Commit 9fb66185 authored by Jeremy Hylton's avatar Jeremy Hylton

Add some simple tests of subtransactions.

parent f416526d
##############################################################################
#
# Copyright (c) 2004 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
r"""
ZODB subtransaction tests
=========================
Subtransactions are provided by a generic transaction interface, but
only supported by ZODB. These tests verify that some of the important
cases work as expected.
>>> import transaction
>>> from ZODB import DB
>>> from ZODB.tests.test_storage import MinimalMemoryStorage
>>> from ZODB.tests.MinPO import MinPO
First create a few objects in the database root with a normal commit.
We're going to make a series of modifications to these objects.
>>> db = DB(MinimalMemoryStorage())
>>> cn = db.open()
>>> rt = cn.root()
>>> def init():
... global a, b, c
... a = rt["a"] = MinPO("a0")
... b = rt["b"] = MinPO("b0")
... c = rt["c"] = MinPO("c0")
... transaction.commit()
>>> init()
We'll also open a second database connection and use it to verify that
the intermediate results of subtransactions are not visible to other
connections.
>>> cn2 = db.open(synch=False)
>>> rt2 = cn2.root()
>>> shadow_a = rt2["a"]
>>> shadow_b = rt2["b"]
>>> shadow_c = rt2["c"]
Subtransaction commit
---------------------
We'll make a series of modifications in subtransactions.
>>> a.value = "a1"
>>> b.value = "b1"
>>> transaction.commit(1)
>>> a.value, b.value
('a1', 'b1')
>>> shadow_a.value, shadow_b.value
('a0', 'b0')
>>> a.value = "a2"
>>> c.value = "c1"
>>> transaction.commit(1)
>>> a.value, c.value
('a2', 'c1')
>>> shadow_a.value, shadow_c.value
('a0', 'c0')
>>> a.value = "a3"
>>> transaction.commit(1)
>>> a.value
'a3'
>>> shadow_a.value
'a0'
>>> transaction.commit()
>>> a.value, b.value, c.value
('a3', 'b1', 'c1')
Subtransaction with nested abort
--------------------------------
>>> init()
>>> a.value = "a1"
>>> transaction.commit(1)
>>> b.value = "b1"
>>> transaction.commit(1)
A sub-transaction abort will undo current changes, reverting to the
database state as of the last sub-transaction commit. There is
(apparently) no way to abort an already-committed subtransaction.
>>> c.value = "c1"
>>> transaction.abort(1)
Multiple aborts have no extra effect.
>>> transaction.abort(1)
>>> a.value, b.value, c.value
('a1', 'b1', 'c0')
>>> transaction.commit()
>>> a.value, b.value, c.value
('a1', 'b1', 'c0')
Subtransaction with top-level abort
-----------------------------------
>>> init()
>>> a.value = "a1"
>>> transaction.commit(1)
>>> b.value = "b1"
>>> transaction.commit(1)
A sub-transaction abort will undo current changes, reverting to the
database state as of the last sub-transaction commit. There is
(apparently) no way to abort an already-committed subtransaction.
>>> c.value = "c1"
>>> transaction.abort(1)
>>> transaction.abort()
>>> a.value, b.value, c.value
('a0', 'b0', 'c0')
"""
import doctest
def test_suite():
return doctest.DocTestSuite()
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