This is a modification of Django 1.3's transaction.commit_on_success() decorator and context manager. It's inspired by snippet 1343 which unfortunately don't work in current Django neither as a context manager.
In my junior projects it works fine but I've not tested in critical projects yet! YMMV !
How it works: it simply counts the nesting level and does the real transaction enter/exit only on first call and last call respectively (code copied from Django's commit_on_success() ). It use thread local storage to save the per-thread nesting level count safely.
To use it just put the code in a file (i.e. nested_commit_on_success.py) and import and use it exacly as normal commit_on_success(), both as decorator (@nested_commit_success) or context manager (with nested_commit_on_success(): ).
Any feedback is welcome!
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 | from django.db.transaction import managed, enter_transaction_management, is_dirty, rollback, commit, leave_transaction_management, _transaction_func
import threading
# storage of nested count
_tl = threading.local()
def nested_commit_on_success(using=None):
def entering(using):
lev = getattr(_tl,"level",0)
lev += 1
_tl.level = lev
if lev >= 2: # is it nested ?
return # yes it's nested, do nothing
else:
# first time, enter transaction
enter_transaction_management(using=using)
managed(True, using=using)
def exiting(exc_value, using):
lev = _tl.level
_tl.level -= 1
if lev >= 2: # is it nested ?
return # yes, do nothing
# last time, must do correct transaction ending
try:
if exc_value is not None:
if is_dirty(using=using):
rollback(using=using)
else:
if is_dirty(using=using):
try:
commit(using=using)
except:
rollback(using=using)
raise
finally:
leave_transaction_management(using=using)
return _transaction_func(entering, exiting, using)
|
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