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CherryPy / cherrypy / test / test_bus.py

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import threading
import time
import unittest

import cherrypy
from cherrypy._cpcompat import get_daemon, set
from cherrypy.process import wspbus


msg = "Listener %d on channel %s: %s."


class PublishSubscribeTests(unittest.TestCase):

    def get_listener(self, channel, index):
        def listener(arg=None):
            self.responses.append(msg % (index, channel, arg))
        return listener

    def test_builtin_channels(self):
        b = wspbus.Bus()

        self.responses, expected = [], []

        for channel in b.listeners:
            for index, priority in enumerate([100, 50, 0, 51]):
                b.subscribe(channel, self.get_listener(channel, index), priority)

        for channel in b.listeners:
            b.publish(channel)
            expected.extend([msg % (i, channel, None) for i in (2, 1, 3, 0)])
            b.publish(channel, arg=79347)
            expected.extend([msg % (i, channel, 79347) for i in (2, 1, 3, 0)])

        self.assertEqual(self.responses, expected)

    def test_custom_channels(self):
        b = wspbus.Bus()

        self.responses, expected = [], []

        custom_listeners = ('hugh', 'louis', 'dewey')
        for channel in custom_listeners:
            for index, priority in enumerate([None, 10, 60, 40]):
                b.subscribe(channel, self.get_listener(channel, index), priority)

        for channel in custom_listeners:
            b.publish(channel, 'ah so')
            expected.extend([msg % (i, channel, 'ah so') for i in (1, 3, 0, 2)])
            b.publish(channel)
            expected.extend([msg % (i, channel, None) for i in (1, 3, 0, 2)])

        self.assertEqual(self.responses, expected)

    def test_listener_errors(self):
        b = wspbus.Bus()

        self.responses, expected = [], []
        channels = [c for c in b.listeners if c != 'log']

        for channel in channels:
            b.subscribe(channel, self.get_listener(channel, 1))
            # This will break since the lambda takes no args.
            b.subscribe(channel, lambda: None, priority=20)

        for channel in channels:
            self.assertRaises(wspbus.ChannelFailures, b.publish, channel, 123)
            expected.append(msg % (1, channel, 123))

        self.assertEqual(self.responses, expected)


class BusMethodTests(unittest.TestCase):

    def log(self, bus):
        self._log_entries = []
        def logit(msg, level):
            self._log_entries.append(msg)
        bus.subscribe('log', logit)

    def assertLog(self, entries):
        self.assertEqual(self._log_entries, entries)

    def get_listener(self, channel, index):
        def listener(arg=None):
            self.responses.append(msg % (index, channel, arg))
        return listener

    def test_start(self):
        b = wspbus.Bus()
        self.log(b)

        self.responses = []
        num = 3
        for index in range(num):
            b.subscribe('start', self.get_listener('start', index))

        b.start()
        try:
            # The start method MUST call all 'start' listeners.
            self.assertEqual(set(self.responses),
                             set([msg % (i, 'start', None) for i in range(num)]))
            # The start method MUST move the state to STARTED
            # (or EXITING, if errors occur)
            self.assertEqual(b.state, b.states.STARTED)
            # The start method MUST log its states.
            self.assertLog(['Bus STARTING', 'Bus STARTED'])
        finally:
            # Exit so the atexit handler doesn't complain.
            b.exit()

    def test_stop(self):
        b = wspbus.Bus()
        self.log(b)

        self.responses = []
        num = 3
        for index in range(num):
            b.subscribe('stop', self.get_listener('stop', index))

        b.stop()

        # The stop method MUST call all 'stop' listeners.
        self.assertEqual(set(self.responses),
                         set([msg % (i, 'stop', None) for i in range(num)]))
        # The stop method MUST move the state to STOPPED
        self.assertEqual(b.state, b.states.STOPPED)
        # The stop method MUST log its states.
        self.assertLog(['Bus STOPPING', 'Bus STOPPED'])

    def test_graceful(self):
        b = wspbus.Bus()
        self.log(b)

        self.responses = []
        num = 3
        for index in range(num):
            b.subscribe('graceful', self.get_listener('graceful', index))

        b.graceful()

