1
# Copyright (C) 2006, 2007 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
"""Wire-level encoding and decoding of requests and responses for the smart
22
from cStringIO import StringIO
28
from bzrlib import debug
29
from bzrlib import errors
30
from bzrlib.smart import message, request
31
from bzrlib.trace import log_exception_quietly, mutter
32
from bzrlib.util.bencode import bdecode_as_tuple, bencode
35
# Protocol version strings. These are sent as prefixes of bzr requests and
36
# responses to identify the protocol version being used. (There are no version
37
# one strings because that version doesn't send any).
38
REQUEST_VERSION_TWO = 'bzr request 2\n'
39
RESPONSE_VERSION_TWO = 'bzr response 2\n'
41
MESSAGE_VERSION_THREE = 'bzr message 3 (bzr 1.6)\n'
42
RESPONSE_VERSION_THREE = REQUEST_VERSION_THREE = MESSAGE_VERSION_THREE
45
def _recv_tuple(from_file):
46
req_line = from_file.readline()
47
return _decode_tuple(req_line)
50
def _decode_tuple(req_line):
51
if req_line is None or req_line == '':
53
if req_line[-1] != '\n':
54
raise errors.SmartProtocolError("request %r not terminated" % req_line)
55
return tuple(req_line[:-1].split('\x01'))
58
def _encode_tuple(args):
59
"""Encode the tuple args to a bytestream."""
60
return '\x01'.join(args) + '\n'
63
class Requester(object):
64
"""Abstract base class for an object that can issue requests on a smart
68
def call(self, *args):
69
"""Make a remote call.
71
:param args: the arguments of this call.
73
raise NotImplementedError(self.call)
75
def call_with_body_bytes(self, args, body):
76
"""Make a remote call with a body.
78
:param args: the arguments of this call.
80
:param body: the body to send with the request.
82
raise NotImplementedError(self.call_with_body_bytes)
84
def call_with_body_readv_array(self, args, body):
85
"""Make a remote call with a readv array.
87
:param args: the arguments of this call.
88
:type body: iterable of (start, length) tuples.
89
:param body: the readv ranges to send with this request.
91
raise NotImplementedError(self.call_with_body_readv_array)
93
def set_headers(self, headers):
94
raise NotImplementedError(self.set_headers)
97
class SmartProtocolBase(object):
98
"""Methods common to client and server"""
100
# TODO: this only actually accomodates a single block; possibly should
101
# support multiple chunks?
102
def _encode_bulk_data(self, body):
103
"""Encode body as a bulk data chunk."""
104
return ''.join(('%d\n' % len(body), body, 'done\n'))
106
def _serialise_offsets(self, offsets):
107
"""Serialise a readv offset list."""
109
for start, length in offsets:
110
txt.append('%d,%d' % (start, length))
111
return '\n'.join(txt)
114
class SmartServerRequestProtocolOne(SmartProtocolBase):
115
"""Server-side encoding and decoding logic for smart version 1."""
117
def __init__(self, backing_transport, write_func, root_client_path='/'):
118
self._backing_transport = backing_transport
119
self._root_client_path = root_client_path
120
self.unused_data = ''
121
self._finished = False
123
self._has_dispatched = False
125
self._body_decoder = None
126
self._write_func = write_func
128
def accept_bytes(self, bytes):
129
"""Take bytes, and advance the internal state machine appropriately.
131
:param bytes: must be a byte string
133
if not isinstance(bytes, str):
134
raise ValueError(bytes)
135
self.in_buffer += bytes
136
if not self._has_dispatched:
137
if '\n' not in self.in_buffer:
138
# no command line yet
140
self._has_dispatched = True
142
first_line, self.in_buffer = self.in_buffer.split('\n', 1)
144
req_args = _decode_tuple(first_line)
145
self.request = request.SmartServerRequestHandler(
146
self._backing_transport, commands=request.request_handlers,
147
root_client_path=self._root_client_path)
148
self.request.dispatch_command(req_args[0], req_args[1:])
149
if self.request.finished_reading:
151
self.unused_data = self.in_buffer
153
self._send_response(self.request.response)
154
except KeyboardInterrupt:
156
except errors.UnknownSmartMethod, err:
157
protocol_error = errors.SmartProtocolError(
158
"bad request %r" % (err.verb,))
159
failure = request.FailedSmartServerResponse(
160
('error', str(protocol_error)))
161
self._send_response(failure)
163
except Exception, exception:
164
# everything else: pass to client, flush, and quit
165
log_exception_quietly()
166
self._send_response(request.FailedSmartServerResponse(
167
('error', str(exception))))
170
if self._has_dispatched:
172
# nothing to do.XXX: this routine should be a single state
174
self.unused_data += self.in_buffer
177
if self._body_decoder is None:
178
self._body_decoder = LengthPrefixedBodyDecoder()
179
self._body_decoder.accept_bytes(self.in_buffer)
180
self.in_buffer = self._body_decoder.unused_data
181
body_data = self._body_decoder.read_pending_data()
182
self.request.accept_body(body_data)
183
if self._body_decoder.finished_reading:
184
self.request.end_of_body()
185
if not self.request.finished_reading:
186
raise AssertionError("no more body, request not finished")
187
if self.request.response is not None:
188
self._send_response(self.request.response)
189
self.unused_data = self.in_buffer
192
if self.request.finished_reading:
193
raise AssertionError(
194
"no response and we have finished reading.")
