~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2010, 2011 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program 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 General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

import errno

import socket

import SocketServer

import threading

from bzrlib import (

    osutils,

    tests,

    )

from bzrlib.tests import test_server

from bzrlib.tests.scenarios import load_tests_apply_scenarios

load_tests = load_tests_apply_scenarios

def portable_socket_pair():

    """Return a pair of TCP sockets connected to each other.

    Unlike socket.socketpair, this should work on Windows.

    """

    listen_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    listen_sock.bind(('127.0.0.1', 0))

    listen_sock.listen(1)

    client_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    client_sock.connect(listen_sock.getsockname())

    server_sock, addr = listen_sock.accept()

    listen_sock.close()

    return server_sock, client_sock

class TCPClient(object):

    def __init__(self):

        self.sock = None

    def connect(self, addr):

        if self.sock is not None:

            raise AssertionError('Already connected to %r'

                                 % (self.sock.getsockname(),))

        self.sock = osutils.connect_socket(addr)

    def disconnect(self):

        if self.sock is not None:

            try:

                self.sock.shutdown(socket.SHUT_RDWR)

                self.sock.close()

            except socket.error, e:

                if e[0] in (errno.EBADF, errno.ENOTCONN):

                    # Right, the socket is already down

                    pass

                else:

                    raise

            self.sock = None

    def write(self, s):

        return self.sock.sendall(s)

    def read(self, bufsize=4096):

        return self.sock.recv(bufsize)

class TCPConnectionHandler(SocketServer.BaseRequestHandler):

    def handle(self):

        self.done = False

        self.handle_connection()

        while not self.done:

            self.handle_connection()

    def readline(self):

        # TODO: We should be buffering any extra data sent, etc. However, in

        #       practice, we don't send extra content, so we haven't bothered

        #       to implement it yet.

        req = self.request.recv(4096)

        # An empty string is allowed, to indicate the end of the connection

        if not req or (req.endswith('\n') and req.count('\n') == 1):

            return req

        raise ValueError('[%r] not a simple line' % (req,))

    def handle_connection(self):

        req = self.readline()

        if not req:

            self.done = True

        elif req == 'ping\n':

            self.request.sendall('pong\n')

        else:

            raise ValueError('[%s] not understood' % req)

class TestTCPServerInAThread(tests.TestCase):

    scenarios = [

        (name, {'server_class': getattr(test_server, name)})

        for name in

        ('TestingTCPServer', 'TestingThreadingTCPServer')]

    # Set by load_tests()

    server_class = None

    def get_server(self, server_class=None, connection_handler_class=None):

        if server_class is not None:

            self.server_class = server_class

        if connection_handler_class is None:

            connection_handler_class = TCPConnectionHandler

        server = test_server.TestingTCPServerInAThread(

            ('localhost', 0), self.server_class, connection_handler_class)

        server.start_server()

        self.addCleanup(server.stop_server)

        return server

    def get_client(self):

        client = TCPClient()

        self.addCleanup(client.disconnect)

        return client

    def get_server_connection(self, server, conn_rank):

        return server.server.clients[conn_rank]

    def assertClientAddr(self, client, server, conn_rank):

        conn = self.get_server_connection(server, conn_rank)

        self.assertEquals(client.sock.getsockname(), conn[1])

    def test_start_stop(self):

        server = self.get_server()

        client = self.get_client()

        server.stop_server()

        # since the server doesn't accept connections anymore attempting to

        # connect should fail

        client = self.get_client()

        self.assertRaises(socket.error,

                          client.connect, (server.host, server.port))

    def test_client_talks_server_respond(self):

        server = self.get_server()

        client = self.get_client()

        client.connect((server.host, server.port))

        self.assertIs(None, client.write('ping\n'))

        resp = client.read()

        self.assertClientAddr(client, server, 0)

        self.assertEquals('pong\n', resp)

    def test_server_fails_to_start(self):

        class CantStart(Exception):

            pass

        class CantStartServer(test_server.TestingTCPServer):

            def server_bind(self):

                raise CantStart()

        # The exception is raised in the main thread

        self.assertRaises(CantStart,

                          self.get_server, server_class=CantStartServer)

    def test_server_fails_while_serving_or_stopping(self):

        class CantConnect(Exception):

            pass

        class FailingConnectionHandler(TCPConnectionHandler):

            def handle(self):

                raise CantConnect()

        server = self.get_server(

            connection_handler_class=FailingConnectionHandler)

