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
# We ignore the desired_count because on sockets it's more efficient to
289
# read large chunks (of _MAX_READ_SIZE bytes) at a time.
290
bytes = osutils.until_no_eintr(self.socket.recv, _MAX_READ_SIZE)
291
self._report_activity(len(bytes), 'read')
294
def terminate_due_to_error(self):
295
# TODO: This should log to a server log file, but no such thing
296
# exists yet. Andrew Bennetts 2006-09-29.
300
def _write_out(self, bytes):
301
osutils.send_all(self.socket, bytes, self._report_activity)
304
class SmartServerPipeStreamMedium(SmartServerStreamMedium):
306
def __init__(self, in_file, out_file, backing_transport):
307
"""Construct new server.
309
:param in_file: Python file from which requests can be read.
310
:param out_file: Python file to write responses.
311
:param backing_transport: Transport for the directory served.
313
SmartServerStreamMedium.__init__(self, backing_transport)
314
if sys.platform == 'win32':
315
# force binary mode for files
317
for f in (in_file, out_file):
318
fileno = getattr(f, 'fileno', None)
320
msvcrt.setmode(fileno(), os.O_BINARY)
324
def _serve_one_request_unguarded(self, protocol):
326
# We need to be careful not to read past the end of the current
327
# request, or else the read from the pipe will block, so we use
328
# protocol.next_read_size().
329
bytes_to_read = protocol.next_read_size()
330
if bytes_to_read == 0:
331
# Finished serving this request.
334
bytes = self.read_bytes(bytes_to_read)
336
# Connection has been closed.
340
protocol.accept_bytes(bytes)
342
def _read_bytes(self, desired_count):
343
return self._in.read(desired_count)
345
def terminate_due_to_error(self):
346
# TODO: This should log to a server log file, but no such thing
347
# exists yet. Andrew Bennetts 2006-09-29.
351
def _write_out(self, bytes):
352
self._out.write(bytes)
355
class SmartClientMediumRequest(object):
356
"""A request on a SmartClientMedium.
358
Each request allows bytes to be provided to it via accept_bytes, and then
359
the response bytes to be read via read_bytes.
362
request.accept_bytes('123')
363
request.finished_writing()
364
result = request.read_bytes(3)
365
request.finished_reading()
367
It is up to the individual SmartClientMedium whether multiple concurrent
368
requests can exist. See SmartClientMedium.get_request to obtain instances
369
of SmartClientMediumRequest, and the concrete Medium you are using for
370
details on concurrency and pipelining.
373
def __init__(self, medium):
374
"""Construct a SmartClientMediumRequest for the medium medium."""
375
self._medium = medium
376
# we track state by constants - we may want to use the same
377
# pattern as BodyReader if it gets more complex.
378
# valid states are: "writing", "reading", "done"
379
self._state = "writing"
381
def accept_bytes(self, bytes):
382
"""Accept bytes for inclusion in this request.
384
This method may not be called after finished_writing() has been
385
called. It depends upon the Medium whether or not the bytes will be
386
immediately transmitted. Message based Mediums will tend to buffer the
387
bytes until finished_writing() is called.
389
:param bytes: A bytestring.
391
if self._state != "writing":
392
raise errors.WritingCompleted(self)
393
self._accept_bytes(bytes)
395
def _accept_bytes(self, bytes):
396
"""Helper for accept_bytes.
398
Accept_bytes checks the state of the request to determing if bytes
399
should be accepted. After that it hands off to _accept_bytes to do the
402
raise NotImplementedError(self._accept_bytes)
404
def finished_reading(self):
405
"""Inform the request that all desired data has been read.
407
This will remove the request from the pipeline for its medium (if the
408
medium supports pipelining) and any further calls to methods on the
409
request will raise ReadingCompleted.
411
if self._state == "writing":
412
raise errors.WritingNotComplete(self)
413
if self._state != "reading":
414
raise errors.ReadingCompleted(self)
416
self._finished_reading()
418
def _finished_reading(self):
419
"""Helper for finished_reading.
