Commit on success unless managed decorator

try:
    from functools import wraps
except ImportError:
    from django.utils.functional import wraps  # Python 2.3, 2.4 fallback.
from django.db import transaction
def commit_on_success_unless_managed(func):
    """
    If the decorated function runs successfully, a commit is made, unless the
    transactions are being managed; if the function produces an exception,
    a rollback is made, again unless transactions are being managed somewhere
    else.
    """
    def _commit_on_success_unless_managed(*args, **kw):
        try:
            if transaction.is_managed():
                forced_managed = False
            else:
                transaction.enter_transaction_management()
                forced_managed = True
            
            try:
                res = func(*args, **kw)
            except:
                # All exceptions must be handled here (even string ones).
                if transaction.is_dirty():
                    if forced_managed:
                        transaction.rollback()
                    else:
                        transaction.rollback_unless_managed()
                raise
            else:
                if transaction.is_dirty():
                    if forced_managed:
                        transaction.commit()
                    else:
                        transaction.commit_unless_managed()
            return res
        finally:
            if forced_managed:
                transaction.leave_transaction_management()
    return wraps(func)(_commit_on_success_unless_managed)