196
def _send_response(self, response):
197
"""Send a smart server response down the output stream."""
199
raise AssertionError('response already sent')
202
self._finished = True
203
self._write_protocol_version()
204
self._write_success_or_failure_prefix(response)
205
self._write_func(_encode_tuple(args))
207
if not isinstance(body, str):
208
raise ValueError(body)
209
bytes = self._encode_bulk_data(body)
210
self._write_func(bytes)
212
def _write_protocol_version(self):
213
"""Write any prefixes this protocol requires.
215
Version one doesn't send protocol versions.
218
def _write_success_or_failure_prefix(self, response):
219
"""Write the protocol specific success/failure prefix.
221
For SmartServerRequestProtocolOne this is omitted but we
222
call is_successful to ensure that the response is valid.
224
response.is_successful()
226
def next_read_size(self):
229
if self._body_decoder is None:
232
return self._body_decoder.next_read_size()
235
class SmartServerRequestProtocolTwo(SmartServerRequestProtocolOne):
236
r"""Version two of the server side of the smart protocol.
238
This prefixes responses with the value of RESPONSE_VERSION_TWO.
241
response_marker = RESPONSE_VERSION_TWO
242
request_marker = REQUEST_VERSION_TWO
244
def _write_success_or_failure_prefix(self, response):
245
"""Write the protocol specific success/failure prefix."""
246
if response.is_successful():
247
self._write_func('success\n')
249
self._write_func('failed\n')
251
def _write_protocol_version(self):
252
r"""Write any prefixes this protocol requires.
254
Version two sends the value of RESPONSE_VERSION_TWO.
256
self._write_func(self.response_marker)
258
def _send_response(self, response):
259
"""Send a smart server response down the output stream."""
261
raise AssertionError('response already sent')
262
self._finished = True
263
self._write_protocol_version()
264
self._write_success_or_failure_prefix(response)
265
self._write_func(_encode_tuple(response.args))
266
if response.body is not None:
267
if not isinstance(response.body, str):
268
raise AssertionError('body must be a str')
269
if not (response.body_stream is None):
270
raise AssertionError(
271
'body_stream and body cannot both be set')
272
bytes = self._encode_bulk_data(response.body)
273
self._write_func(bytes)
274
elif response.body_stream is not None:
275
_send_stream(response.body_stream, self._write_func)
278
def _send_stream(stream, write_func):
279
write_func('chunked\n')
280
_send_chunks(stream, write_func)
284
def _send_chunks(stream, write_func):
286
if isinstance(chunk, str):
287
bytes = "%x\n%s" % (len(chunk), chunk)
289
elif isinstance(chunk, request.FailedSmartServerResponse):
291
_send_chunks(chunk.args, write_func)
294
raise errors.BzrError(
295
'Chunks must be str or FailedSmartServerResponse, got %r'
299
class _NeedMoreBytes(Exception):
300
"""Raise this inside a _StatefulDecoder to stop decoding until more bytes
304
def __init__(self, count=None):
307
:param count: the total number of bytes needed by the current state.
308
May be None if the number of bytes needed is unknown.
313
class _StatefulDecoder(object):
314
"""Base class for writing state machines to decode byte streams.
316
Subclasses should provide a self.state_accept attribute that accepts bytes
317
and, if appropriate, updates self.state_accept to a different function.
318
accept_bytes will call state_accept as often as necessary to make sure the
319
state machine has progressed as far as possible before it returns.
321
See ProtocolThreeDecoder for an example subclass.
325
self.finished_reading = False
326
self._in_buffer_list = []
327
self._in_buffer_len = 0
328
self.unused_data = ''
329
self.bytes_left = None
330
self._number_needed_bytes = None
332
def _get_in_buffer(self):
333
if len(self._in_buffer_list) == 1:
334
return self._in_buffer_list[0]
335
in_buffer = ''.join(self._in_buffer_list)
336
if len(in_buffer) != self._in_buffer_len:
337
raise AssertionError(
338
"Length of buffer did not match expected value: %s != %s"
339
% self._in_buffer_len, len(in_buffer))
340
self._in_buffer_list = [in_buffer]
343
def _get_in_bytes(self, count):
344
"""Grab X bytes from the input_buffer.
346
Callers should have already checked that self._in_buffer_len is >
347
count. Note, this does not consume the bytes from the buffer. The
348
caller will still need to call _get_in_buffer() and then
349
_set_in_buffer() if they actually need to consume the bytes.
351
# check if we can yield the bytes from just the first entry in our list
352
if len(self._in_buffer_list) == 0:
353
raise AssertionError('Callers must be sure we have buffered bytes'
354
' before calling _get_in_bytes')
355
if len(self._in_buffer_list[0]) > count:
356
return self._in_buffer_list[0][:count]
357
# We can't yield it from the first buffer, so collapse all buffers, and
359
in_buf = self._get_in_buffer()
360
return in_buf[:count]
362
def _set_in_buffer(self, new_buf):
363
if new_buf is not None:
364
self._in_buffer_list = [new_buf]
365
self._in_buffer_len = len(new_buf)
367
self._in_buffer_list = []
368
self._in_buffer_len = 0
370
def accept_bytes(self, bytes):
371
"""Decode as much of bytes as possible.
