1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
|
# Copyright (C) 2006-2011 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
"""Server for smart-server protocol."""
from __future__ import absolute_import
import errno
import os.path
import socket
import sys
import time
import threading
from bzrlib.hooks import Hooks
from bzrlib import (
errors,
trace,
transport as _mod_transport,
)
from bzrlib.i18n import gettext
from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
from bzrlib.smart import (
medium,
signals,
)
from bzrlib.transport import (
chroot,
pathfilter,
)
from bzrlib import (
config,
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.
"""
# This is the timeout on the socket we use .accept() on. It is exposed here
# so the test suite can set it faster. (It thread.interrupt_main() will not
# fire a KeyboardInterrupt during socket.accept)
_ACCEPT_TIMEOUT = 1.0
_SHUTDOWN_POLL_TIMEOUT = 1.0
_LOG_WAITING_TIMEOUT = 10.0
_timer = time.time
def __init__(self, backing_transport, root_client_path='/',
client_timeout=None):
"""Construct a new server.
To actually start it running, call either start_background_thread or
serve.
:param backing_transport: The transport to serve.
:param root_client_path: The client path that will correspond to root
of backing_transport.
:param client_timeout: See SmartServerSocketStreamMedium's timeout
parameter.
"""
self.backing_transport = backing_transport
self.root_client_path = root_client_path
self._client_timeout = client_timeout
self._active_connections = []
# This is set to indicate we want to wait for clients to finish before
# we disconnect.
self._gracefully_stopping = False
def start_server(self, host, port):
"""Create the server listening socket.
:param host: Name of the interface to listen on.
:param port: TCP port to listen on, or 0 to allocate a transient port.
"""
# 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(self._ACCEPT_TIMEOUT)
# Once we start accept()ing connections, we set started.
self._started = threading.Event()
# Once we stop accept()ing connections (and are closing the socket) we
# set _stopped
self._stopped = threading.Event()
# Once we have finished waiting for all clients, etc. We set
# _fully_stopped
self._fully_stopped = threading.Event()
def _backing_urls(self):
# 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. filtered-36195:///)
# 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.
urls = [self.backing_transport.base]
try:
urls.append(self.backing_transport.external_url())
except errors.InProcessTransport:
pass
return urls
def run_server_started_hooks(self, backing_urls=None):
if backing_urls is None:
backing_urls = self._backing_urls()
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)
def run_server_stopped_hooks(self, backing_urls=None):
if backing_urls is None:
backing_urls = self._backing_urls()
for hook in SmartTCPServer.hooks['server_stopped']:
hook(backing_urls, self.get_url())
def _stop_gracefully(self):
trace.note(gettext('Requested to stop gracefully'))
self._should_terminate = True
self._gracefully_stopping = True
for handler, _ in self._active_connections:
handler._stop_gracefully()
def _wait_for_clients_to_disconnect(self):
self._poll_active_connections()
if not self._active_connections:
return
trace.note(gettext('Waiting for %d client(s) to finish')
% (len(self._active_connections),))
t_next_log = self._timer() + self._LOG_WAITING_TIMEOUT
while self._active_connections:
now = self._timer()
if now >= t_next_log:
trace.note(gettext('Still waiting for %d client(s) to finish')
% (len(self._active_connections),))
t_next_log = now + self._LOG_WAITING_TIMEOUT
self._poll_active_connections(self._SHUTDOWN_POLL_TIMEOUT)
def serve(self, thread_name_suffix=''):
# Note: There is a temptation to do
# signals.register_on_hangup(id(self), self._stop_gracefully)
# However, that creates a temporary object which is a bound
# method. signals._on_sighup is a WeakKeyDictionary so it
# immediately gets garbage collected, because nothing else
# references it. Instead, we need to keep a real reference to the
# bound method for the lifetime of the serve() function.
stop_gracefully = self._stop_gracefully
signals.register_on_hangup(id(self), stop_gracefully)