        # The graceful method MUST call all 'graceful' listeners.
        self.assertEqual(set(self.responses),
                         set([msg % (i, 'graceful', None) for i in range(num)]))
        # The graceful method MUST log its states.
        self.assertLog(['Bus graceful'])

    def test_exit(self):
        b = wspbus.Bus()
        self.log(b)

        self.responses = []
        num = 3
        for index in range(num):
            b.subscribe('stop', self.get_listener('stop', index))
            b.subscribe('exit', self.get_listener('exit', index))

        b.exit()

        # The exit method MUST call all 'stop' listeners,
        # and then all 'exit' listeners.
        self.assertEqual(set(self.responses),
                         set([msg % (i, 'stop', None) for i in range(num)] +
                             [msg % (i, 'exit', None) for i in range(num)]))
        # The exit method MUST move the state to EXITING
        self.assertEqual(b.state, b.states.EXITING)
        # The exit method MUST log its states.
        self.assertLog(['Bus STOPPING', 'Bus STOPPED', 'Bus EXITING', 'Bus EXITED'])

    def test_wait(self):
        b = wspbus.Bus()

        def f(method):
            time.sleep(0.2)
            getattr(b, method)()

        for method, states in [('start', [b.states.STARTED]),
                               ('stop', [b.states.STOPPED]),
                               ('start', [b.states.STARTING, b.states.STARTED]),
                               ('exit', [b.states.EXITING]),
                               ]:
            threading.Thread(target=f, args=(method,)).start()
            b.wait(states)

            # The wait method MUST wait for the given state(s).
            if b.state not in states:
                self.fail("State %r not in %r" % (b.state, states))

    def test_block(self):
        b = wspbus.Bus()
        self.log(b)

        def f():
            time.sleep(0.2)
            b.exit()
        def g():
            time.sleep(0.4)
        threading.Thread(target=f).start()
        threading.Thread(target=g).start()
        threads = [t for t in threading.enumerate() if not get_daemon(t)]
        self.assertEqual(len(threads), 3)

        b.block()

        # The block method MUST wait for the EXITING state.
        self.assertEqual(b.state, b.states.EXITING)
        # The block method MUST wait for ALL non-main, non-daemon threads to finish.
        threads = [t for t in threading.enumerate() if not get_daemon(t)]
        self.assertEqual(len(threads), 1)
        # The last message will mention an indeterminable thread name; ignore it
        self.assertEqual(self._log_entries[:-1],
                         ['Bus STOPPING', 'Bus STOPPED',
                          'Bus EXITING', 'Bus EXITED',
                          'Waiting for child threads to terminate...'])

    def test_start_with_callback(self):
        b = wspbus.Bus()
        self.log(b)
        try:
            events = []
            def f(*args, **kwargs):
                events.append(("f", args, kwargs))
            def g():
                events.append("g")
            b.subscribe("start", g)
            b.start_with_callback(f, (1, 3, 5), {"foo": "bar"})
            # Give wait() time to run f()
            time.sleep(0.2)

            # The callback method MUST wait for the STARTED state.
            self.assertEqual(b.state, b.states.STARTED)
            # The callback method MUST run after all start methods.
            self.assertEqual(events, ["g", ("f", (1, 3, 5), {"foo": "bar"})])
        finally:
            b.exit()

    def test_log(self):
        b = wspbus.Bus()
        self.log(b)
        self.assertLog([])

        # Try a normal message.
        expected = []
        for msg in ["O mah darlin'"] * 3 + ["Clementiiiiiiiine"]:
            b.log(msg)
            expected.append(msg)
            self.assertLog(expected)

        # Try an error message
        try:
            foo
        except NameError:
            b.log("You are lost and gone forever", traceback=True)
            lastmsg = self._log_entries[-1]
            if "Traceback" not in lastmsg or "NameError" not in lastmsg:
                self.fail("Last log message %r did not contain "
                          "the expected traceback." % lastmsg)
        else:
            self.fail("NameError was not raised as expected.")


if __name__ == "__main__":
    unittest.main()