1
# Copyright (C) 2006 Canonical Ltd
3
# This program is free software; you can redistribute it and/or modify
4
# it under the terms of the GNU General Public License as published by
5
# the Free Software Foundation; either version 2 of the License, or
6
# (at your option) any later version.
8
# This program is distributed in the hope that it will be useful,
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11
# GNU General Public License for more details.
13
# You should have received a copy of the GNU General Public License
14
# along with this program; if not, write to the Free Software
15
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17
"""The 'medium' layer for the smart servers and clients.
19
"Medium" here is the noun meaning "a means of transmission", not the adjective
20
for "the quality between big and small."
22
Media carry the bytes of the requests somehow (e.g. via TCP, wrapped in HTTP, or
23
over SSH), and pass them to and from the protocol logic. See the overview in
24
bzrlib/transport/smart/__init__.py.
33
from bzrlib.lazy_import import lazy_import
34
lazy_import(globals(), """
46
from bzrlib.smart import client, protocol, request, vfs
47
from bzrlib.transport import ssh
51
# We must not read any more than 64k at a time so we don't risk "no buffer
52
# space available" errors on some platforms. Windows in particular is likely
53
# to give error 10053 or 10055 if we read more than 64k from a socket.
54
_MAX_READ_SIZE = 64 * 1024
57
def _get_protocol_factory_for_bytes(bytes):
58
"""Determine the right protocol factory for 'bytes'.
60
This will return an appropriate protocol factory depending on the version
61
of the protocol being used, as determined by inspecting the given bytes.
62
The bytes should have at least one newline byte (i.e. be a whole line),
63
otherwise it's possible that a request will be incorrectly identified as
66
Typical use would be::
68
factory, unused_bytes = _get_protocol_factory_for_bytes(bytes)
69
server_protocol = factory(transport, write_func, root_client_path)
70
server_protocol.accept_bytes(unused_bytes)
72
:param bytes: a str of bytes of the start of the request.
73
:returns: 2-tuple of (protocol_factory, unused_bytes). protocol_factory is
74
a callable that takes three args: transport, write_func,
75
root_client_path. unused_bytes are any bytes that were not part of a
76
protocol version marker.
78
if bytes.startswith(protocol.MESSAGE_VERSION_THREE):
79
protocol_factory = protocol.build_server_protocol_three
80
bytes = bytes[len(protocol.MESSAGE_VERSION_THREE):]
81
elif bytes.startswith(protocol.REQUEST_VERSION_TWO):
82
protocol_factory = protocol.SmartServerRequestProtocolTwo
83
bytes = bytes[len(protocol.REQUEST_VERSION_TWO):]
85
protocol_factory = protocol.SmartServerRequestProtocolOne
86
return protocol_factory, bytes
89
def _get_line(read_bytes_func):
90
"""Read bytes using read_bytes_func until a newline byte.
92
This isn't particularly efficient, so should only be used when the
93
expected size of the line is quite short.
95
:returns: a tuple of two strs: (line, excess)
99
while newline_pos == -1:
100
new_bytes = read_bytes_func(1)
103
# Ran out of bytes before receiving a complete line.
105
newline_pos = bytes.find('\n')
106
line = bytes[:newline_pos+1]
107
excess = bytes[newline_pos+1:]
111
class SmartMedium(object):
112
"""Base class for smart protocol media, both client- and server-side."""
115
self._push_back_buffer = None
117
def _push_back(self, bytes):
118
"""Return unused bytes to the medium, because they belong to the next
121
This sets the _push_back_buffer to the given bytes.
123
if self._push_back_buffer is not None:
124
raise AssertionError(
125
"_push_back called when self._push_back_buffer is %r"
126
% (self._push_back_buffer,))
129
self._push_back_buffer = bytes
131
def _get_push_back_buffer(self):
132
if self._push_back_buffer == '':
133
raise AssertionError(
134
'%s._push_back_buffer should never be the empty string, '
135
'which can be confused with EOF' % (self,))
136
bytes = self._push_back_buffer
137
self._push_back_buffer = None
140
def read_bytes(self, desired_count):
141
"""Read some bytes from this medium.