373
If 'bytes' contains too much data it will be appended to
376
finished_reading will be set when no more data is required. Further
377
data will be appended to self.unused_data.
379
# accept_bytes is allowed to change the state
380
self._number_needed_bytes = None
381
# lsprof puts a very large amount of time on this specific call for
383
self._in_buffer_list.append(bytes)
384
self._in_buffer_len += len(bytes)
386
# Run the function for the current state.
387
current_state = self.state_accept
389
while current_state != self.state_accept:
390
# The current state has changed. Run the function for the new
391
# current state, so that it can:
392
# - decode any unconsumed bytes left in a buffer, and
393
# - signal how many more bytes are expected (via raising
395
current_state = self.state_accept
397
except _NeedMoreBytes, e:
398
self._number_needed_bytes = e.count
401
class ChunkedBodyDecoder(_StatefulDecoder):
402
"""Decoder for chunked body data.
404
This is very similar the HTTP's chunked encoding. See the description of
405
streamed body data in `doc/developers/network-protocol.txt` for details.
409
_StatefulDecoder.__init__(self)
410
self.state_accept = self._state_accept_expecting_header
411
self.chunk_in_progress = None
412
self.chunks = collections.deque()
414
self.error_in_progress = None
416
def next_read_size(self):
417
# Note: the shortest possible chunk is 2 bytes: '0\n', and the
418
# end-of-body marker is 4 bytes: 'END\n'.
419
if self.state_accept == self._state_accept_reading_chunk:
420
# We're expecting more chunk content. So we're expecting at least
421
# the rest of this chunk plus an END chunk.
422
return self.bytes_left + 4
423
elif self.state_accept == self._state_accept_expecting_length:
424
if self._in_buffer_len == 0:
425
# We're expecting a chunk length. There's at least two bytes
426
# left: a digit plus '\n'.
429
# We're in the middle of reading a chunk length. So there's at
430
# least one byte left, the '\n' that terminates the length.
432
elif self.state_accept == self._state_accept_reading_unused:
434
elif self.state_accept == self._state_accept_expecting_header:
435
return max(0, len('chunked\n') - self._in_buffer_len)
437
raise AssertionError("Impossible state: %r" % (self.state_accept,))
439
def read_next_chunk(self):
441
return self.chunks.popleft()
445
def _extract_line(self):
446
in_buf = self._get_in_buffer()
447
pos = in_buf.find('\n')
449
# We haven't read a complete line yet, so request more bytes before
451
raise _NeedMoreBytes(1)
453
# Trim the prefix (including '\n' delimiter) from the _in_buffer.
454
self._set_in_buffer(in_buf[pos+1:])
458
self.unused_data = self._get_in_buffer()
459
self._in_buffer_list = []
460
self._in_buffer_len = 0
461
self.state_accept = self._state_accept_reading_unused
463
error_args = tuple(self.error_in_progress)
464
self.chunks.append(request.FailedSmartServerResponse(error_args))
465
self.error_in_progress = None
466
self.finished_reading = True
468
def _state_accept_expecting_header(self):
469
prefix = self._extract_line()
470
if prefix == 'chunked':
471
self.state_accept = self._state_accept_expecting_length
473
raise errors.SmartProtocolError(
474
'Bad chunked body header: "%s"' % (prefix,))
476
def _state_accept_expecting_length(self):
477
prefix = self._extract_line()
480
self.error_in_progress = []
481
self._state_accept_expecting_length()
483
elif prefix == 'END':
484
# We've read the end-of-body marker.
485
# Any further bytes are unused data, including the bytes left in
490
self.bytes_left = int(prefix, 16)
491
self.chunk_in_progress = ''
492
self.state_accept = self._state_accept_reading_chunk
494
def _state_accept_reading_chunk(self):
495
in_buf = self._get_in_buffer()
496
in_buffer_len = len(in_buf)
497
self.chunk_in_progress += in_buf[:self.bytes_left]
498
self._set_in_buffer(in_buf[self.bytes_left:])
499
self.bytes_left -= in_buffer_len
500
if self.bytes_left <= 0:
501
# Finished with chunk
502
self.bytes_left = None
504
self.error_in_progress.append(self.chunk_in_progress)
506
self.chunks.append(self.chunk_in_progress)
507
self.chunk_in_progress = None
508
self.state_accept = self._state_accept_expecting_length
510
def _state_accept_reading_unused(self):
511
self.unused_data += self._get_in_buffer()
512
self._in_buffer_list = []
515
class LengthPrefixedBodyDecoder(_StatefulDecoder):
516
"""Decodes the length-prefixed bulk data."""
519
_StatefulDecoder.__init__(self)
520
self.state_accept = self._state_accept_expecting_length
521
self.state_read = self._state_read_no_data
523
self._trailer_buffer = ''
525
def next_read_size(self):
526
if self.bytes_left is not None:
527
# Ideally we want to read all the remainder of the body and the
529
return self.bytes_left + 5
530
elif self.state_accept == self._state_accept_reading_trailer:
531
# Just the trailer left
532
return 5 - len(self._trailer_buffer)
533
elif self.state_accept == self._state_accept_expecting_length:
534
# There's still at least 6 bytes left ('\n' to end the length, plus
538
# Reading excess data. Either way, 1 byte at a time is fine.
541
def read_pending_data(self):
542
"""Return any pending data that has been decoded."""
