.
"""
if connection:
connection.rollback()
else:
assert not using_gevent()
get_connection(using).rollback()
def get_autocommit(using=None, connection=None):
"""
Get the autocommit status of the connection.
"""
if connection:
connection.get_autocommit()
else:
assert not using_gevent()
return get_connection(using).get_autocommit()
def get_connection(using=None):
"""
Get a database connection by name, or the default database connection
if no name is provided.
"""
assert not using_gevent()
if using is None:
using = DEFAULT_DB_ALIAS
return connections[using]
def savepoint_commit(sid, using=None, connection=None):
"""
Commits the most recent savepoint (if one exists). Does nothing if
savepoints are not supported.
"""
if connection:
connection.savepoint_commit(sid)
else:
assert not using_gevent()
get_connection(using).savepoint_commit(sid)
def is_dirty(using=None, connection=None):
"""
Returns True if the current transaction requires a commit for changes to
happen.
"""
if connection:
connection.is_dirty()
else:
assert not using_gevent()
return get_connection(using).is_dirty()
def is_dirty(using=None, connection=None):
"""
Returns True if the current transaction requires a commit for changes to
happen.
"""
if connection:
connection.is_dirty()
else:
assert not using_gevent()
return get_connection(using).is_dirty()
def get_connection(using=None):
"""
Get a database connection by name, or the default database connection
if no name is provided.
"""
assert not using_gevent()
if using is None:
using = DEFAULT_DB_ALIAS
return connections[using]
def savepoint_commit(sid, using=None, connection=None):
"""
Commits the most recent savepoint (if one exists). Does nothing if
savepoints are not supported.
"""
if connection:
connection.savepoint_commit(sid)
else:
assert not using_gevent()
get_connection(using).savepoint_commit(sid)
def leave_transaction_management(using=None, connection=None):
"""
Leaves transaction management for a running thread. A dirty flag is carried
over to the surrounding block, as a commit will commit all changes, even
those from outside. (Commits are on connection level.)
"""
if connection:
connection.leave_transaction_management()
else:
assert not using_gevent()
get_connection(using).leave_transaction_management()
def set_clean(using=None, connection=None):
"""
Resets a dirty flag for the current thread and code streak. This can be used
to decide in a managed block of code to decide whether a commit or rollback
should happen.
"""
if connection:
connection.set_clean()
else:
assert not using_gevent()
get_connection(using).set_clean()
def savepoint(using=None, connection=None):
"""
Creates a savepoint (if supported and required by the backend) inside the
current transaction. Returns an identifier for the savepoint that will be
used for the subsequent rollback or commit.
"""
if connection:
connection.savepoint()
else:
assert not using_gevent()
return get_connection(using).savepoint()
def set_clean(using=None, connection=None):
"""
Resets a dirty flag for the current thread and code streak. This can be used
to decide in a managed block of code to decide whether a commit or rollback
should happen.
"""
if connection:
connection.set_clean()
else:
assert not using_gevent()
get_connection(using).set_clean()
def set_dirty(using=None, connection=None):
"""
Sets a dirty flag for the current thread and code streak. This can be used
to decide in a managed block of code to decide whether there are open
changes waiting for commit.
"""
if connection:
connection.set_dirty()
else:
assert not using_gevent()
get_connection(using).set_dirty()
def set_dirty(using=None, connection=None):
"""
Sets a dirty flag for the current thread and code streak. This can be used
to decide in a managed block of code to decide whether there are open
changes waiting for commit.
"""
if connection:
connection.set_dirty()
else:
assert not using_gevent()
get_connection(using).set_dirty()
def leave_transaction_management(using=None, connection=None):
"""
Leaves transaction management for a running thread. A dirty flag is carried
over to the surrounding block, as a commit will commit all changes, even
those from outside. (Commits are on connection level.)
"""
if connection:
connection.leave_transaction_management()
else:
assert not using_gevent()
get_connection(using).leave_transaction_management()
def savepoint(using=None, connection=None):
"""
Creates a savepoint (if supported and required by the backend) inside the
current transaction. Returns an identifier for the savepoint that will be
used for the subsequent rollback or commit.