143
:returns: some bytes, possibly more or less than the number requested
144
in 'desired_count' depending on the medium.
146
if self._push_back_buffer is not None:
147
return self._get_push_back_buffer()
148
bytes_to_read = min(desired_count, _MAX_READ_SIZE)
149
return self._read_bytes(bytes_to_read)
151
def _read_bytes(self, count):
152
raise NotImplementedError(self._read_bytes)
155
"""Read bytes from this request's response until a newline byte.
157
This isn't particularly efficient, so should only be used when the
158
expected size of the line is quite short.
160
:returns: a string of bytes ending in a newline (byte 0x0A).
162
line, excess = _get_line(self.read_bytes)
163
self._push_back(excess)
166
def _report_activity(self, bytes, direction):
167
"""Notify that this medium has activity.
169
Implementations should call this from all methods that actually do IO.
170
Be careful that it's not called twice, if one method is implemented on
173
:param bytes: Number of bytes read or written.
174
:param direction: 'read' or 'write' or None.
176
ui.ui_factory.report_transport_activity(self, bytes, direction)
179
class SmartServerStreamMedium(SmartMedium):
180
"""Handles smart commands coming over a stream.
182
The stream may be a pipe connected to sshd, or a tcp socket, or an
183
in-process fifo for testing.
185
One instance is created for each connected client; it can serve multiple
186
requests in the lifetime of the connection.
188
The server passes requests through to an underlying backing transport,
189
which will typically be a LocalTransport looking at the server's filesystem.
191
:ivar _push_back_buffer: a str of bytes that have been read from the stream
192
but not used yet, or None if there are no buffered bytes. Subclasses
193
should make sure to exhaust this buffer before reading more bytes from
194
the stream. See also the _push_back method.
197
def __init__(self, backing_transport, root_client_path='/'):
198
"""Construct new server.
200
:param backing_transport: Transport for the directory served.
202
# backing_transport could be passed to serve instead of __init__
203
self.backing_transport = backing_transport
204
self.root_client_path = root_client_path
205
self.finished = False
206
SmartMedium.__init__(self)
209
"""Serve requests until the client disconnects."""
210
# Keep a reference to stderr because the sys module's globals get set to
211
# None during interpreter shutdown.
212
from sys import stderr
214
while not self.finished:
215
server_protocol = self._build_protocol()
216
self._serve_one_request(server_protocol)
218
stderr.write("%s terminating on exception %s\n" % (self, e))
221
def _build_protocol(self):
222
"""Identifies the version of the incoming request, and returns an
223
a protocol object that can interpret it.
225
If more bytes than the version prefix of the request are read, they will
226
be fed into the protocol before it is returned.
228
:returns: a SmartServerRequestProtocol.
230
bytes = self._get_line()
231
protocol_factory, unused_bytes = _get_protocol_factory_for_bytes(bytes)
232
protocol = protocol_factory(
233
self.backing_transport, self._write_out, self.root_client_path)
234
protocol.accept_bytes(unused_bytes)
237
def _serve_one_request(self, protocol):
238
"""Read one request from input, process, send back a response.
240
:param protocol: a SmartServerRequestProtocol.
243
self._serve_one_request_unguarded(protocol)
244
except KeyboardInterrupt:
247
self.terminate_due_to_error()
249
def terminate_due_to_error(self):
250
"""Called when an unhandled exception from the protocol occurs."""
251
raise NotImplementedError(self.terminate_due_to_error)
253
def _read_bytes(self, desired_count):
254
"""Get some bytes from the medium.
256
:param desired_count: number of bytes we want to read.
