130 lines
4.4 KiB
Python
130 lines
4.4 KiB
Python
"""Tests for util.db module."""
|
|
|
|
import ddt
|
|
import threading
|
|
import time
|
|
import unittest
|
|
|
|
from django.contrib.auth.models import User
|
|
from django.db import connection, IntegrityError
|
|
from django.db.transaction import commit_on_success, TransactionManagementError
|
|
from django.test import TestCase, TransactionTestCase
|
|
|
|
from util.db import commit_on_success_with_read_committed, generate_int_id
|
|
|
|
|
|
@ddt.ddt
|
|
class TransactionIsolationLevelsTestCase(TransactionTestCase):
|
|
"""
|
|
Tests the effects of changing transaction isolation level to READ COMMITTED instead of REPEATABLE READ.
|
|
|
|
Note: This TestCase only works with MySQL.
|
|
|
|
To run it on devstack:
|
|
1. Add TEST_RUNNER = 'django_nose.NoseTestSuiteRunner' to envs/devstack.py
|
|
2. Run "./manage.py lms --settings=devstack test util.tests.test_db"
|
|
"""
|
|
|
|
@ddt.data(
|
|
(commit_on_success, IntegrityError, None, True),
|
|
(commit_on_success_with_read_committed, type(None), False, True),
|
|
)
|
|
@ddt.unpack
|
|
def test_concurrent_requests(self, transaction_decorator, exception_class, created_in_1, created_in_2):
|
|
"""
|
|
Test that when isolation level is set to READ COMMITTED get_or_create()
|
|
for the same row in concurrent requests does not raise an IntegrityError.
|
|
"""
|
|
|
|
if connection.vendor != 'mysql':
|
|
raise unittest.SkipTest('Only works on MySQL.')
|
|
|
|
class RequestThread(threading.Thread):
|
|
""" A thread which runs a dummy view."""
|
|
def __init__(self, delay, **kwargs):
|
|
super(RequestThread, self).__init__(**kwargs)
|
|
self.delay = delay
|
|
self.status = {}
|
|
|
|
@transaction_decorator
|
|
def run(self):
|
|
"""A dummy view."""
|
|
try:
|
|
try:
|
|
User.objects.get(username='student', email='student@edx.org')
|
|
except User.DoesNotExist:
|
|
pass
|
|
else:
|
|
raise AssertionError('Did not raise User.DoesNotExist.')
|
|
|
|
if self.delay > 0:
|
|
time.sleep(self.delay)
|
|
|
|
__, created = User.objects.get_or_create(username='student', email='student@edx.org')
|
|
except Exception as exception: # pylint: disable=broad-except
|
|
self.status['exception'] = exception
|
|
else:
|
|
self.status['created'] = created
|
|
|
|
thread1 = RequestThread(delay=1)
|
|
thread2 = RequestThread(delay=0)
|
|
|
|
thread1.start()
|
|
thread2.start()
|
|
thread2.join()
|
|
thread1.join()
|
|
|
|
self.assertIsInstance(thread1.status.get('exception'), exception_class)
|
|
self.assertEqual(thread1.status.get('created'), created_in_1)
|
|
|
|
self.assertIsNone(thread2.status.get('exception'))
|
|
self.assertEqual(thread2.status.get('created'), created_in_2)
|
|
|
|
def test_transaction_nesting(self):
|
|
"""Test that the decorator raises an error if there are already more than 1 levels of nested transactions."""
|
|
|
|
if connection.vendor != 'mysql':
|
|
raise unittest.SkipTest('Only works on MySQL.')
|
|
|
|
def do_nothing():
|
|
"""Just return."""
|
|
return
|
|
|
|
commit_on_success_with_read_committed(do_nothing)()
|
|
|
|
with commit_on_success():
|
|
commit_on_success_with_read_committed(do_nothing)()
|
|
|
|
with self.assertRaises(TransactionManagementError):
|
|
with commit_on_success():
|
|
with commit_on_success():
|
|
commit_on_success_with_read_committed(do_nothing)()
|
|
|
|
|
|
@ddt.ddt
|
|
class GenerateIntIdTestCase(TestCase):
|
|
"""Tests for `generate_int_id`"""
|
|
@ddt.data(10)
|
|
def test_no_used_ids(self, times):
|
|
"""
|
|
Verify that we get a random integer within the specified range
|
|
when there are no used ids.
|
|
"""
|
|
minimum = 1
|
|
maximum = times
|
|
for i in range(times):
|
|
self.assertIn(generate_int_id(minimum, maximum), range(minimum, maximum + 1))
|
|
|
|
@ddt.data(10)
|
|
def test_used_ids(self, times):
|
|
"""
|
|
Verify that we get a random integer within the specified range
|
|
but not in a list of used ids.
|
|
"""
|
|
minimum = 1
|
|
maximum = times
|
|
used_ids = {2, 4, 6, 8}
|
|
for i in range(times):
|
|
int_id = generate_int_id(minimum, maximum, used_ids)
|
|
self.assertIn(int_id, list(set(range(minimum, maximum + 1)) - used_ids))
|