543
return self.state_read()
545
def _state_accept_expecting_length(self):
546
in_buf = self._get_in_buffer()
547
pos = in_buf.find('\n')
550
self.bytes_left = int(in_buf[:pos])
551
self._set_in_buffer(in_buf[pos+1:])
552
self.state_accept = self._state_accept_reading_body
553
self.state_read = self._state_read_body_buffer
555
def _state_accept_reading_body(self):
556
in_buf = self._get_in_buffer()
558
self.bytes_left -= len(in_buf)
559
self._set_in_buffer(None)
560
if self.bytes_left <= 0:
562
if self.bytes_left != 0:
563
self._trailer_buffer = self._body[self.bytes_left:]
564
self._body = self._body[:self.bytes_left]
565
self.bytes_left = None
566
self.state_accept = self._state_accept_reading_trailer
568
def _state_accept_reading_trailer(self):
569
self._trailer_buffer += self._get_in_buffer()
570
self._set_in_buffer(None)
571
# TODO: what if the trailer does not match "done\n"? Should this raise
572
# a ProtocolViolation exception?
573
if self._trailer_buffer.startswith('done\n'):
574
self.unused_data = self._trailer_buffer[len('done\n'):]
575
self.state_accept = self._state_accept_reading_unused
576
self.finished_reading = True
578
def _state_accept_reading_unused(self):
579
self.unused_data += self._get_in_buffer()
580
self._set_in_buffer(None)
582
def _state_read_no_data(self):
585
def _state_read_body_buffer(self):
591
class SmartClientRequestProtocolOne(SmartProtocolBase, Requester,
592
message.ResponseHandler):
593
"""The client-side protocol for smart version 1."""
595
def __init__(self, request):
596
"""Construct a SmartClientRequestProtocolOne.
598
:param request: A SmartClientMediumRequest to serialise onto and
601
self._request = request
602
self._body_buffer = None
603
self._request_start_time = None
604
self._last_verb = None
607
def set_headers(self, headers):
608
self._headers = dict(headers)
610
def call(self, *args):
611
if 'hpss' in debug.debug_flags:
612
mutter('hpss call: %s', repr(args)[1:-1])
613
if getattr(self._request._medium, 'base', None) is not None:
614
mutter(' (to %s)', self._request._medium.base)
615
self._request_start_time = time.time()
616
self._write_args(args)
617
self._request.finished_writing()
618
self._last_verb = args[0]
620
def call_with_body_bytes(self, args, body):
621
"""Make a remote call of args with body bytes 'body'.
623
After calling this, call read_response_tuple to find the result out.
625
if 'hpss' in debug.debug_flags:
626
mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
627
if getattr(self._request._medium, '_path', None) is not None:
628
mutter(' (to %s)', self._request._medium._path)
629
mutter(' %d bytes', len(body))
630
self._request_start_time = time.time()
631
if 'hpssdetail' in debug.debug_flags:
632
mutter('hpss body content: %s', body)
633
self._write_args(args)
634
bytes = self._encode_bulk_data(body)
635
self._request.accept_bytes(bytes)
636
self._request.finished_writing()
637
self._last_verb = args[0]
639
def call_with_body_readv_array(self, args, body):
640
"""Make a remote call with a readv array.
642
The body is encoded with one line per readv offset pair. The numbers in
643
each pair are separated by a comma, and no trailing \n is emitted.
645
if 'hpss' in debug.debug_flags:
646
mutter('hpss call w/readv: %s', repr(args)[1:-1])
647
if getattr(self._request._medium, '_path', None) is not None:
648
mutter(' (to %s)', self._request._medium._path)
649
self._request_start_time = time.time()
650
self._write_args(args)
651
readv_bytes = self._serialise_offsets(body)
652
bytes = self._encode_bulk_data(readv_bytes)
653
self._request.accept_bytes(bytes)
654
self._request.finished_writing()
655
if 'hpss' in debug.debug_flags:
656
mutter(' %d bytes in readv request', len(readv_bytes))
657
self._last_verb = args[0]
659
def call_with_body_stream(self, args, stream):
660
# Protocols v1 and v2 don't support body streams. So it's safe to
661
# assume that a v1/v2 server doesn't support whatever method we're
662
# trying to call with a body stream.
663
self._request.finished_writing()
664
self._request.finished_reading()
665
raise errors.UnknownSmartMethod(args[0])
667
def cancel_read_body(self):
668
"""After expecting a body, a response code may indicate one otherwise.
670
This method lets the domain client inform the protocol that no body
671
will be transmitted. This is a terminal method: after calling it the
672
protocol is not able to be used further.
674
self._request.finished_reading()
676
def _read_response_tuple(self):
677
result = self._recv_tuple()
678
if 'hpss' in debug.debug_flags:
679
if self._request_start_time is not None:
680
mutter(' result: %6.3fs %s',
681
time.time() - self._request_start_time,
683
self._request_start_time = None
685
mutter(' result: %s', repr(result)[1:-1])
688
def read_response_tuple(self, expect_body=False):
689
"""Read a response tuple from the wire.