258
raise NotImplementedError(self._read_bytes)
261
class SmartServerSocketStreamMedium(SmartServerStreamMedium):
263
def __init__(self, sock, backing_transport, root_client_path='/'):
266
:param sock: the socket the server will read from. It will be put
269
SmartServerStreamMedium.__init__(
270
self, backing_transport, root_client_path=root_client_path)
271
sock.setblocking(True)
274
def _serve_one_request_unguarded(self, protocol):
275
while protocol.next_read_size():
276
# We can safely try to read large chunks. If there is less data
277
# than _MAX_READ_SIZE ready, the socket wil just return a short
278
# read immediately rather than block.
279
bytes = self.read_bytes(_MAX_READ_SIZE)
283
protocol.accept_bytes(bytes)
285
self._push_back(protocol.unused_data)
287
def _read_bytes(self, desired_count):
288
return _read_bytes_from_socket(
289
self.socket.recv, desired_count, self._report_activity)
291
def terminate_due_to_error(self):
292
# TODO: This should log to a server log file, but no such thing
293
# exists yet. Andrew Bennetts 2006-09-29.
297
def _write_out(self, bytes):
298
osutils.send_all(self.socket, bytes, self._report_activity)
301
class SmartServerPipeStreamMedium(SmartServerStreamMedium):
303
def __init__(self, in_file, out_file, backing_transport):
304
"""Construct new server.
306
:param in_file: Python file from which requests can be read.
307
:param out_file: Python file to write responses.
308
:param backing_transport: Transport for the directory served.
310
SmartServerStreamMedium.__init__(self, backing_transport)
311
if sys.platform == 'win32':
312
# force binary mode for files
314
for f in (in_file, out_file):
315
fileno = getattr(f, 'fileno', None)
317
msvcrt.setmode(fileno(), os.O_BINARY)
321
def _serve_one_request_unguarded(self, protocol):
323
# We need to be careful not to read past the end of the current
324
# request, or else the read from the pipe will block, so we use
325
# protocol.next_read_size().
326
bytes_to_read = protocol.next_read_size()
327
if bytes_to_read == 0:
328
# Finished serving this request.
331
bytes = self.read_bytes(bytes_to_read)
333
# Connection has been closed.
337
protocol.accept_bytes(bytes)
339
def _read_bytes(self, desired_count):
340
return self._in.read(desired_count)
342
def terminate_due_to_error(self):
343
# TODO: This should log to a server log file, but no such thing
344
# exists yet. Andrew Bennetts 2006-09-29.
348
def _write_out(self, bytes):
349
self._out.write(bytes)
352
class SmartClientMediumRequest(object):
353
"""A request on a SmartClientMedium.
355
Each request allows bytes to be provided to it via accept_bytes, and then
356
the response bytes to be read via read_bytes.
359
request.accept_bytes('123')
360
request.finished_writing()
361
result = request.read_bytes(3)
362
request.finished_reading()
364
It is up to the individual SmartClientMedium whether multiple concurrent
365
requests can exist. See SmartClientMedium.get_request to obtain instances
366
of SmartClientMediumRequest, and the concrete Medium you are using for
367
details on concurrency and pipelining.
370
def __init__(self, medium):
371
"""Construct a SmartClientMediumRequest for the medium medium."""
372
self._medium = medium
373
# we track state by constants - we may want to use the same
374
# pattern as BodyReader if it gets more complex.
375
# valid states are: "writing", "reading", "done"
376
self._state = "writing"
378
def accept_bytes(self, bytes):
379
"""Accept bytes for inclusion in this request.
381
This method may not be called after finished_writing() has been
382
called. It depends upon the Medium whether or not the bytes will be
383
immediately transmitted. Message based Mediums will tend to buffer the
384
bytes until finished_writing() is called.
386
:param bytes: A bytestring.
388
if self._state != "writing":
389
raise errors.WritingCompleted(self)
390
self._accept_bytes(bytes)
392
def _accept_bytes(self, bytes):
393
"""Helper for accept_bytes.
395
Accept_bytes checks the state of the request to determing if bytes
396
should be accepted. After that it hands off to _accept_bytes to do the
399
raise NotImplementedError(self._accept_bytes)
401
def finished_reading(self):
402
"""Inform the request that all desired data has been read.
404
This will remove the request from the pipeline for its medium (if the
405
medium supports pipelining) and any further calls to methods on the
406
request will raise ReadingCompleted.
408
if self._state == "writing":
409
raise errors.WritingNotComplete(self)
410
if self._state != "reading":
411
raise errors.ReadingCompleted(self)
413
self._finished_reading()
415
def _finished_reading(self):
416
"""Helper for finished_reading.