self._should_terminate = False
# for hooks we are letting code know that a server has started (and
# later stopped).
self.run_server_started_hooks()
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, or if we get a signal we
# can get EINTR, any other socket errors should get
# logged.
if e.args[0] not in (errno.EBADF, errno.EINTR):
trace.warning(gettext("listening socket error: %s")
% (e,))
else:
if self._should_terminate:
conn.close()
break
self.serve_conn(conn, thread_name_suffix)
# Cleanout any threads that have finished processing.
self._poll_active_connections()
except KeyboardInterrupt:
# dont log when CTRL-C'd.
raise
except Exception, e:
trace.report_exception(sys.exc_info(), sys.stderr)
raise
finally:
try:
# ensure the server socket is closed.
self._server_socket.close()
except self._socket_error:
# ignore errors on close
pass
self._stopped.set()
signals.unregister_on_hangup(id(self))
self.run_server_stopped_hooks()
if self._gracefully_stopping:
self._wait_for_clients_to_disconnect()
self._fully_stopped.set()
def get_url(self):
"""Return the url of the server"""
return "bzr://%s:%s/" % (self._sockname[0], self._sockname[1])
def _make_handler(self, conn):
return medium.SmartServerSocketStreamMedium(
conn, self.backing_transport, self.root_client_path,
timeout=self._client_timeout)
def _poll_active_connections(self, timeout=0.0):
"""Check to see if any active connections have finished.
This will iterate through self._active_connections, and update any
connections that are finished.
:param timeout: The timeout to pass to thread.join(). By default, we
set it to 0, so that we don't hang if threads are not done yet.
:return: None
"""
still_active = []
for handler, thread in self._active_connections:
thread.join(timeout)
if thread.isAlive():
still_active.append((handler, thread))
self._active_connections = still_active
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)
thread_name = 'smart-server-child' + thread_name_suffix
handler = self._make_handler(conn)
connection_thread = threading.Thread(
None, handler.serve, name=thread_name)
self._active_connections.append((handler, connection_thread))
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, "bzrlib.smart.server", "SmartTCPServer.hooks")
self.add_hook('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))
self.add_hook('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))
self.add_hook('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))
self.add_hook('server_exception',
"Called by the bzr server when an exception occurs. "
"server_exception is called with the sys.exc_info() tuple "
"return true for the hook if the exception has been handled, "
"in which case the server will exit normally.", (2, 4))
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 = _mod_transport.get_transport_from_url(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 = _mod_transport.get_transport_from_url(expand_userdirs.get_url())
self.transport = transport
def _get_stdin_stdout(self):
return sys.stdin, sys.stdout
def _make_smart_server(self, host, port, inet, timeout):
if timeout is None:
c = config.GlobalStack()
timeout = c.get('serve.client_timeout')
if inet:
stdin, stdout = self._get_stdin_stdout()
smart_server = medium.SmartServerPipeStreamMedium(
stdin, stdout, self.transport, timeout=timeout)
else:
if host is None:
host = medium.BZR_DEFAULT_INTERFACE
if port is None:
port = medium.BZR_DEFAULT_PORT
smart_server = SmartTCPServer(self.transport,
client_timeout=timeout)
smart_server.start_server(host, port)
trace.note(gettext('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
orig = signals.install_sighup_handler()
def restore_signals():
signals.restore_sighup_handler(orig)
self.cleanups.append(restore_signals)
def set_up(self, transport, host, port, inet, timeout):
self._make_backing_transport(transport)
self._make_smart_server(host, port, inet, timeout)
self._change_globals()
def tear_down(self):
for cleanup in reversed(self.cleanups):
cleanup()
def serve_bzr(transport, host=None, port=None, inet=False, timeout=None):
"""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, timeout)
bzr_server.smart_server.serve()
except:
hook_caught_exception = False
for hook in SmartTCPServer.hooks['server_exception']:
hook_caught_exception = hook(sys.exc_info())
if not hook_caught_exception:
raise
finally:
bzr_server.tear_down()
|