691
This should only be called once.
693
result = self._read_response_tuple()
694
self._response_is_unknown_method(result)
695
self._raise_args_if_error(result)
697
self._request.finished_reading()
700
def _raise_args_if_error(self, result_tuple):
701
# Later protocol versions have an explicit flag in the protocol to say
702
# if an error response is "failed" or not. In version 1 we don't have
703
# that luxury. So here is a complete list of errors that can be
704
# returned in response to existing version 1 smart requests. Responses
705
# starting with these codes are always "failed" responses.
712
'UnicodeEncodeError',
713
'UnicodeDecodeError',
719
'UnlockableTransport',
725
if result_tuple[0] in v1_error_codes:
726
self._request.finished_reading()
727
raise errors.ErrorFromSmartServer(result_tuple)
729
def _response_is_unknown_method(self, result_tuple):
730
"""Raise UnexpectedSmartServerResponse if the response is an 'unknonwn
731
method' response to the request.
733
:param response: The response from a smart client call_expecting_body
735
:param verb: The verb used in that call.
736
:raises: UnexpectedSmartServerResponse
738
if (result_tuple == ('error', "Generic bzr smart protocol error: "
739
"bad request '%s'" % self._last_verb) or
740
result_tuple == ('error', "Generic bzr smart protocol error: "
741
"bad request u'%s'" % self._last_verb)):
742
# The response will have no body, so we've finished reading.
743
self._request.finished_reading()
744
raise errors.UnknownSmartMethod(self._last_verb)
746
def read_body_bytes(self, count=-1):
747
"""Read bytes from the body, decoding into a byte stream.
749
We read all bytes at once to ensure we've checked the trailer for
750
errors, and then feed the buffer back as read_body_bytes is called.
752
if self._body_buffer is not None:
753
return self._body_buffer.read(count)
754
_body_decoder = LengthPrefixedBodyDecoder()
756
while not _body_decoder.finished_reading:
757
bytes = self._request.read_bytes(_body_decoder.next_read_size())
759
# end of file encountered reading from server
760
raise errors.ConnectionReset(
761
"Connection lost while reading response body.")
762
_body_decoder.accept_bytes(bytes)
763
self._request.finished_reading()
764
self._body_buffer = StringIO(_body_decoder.read_pending_data())
765
# XXX: TODO check the trailer result.
766
if 'hpss' in debug.debug_flags:
767
mutter(' %d body bytes read',
768
len(self._body_buffer.getvalue()))
769
return self._body_buffer.read(count)
771
def _recv_tuple(self):
772
"""Receive a tuple from the medium request."""
773
return _decode_tuple(self._request.read_line())
775
def query_version(self):
776
"""Return protocol version number of the server."""
778
resp = self.read_response_tuple()
779
if resp == ('ok', '1'):
781
elif resp == ('ok', '2'):
784
raise errors.SmartProtocolError("bad response %r" % (resp,))
786
def _write_args(self, args):
787
self._write_protocol_version()
788
bytes = _encode_tuple(args)
789
self._request.accept_bytes(bytes)
791
def _write_protocol_version(self):
792
"""Write any prefixes this protocol requires.
794
Version one doesn't send protocol versions.
798
class SmartClientRequestProtocolTwo(SmartClientRequestProtocolOne):
799
"""Version two of the client side of the smart protocol.
801
This prefixes the request with the value of REQUEST_VERSION_TWO.
804
response_marker = RESPONSE_VERSION_TWO
805
request_marker = REQUEST_VERSION_TWO
807
def read_response_tuple(self, expect_body=False):
808
"""Read a response tuple from the wire.
810
This should only be called once.
812
version = self._request.read_line()
813
if version != self.response_marker:
814
self._request.finished_reading()
815
raise errors.UnexpectedProtocolVersionMarker(version)
816
response_status = self._request.read_line()
817
result = SmartClientRequestProtocolOne._read_response_tuple(self)
818
self._response_is_unknown_method(result)
819
if response_status == 'success\n':
820
self.response_status = True
822
self._request.finished_reading()
824
elif response_status == 'failed\n':
825
self.response_status = False
826
self._request.finished_reading()
827
raise errors.ErrorFromSmartServer(result)
829
raise errors.SmartProtocolError(
830
'bad protocol status %r' % response_status)
832
def _write_protocol_version(self):
833
"""Write any prefixes this protocol requires.
835
Version two sends the value of REQUEST_VERSION_TWO.
837
self._request.accept_bytes(self.request_marker)
839
def read_streamed_body(self):
840
"""Read bytes from the body, decoding into a byte stream.
842
# Read no more than 64k at a time so that we don't risk error 10055 (no
843
# buffer space available) on Windows.
844
_body_decoder = ChunkedBodyDecoder()
845
while not _body_decoder.finished_reading:
846
bytes = self._request.read_bytes(_body_decoder.next_read_size())
848
# end of file encountered reading from server
849
raise errors.ConnectionReset(
850
"Connection lost while reading streamed body.")
