135
class _SFTPReadvHelper(object):
136
"""A class to help with managing the state of a readv request."""
138
# See _get_requests for an explanation.
139
_max_request_size = 32768
141
def __init__(self, original_offsets, relpath, _report_activity):
142
"""Create a new readv helper.
144
:param original_offsets: The original requests given by the caller of
146
:param relpath: The name of the file (if known)
147
:param _report_activity: A Transport._report_activity bound method,
148
to be called as data arrives.
150
self.original_offsets = list(original_offsets)
151
self.relpath = relpath
152
self._report_activity = _report_activity
154
def _get_requests(self):
155
"""Break up the offsets into individual requests over sftp.
157
The SFTP spec only requires implementers to support 32kB requests. We
158
could try something larger (openssh supports 64kB), but then we have to
159
handle requests that fail.
160
So instead, we just break up our maximum chunks into 32kB chunks, and
161
asyncronously requests them.
162
Newer versions of paramiko would do the chunking for us, but we want to
163
start processing results right away, so we do it ourselves.
165
# TODO: Because we issue async requests, we don't 'fudge' any extra
166
# data. I'm not 100% sure that is the best choice.
168
# The first thing we do, is to collapse the individual requests as much
169
# as possible, so we don't issues requests <32kB
170
sorted_offsets = sorted(self.original_offsets)
171
coalesced = list(ConnectedTransport._coalesce_offsets(sorted_offsets,
172
limit=0, fudge_factor=0))
174
for c_offset in coalesced:
175
start = c_offset.start
176
size = c_offset.length
178
# Break this up into 32kB requests
180
next_size = min(size, self._max_request_size)
181
requests.append((start, next_size))
184
if 'sftp' in debug.debug_flags:
185
mutter('SFTP.readv(%s) %s offsets => %s coalesced => %s requests',
186
self.relpath, len(sorted_offsets), len(coalesced),
190
def request_and_yield_offsets(self, fp):
191
"""Request the data from the remote machine, yielding the results.
193
:param fp: A Paramiko SFTPFile object that supports readv.
194
:return: Yield the data requested by the original readv caller, one by
197
requests = self._get_requests()
198
offset_iter = iter(self.original_offsets)
199
cur_offset, cur_size = offset_iter.next()
200
# paramiko .readv() yields strings that are in the order of the requests
201
# So we track the current request to know where the next data is
202
# being returned from.
208
# This is used to buffer chunks which we couldn't process yet
209
# It is (start, end, data) tuples.
211
# Create an 'unlimited' data stream, so we stop based on requests,
212
# rather than just because the data stream ended. This lets us detect
214
data_stream = itertools.chain(fp.readv(requests),
215
itertools.repeat(None))
216
for (start, length), data in itertools.izip(requests, data_stream):
218
if cur_coalesced is not None:
219
raise errors.ShortReadvError(self.relpath,
220
start, length, len(data))
221
if len(data) != length:
222
raise errors.ShortReadvError(self.relpath,
223
start, length, len(data))
224
self._report_activity(length, 'read')
226
# This is the first request, just buffer it
227
buffered_data = [data]
228
buffered_len = length
230
elif start == last_end:
231
# The data we are reading fits neatly on the previous
232
# buffer, so this is all part of a larger coalesced range.
233
buffered_data.append(data)