421
finished_reading checks the state of the request to determine if
422
finished_reading is allowed, and if it is hands off to _finished_reading
423
to perform the action.
425
raise NotImplementedError(self._finished_reading)
427
def finished_writing(self):
428
"""Finish the writing phase of this request.
430
This will flush all pending data for this request along the medium.
431
After calling finished_writing, you may not call accept_bytes anymore.
433
if self._state != "writing":
434
raise errors.WritingCompleted(self)
435
self._state = "reading"
436
self._finished_writing()
438
def _finished_writing(self):
439
"""Helper for finished_writing.
441
finished_writing checks the state of the request to determine if
442
finished_writing is allowed, and if it is hands off to _finished_writing
443
to perform the action.
445
raise NotImplementedError(self._finished_writing)
447
def read_bytes(self, count):
448
"""Read bytes from this requests response.
450
This method will block and wait for count bytes to be read. It may not
451
be invoked until finished_writing() has been called - this is to ensure
452
a message-based approach to requests, for compatibility with message
453
based mediums like HTTP.
455
if self._state == "writing":
456
raise errors.WritingNotComplete(self)
457
if self._state != "reading":
458
raise errors.ReadingCompleted(self)
459
return self._read_bytes(count)
461
def _read_bytes(self, count):
462
"""Helper for SmartClientMediumRequest.read_bytes.
464
read_bytes checks the state of the request to determing if bytes
465
should be read. After that it hands off to _read_bytes to do the
468
By default this forwards to self._medium.read_bytes because we are
469
operating on the medium's stream.
471
return self._medium.read_bytes(count)
474
line = self._read_line()
475
if not line.endswith('\n'):
476
# end of file encountered reading from server
477
raise errors.ConnectionReset(
478
"please check connectivity and permissions")
481
def _read_line(self):
482
"""Helper for SmartClientMediumRequest.read_line.
484
By default this forwards to self._medium._get_line because we are
485
operating on the medium's stream.
487
return self._medium._get_line()
490
class _DebugCounter(object):
491
"""An object that counts the HPSS calls made to each client medium.
493
When a medium is garbage-collected, or failing that when atexit functions
494
are run, the total number of calls made on that medium are reported via
499
self.counts = weakref.WeakKeyDictionary()
500
client._SmartClient.hooks.install_named_hook(
501
'call', self.increment_call_count, 'hpss call counter')
502
atexit.register(self.flush_all)
504
def track(self, medium):
505
"""Start tracking calls made to a medium.
507
This only keeps a weakref to the medium, so shouldn't affect the
510
medium_repr = repr(medium)
511
# Add this medium to the WeakKeyDictionary
512
self.counts[medium] = dict(count=0, vfs_count=0,
513
medium_repr=medium_repr)
514
# Weakref callbacks are fired in reverse order of their association
515
# with the referenced object. So we add a weakref *after* adding to
516
# the WeakKeyDict so that we can report the value from it before the
517
# entry is removed by the WeakKeyDict's own callback.
518
ref = weakref.ref(medium, self.done)
520
def increment_call_count(self, params):
521
# Increment the count in the WeakKeyDictionary
522
value = self.counts[params.medium]
524
request_method = request.request_handlers.get(params.method)
525
if issubclass(request_method, vfs.VfsRequest):
526
value['vfs_count'] += 1
529
value = self.counts[ref]
530
count, vfs_count, medium_repr = (
531
value['count'], value['vfs_count'], value['medium_repr'])
532
# In case this callback is invoked for the same ref twice (by the
533
# weakref callback and by the atexit function), set the call count back
534
# to 0 so this item won't be reported twice.
536
value['vfs_count'] = 0
538
trace.note('HPSS calls: %d (%d vfs) %s',
539
count, vfs_count, medium_repr)
542
for ref in list(self.counts.keys()):
545
_debug_counter = None
548
class SmartClientMedium(SmartMedium):
549
"""Smart client is a medium for sending smart protocol requests over."""