        # The server won't fail until a client connect

        client = self.get_client()

        client.connect((server.host, server.port))

        # We make sure the server wants to handle a request, but the request is

        # guaranteed to fail. However, the server should make sure that the

        # connection gets closed, and stop_server should then raise the

        # original exception.

        client.write('ping\n')

        try:

            self.assertEqual('', client.read())

        except socket.error, e:

            # On Windows, failing during 'handle' means we get

            # 'forced-close-of-connection'. Possibly because we haven't

            # processed the write request before we close the socket.

            WSAECONNRESET = 10054

            if e.errno in (WSAECONNRESET,):

                pass

        # Now the server has raised the exception in its own thread

        self.assertRaises(CantConnect, server.stop_server)

    def test_server_crash_while_responding(self):

        sync = threading.Event()

        sync.clear()

        class FailToRespond(Exception):

            pass

        class FailingDuringResponseHandler(TCPConnectionHandler):

            def handle_connection(self):

                req = self.readline()

                threading.currentThread().set_sync_event(sync)

                raise FailToRespond()

        server = self.get_server(

            connection_handler_class=FailingDuringResponseHandler)

        client = self.get_client()

        client.connect((server.host, server.port))

        client.write('ping\n')

        sync.wait()

        self.assertEqual('', client.read()) # connection closed

        self.assertRaises(FailToRespond, server.pending_exception)

    def test_exception_swallowed_while_serving(self):

        sync = threading.Event()

        sync.clear()

        class CantServe(Exception):

            pass

        class FailingWhileServingConnectionHandler(TCPConnectionHandler):

            def handle(self):

                # We want to sync with the thread that is serving the

                # connection.

                threading.currentThread().set_sync_event(sync)

                raise CantServe()

        server = self.get_server(

            connection_handler_class=FailingWhileServingConnectionHandler)

        # Install the exception swallower

        server.set_ignored_exceptions(CantServe)

        client = self.get_client()

        # Connect to the server so the exception is raised there

        client.connect((server.host, server.port))

        # Wait for the exception to propagate.

        sync.wait()

        self.assertEqual('', client.read()) # connection closed

        # The connection wasn't served properly but the exception should have

        # been swallowed.

        server.pending_exception()

    def test_handle_request_closes_if_it_doesnt_process(self):

        server = self.get_server()

        client = self.get_client()

        server.server.serving = False

        client.connect((server.host, server.port))

        self.assertEqual('', client.read())

class TestTestingSmartServer(tests.TestCase):

    def test_sets_client_timeout(self):

        server = test_server.TestingSmartServer(('localhost', 0), None, None,

            root_client_path='/no-such-client/path')

        self.assertEqual(test_server._DEFAULT_TESTING_CLIENT_TIMEOUT,

                         server._client_timeout)

        sock = socket.socket()

        h = server._make_handler(sock)

        self.assertEqual(test_server._DEFAULT_TESTING_CLIENT_TIMEOUT,

                         h._client_timeout)

class FakeServer(object):

    """Minimal implementation to pass to TestingSmartConnectionHandler"""

    backing_transport = None

    root_client_path = '/'

class TestTestingSmartConnectionHandler(tests.TestCase):

    def test_connection_timeout_suppressed(self):

        self.overrideAttr(test_server, '_DEFAULT_TESTING_CLIENT_TIMEOUT', 0.01)

        s = FakeServer()

        server_sock, client_sock = portable_socket_pair()

        # This should timeout quickly, but not generate an exception.

        handler = test_server.TestingSmartConnectionHandler(server_sock,

            server_sock.getpeername(), s)

    def test_connection_shutdown_while_serving_no_error(self):

        s = FakeServer()

        server_sock, client_sock = portable_socket_pair()

        class ShutdownConnectionHandler(

            test_server.TestingSmartConnectionHandler):

            def _build_protocol(self):

                self.finished = True

                return super(ShutdownConnectionHandler, self)._build_protocol()

        # This should trigger shutdown after the entering _build_protocol, and

        # we should exit cleanly, without raising an exception.

        handler = ShutdownConnectionHandler(server_sock,

            server_sock.getpeername(), s)