234
buffered_len += length
236
# We have an 'interrupt' in the data stream. So we know we are
237
# at a request boundary.
239
# We haven't consumed the buffer so far, so put it into
240
# data_chunks, and continue.
241
buffered = ''.join(buffered_data)
242
data_chunks.append((input_start, buffered))
244
buffered_data = [data]
245
buffered_len = length
246
last_end = start + length
247
if input_start == cur_offset and cur_size <= buffered_len:
248
# Simplify the next steps a bit by transforming buffered_data
249
# into a single string. We also have the nice property that
250
# when there is only one string ''.join([x]) == x, so there is
252
buffered = ''.join(buffered_data)
253
# Clean out buffered data so that we keep memory
257
# TODO: We *could* also consider the case where cur_offset is in
258
# in the buffered range, even though it doesn't *start*
259
# the buffered range. But for packs we pretty much always
260
# read in order, so you won't get any extra data in the
262
while (input_start == cur_offset
263
and (buffered_offset + cur_size) <= buffered_len):
264
# We've buffered enough data to process this request, spit it
266
cur_data = buffered[buffered_offset:buffered_offset + cur_size]
267
# move the direct pointer into our buffered data
268
buffered_offset += cur_size
269
# Move the start-of-buffer pointer
270
input_start += cur_size
271
# Yield the requested data
272
yield cur_offset, cur_data
273
cur_offset, cur_size = offset_iter.next()
274
# at this point, we've consumed as much of buffered as we can,
275
# so break off the portion that we consumed
276
if buffered_offset == len(buffered_data):
277
# No tail to leave behind
281
buffered = buffered[buffered_offset:]
282
buffered_data = [buffered]
283
buffered_len = len(buffered)
285
buffered = ''.join(buffered_data)
287
data_chunks.append((input_start, buffered))
289
if 'sftp' in debug.debug_flags:
290
mutter('SFTP readv left with %d out-of-order bytes',
291
sum(map(lambda x: len(x[1]), data_chunks)))
292
# We've processed all the readv data, at this point, anything we
293
# couldn't process is in data_chunks. This doesn't happen often, so
294
# this code path isn't optimized
295
# We use an interesting process for data_chunks
296
# Specifically if we have "bisect_left([(start, len, entries)],
298
# If start == qstart, then we get the specific node. Otherwise we
299
# get the previous node
301
idx = bisect.bisect_left(data_chunks, (cur_offset,))
302
if idx < len(data_chunks) and data_chunks[idx][0] == cur_offset:
303
# The data starts here
304
data = data_chunks[idx][1][:cur_size]
306
# The data is in a portion of a previous page
308
sub_offset = cur_offset - data_chunks[idx][0]
309
data = data_chunks[idx][1]
310
data = data[sub_offset:sub_offset + cur_size]
312
# We are missing the page where the data should be found,
315
if len(data) != cur_size:
316
raise AssertionError('We must have miscalulated.'
317
' We expected %d bytes, but only found %d'
318
% (cur_size, len(data)))
319
yield cur_offset, data
320
cur_offset, cur_size = offset_iter.next()
323
133
class SFTPTransport(ConnectedTransport):
324
134
"""Transport implementation for SFTP access."""
454
245
readv = getattr(fp, 'readv', None)
456
247
return self._sftp_readv(fp, offsets, relpath)
457
if 'sftp' in debug.debug_flags:
458
mutter('seek and read %s offsets', len(offsets))
248
mutter('seek and read %s offsets', len(offsets))
459
249
return self._seek_and_read(fp, offsets, relpath)
460
250
except (IOError, paramiko.SSHException), e:
461
251
self._translate_io_exception(e, path, ': error retrieving')
463
def recommended_page_size(self):
464
"""See Transport.recommended_page_size().
466
For SFTP we suggest a large page size to reduce the overhead
467
introduced by latency.
471
def _sftp_readv(self, fp, offsets, relpath):
253
def _sftp_readv(self, fp, offsets, relpath='<unknown>'):
472
254
"""Use the readv() member of fp to do async readv.
474
Then read them using paramiko.readv(). paramiko.readv()
256
And then read them using paramiko.readv(). paramiko.readv()
475
257
does not support ranges > 64K, so it caps the request size, and
476
just reads until it gets all the stuff it wants.
258
just reads until it gets all the stuff it wants
478
helper = _SFTPReadvHelper(offsets, relpath, self._report_activity)
479
return helper.request_and_yield_offsets(fp)
260
offsets = list(offsets)
261
sorted_offsets = sorted(offsets)
