/brz/remove-bazaar

# Copyright (C) 2006, 2007, 2008 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

"""Server for smart-server protocol."""

import errno

import os.path

import socket

import sys

import threading

from bzrlib.hooks import HookPoint, Hooks

from bzrlib import (

    errors,

    trace,

    transport,

)

from bzrlib.lazy_import import lazy_import

lazy_import(globals(), """

from bzrlib.smart import medium

from bzrlib.transport import (

    chroot,

    get_transport,

    pathfilter,

    )

from bzrlib import (

    urlutils,

    )

""")

class SmartTCPServer(object):

    """Listens on a TCP socket and accepts connections from smart clients.

    Each connection will be served by a SmartServerSocketStreamMedium running in

    a thread.

    hooks: An instance of SmartServerHooks.

    """

    def __init__(self, backing_transport, host='127.0.0.1', port=0,

                 root_client_path='/'):

        """Construct a new server.

        To actually start it running, call either start_background_thread or

        serve.

        :param backing_transport: The transport to serve.

        :param host: Name of the interface to listen on.

        :param port: TCP port to listen on, or 0 to allocate a transient port.

        :param root_client_path: The client path that will correspond to root

            of backing_transport.

        """

        # let connections timeout so that we get a chance to terminate

        # Keep a reference to the exceptions we want to catch because the socket

        # module's globals get set to None during interpreter shutdown.

        from socket import timeout as socket_timeout

        from socket import error as socket_error

        self._socket_error = socket_error

        self._socket_timeout = socket_timeout

        addrs = socket.getaddrinfo(host, port, socket.AF_UNSPEC,

            socket.SOCK_STREAM, 0, socket.AI_PASSIVE)[0]

        (family, socktype, proto, canonname, sockaddr) = addrs

        self._server_socket = socket.socket(family, socktype, proto)

        # SO_REUSERADDR has a different meaning on Windows

        if sys.platform != 'win32':

            self._server_socket.setsockopt(socket.SOL_SOCKET,

                socket.SO_REUSEADDR, 1)

        try:

            self._server_socket.bind(sockaddr)

        except self._socket_error, message:

            raise errors.CannotBindAddress(host, port, message)

        self._sockname = self._server_socket.getsockname()

        self.port = self._sockname[1]

        self._server_socket.listen(1)

        self._server_socket.settimeout(1)

        self.backing_transport = backing_transport

        self._started = threading.Event()

        self._stopped = threading.Event()

        self.root_client_path = root_client_path

    def serve(self, thread_name_suffix=''):

        self._should_terminate = False

        # for hooks we are letting code know that a server has started (and

        # later stopped).

        # There are three interesting urls:

        # The URL the server can be contacted on. (e.g. bzr://host/)

        # The URL that a commit done on the same machine as the server will

        # have within the servers space. (e.g. file:///home/user/source)

        # The URL that will be given to other hooks in the same process -

        # the URL of the backing transport itself. (e.g. chroot+:///)

        # We need all three because:

        #  * other machines see the first

        #  * local commits on this machine should be able to be mapped to

        #    this server

        #  * commits the server does itself need to be mapped across to this

        #    server.

        # The latter two urls are different aliases to the servers url,

        # so we group those in a list - as there might be more aliases

        # in the future.

        backing_urls = [self.backing_transport.base]

        try:

            backing_urls.append(self.backing_transport.external_url())

        except errors.InProcessTransport:

            pass

        for hook in SmartTCPServer.hooks['server_started']:

            hook(backing_urls, self.get_url())

        for hook in SmartTCPServer.hooks['server_started_ex']:

            hook(backing_urls, self)

        self._started.set()

        try:

            try:

                while not self._should_terminate:

                    try:

                        conn, client_addr = self._server_socket.accept()

                    except self._socket_timeout:

                        # just check if we're asked to stop

                        pass

                    except self._socket_error, e:

                        # if the socket is closed by stop_background_thread

                        # we might get a EBADF here, any other socket errors

                        # should get logged.

                        if e.args[0] != errno.EBADF:

                            trace.warning("listening socket error: %s", e)

                    else:

                        self.serve_conn(conn, thread_name_suffix)

            except KeyboardInterrupt:

                # dont log when CTRL-C'd.

                raise

            except Exception, e:

                trace.report_exception(sys.exc_info(), sys.stderr)

                raise

        finally:

            self._stopped.set()

            try:

                # ensure the server socket is closed.

                self._server_socket.close()

            except self._socket_error:

                # ignore errors on close

                pass

            for hook in SmartTCPServer.hooks['server_stopped']:

                hook(backing_urls, self.get_url())

    def get_url(self):

        """Return the url of the server"""

        return "bzr://%s:%d/" % self._sockname

    def serve_conn(self, conn, thread_name_suffix):

        # For WIN32, where the timeout value from the listening socket

        # propagates to the newly accepted socket.

        conn.setblocking(True)

        conn.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)

        handler = medium.SmartServerSocketStreamMedium(

            conn, self.backing_transport, self.root_client_path)

        thread_name = 'smart-server-child' + thread_name_suffix

        connection_thread = threading.Thread(

            None, handler.serve, name=thread_name)

        connection_thread.setDaemon(True)

        connection_thread.start()

        return connection_thread

    def start_background_thread(self, thread_name_suffix=''):

        self._started.clear()

        self._server_thread = threading.Thread(None,

                self.serve, args=(thread_name_suffix,),

                name='server-' + self.get_url())

        self._server_thread.setDaemon(True)

        self._server_thread.start()

        self._started.wait()

    def stop_background_thread(self):

        self._stopped.clear()

        # tell the main loop to quit on the next iteration.

        self._should_terminate = True

        # close the socket - gives error to connections from here on in,

        # rather than a connection reset error to connections made during

        # the period between setting _should_terminate = True and

        # the current request completing/aborting. It may also break out the

        # main loop if it was currently in accept() (on some platforms).

        try:

            self._server_socket.close()

        except self._socket_error:

            # ignore errors on close

            pass

        if not self._stopped.isSet():

            # server has not stopped (though it may be stopping)

            # its likely in accept(), so give it a connection

            temp_socket = socket.socket()

            temp_socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)

            if not temp_socket.connect_ex(self._sockname):

                # and close it immediately: we dont choose to send any requests.

                temp_socket.close()

        self._stopped.wait()

        self._server_thread.join()

class SmartServerHooks(Hooks):

    """Hooks for the smart server."""

    def __init__(self):

        """Create the default hooks.

        These are all empty initially, because by default nothing should get

        notified.

        """

        Hooks.__init__(self)

        self.create_hook(HookPoint('server_started',

            "Called by the bzr server when it starts serving a directory. "

            "server_started is called with (backing urls, public url), "

            "where backing_url is a list of URLs giving the "

            "server-specific directory locations, and public_url is the "

            "public URL for the directory being served.", (0, 16), None))

        self.create_hook(HookPoint('server_started_ex',

            "Called by the bzr server when it starts serving a directory. "

            "server_started is called with (backing_urls, server_obj).",

            (1, 17), None))

        self.create_hook(HookPoint('server_stopped',

            "Called by the bzr server when it stops serving a directory. "

            "server_stopped is called with the same parameters as the "

            "server_started hook: (backing_urls, public_url).", (0, 16), None))

SmartTCPServer.hooks = SmartServerHooks()

class SmartTCPServer_for_testing(SmartTCPServer):

    """Server suitable for use by transport tests.

    This server is backed by the process's cwd.

    """

    def __init__(self, thread_name_suffix=''):

        SmartTCPServer.__init__(self, None)

        self.client_path_extra = None

        self.thread_name_suffix = thread_name_suffix

        # We collect the sockets/threads used by the clients so we can

        # close/join them when shutting down

        self.clients = []

    def get_backing_transport(self, backing_transport_server):

        """Get a backing transport from a server we are decorating."""

        return transport.get_transport(backing_transport_server.get_url())

    def setUp(self, backing_transport_server=None,

              client_path_extra='/extra/'):

        """Set up server for testing.