851
_body_decoder.accept_bytes(bytes)
852
for body_bytes in iter(_body_decoder.read_next_chunk, None):
853
if 'hpss' in debug.debug_flags and type(body_bytes) is str:
854
mutter(' %d byte chunk read',
857
self._request.finished_reading()
860
def build_server_protocol_three(backing_transport, write_func,
862
request_handler = request.SmartServerRequestHandler(
863
backing_transport, commands=request.request_handlers,
864
root_client_path=root_client_path)
865
responder = ProtocolThreeResponder(write_func)
866
message_handler = message.ConventionalRequestHandler(request_handler, responder)
867
return ProtocolThreeDecoder(message_handler)
870
class ProtocolThreeDecoder(_StatefulDecoder):
872
response_marker = RESPONSE_VERSION_THREE
873
request_marker = REQUEST_VERSION_THREE
875
def __init__(self, message_handler, expect_version_marker=False):
876
_StatefulDecoder.__init__(self)
877
self._has_dispatched = False
879
if expect_version_marker:
880
self.state_accept = self._state_accept_expecting_protocol_version
881
# We're expecting at least the protocol version marker + some
883
self._number_needed_bytes = len(MESSAGE_VERSION_THREE) + 4
885
self.state_accept = self._state_accept_expecting_headers
886
self._number_needed_bytes = 4
887
self.decoding_failed = False
888
self.request_handler = self.message_handler = message_handler
890
def accept_bytes(self, bytes):
891
self._number_needed_bytes = None
893
_StatefulDecoder.accept_bytes(self, bytes)
894
except KeyboardInterrupt:
896
except errors.SmartMessageHandlerError, exception:
897
# We do *not* set self.decoding_failed here. The message handler
898
# has raised an error, but the decoder is still able to parse bytes
899
# and determine when this message ends.
900
log_exception_quietly()
901
self.message_handler.protocol_error(exception.exc_value)
902
# The state machine is ready to continue decoding, but the
903
# exception has interrupted the loop that runs the state machine.
904
# So we call accept_bytes again to restart it.
905
self.accept_bytes('')
906
except Exception, exception:
907
# The decoder itself has raised an exception. We cannot continue
909
self.decoding_failed = True
910
if isinstance(exception, errors.UnexpectedProtocolVersionMarker):
911
# This happens during normal operation when the client tries a
912
# protocol version the server doesn't understand, so no need to
913
# log a traceback every time.
914
# Note that this can only happen when
915
# expect_version_marker=True, which is only the case on the
919
log_exception_quietly()
920
self.message_handler.protocol_error(exception)
922
def _extract_length_prefixed_bytes(self):
923
if self._in_buffer_len < 4:
924
# A length prefix by itself is 4 bytes, and we don't even have that
926
raise _NeedMoreBytes(4)
927
(length,) = struct.unpack('!L', self._get_in_bytes(4))
928
end_of_bytes = 4 + length
929
if self._in_buffer_len < end_of_bytes:
930
# We haven't yet read as many bytes as the length-prefix says there
932
raise _NeedMoreBytes(end_of_bytes)
933
# Extract the bytes from the buffer.
934
in_buf = self._get_in_buffer()
935
bytes = in_buf[4:end_of_bytes]
936
self._set_in_buffer(in_buf[end_of_bytes:])
939
def _extract_prefixed_bencoded_data(self):
940
prefixed_bytes = self._extract_length_prefixed_bytes()
942
decoded = bdecode_as_tuple(prefixed_bytes)
944
raise errors.SmartProtocolError(
945
'Bytes %r not bencoded' % (prefixed_bytes,))
948
def _extract_single_byte(self):
949
if self._in_buffer_len == 0:
950
# The buffer is empty
951
raise _NeedMoreBytes(1)
952
in_buf = self._get_in_buffer()
954
self._set_in_buffer(in_buf[1:])
957
def _state_accept_expecting_protocol_version(self):
958
needed_bytes = len(MESSAGE_VERSION_THREE) - self._in_buffer_len
959
in_buf = self._get_in_buffer()
961
# We don't have enough bytes to check if the protocol version
962
# marker is right. But we can check if it is already wrong by
963
# checking that the start of MESSAGE_VERSION_THREE matches what
965
# [In fact, if the remote end isn't bzr we might never receive
966
# len(MESSAGE_VERSION_THREE) bytes. So if the bytes we have so far
967
# are wrong then we should just raise immediately rather than
969
if not MESSAGE_VERSION_THREE.startswith(in_buf):
970
# We have enough bytes to know the protocol version is wrong
971
raise errors.UnexpectedProtocolVersionMarker(in_buf)
972
raise _NeedMoreBytes(len(MESSAGE_VERSION_THREE))
973
if not in_buf.startswith(MESSAGE_VERSION_THREE):
974
raise errors.UnexpectedProtocolVersionMarker(in_buf)
975
self._set_in_buffer(in_buf[len(MESSAGE_VERSION_THREE):])
976
self.state_accept = self._state_accept_expecting_headers
978
def _state_accept_expecting_headers(self):
979
decoded = self._extract_prefixed_bencoded_data()
980
if type(decoded) is not dict:
981
raise errors.SmartProtocolError(
982
'Header object %r is not a dict' % (decoded,))
983
self.state_accept = self._state_accept_expecting_message_part
985
self.message_handler.headers_received(decoded)
987
raise errors.SmartMessageHandlerError(sys.exc_info())
989
def _state_accept_expecting_message_part(self):
990
message_part_kind = self._extract_single_byte()
991
if message_part_kind == 'o':
992
self.state_accept = self._state_accept_expecting_one_byte
993
elif message_part_kind == 's':
994
self.state_accept = self._state_accept_expecting_structure
995
elif message_part_kind == 'b':
996
self.state_accept = self._state_accept_expecting_bytes
997
elif message_part_kind == 'e':
1000
raise errors.SmartProtocolError(
1001
'Bad message kind byte: %r' % (message_part_kind,))
1003
def _state_accept_expecting_one_byte(self):
1004
byte = self._extract_single_byte()
1005
self.state_accept = self._state_accept_expecting_message_part
1007
self.message_handler.byte_part_received(byte)
1009
raise errors.SmartMessageHandlerError(sys.exc_info())
1011
def _state_accept_expecting_bytes(self):