551
def __init__(self, base):
552
super(SmartClientMedium, self).__init__()
554
self._protocol_version_error = None
555
self._protocol_version = None
556
self._done_hello = False
557
# Be optimistic: we assume the remote end can accept new remote
558
# requests until we get an error saying otherwise.
559
# _remote_version_is_before tracks the bzr version the remote side
560
# can be based on what we've seen so far.
561
self._remote_version_is_before = None
562
# Install debug hook function if debug flag is set.
563
if 'hpss' in debug.debug_flags:
564
global _debug_counter
565
if _debug_counter is None:
566
_debug_counter = _DebugCounter()
567
_debug_counter.track(self)
569
def _is_remote_before(self, version_tuple):
570
"""Is it possible the remote side supports RPCs for a given version?
574
needed_version = (1, 2)
575
if medium._is_remote_before(needed_version):
576
fallback_to_pre_1_2_rpc()
580
except UnknownSmartMethod:
581
medium._remember_remote_is_before(needed_version)
582
fallback_to_pre_1_2_rpc()
584
:seealso: _remember_remote_is_before
586
if self._remote_version_is_before is None:
587
# So far, the remote side seems to support everything
589
return version_tuple >= self._remote_version_is_before
591
def _remember_remote_is_before(self, version_tuple):
592
"""Tell this medium that the remote side is older the given version.
594
:seealso: _is_remote_before
596
if (self._remote_version_is_before is not None and
597
version_tuple > self._remote_version_is_before):
598
# We have been told that the remote side is older than some version
599
# which is newer than a previously supplied older-than version.
600
# This indicates that some smart verb call is not guarded
601
# appropriately (it should simply not have been tried).
602
raise AssertionError(
603
"_remember_remote_is_before(%r) called, but "
604
"_remember_remote_is_before(%r) was called previously."
605
% (version_tuple, self._remote_version_is_before))
606
self._remote_version_is_before = version_tuple
608
def protocol_version(self):
609
"""Find out if 'hello' smart request works."""
610
if self._protocol_version_error is not None:
611
raise self._protocol_version_error
612
if not self._done_hello:
614
medium_request = self.get_request()
615
# Send a 'hello' request in protocol version one, for maximum
616
# backwards compatibility.
617
client_protocol = protocol.SmartClientRequestProtocolOne(medium_request)
618
client_protocol.query_version()
619
self._done_hello = True
620
except errors.SmartProtocolError, e:
621
# Cache the error, just like we would cache a successful
623
self._protocol_version_error = e
627
def should_probe(self):
628
"""Should RemoteBzrDirFormat.probe_transport send a smart request on
631
Some transports are unambiguously smart-only; there's no need to check
632
if the transport is able to carry smart requests, because that's all
633
it is for. In those cases, this method should return False.
635
But some HTTP transports can sometimes fail to carry smart requests,
636
but still be usuable for accessing remote bzrdirs via plain file
637
accesses. So for those transports, their media should return True here
638
so that RemoteBzrDirFormat can determine if it is appropriate for that
643
def disconnect(self):
644
"""If this medium maintains a persistent connection, close it.
646
The default implementation does nothing.
649
def remote_path_from_transport(self, transport):
650
"""Convert transport into a path suitable for using in a request.
652
Note that the resulting remote path doesn't encode the host name or
653
anything but path, so it is only safe to use it in requests sent over
654
the medium from the matching transport.
656
medium_base = urlutils.join(self.base, '/')
657
rel_url = urlutils.relative_url(medium_base, transport.base)
658
return urllib.unquote(rel_url)
661
class SmartClientStreamMedium(SmartClientMedium):
662
"""Stream based medium common class.
664
SmartClientStreamMediums operate on a stream. All subclasses use a common
665
SmartClientStreamMediumRequest for their requests, and should implement
666
_accept_bytes and _read_bytes to allow the request objects to send and
670
def __init__(self, base):
671
SmartClientMedium.__init__(self, base)
672
self._current_request = None
674
def accept_bytes(self, bytes):
675
self._accept_bytes(bytes)
678
"""The SmartClientStreamMedium knows how to close the stream when it is
684
"""Flush the output stream.