418
finished_reading checks the state of the request to determine if
419
finished_reading is allowed, and if it is hands off to _finished_reading
420
to perform the action.
422
raise NotImplementedError(self._finished_reading)
424
def finished_writing(self):
425
"""Finish the writing phase of this request.
427
This will flush all pending data for this request along the medium.
428
After calling finished_writing, you may not call accept_bytes anymore.
430
if self._state != "writing":
431
raise errors.WritingCompleted(self)
432
self._state = "reading"
433
self._finished_writing()
435
def _finished_writing(self):
436
"""Helper for finished_writing.
438
finished_writing checks the state of the request to determine if
439
finished_writing is allowed, and if it is hands off to _finished_writing
440
to perform the action.
442
raise NotImplementedError(self._finished_writing)
444
def read_bytes(self, count):
445
"""Read bytes from this requests response.
447
This method will block and wait for count bytes to be read. It may not
448
be invoked until finished_writing() has been called - this is to ensure
449
a message-based approach to requests, for compatibility with message
450
based mediums like HTTP.
452
if self._state == "writing":
453
raise errors.WritingNotComplete(self)
454
if self._state != "reading":
455
raise errors.ReadingCompleted(self)
456
return self._read_bytes(count)
458
def _read_bytes(self, count):
459
"""Helper for SmartClientMediumRequest.read_bytes.
461
read_bytes checks the state of the request to determing if bytes
462
should be read. After that it hands off to _read_bytes to do the
465
By default this forwards to self._medium.read_bytes because we are
466
operating on the medium's stream.
468
return self._medium.read_bytes(count)
471
line = self._read_line()
472
if not line.endswith('\n'):
473
# end of file encountered reading from server
474
raise errors.ConnectionReset(
475
"Unexpected end of message. Please check connectivity "
476
"and permissions, and report a bug if problems persist.")
479
def _read_line(self):
480
"""Helper for SmartClientMediumRequest.read_line.
482
By default this forwards to self._medium._get_line because we are
483
operating on the medium's stream.
485
return self._medium._get_line()
488
class _DebugCounter(object):
489
"""An object that counts the HPSS calls made to each client medium.
491
When a medium is garbage-collected, or failing that when atexit functions
492
are run, the total number of calls made on that medium are reported via
497
self.counts = weakref.WeakKeyDictionary()
498
client._SmartClient.hooks.install_named_hook(
499
'call', self.increment_call_count, 'hpss call counter')
500
atexit.register(self.flush_all)
502
def track(self, medium):
503
"""Start tracking calls made to a medium.
505
This only keeps a weakref to the medium, so shouldn't affect the
508
medium_repr = repr(medium)
509
# Add this medium to the WeakKeyDictionary
510
self.counts[medium] = dict(count=0, vfs_count=0,
511
medium_repr=medium_repr)
512
# Weakref callbacks are fired in reverse order of their association
513
# with the referenced object. So we add a weakref *after* adding to
514
# the WeakKeyDict so that we can report the value from it before the
515
# entry is removed by the WeakKeyDict's own callback.
516
ref = weakref.ref(medium, self.done)
518
def increment_call_count(self, params):
519
# Increment the count in the WeakKeyDictionary
520
value = self.counts[params.medium]
523
request_method = request.request_handlers.get(params.method)
525
# A method we don't know about doesn't count as a VFS method.
527
if issubclass(request_method, vfs.VfsRequest):
528
value['vfs_count'] += 1
531
value = self.counts[ref]
532
count, vfs_count, medium_repr = (
533
value['count'], value['vfs_count'], value['medium_repr'])
534
# In case this callback is invoked for the same ref twice (by the
535
# weakref callback and by the atexit function), set the call count back
536
# to 0 so this item won't be reported twice.
538
value['vfs_count'] = 0
540
trace.note('HPSS calls: %d (%d vfs) %s',
541
count, vfs_count, medium_repr)
544
for ref in list(self.counts.keys()):
547
_debug_counter = None
550
class SmartClientMedium(SmartMedium):
551
"""Smart client is a medium for sending smart protocol requests over."""
