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#!/usr/bin/env python
# test_green.py - unit test for _async wait callback
#
# Copyright (C) 2010-2011 Daniele Varrazzo <daniele.varrazzo@gmail.com>
#
# psycopg2 is free software: you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# In addition, as a special exception, the copyright holders give
# permission to link this program with the OpenSSL library (or with
# modified versions of OpenSSL that use the same license as OpenSSL),
# and distribute linked combinations including the two.
#
# You must obey the GNU Lesser General Public License in all respects for
# all of the code used other than OpenSSL.
#
# psycopg2 is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
# License for more details.
import unittest
import psycopg2
import psycopg2.extensions
import psycopg2.extras
from .testutils import ConnectingTestCase
class ConnectionStub(object):
"""A `connection` wrapper allowing analysis of the `poll()` calls."""
def __init__(self, conn):
self.conn = conn
self.polls = []
def fileno(self):
return self.conn.fileno()
def poll(self):
rv = self.conn.poll()
self.polls.append(rv)
return rv
class GreenTestCase(ConnectingTestCase):
def setUp(self):
self._cb = psycopg2.extensions.get_wait_callback()
psycopg2.extensions.set_wait_callback(psycopg2.extras.wait_select)
ConnectingTestCase.setUp(self)
def tearDown(self):
ConnectingTestCase.tearDown(self)
psycopg2.extensions.set_wait_callback(self._cb)
def set_stub_wait_callback(self, conn):
stub = ConnectionStub(conn)
psycopg2.extensions.set_wait_callback(
lambda conn: psycopg2.extras.wait_select(stub))
return stub
def test_flush_on_write(self):
# a very large query requires a flush loop to be sent to the backend
conn = self.conn
stub = self.set_stub_wait_callback(conn)
curs = conn.cursor()
for mb in 1, 5, 10, 20, 50:
size = mb * 1024 * 1024
del stub.polls[:]
curs.execute("select %s;", ('x' * size,))
self.assertEqual(size, len(curs.fetchone()[0]))
if stub.polls.count(psycopg2.extensions.POLL_WRITE) > 1:
return
# This is more a testing glitch than an error: it happens
# on high load on linux: probably because the kernel has more
# buffers ready. A warning may be useful during development,
# but an error is bad during regression testing.
import warnings
warnings.warn("sending a large query didn't trigger block on write.")
def test_error_in_callback(self):
# behaviour changed after issue #113: if there is an error in the
# callback for the moment we don't have a way to reset the connection
# without blocking (ticket #113) so just close it.
conn = self.conn
curs = conn.cursor()
curs.execute("select 1") # have a BEGIN
curs.fetchone()
# now try to do something that will fail in the callback
psycopg2.extensions.set_wait_callback(lambda conn: 1//0)
self.assertRaises(ZeroDivisionError, curs.execute, "select 2")
self.assertTrue(conn.closed)
def test_dont_freak_out(self):
# if there is an error in a green query, don't freak out and close
# the connection
conn = self.conn
curs = conn.cursor()
self.assertRaises(psycopg2.ProgrammingError,
curs.execute, "select the unselectable")
# check that the connection is left in an usable state
self.assertTrue(not conn.closed)
conn.rollback()
curs.execute("select 1")
self.assertEqual(curs.fetchone()[0], 1)
def test_suite():
return unittest.TestLoader().loadTestsFromName(__name__)
if __name__ == "__main__":
unittest.main()
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