686
This method is used by the SmartClientStreamMediumRequest to ensure that
687
all data for a request is sent, to avoid long timeouts or deadlocks.
689
raise NotImplementedError(self._flush)
691
def get_request(self):
692
"""See SmartClientMedium.get_request().
694
SmartClientStreamMedium always returns a SmartClientStreamMediumRequest
697
return SmartClientStreamMediumRequest(self)
700
class SmartSimplePipesClientMedium(SmartClientStreamMedium):
701
"""A client medium using simple pipes.
703
This client does not manage the pipes: it assumes they will always be open.
706
def __init__(self, readable_pipe, writeable_pipe, base):
707
SmartClientStreamMedium.__init__(self, base)
708
self._readable_pipe = readable_pipe
709
self._writeable_pipe = writeable_pipe
711
def _accept_bytes(self, bytes):
712
"""See SmartClientStreamMedium.accept_bytes."""
713
self._writeable_pipe.write(bytes)
714
self._report_activity(len(bytes), 'write')
717
"""See SmartClientStreamMedium._flush()."""
718
self._writeable_pipe.flush()
720
def _read_bytes(self, count):
721
"""See SmartClientStreamMedium._read_bytes."""
722
bytes = self._readable_pipe.read(count)
723
self._report_activity(len(bytes), 'read')
727
class SmartSSHClientMedium(SmartClientStreamMedium):
728
"""A client medium using SSH."""
730
def __init__(self, host, port=None, username=None, password=None,
731
base=None, vendor=None, bzr_remote_path=None):
732
"""Creates a client that will connect on the first use.
734
:param vendor: An optional override for the ssh vendor to use. See
735
bzrlib.transport.ssh for details on ssh vendors.
737
self._connected = False
739
self._password = password
741
self._username = username
742
# SmartClientStreamMedium stores the repr of this object in its
743
# _DebugCounter so we have to store all the values used in our repr
744
# method before calling the super init.
745
SmartClientStreamMedium.__init__(self, base)
746
self._read_from = None
747
self._ssh_connection = None
748
self._vendor = vendor
749
self._write_to = None
750
self._bzr_remote_path = bzr_remote_path
751
# for the benefit of progress making a short description of this
753
self._scheme = 'bzr+ssh'
756
return "%s(connected=%r, username=%r, host=%r, port=%r)" % (
757
self.__class__.__name__,
763
def _accept_bytes(self, bytes):
764
"""See SmartClientStreamMedium.accept_bytes."""
765
self._ensure_connection()
766
self._write_to.write(bytes)
767
self._report_activity(len(bytes), 'write')
769
def disconnect(self):
770
"""See SmartClientMedium.disconnect()."""
771
if not self._connected:
773
self._read_from.close()
774
self._write_to.close()
775
self._ssh_connection.close()
776
self._connected = False
778
def _ensure_connection(self):
779
"""Connect this medium if not already connected."""
782
if self._vendor is None:
783
vendor = ssh._get_ssh_vendor()
785
vendor = self._vendor
786
self._ssh_connection = vendor.connect_ssh(self._username,
787
self._password, self._host, self._port,
788
command=[self._bzr_remote_path, 'serve', '--inet',
789
'--directory=/', '--allow-writes'])
790
self._read_from, self._write_to = \
791
self._ssh_connection.get_filelike_channels()
792
self._connected = True
795
"""See SmartClientStreamMedium._flush()."""
796
self._write_to.flush()
798
def _read_bytes(self, count):
799
"""See SmartClientStreamMedium.read_bytes."""
800
if not self._connected:
801
raise errors.MediumNotConnected(self)
802
bytes_to_read = min(count, _MAX_READ_SIZE)
803
bytes = self._read_from.read(bytes_to_read)
804
self._report_activity(len(bytes), 'read')
808
# Port 4155 is the default port for bzr://, registered with IANA.
809
BZR_DEFAULT_INTERFACE = None
810
BZR_DEFAULT_PORT = 4155
813
class SmartTCPClientMedium(SmartClientStreamMedium):
814
"""A client medium using TCP."""