        :param backing_transport_server: backing server to use.  If not

            specified, a LocalURLServer at the current working directory will

            be used.

        :param client_path_extra: a path segment starting with '/' to append to

            the root URL for this server.  For instance, a value of '/foo/bar/'

            will mean the root of the backing transport will be published at a

            URL like `bzr://127.0.0.1:nnnn/foo/bar/`, rather than

            `bzr://127.0.0.1:nnnn/`.  Default value is `extra`, so that tests

            by default will fail unless they do the necessary path translation.

        """

        if not client_path_extra.startswith('/'):

            raise ValueError(client_path_extra)

        from bzrlib.transport.chroot import ChrootServer

        if backing_transport_server is None:

            from bzrlib.transport.local import LocalURLServer

            backing_transport_server = LocalURLServer()

        self.chroot_server = ChrootServer(

            self.get_backing_transport(backing_transport_server))

        self.chroot_server.setUp()

        self.backing_transport = transport.get_transport(

            self.chroot_server.get_url())

        self.root_client_path = self.client_path_extra = client_path_extra

        self.start_background_thread(self.thread_name_suffix)

    def serve_conn(self, conn, thread_name_suffix):

        conn_thread = super(SmartTCPServer_for_testing, self).serve_conn(

            conn, thread_name_suffix)

        self.clients.append((conn, conn_thread))

        return conn_thread

    def shutdown_client(self, client_socket):

        """Properly shutdown a client socket.

        Under some circumstances (as in bug #383920), we need to force the

        shutdown as python delays it until gc occur otherwise and the client

        may hang.

        This should be called only when no other thread is trying to use the

        socket.

        """

        try:

            # The request process has been completed, the thread is about to

            # die, let's shutdown the socket if we can.

            client_socket.shutdown(socket.SHUT_RDWR)

        except (socket.error, select.error), e:

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

                # Right, the socket is already down

                pass

            else:

                raise

    def tearDown(self):

        self.stop_background_thread()

        # Let's close all our pending clients too

        for sock, thread in self.clients:

            self.shutdown_client(sock)

            thread.join()

            del thread

        self.clients = []

        self.chroot_server.tearDown()

    def get_url(self):

        url = super(SmartTCPServer_for_testing, self).get_url()

        return url[:-1] + self.client_path_extra

    def get_bogus_url(self):

        """Return a URL which will fail to connect"""

        return 'bzr://127.0.0.1:1/'

class ReadonlySmartTCPServer_for_testing(SmartTCPServer_for_testing):

    """Get a readonly server for testing."""

    def get_backing_transport(self, backing_transport_server):

        """Get a backing transport from a server we are decorating."""

        url = 'readonly+' + backing_transport_server.get_url()

        return transport.get_transport(url)

class SmartTCPServer_for_testing_v2_only(SmartTCPServer_for_testing):

    """A variation of SmartTCPServer_for_testing that limits the client to

    using RPCs in protocol v2 (i.e. bzr <= 1.5).

    """

    def get_url(self):

        url = super(SmartTCPServer_for_testing_v2_only, self).get_url()

        url = 'bzr-v2://' + url[len('bzr://'):]

        return url

class ReadonlySmartTCPServer_for_testing_v2_only(SmartTCPServer_for_testing_v2_only):

    """Get a readonly server for testing."""

    def get_backing_transport(self, backing_transport_server):

        """Get a backing transport from a server we are decorating."""

        url = 'readonly+' + backing_transport_server.get_url()

        return transport.get_transport(url)

def _local_path_for_transport(transport):

    """Return a local path for transport, if reasonably possible.

    This function works even if transport's url has a "readonly+" prefix,

    unlike local_path_from_url.

    This essentially recovers the --directory argument the user passed to "bzr

    serve" from the transport passed to serve_bzr.

