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import testbase
import sys, weakref
from sqlalchemy import create_engine, exceptions
from testlib import *
class MockDisconnect(Exception):
pass
class MockDBAPI(object):
def __init__(self):
self.paramstyle = 'named'
self.connections = weakref.WeakKeyDictionary()
def connect(self, *args, **kwargs):
return MockConnection(self)
def shutdown(self):
for c in self.connections:
c.explode[0] = True
Error = MockDisconnect
class MockConnection(object):
def __init__(self, dbapi):
dbapi.connections[self] = True
self.explode = [False]
def rollback(self):
pass
def commit(self):
pass
def cursor(self):
return MockCursor(self)
def close(self):
pass
class MockCursor(object):
def __init__(self, parent):
self.explode = parent.explode
self.description = None
def execute(self, *args, **kwargs):
if self.explode[0]:
raise MockDisconnect("Lost the DB connection")
else:
return
def close(self):
pass
class MockReconnectTest(PersistTest):
def setUp(self):
global db, dbapi
dbapi = MockDBAPI()
# create engine using our current dburi
db = create_engine('postgres://foo:bar@localhost/test', module=dbapi)
# monkeypatch disconnect checker
db.dialect.is_disconnect = lambda e: isinstance(e, MockDisconnect)
def test_reconnect(self):
"""test that an 'is_disconnect' condition will invalidate the connection, and additionally
dispose the previous connection pool and recreate."""
pid = id(db.pool)
# make a connection
conn = db.connect()
# connection works
conn.execute("SELECT 1")
# create a second connection within the pool, which we'll ensure also goes away
conn2 = db.connect()
conn2.close()
# two connections opened total now
assert len(dbapi.connections) == 2
# set it to fail
dbapi.shutdown()
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError:
pass
# assert was invalidated
assert not conn.closed
assert conn.invalidated
# close shouldnt break
conn.close()
assert id(db.pool) != pid
# ensure all connections closed (pool was recycled)
assert len(dbapi.connections) == 0
conn =db.connect()
conn.execute("SELECT 1")
conn.close()
assert len(dbapi.connections) == 1
def test_invalidate_trans(self):
conn = db.connect()
trans = conn.begin()
dbapi.shutdown()
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError:
pass
# assert was invalidated
assert len(dbapi.connections) == 0
assert not conn.closed
assert conn.invalidated
assert trans.is_active
try:
conn.execute("SELECT 1")
assert False
except exceptions.InvalidRequestError, e:
assert str(e) == "Can't reconnect until invalid transaction is rolled back"
assert trans.is_active
try:
trans.commit()
assert False
except exceptions.InvalidRequestError, e:
assert str(e) == "Can't reconnect until invalid transaction is rolled back"
assert trans.is_active
trans.rollback()
assert not trans.is_active
conn.execute("SELECT 1")
assert not conn.invalidated
assert len(dbapi.connections) == 1
def test_conn_reusable(self):
conn = db.connect()
conn.execute("SELECT 1")
assert len(dbapi.connections) == 1
dbapi.shutdown()
# raises error
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError:
pass
assert not conn.closed
assert conn.invalidated
# ensure all connections closed (pool was recycled)
assert len(dbapi.connections) == 0
# test reconnects
conn.execute("SELECT 1")
assert not conn.invalidated
assert len(dbapi.connections) == 1
class RealReconnectTest(PersistTest):
def setUp(self):
global engine
engine = engines.reconnecting_engine()
def tearDown(self):
engine.dispose()
def test_reconnect(self):
conn = engine.connect()
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
assert not conn.closed
engine.test_shutdown()
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError, e:
if not e.connection_invalidated:
raise
assert not conn.closed
assert conn.invalidated
assert conn.invalidated
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
assert not conn.invalidated
# one more time
engine.test_shutdown()
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError, e:
if not e.connection_invalidated:
raise
assert conn.invalidated
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
assert not conn.invalidated
conn.close()
def test_close(self):
conn = engine.connect()
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
assert not conn.closed
engine.test_shutdown()
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError, e:
if not e.connection_invalidated:
raise
conn.close()
conn = engine.connect()
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
def test_with_transaction(self):
conn = engine.connect()
trans = conn.begin()
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
assert not conn.closed
engine.test_shutdown()
try:
conn.execute("SELECT 1")
assert False
except exceptions.DBAPIError, e:
if not e.connection_invalidated:
raise
assert not conn.closed
assert conn.invalidated
assert trans.is_active
try:
conn.execute("SELECT 1")
assert False
except exceptions.InvalidRequestError, e:
assert str(e) == "Can't reconnect until invalid transaction is rolled back"
assert trans.is_active
try:
trans.commit()
assert False
except exceptions.InvalidRequestError, e:
assert str(e) == "Can't reconnect until invalid transaction is rolled back"
assert trans.is_active
trans.rollback()
assert not trans.is_active
assert conn.invalidated
self.assertEquals(conn.execute("SELECT 1").scalar(), 1)
assert not conn.invalidated
if __name__ == '__main__':
testbase.main()
|