816
def __init__(self, host, port, base):
817
"""Creates a client that will connect on the first use."""
818
SmartClientStreamMedium.__init__(self, base)
819
self._connected = False
824
def _accept_bytes(self, bytes):
825
"""See SmartClientMedium.accept_bytes."""
826
self._ensure_connection()
827
osutils.send_all(self._socket, bytes, self._report_activity)
829
def disconnect(self):
830
"""See SmartClientMedium.disconnect()."""
831
if not self._connected:
835
self._connected = False
837
def _ensure_connection(self):
838
"""Connect this medium if not already connected."""
841
if self._port is None:
842
port = BZR_DEFAULT_PORT
844
port = int(self._port)
846
sockaddrs = socket.getaddrinfo(self._host, port, socket.AF_UNSPEC,
847
socket.SOCK_STREAM, 0, 0)
848
except socket.gaierror, (err_num, err_msg):
849
raise errors.ConnectionError("failed to lookup %s:%d: %s" %
850
(self._host, port, err_msg))
851
# Initialize err in case there are no addresses returned:
852
err = socket.error("no address found for %s" % self._host)
853
for (family, socktype, proto, canonname, sockaddr) in sockaddrs:
855
self._socket = socket.socket(family, socktype, proto)
856
self._socket.setsockopt(socket.IPPROTO_TCP,
857
socket.TCP_NODELAY, 1)
858
self._socket.connect(sockaddr)
859
except socket.error, err:
860
if self._socket is not None:
865
if self._socket is None:
866
# socket errors either have a (string) or (errno, string) as their
868
if type(err.args) is str:
871
err_msg = err.args[1]
872
raise errors.ConnectionError("failed to connect to %s:%d: %s" %
873
(self._host, port, err_msg))
874
self._connected = True
877
"""See SmartClientStreamMedium._flush().
879
For TCP we do no flushing. We may want to turn off TCP_NODELAY and
880
add a means to do a flush, but that can be done in the future.
883
def _read_bytes(self, count):
884
"""See SmartClientMedium.read_bytes."""
885
if not self._connected:
886
raise errors.MediumNotConnected(self)
887
# We ignore the desired_count because on sockets it's more efficient to
888
# read large chunks (of _MAX_READ_SIZE bytes) at a time.
890
bytes = osutils.until_no_eintr(self._socket.recv, _MAX_READ_SIZE)
891
except socket.error, e:
892
if len(e.args) and e.args[0] == errno.ECONNRESET:
893
# Callers expect an empty string in that case
898
self._report_activity(len(bytes), 'read')
902
class SmartClientStreamMediumRequest(SmartClientMediumRequest):
903
"""A SmartClientMediumRequest that works with an SmartClientStreamMedium."""
905
def __init__(self, medium):
906
SmartClientMediumRequest.__init__(self, medium)
907
# check that we are safe concurrency wise. If some streams start
908
# allowing concurrent requests - i.e. via multiplexing - then this
909
# assert should be moved to SmartClientStreamMedium.get_request,
910
# and the setting/unsetting of _current_request likewise moved into
911
# that class : but its unneeded overhead for now. RBC 20060922
912
if self._medium._current_request is not None:
913
raise errors.TooManyConcurrentRequests(self._medium)
914
self._medium._current_request = self
916
def _accept_bytes(self, bytes):
917
"""See SmartClientMediumRequest._accept_bytes.
919
This forwards to self._medium._accept_bytes because we are operating
920
on the mediums stream.
922
self._medium._accept_bytes(bytes)
924
def _finished_reading(self):
925
"""See SmartClientMediumRequest._finished_reading.
927
This clears the _current_request on self._medium to allow a new
928
request to be created.
930
if self._medium._current_request is not self:
931
raise AssertionError()
932
self._medium._current_request = None
934
def _finished_writing(self):
935
"""See SmartClientMediumRequest._finished_writing.
937
This invokes self._medium._flush to ensure all bytes are transmitted.
939
self._medium._flush()
added
removed
bzrlib/smart/medium.py