    """

    try:

        base_url = transport.external_url()

    except (errors.InProcessTransport, NotImplementedError):

        return None

    else:

        # Strip readonly prefix

        if base_url.startswith('readonly+'):

            base_url = base_url[len('readonly+'):]

        try:

            return urlutils.local_path_from_url(base_url)

        except errors.InvalidURL:

            return None

class BzrServerFactory(object):

    """Helper class for serve_bzr."""

    def __init__(self, userdir_expander=None, get_base_path=None):

        self.cleanups = []

        self.base_path = None

        self.backing_transport = None

        if userdir_expander is None:

            userdir_expander = os.path.expanduser

        self.userdir_expander = userdir_expander

        if get_base_path is None:

            get_base_path = _local_path_for_transport

        self.get_base_path = get_base_path

    def _expand_userdirs(self, path):

        """Translate /~/ or /~user/ to e.g. /home/foo, using

        self.userdir_expander (os.path.expanduser by default).

        If the translated path would fall outside base_path, or the path does

        not start with ~, then no translation is applied.

        If the path is inside, it is adjusted to be relative to the base path.

        e.g. if base_path is /home, and the expanded path is /home/joe, then

        the translated path is joe.

        """

        result = path

        if path.startswith('~'):

            expanded = self.userdir_expander(path)

            if not expanded.endswith('/'):

                expanded += '/'

            if expanded.startswith(self.base_path):

                result = expanded[len(self.base_path):]

        return result

    def _make_expand_userdirs_filter(self, transport):

        return pathfilter.PathFilteringServer(transport, self._expand_userdirs)

    def _make_backing_transport(self, transport):

        """Chroot transport, and decorate with userdir expander."""

        self.base_path = self.get_base_path(transport)

        chroot_server = chroot.ChrootServer(transport)

        chroot_server.setUp()

        self.cleanups.append(chroot_server.tearDown)

        transport = get_transport(chroot_server.get_url())

        if self.base_path is not None:

            # Decorate the server's backing transport with a filter that can

            # expand homedirs.

            expand_userdirs = self._make_expand_userdirs_filter(transport)

            expand_userdirs.setUp()

            self.cleanups.append(expand_userdirs.tearDown)

            transport = get_transport(expand_userdirs.get_url())

        self.transport = transport

    def _make_smart_server(self, host, port, inet):

        if inet:

            smart_server = medium.SmartServerPipeStreamMedium(

                sys.stdin, sys.stdout, self.transport)

        else:

            if host is None:

                host = medium.BZR_DEFAULT_INTERFACE

            if port is None:

                port = medium.BZR_DEFAULT_PORT

            smart_server = SmartTCPServer(self.transport, host=host, port=port)

            trace.note('listening on port: %s' % smart_server.port)

        self.smart_server = smart_server

    def _change_globals(self):

        from bzrlib import lockdir, ui

        # For the duration of this server, no UI output is permitted. note

        # that this may cause problems with blackbox tests. This should be

        # changed with care though, as we dont want to use bandwidth sending

        # progress over stderr to smart server clients!

        old_factory = ui.ui_factory

        old_lockdir_timeout = lockdir._DEFAULT_TIMEOUT_SECONDS

        def restore_default_ui_factory_and_lockdir_timeout():

            ui.ui_factory = old_factory

            lockdir._DEFAULT_TIMEOUT_SECONDS = old_lockdir_timeout

        self.cleanups.append(restore_default_ui_factory_and_lockdir_timeout)

        ui.ui_factory = ui.SilentUIFactory()

        lockdir._DEFAULT_TIMEOUT_SECONDS = 0

    def set_up(self, transport, host, port, inet):

        self._make_backing_transport(transport)

        self._make_smart_server(host, port, inet)

        self._change_globals()

    def tear_down(self):

        for cleanup in reversed(self.cleanups):

            cleanup()

def serve_bzr(transport, host=None, port=None, inet=False):

    """This is the default implementation of 'bzr serve'.

    It creates a TCP or pipe smart server on 'transport, and runs it.  The

    transport will be decorated with a chroot and pathfilter (using

    os.path.expanduser).

    """

    bzr_server = BzrServerFactory()

    try:

        bzr_server.set_up(transport, host, port, inet)

        bzr_server.smart_server.serve()

    finally:

        bzr_server.tear_down()