1012
# XXX: this should not buffer whole message part, but instead deliver
1013
# the bytes as they arrive.
1014
prefixed_bytes = self._extract_length_prefixed_bytes()
1015
self.state_accept = self._state_accept_expecting_message_part
1017
self.message_handler.bytes_part_received(prefixed_bytes)
1019
raise errors.SmartMessageHandlerError(sys.exc_info())
1021
def _state_accept_expecting_structure(self):
1022
structure = self._extract_prefixed_bencoded_data()
1023
self.state_accept = self._state_accept_expecting_message_part
1025
self.message_handler.structure_part_received(structure)
1027
raise errors.SmartMessageHandlerError(sys.exc_info())
1030
self.unused_data = self._get_in_buffer()
1031
self._set_in_buffer(None)
1032
self.state_accept = self._state_accept_reading_unused
1034
self.message_handler.end_received()
1036
raise errors.SmartMessageHandlerError(sys.exc_info())
1038
def _state_accept_reading_unused(self):
1039
self.unused_data = self._get_in_buffer()
1040
self._set_in_buffer(None)
1042
def next_read_size(self):
1043
if self.state_accept == self._state_accept_reading_unused:
1045
elif self.decoding_failed:
1046
# An exception occured while processing this message, probably from
1047
# self.message_handler. We're not sure that this state machine is
1048
# in a consistent state, so just signal that we're done (i.e. give
1052
if self._number_needed_bytes is not None:
1053
return self._number_needed_bytes - self._in_buffer_len
1055
raise AssertionError("don't know how many bytes are expected!")
1058
class _ProtocolThreeEncoder(object):
1060
response_marker = request_marker = MESSAGE_VERSION_THREE
1062
def __init__(self, write_func):
1064
self._real_write_func = write_func
1066
def _write_func(self, bytes):
1067
self._buf.append(bytes)
1068
if len(self._buf) > 100:
1073
self._real_write_func(''.join(self._buf))
1076
def _serialise_offsets(self, offsets):
1077
"""Serialise a readv offset list."""
1079
for start, length in offsets:
1080
txt.append('%d,%d' % (start, length))
1081
return '\n'.join(txt)
1083
def _write_protocol_version(self):
1084
self._write_func(MESSAGE_VERSION_THREE)
1086
def _write_prefixed_bencode(self, structure):
1087
bytes = bencode(structure)
1088
self._write_func(struct.pack('!L', len(bytes)))
1089
self._write_func(bytes)
1091
def _write_headers(self, headers):
1092
self._write_prefixed_bencode(headers)
1094
def _write_structure(self, args):
1095
self._write_func('s')
1098
if type(arg) is unicode:
1099
utf8_args.append(arg.encode('utf8'))
1101
utf8_args.append(arg)
1102
self._write_prefixed_bencode(utf8_args)
1104
def _write_end(self):
1105
self._write_func('e')
1108
def _write_prefixed_body(self, bytes):
1109
self._write_func('b')
1110
self._write_func(struct.pack('!L', len(bytes)))
1111
self._write_func(bytes)
1113
def _write_chunked_body_start(self):
1114
self._write_func('oC')
1116
def _write_error_status(self):
1117
self._write_func('oE')
1119
def _write_success_status(self):
1120
self._write_func('oS')
1123
class ProtocolThreeResponder(_ProtocolThreeEncoder):
1125
def __init__(self, write_func):
1126
_ProtocolThreeEncoder.__init__(self, write_func)
1127
self.response_sent = False
1128
self._headers = {'Software version': bzrlib.__version__}
1130
def send_error(self, exception):
1131
if self.response_sent:
1132
raise AssertionError(
1133
"send_error(%s) called, but response already sent."
1135
if isinstance(exception, errors.UnknownSmartMethod):
1136
failure = request.FailedSmartServerResponse(
1137
('UnknownMethod', exception.verb))
1138
self.send_response(failure)
1140
self.response_sent = True
1141
self._write_protocol_version()
1142
self._write_headers(self._headers)
1143
self._write_error_status()
1144
self._write_structure(('error', str(exception)))
1147
def send_response(self, response):
1148
if self.response_sent:
1149
raise AssertionError(
1150
"send_response(%r) called, but response already sent."