553
def __init__(self, base):
554
super(SmartClientMedium, self).__init__()
556
self._protocol_version_error = None
557
self._protocol_version = None
558
self._done_hello = False
559
# Be optimistic: we assume the remote end can accept new remote
560
# requests until we get an error saying otherwise.
561
# _remote_version_is_before tracks the bzr version the remote side
562
# can be based on what we've seen so far.
563
self._remote_version_is_before = None
564
# Install debug hook function if debug flag is set.
565
if 'hpss' in debug.debug_flags:
566
global _debug_counter
567
if _debug_counter is None:
568
_debug_counter = _DebugCounter()
569
_debug_counter.track(self)
571
def _is_remote_before(self, version_tuple):
572
"""Is it possible the remote side supports RPCs for a given version?
576
needed_version = (1, 2)
577
if medium._is_remote_before(needed_version):
578
fallback_to_pre_1_2_rpc()
582
except UnknownSmartMethod:
583
medium._remember_remote_is_before(needed_version)
584
fallback_to_pre_1_2_rpc()
586
:seealso: _remember_remote_is_before
588
if self._remote_version_is_before is None:
589
# So far, the remote side seems to support everything
591
return version_tuple >= self._remote_version_is_before
593
def _remember_remote_is_before(self, version_tuple):
594
"""Tell this medium that the remote side is older the given version.
596
:seealso: _is_remote_before
598
if (self._remote_version_is_before is not None and
599
version_tuple > self._remote_version_is_before):
600
# We have been told that the remote side is older than some version
601
# which is newer than a previously supplied older-than version.
602
# This indicates that some smart verb call is not guarded
603
# appropriately (it should simply not have been tried).
604
raise AssertionError(
605
"_remember_remote_is_before(%r) called, but "
606
"_remember_remote_is_before(%r) was called previously."
607
% (version_tuple, self._remote_version_is_before))
608
self._remote_version_is_before = version_tuple
610
def protocol_version(self):
611
"""Find out if 'hello' smart request works."""
612
if self._protocol_version_error is not None:
613
raise self._protocol_version_error
614
if not self._done_hello:
616
medium_request = self.get_request()
617
# Send a 'hello' request in protocol version one, for maximum
618
# backwards compatibility.
619
client_protocol = protocol.SmartClientRequestProtocolOne(medium_request)
620
client_protocol.query_version()
621
self._done_hello = True
622
except errors.SmartProtocolError, e:
623
# Cache the error, just like we would cache a successful
625
self._protocol_version_error = e
629
def should_probe(self):
630
"""Should RemoteBzrDirFormat.probe_transport send a smart request on
633
Some transports are unambiguously smart-only; there's no need to check
634
if the transport is able to carry smart requests, because that's all
635
it is for. In those cases, this method should return False.
637
But some HTTP transports can sometimes fail to carry smart requests,
638
but still be usuable for accessing remote bzrdirs via plain file
639
accesses. So for those transports, their media should return True here
640
so that RemoteBzrDirFormat can determine if it is appropriate for that
645
def disconnect(self):
646
"""If this medium maintains a persistent connection, close it.
648
The default implementation does nothing.
651
def remote_path_from_transport(self, transport):
652
"""Convert transport into a path suitable for using in a request.
654
Note that the resulting remote path doesn't encode the host name or
655
anything but path, so it is only safe to use it in requests sent over
656
the medium from the matching transport.
658
medium_base = urlutils.join(self.base, '/')
659
rel_url = urlutils.relative_url(medium_base, transport.base)
660
return urllib.unquote(rel_url)
663
class SmartClientStreamMedium(SmartClientMedium):
664
"""Stream based medium common class.
666
SmartClientStreamMediums operate on a stream. All subclasses use a common
667
SmartClientStreamMediumRequest for their requests, and should implement
668
_accept_bytes and _read_bytes to allow the request objects to send and
672
def __init__(self, base):
673
SmartClientMedium.__init__(self, base)
674
self._current_request = None
676
def accept_bytes(self, bytes):
677
self._accept_bytes(bytes)
680
"""The SmartClientStreamMedium knows how to close the stream when it is
686
"""Flush the output stream.
