# Copyright (C) 2006-2010 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
from socket import 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:
if self._should_terminate:
break
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()
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()
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.start_server()
self.cleanups.append(chroot_server.stop_server)
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.start_server()
self.cleanups.append(expand_userdirs.stop_server)
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()
|