"""
if connection:
connection.savepoint()
else:
assert not using_gevent()
return get_connection(using).savepoint()
def atomic(using=None, savepoint=True, connection=None):
# Bare decorator: @atomic -- although the first argument is called
# `using`, it's actually the function being decorated.
# @atomic
if callable(using):
# 在使用gevent时，connection是动态获取的，因此不能直接使用 @atomic
assert not using_gevent()
return Atomic(DEFAULT_DB_ALIAS, savepoint)(using)
# Decorator: @atomic(...) or context manager: with atomic(...): ...
else:
# with atomic(conneciton=xxx)
return Atomic(using, savepoint, connection=connection)
def atomic(using=None, savepoint=True, connection=None):
# Bare decorator: @atomic -- although the first argument is called
# `using`, it's actually the function being decorated.
# @atomic
if callable(using):
# 在使用gevent时，connection是动态获取的，因此不能直接使用 @atomic
assert not using_gevent()
return Atomic(DEFAULT_DB_ALIAS, savepoint)(using)
# Decorator: @atomic(...) or context manager: with atomic(...): ...
else:
# with atomic(conneciton=xxx)
return Atomic(using, savepoint, connection=connection)
def commit(using=None, connection=None):
"""
Commits a transaction and resets the dirty flag.
"""
from django.db.backends import BaseDatabaseWrapper
if isinstance(using, BaseDatabaseWrapper):
connection = using
using = None
if connection:
connection.commit()
else:
assert not using_gevent()
get_connection(using).commit()
def commit(using=None, connection=None):
"""
Commits a transaction and resets the dirty flag.
"""
from django.db.backends import BaseDatabaseWrapper
if isinstance(using, BaseDatabaseWrapper):
connection = using
using = None
if connection:
connection.commit()
else:
assert not using_gevent()
get_connection(using).commit()
def enter_transaction_management(managed=True, using=None, forced=False, connection=None):
"""
Enters transaction management for a running thread. It must be balanced with
the appropriate leave_transaction_management call, since the actual state is
managed as a stack.
The state and dirty flag are carried over from the surrounding block or
from the settings, if there is no surrounding block (dirty is always false
when no current block is running).
"""
if connection:
connection.enter_transaction_management(managed, forced)
else:
assert not using_gevent()
get_connection(using).enter_transaction_management(managed, forced)
def set_autocommit(autocommit, using=None, connection=None):
"""
Set the autocommit status of the connection.
"""
# set_autocommit(True, connection)
from django.db.backends import BaseDatabaseWrapper
if isinstance(using, BaseDatabaseWrapper):
connection = using
using = None
if connection:
connection.set_autocommit(autocommit)
else:
assert not using_gevent()
return get_connection(using).set_autocommit(autocommit)
def set_autocommit(autocommit, using=None, connection=None):
"""
Set the autocommit status of the connection.
"""
# set_autocommit(True, connection)
from django.db.backends import BaseDatabaseWrapper
if isinstance(using, BaseDatabaseWrapper):
connection = using
using = None
if connection:
connection.set_autocommit(autocommit)
else:
assert not using_gevent()
return get_connection(using).set_autocommit(autocommit)
def abort(using=None, connection=None):
"""
Roll back any ongoing transactions and clean the transaction management
state of the connection.
This method is to be used only in cases where using balanced
leave_transaction_management() calls isn't possible. For example after a
request has finished, the transaction state isn't known, yet the connection
must be cleaned up for the next request.
"""
# 清空状态
if connection:
connection.abort()
else:
assert not using_gevent()
get_connection(using).abort()
def abort(using=None, connection=None):
"""
Roll back any ongoing transactions and clean the transaction management
state of the connection.
This method is to be used only in cases where using balanced
leave_transaction_management() calls isn't possible. For example after a
request has finished, the transaction state isn't known, yet the connection
must be cleaned up for the next request.
"""
# 清空状态
if connection:
connection.abort()
else:
assert not using_gevent()
get_connection(using).abort()
def set_rollback(rollback, using=None, connection=None):
"""
Sets or unsets the "needs rollback" flag -- for *advanced use* only.
When `rollback` is `True`, it triggers a rollback when exiting the
innermost enclosing atomic block that has `savepoint=True` (that's the
default). Use this to force a rollback without raising an exception.
When `rollback` is `False`, it prevents such a rollback. Use this only
after rolling back to a known-good state! Otherwise, you break the atomic
block and data corruption may occur.
"""
if connection:
connection.set_rollback(rollback)
else:
assert not using_gevent()
return get_connection(using).set_rollback(rollback)
def set_rollback(rollback, using=None, connection=None):
"""
Sets or unsets the "needs rollback" flag -- for *advanced use* only.
When `rollback` is `True`, it triggers a rollback when exiting the
innermost enclosing atomic block that has `savepoint=True` (that's the
default). Use this to force a rollback without raising an exception.