688
This method is used by the SmartClientStreamMediumRequest to ensure that
689
all data for a request is sent, to avoid long timeouts or deadlocks.
691
raise NotImplementedError(self._flush)
693
def get_request(self):
694
"""See SmartClientMedium.get_request().
696
SmartClientStreamMedium always returns a SmartClientStreamMediumRequest
699
return SmartClientStreamMediumRequest(self)
702
class SmartSimplePipesClientMedium(SmartClientStreamMedium):
703
"""A client medium using simple pipes.
705
This client does not manage the pipes: it assumes they will always be open.
708
def __init__(self, readable_pipe, writeable_pipe, base):
709
SmartClientStreamMedium.__init__(self, base)
710
self._readable_pipe = readable_pipe
711
self._writeable_pipe = writeable_pipe
713
def _accept_bytes(self, bytes):
714
"""See SmartClientStreamMedium.accept_bytes."""
715
self._writeable_pipe.write(bytes)
716
self._report_activity(len(bytes), 'write')
719
"""See SmartClientStreamMedium._flush()."""
720
self._writeable_pipe.flush()
722
def _read_bytes(self, count):
723
"""See SmartClientStreamMedium._read_bytes."""
724
bytes = self._readable_pipe.read(count)
725
self._report_activity(len(bytes), 'read')
729
class SmartSSHClientMedium(SmartClientStreamMedium):
730
"""A client medium using SSH."""
732
def __init__(self, host, port=None, username=None, password=None,
733
base=None, vendor=None, bzr_remote_path=None):
734
"""Creates a client that will connect on the first use.
736
:param vendor: An optional override for the ssh vendor to use. See
737
bzrlib.transport.ssh for details on ssh vendors.
739
self._connected = False
741
self._password = password
743
self._username = username
744
# SmartClientStreamMedium stores the repr of this object in its
745
# _DebugCounter so we have to store all the values used in our repr
746
# method before calling the super init.
747
SmartClientStreamMedium.__init__(self, base)
748
self._read_from = None
749
self._ssh_connection = None
750
self._vendor = vendor
751
self._write_to = None
752
self._bzr_remote_path = bzr_remote_path
753
# for the benefit of progress making a short description of this
755
self._scheme = 'bzr+ssh'
758
return "%s(connected=%r, username=%r, host=%r, port=%r)" % (
759
self.__class__.__name__,
765
def _accept_bytes(self, bytes):
766
"""See SmartClientStreamMedium.accept_bytes."""
767
self._ensure_connection()
768
self._write_to.write(bytes)
769
self._report_activity(len(bytes), 'write')
771
def disconnect(self):
772
"""See SmartClientMedium.disconnect()."""
773
if not self._connected:
775
self._read_from.close()
776
self._write_to.close()
777
self._ssh_connection.close()
778
self._connected = False
780
def _ensure_connection(self):
781
"""Connect this medium if not already connected."""
784
if self._vendor is None:
785
vendor = ssh._get_ssh_vendor()
787
vendor = self._vendor
788
self._ssh_connection = vendor.connect_ssh(self._username,
789
self._password, self._host, self._port,
790
command=[self._bzr_remote_path, 'serve', '--inet',
791
'--directory=/', '--allow-writes'])
792
self._read_from, self._write_to = \
793
self._ssh_connection.get_filelike_channels()
794
self._connected = True
797
"""See SmartClientStreamMedium._flush()."""
798
self._write_to.flush()
800
def _read_bytes(self, count):
801
"""See SmartClientStreamMedium.read_bytes."""
802
if not self._connected:
803
raise errors.MediumNotConnected(self)
804
bytes_to_read = min(count, _MAX_READ_SIZE)
805
bytes = self._read_from.read(bytes_to_read)
806
self._report_activity(len(bytes), 'read')
810
# Port 4155 is the default port for bzr://, registered with IANA.
811
BZR_DEFAULT_INTERFACE = None
812
BZR_DEFAULT_PORT = 4155
815
class SmartTCPClientMedium(SmartClientStreamMedium):
816
"""A client medium using TCP."""
818
def __init__(self, host, port, base):
819
"""Creates a client that will connect on the first use."""
