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
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
#!/usr/bin/env python
#
# Public Domain 2014-present MongoDB, Inc.
# Public Domain 2008-2014 WiredTiger, Inc.
#
# This is free and unencumbered software released into the public domain.
#
# Anyone is free to copy, modify, publish, use, compile, sell, or
# distribute this software, either in source code form or as a compiled
# binary, for any purpose, commercial or non-commercial, and by any
# means.
#
# In jurisdictions that recognize copyright laws, the author or authors
# of this software dedicate any and all copyright interest in the
# software to the public domain. We make this dedication for the benefit
# of the public at large and to the detriment of our heirs and
# successors. We intend this dedication to be an overt act of
# relinquishment in perpetuity of all present and future rights to this
# software under copyright law.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# test_txn20.py
# Transactions: more granular testing of isolation levels
#
import wttest
from wtscenario import make_scenarios
class test_txn20(wttest.WiredTigerTestCase):
uri = 'table:test_txn'
format_values = [
('string-row', dict(key_format='S', key='key', \
value_format='S', old_value='value:old', new_value='value:new')),
('column', dict(key_format='r', key=12, \
value_format='S', old_value='value:old', new_value='value:new')),
('column-fix', dict(key_format='r', key=12, \
value_format='8t', old_value=89, new_value=167)),
]
iso_types = [
('isolation_read_uncommitted', dict(isolation='read-uncommitted')),
('isolation_read_committed', dict(isolation='read-committed')),
('isolation_snapshot', dict(isolation='snapshot'))
]
scenarios = make_scenarios(format_values, iso_types)
old_value = 'value: old'
new_value = 'value: new'
def test_isolation_level(self):
config = 'key_format={},value_format={}'.format(self.key_format, self.value_format)
self.session.create(self.uri, config)
cursor = self.session.open_cursor(self.uri, None)
cursor[self.key] = self.old_value
# Make an update and don't commit it just yet. We should see the update
# from the 'read-uncommitted' isolation level.
self.session.begin_transaction()
cursor[self.key] = self.new_value
s = self.conn.open_session()
cursor = s.open_cursor(self.uri, None)
s.begin_transaction('isolation=' + self.isolation)
if self.isolation == 'read-uncommitted':
# Unlike the 'read-committed' and 'snapshot' isolation levels, we're
# not protected from dirty reads so we'll see the update above even
# though its respective transaction has not been committed.
self.assertEqual(cursor[self.key], self.new_value)
else:
self.assertEqual(cursor[self.key], self.old_value)
# Commit the update now. We should see the update from the
# 'read-committed' and 'read-uncommitted' isolation levels.
self.session.commit_transaction()
if self.isolation == 'snapshot':
# We should never see the updates above since it wasn't committed at
# the time of the snapshot.
self.assertEqual(cursor[self.key], self.old_value)
else:
# Unlike the 'snapshot' isolation level, 'read-committed' is not
# protected from non-repeatable reads so we'll see an update
# that wasn't visible earlier in our previous read. As before,
# 'read-uncommitted' will still see the new value.
self.assertEqual(cursor[self.key], self.new_value)
if __name__ == '__main__':
wttest.run()
|
