How to use pycares - 10 common examples

def wait(self):
        while True:
            read_fds, write_fds = self.channel.getsock()
            if not read_fds and not write_fds:
                break
            timeout = self.channel.timeout()
            if timeout == 0.0:
                self.channel.process_fd(pycares.ARES_SOCKET_BAD, pycares.ARES_SOCKET_BAD)
                continue
            rlist, wlist, xlist = select.select(read_fds, write_fds, [], timeout)
            for fd in rlist:
                self.channel.process_fd(fd, pycares.ARES_SOCKET_BAD)
            for fd in wlist:
                self.channel.process_fd(pycares.ARES_SOCKET_BAD, fd)

def wait(self):
        while True:
            read_fds, write_fds = self.channel.getsock()
            if not read_fds and not write_fds:
                break
            timeout = self.channel.timeout()
            if timeout == 0.0:
                self.channel.process_fd(pycares.ARES_SOCKET_BAD, pycares.ARES_SOCKET_BAD)
                continue
            rlist, wlist, xlist = select.select(read_fds, write_fds, [], timeout)
            for fd in rlist:
                self.channel.process_fd(fd, pycares.ARES_SOCKET_BAD)
            for fd in wlist:
                self.channel.process_fd(pycares.ARES_SOCKET_BAD, fd)

def test_channel_local_ip(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel = pycares.Channel(timeout=5.0, tries=1, servers=['8.8.8.8'], local_ip='127.0.0.1')
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.wait()
        self.assertEqual(self.result, None)
        self.assertEqual(self.errorno, pycares.errno.ARES_ECONNREFUSED)

def test_channel_nameservers(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel = pycares.Channel(timeout=5.0, tries=1, servers=['8.8.8.8'])
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.wait()
        self.assertNoError(self.errorno)

def test_channel_timeout(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel = pycares.Channel(timeout=0.5, tries=1)
        self.channel.gethostbyname('google.com', socket.AF_INET, cb)
        timeout = self.channel.timeout()
        self.assertTrue(timeout > 0.0)
        self.channel.cancel()
        self.wait()
        self.assertEqual(self.result, None)
        self.assertEqual(self.errorno, pycares.errno.ARES_ECANCELLED)

def test_idna_encoding(self):
        host = 'españa.icom.museum'
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        # try encoding it as utf-8
        self.channel.gethostbyname(host.encode(), socket.AF_INET, cb)
        self.wait()
        self.assertEqual(self.errorno, pycares.errno.ARES_ENOTFOUND)
        self.assertEqual(self.result, None)
        # use it as is (it's IDNA encoded internally)
        self.channel.gethostbyname(host, socket.AF_INET, cb)
        self.wait()
        self.assertNoError(self.errorno)
        self.assertEqual(type(self.result), pycares.ares_host_result)

def test_query_timeout(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel.servers = ['1.2.3.4']
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.wait()
        self.assertEqual(self.result, None)
        self.assertEqual(self.errorno, pycares.errno.ARES_ETIMEOUT)

def test_search(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel = pycares.Channel(timeout=5.0, tries=1, domains=['google.com'])
        self.channel.search('cloud', pycares.QUERY_TYPE_A, cb)
        self.wait()
        self.assertNoError(self.errorno)
        for r in self.result:
            self.assertEqual(type(r), pycares.ares_query_a_result)
            self.assertNotEqual(r.host, None)

def test_custom_resolvconf(self):
        self.result, self.errorno = None, None
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
        self.channel = pycares.Channel(tries=1, timeout=2.0, resolvconf_path=os.path.join(FIXTURES_PATH, 'badresolv.conf'))
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.wait()
        self.assertEqual(self.result, None)
        self.assertEqual(self.errorno, pycares.errno.ARES_ETIMEOUT)

def test_query_a_rotate(self):
        self.result, self.errorno = None, None
        self.errorno_count, self.count = 0, 0
        def cb(result, errorno):
            self.result, self.errorno = result, errorno
            if errorno:
                self.errorno_count += 1
            self.count += 1
        self.channel = pycares.Channel(timeout=1.0, tries=1, rotate=True)
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.channel.query('google.com', pycares.QUERY_TYPE_A, cb)
        self.wait()
        self.assertEqual(self.count, 3)
        self.assertEqual(self.errorno_count, 0)