When `rollback` is `False`, it prevents such a rollback. Use this only
after rolling back to a known-good state! Otherwise, you break the atomic
block and data corruption may occur.
"""
if connection:
connection.set_rollback(rollback)
else:
assert not using_gevent()
return get_connection(using).set_rollback(rollback)
def enter_transaction_management(managed=True,
using=None,
forced=False,
connection=None):
"""
Enters transaction management for a running thread. It must be balanced with
the appropriate leave_transaction_management call, since the actual state is
managed as a stack.
The state and dirty flag are carried over from the surrounding block or
from the settings, if there is no surrounding block (dirty is always false
when no current block is running).
"""
if connection:
connection.enter_transaction_management(managed, forced)
else:
assert not using_gevent()
get_connection(using).enter_transaction_management(managed, forced)
def autocommit(using=None, connection=None):
"""
Decorator that activates commit on save. This is Django's default behavior;
this decorator is useful if you globally activated transaction management in
your settings file and want the default behavior in some view functions.
"""
warnings.warn("autocommit is deprecated in favor of set_autocommit.",
RemovedInDjango18Warning, stacklevel=2)
# 如果使用gevent, 则不允许直接使用 @autocommit
if not connection:
assert not using_gevent()
def entering(using, connection = None):
enter_transaction_management(managed=False, using=using, connection=connection)
def exiting(exc_type, using, connection = None):
leave_transaction_management(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def commit_manually(using=None, connection=None):
"""
Decorator that activates manual transaction control. It just disables
automatic transaction control and doesn't do any commit/rollback of its
own -- it's up to the user to call the commit and rollback functions
themselves.
"""
warnings.warn("commit_manually is deprecated in favor of set_autocommit.",
RemovedInDjango18Warning, stacklevel=2)
if not connection:
assert not using_gevent()
def entering(using, connection):
enter_transaction_management(using=using, connection=connection)
def exiting(exc_type, using, connection):
leave_transaction_management(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def commit_manually(using=None, connection=None):
"""
Decorator that activates manual transaction control. It just disables
automatic transaction control and doesn't do any commit/rollback of its
own -- it's up to the user to call the commit and rollback functions
themselves.
"""
warnings.warn("commit_manually is deprecated in favor of set_autocommit.",
RemovedInDjango18Warning,
stacklevel=2)
if not connection:
assert not using_gevent()
def entering(using, connection):
enter_transaction_management(using=using, connection=connection)
def exiting(exc_type, using, connection):
leave_transaction_management(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def _transaction_func(entering, exiting, using, connection=None):
"""
Takes 3 things, an entering function (what to do to start this block of
transaction management), an exiting function (what to do to end it, on both
success and failure, and using which can be: None, indicating using is
DEFAULT_DB_ALIAS, a callable, indicating that using is DEFAULT_DB_ALIAS and
to return the function already wrapped.
Returns either a Transaction objects, which is both a decorator and a
context manager, or a wrapped function, if using is a callable.
"""
# Note that although the first argument is *called* `using`, it
# may actually be a function; @autocommit and @autocommit('foo')
# are both allowed forms.
# TODO:
if not connection:
assert not using_gevent()
if using is None:
using = DEFAULT_DB_ALIAS
if callable(using):
return Transaction(entering, exiting, DEFAULT_DB_ALIAS, connection=connection)(using)
return Transaction(entering, exiting, using, connection=connection)
def autocommit(using=None, connection=None):
"""
Decorator that activates commit on save. This is Django's default behavior;
this decorator is useful if you globally activated transaction management in
your settings file and want the default behavior in some view functions.
"""
warnings.warn("autocommit is deprecated in favor of set_autocommit.",
RemovedInDjango18Warning,
stacklevel=2)
# 如果使用gevent, 则不允许直接使用 @autocommit
if not connection:
assert not using_gevent()
def entering(using, connection=None):
enter_transaction_management(managed=False,
using=using,
connection=connection)
def exiting(exc_type, using, connection=None):
leave_transaction_management(using=using, connection=connection)
return _transaction_func(entering, exiting, using, connection=connection)
def __init__(self, using, savepoint, connection=None):
self.using = using
self.savepoint = savepoint
assert connection or (not using_gevent())
self.connection = connection
def __init__(self, using, savepoint, connection=None):
self.using = using
self.savepoint = savepoint
assert connection or (not using_gevent())
self.connection = connection