1152
self.response_sent = True
1153
self._write_protocol_version()
1154
self._write_headers(self._headers)
1155
if response.is_successful():
1156
self._write_success_status()
1158
self._write_error_status()
1159
self._write_structure(response.args)
1160
if response.body is not None:
1161
self._write_prefixed_body(response.body)
1162
elif response.body_stream is not None:
1163
for exc_info, chunk in _iter_with_errors(response.body_stream):
1164
if exc_info is not None:
1165
self._write_error_status()
1166
error_struct = request._translate_error(exc_info[1])
1167
self._write_structure(error_struct)
1170
if isinstance(chunk, request.FailedSmartServerResponse):
1171
self._write_error_status()
1172
self._write_structure(chunk.args)
1174
self._write_prefixed_body(chunk)
1178
def _iter_with_errors(iterable):
1179
"""Handle errors from iterable.next().
1183
for exc_info, value in _iter_with_errors(iterable):
1186
This is a safer alternative to::
1189
for value in iterable:
1194
Because the latter will catch errors from the for-loop body, not just
1197
If an error occurs, exc_info will be a exc_info tuple, and the generator
1198
will terminate. Otherwise exc_info will be None, and value will be the
1199
value from iterable.next(). Note that KeyboardInterrupt and SystemExit
1200
will not be itercepted.
1202
iterator = iter(iterable)
1205
yield None, iterator.next()
1206
except StopIteration:
1208
except (KeyboardInterrupt, SystemExit):
1211
yield sys.exc_info(), None
1215
class ProtocolThreeRequester(_ProtocolThreeEncoder, Requester):
1217
def __init__(self, medium_request):
1218
_ProtocolThreeEncoder.__init__(self, medium_request.accept_bytes)
1219
self._medium_request = medium_request
1222
def set_headers(self, headers):
1223
self._headers = headers.copy()
1225
def call(self, *args):
1226
if 'hpss' in debug.debug_flags:
1227
mutter('hpss call: %s', repr(args)[1:-1])
1228
base = getattr(self._medium_request._medium, 'base', None)
1229
if base is not None:
1230
mutter(' (to %s)', base)
1231
self._request_start_time = time.time()
1232
self._write_protocol_version()
1233
self._write_headers(self._headers)
1234
self._write_structure(args)
1236
self._medium_request.finished_writing()
1238
def call_with_body_bytes(self, args, body):
1239
"""Make a remote call of args with body bytes 'body'.
1241
After calling this, call read_response_tuple to find the result out.
1243
if 'hpss' in debug.debug_flags:
1244
mutter('hpss call w/body: %s (%r...)', repr(args)[1:-1], body[:20])
1245
path = getattr(self._medium_request._medium, '_path', None)
1246
if path is not None:
1247
mutter(' (to %s)', path)
1248
mutter(' %d bytes', len(body))
1249
self._request_start_time = time.time()
1250
self._write_protocol_version()
1251
self._write_headers(self._headers)
1252
self._write_structure(args)
1253
self._write_prefixed_body(body)
1255
self._medium_request.finished_writing()
1257
def call_with_body_readv_array(self, args, body):
1258
"""Make a remote call with a readv array.
1260
The body is encoded with one line per readv offset pair. The numbers in
1261
each pair are separated by a comma, and no trailing \n is emitted.
1263
if 'hpss' in debug.debug_flags:
1264
mutter('hpss call w/readv: %s', repr(args)[1:-1])
1265
path = getattr(self._medium_request._medium, '_path', None)
1266
if path is not None:
1267
mutter(' (to %s)', path)
1268
self._request_start_time = time.time()
1269
self._write_protocol_version()
1270
self._write_headers(self._headers)
1271
self._write_structure(args)
1272
readv_bytes = self._serialise_offsets(body)
1273
if 'hpss' in debug.debug_flags:
1274
mutter(' %d bytes in readv request', len(readv_bytes))
1275
self._write_prefixed_body(readv_bytes)
1277
self._medium_request.finished_writing()
1279
def call_with_body_stream(self, args, stream):
1280
if 'hpss' in debug.debug_flags:
1281
mutter('hpss call w/body stream: %r', args)
1282
path = getattr(self._medium_request._medium, '_path', None)
1283
if path is not None:
1284
mutter(' (to %s)', path)
1285
self._request_start_time = time.time()
1286
self._write_protocol_version()
1287
self._write_headers(self._headers)
1288
self._write_structure(args)
1289
# TODO: notice if the server has sent an early error reply before we
1290
# have finished sending the stream. We would notice at the end
1291
# anyway, but if the medium can deliver it early then it's good
1292
# to short-circuit the whole request...
1293
for exc_info, part in _iter_with_errors(stream):
1294
if exc_info is not None:
1295
# Iterating the stream failed. Cleanly abort the request.
1296
self._write_error_status()
1297
# Currently the client unconditionally sends ('error',) as the
1299
self._write_structure(('error',))
1301
self._medium_request.finished_writing()
1302
raise exc_info[0], exc_info[1], exc_info[2]
1304
self._write_prefixed_body(part)
1307
self._medium_request.finished_writing()
added
removed
bzrlib/smart/protocol.py