820
SmartClientStreamMedium.__init__(self, base)
821
self._connected = False
826
def _accept_bytes(self, bytes):
827
"""See SmartClientMedium.accept_bytes."""
828
self._ensure_connection()
829
osutils.send_all(self._socket, bytes, self._report_activity)
831
def disconnect(self):
832
"""See SmartClientMedium.disconnect()."""
833
if not self._connected:
837
self._connected = False
839
def _ensure_connection(self):
840
"""Connect this medium if not already connected."""
843
if self._port is None:
844
port = BZR_DEFAULT_PORT
846
port = int(self._port)
848
sockaddrs = socket.getaddrinfo(self._host, port, socket.AF_UNSPEC,
849
socket.SOCK_STREAM, 0, 0)
850
except socket.gaierror, (err_num, err_msg):
851
raise errors.ConnectionError("failed to lookup %s:%d: %s" %
852
(self._host, port, err_msg))
853
# Initialize err in case there are no addresses returned:
854
err = socket.error("no address found for %s" % self._host)
855
for (family, socktype, proto, canonname, sockaddr) in sockaddrs:
857
self._socket = socket.socket(family, socktype, proto)
858
self._socket.setsockopt(socket.IPPROTO_TCP,
859
socket.TCP_NODELAY, 1)
860
self._socket.connect(sockaddr)
861
except socket.error, err:
862
if self._socket is not None:
867
if self._socket is None:
868
# socket errors either have a (string) or (errno, string) as their
870
if type(err.args) is str:
873
err_msg = err.args[1]
874
raise errors.ConnectionError("failed to connect to %s:%d: %s" %
875
(self._host, port, err_msg))
876
self._connected = True
879
"""See SmartClientStreamMedium._flush().
881
For TCP we do no flushing. We may want to turn off TCP_NODELAY and
882
add a means to do a flush, but that can be done in the future.
885
def _read_bytes(self, count):
886
"""See SmartClientMedium.read_bytes."""
887
if not self._connected:
888
raise errors.MediumNotConnected(self)
889
return _read_bytes_from_socket(
890
self._socket.recv, count, self._report_activity)
893
class SmartClientStreamMediumRequest(SmartClientMediumRequest):
894
"""A SmartClientMediumRequest that works with an SmartClientStreamMedium."""
896
def __init__(self, medium):
897
SmartClientMediumRequest.__init__(self, medium)
898
# check that we are safe concurrency wise. If some streams start
899
# allowing concurrent requests - i.e. via multiplexing - then this
900
# assert should be moved to SmartClientStreamMedium.get_request,
901
# and the setting/unsetting of _current_request likewise moved into
902
# that class : but its unneeded overhead for now. RBC 20060922
903
if self._medium._current_request is not None:
904
raise errors.TooManyConcurrentRequests(self._medium)
905
self._medium._current_request = self
907
def _accept_bytes(self, bytes):
908
"""See SmartClientMediumRequest._accept_bytes.
910
This forwards to self._medium._accept_bytes because we are operating
911
on the mediums stream.
913
self._medium._accept_bytes(bytes)
915
def _finished_reading(self):
916
"""See SmartClientMediumRequest._finished_reading.
918
This clears the _current_request on self._medium to allow a new
919
request to be created.
921
if self._medium._current_request is not self:
922
raise AssertionError()
923
self._medium._current_request = None
925
def _finished_writing(self):
926
"""See SmartClientMediumRequest._finished_writing.
928
This invokes self._medium._flush to ensure all bytes are transmitted.
930
self._medium._flush()
933
def _read_bytes_from_socket(sock, desired_count, report_activity):
934
# We ignore the desired_count because on sockets it's more efficient to
935
# read large chunks (of _MAX_READ_SIZE bytes) at a time.
937
bytes = osutils.until_no_eintr(sock, _MAX_READ_SIZE)
938
except socket.error, e:
939
if len(e.args) and e.args[0] in (errno.ECONNRESET, 10054):
940
# The connection was closed by the other side. Callers expect an
941
# empty string to signal end-of-stream.
946
report_activity(len(bytes), 'read')
added
removed
bzrlib/smart/medium.py