263
# The algorithm works as follows:
264
# 1) Coalesce nearby reads into a single chunk
265
# This generates a list of combined regions, the total size
266
# and the size of the sub regions. This coalescing step is limited
267
# in the number of nearby chunks to combine, and is allowed to
268
# skip small breaks in the requests. Limiting it makes sure that
269
# we can start yielding some data earlier, and skipping means we
270
# make fewer requests. (Beneficial even when using async)
271
# 2) Break up this combined regions into chunks that are smaller
272
# than 64KiB. Technically the limit is 65536, but we are a
273
# little bit conservative. This is because sftp has a maximum
274
# return chunk size of 64KiB (max size of an unsigned short)
275
# 3) Issue a readv() to paramiko to create an async request for
277
# 4) Read in the data as it comes back, until we've read one
278
# continuous section as determined in step 1
279
# 5) Break up the full sections into hunks for the original requested
280
# offsets. And put them in a cache
281
# 6) Check if the next request is in the cache, and if it is, remove
282
# it from the cache, and yield its data. Continue until no more
283
# entries are in the cache.
284
# 7) loop back to step 4 until all data has been read
286
# TODO: jam 20060725 This could be optimized one step further, by
287
# attempting to yield whatever data we have read, even before
288
# the first coallesced section has been fully processed.
290
# When coalescing for use with readv(), we don't really need to
291
# use any fudge factor, because the requests are made asynchronously
292
coalesced = list(self._coalesce_offsets(sorted_offsets,
293
limit=self._max_readv_combine,
297
for c_offset in coalesced:
298
start = c_offset.start
299
size = c_offset.length
301
# We need to break this up into multiple requests
303
next_size = min(size, self._max_request_size)
304
requests.append((start, next_size))
308
mutter('SFTP.readv() %s offsets => %s coalesced => %s requests',
309
len(offsets), len(coalesced), len(requests))
311
# Queue the current read until we have read the full coalesced section
314
cur_coalesced_stack = iter(coalesced)
315
cur_coalesced = cur_coalesced_stack.next()
317
# Cache the results, but only until they have been fulfilled
319
# turn the list of offsets into a stack
320
offset_stack = iter(offsets)
321
cur_offset_and_size = offset_stack.next()
323
for data in fp.readv(requests):
325
cur_data_len += len(data)
327
if cur_data_len < cur_coalesced.length:
329
assert cur_data_len == cur_coalesced.length, \
330
"Somehow we read too much: %s != %s" % (cur_data_len,
331
cur_coalesced.length)
332
all_data = ''.join(cur_data)
336
for suboffset, subsize in cur_coalesced.ranges:
337
key = (cur_coalesced.start+suboffset, subsize)
338
data_map[key] = all_data[suboffset:suboffset+subsize]
340
# Now that we've read some data, see if we can yield anything back
341
while cur_offset_and_size in data_map:
342
this_data = data_map.pop(cur_offset_and_size)
343
yield cur_offset_and_size[0], this_data
344
cur_offset_and_size = offset_stack.next()
346
# We read a coalesced entry, so mark it as done
348
# Now that we've read all of the data for this coalesced section
350
cur_coalesced = cur_coalesced_stack.next()
352
if cur_coalesced is not None:
353
raise errors.ShortReadvError(relpath, cur_coalesced.start,
354
cur_coalesced.length, len(data))
481
356
def put_file(self, relpath, f, mode=None):
712
# ------------- server test implementation --------------
715
from bzrlib.tests.stub_sftp import StubServer, StubSFTPServer
717
STUB_SERVER_KEY = """
718
-----BEGIN RSA PRIVATE KEY-----
719
MIICWgIBAAKBgQDTj1bqB4WmayWNPB+8jVSYpZYk80Ujvj680pOTh2bORBjbIAyz
720
oWGW+GUjzKxTiiPvVmxFgx5wdsFvF03v34lEVVhMpouqPAYQ15N37K/ir5XY+9m/
721
d8ufMCkjeXsQkKqFbAlQcnWMCRnOoPHS3I4vi6hmnDDeeYTSRvfLbW0fhwIBIwKB
722
gBIiOqZYaoqbeD9OS9z2K9KR2atlTxGxOJPXiP4ESqP3NVScWNwyZ3NXHpyrJLa0
723
EbVtzsQhLn6rF+TzXnOlcipFvjsem3iYzCpuChfGQ6SovTcOjHV9z+hnpXvQ/fon
724
soVRZY65wKnF7IAoUwTmJS9opqgrN6kRgCd3DASAMd1bAkEA96SBVWFt/fJBNJ9H
725
tYnBKZGw0VeHOYmVYbvMSstssn8un+pQpUm9vlG/bp7Oxd/m+b9KWEh2xPfv6zqU
726
avNwHwJBANqzGZa/EpzF4J8pGti7oIAPUIDGMtfIcmqNXVMckrmzQ2vTfqtkEZsA
727
4rE1IERRyiJQx6EJsz21wJmGV9WJQ5kCQQDwkS0uXqVdFzgHO6S++tjmjYcxwr3g
728
H0CoFYSgbddOT6miqRskOQF3DZVkJT3kyuBgU2zKygz52ukQZMqxCb1fAkASvuTv
729
qfpH87Qq5kQhNKdbbwbmd2NxlNabazPijWuphGTdW0VfJdWfklyS2Kr+iqrs/5wV
730
HhathJt636Eg7oIjAkA8ht3MQ+XSl9yIJIS8gVpbPxSw5OMfw0PjVE7tBdQruiSc
731
nvuQES5C9BMHjF39LZiGH1iLQy7FgdHyoP+eodI7
732
-----END RSA PRIVATE KEY-----
736
class SocketListener(threading.Thread):
738
def __init__(self, callback):
739
threading.Thread.__init__(self)
740
self._callback = callback
741
self._socket = socket.socket()
742
self._socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
743
self._socket.bind(('localhost', 0))
744
self._socket.listen(1)
745
self.port = self._socket.getsockname()[1]
746
self._stop_event = threading.Event()
749
# called from outside this thread
750
self._stop_event.set()
751
# use a timeout here, because if the test fails, the server thread may
752
# never notice the stop_event.
758
readable, writable_unused, exception_unused = \
759
select.select([self._socket], [], [], 0.1)
760
if self._stop_event.isSet():
762
if len(readable) == 0:
765
s, addr_unused = self._socket.accept()
766
# because the loopback socket is inline, and transports are
767
# never explicitly closed, best to launch a new thread.
768
threading.Thread(target=self._callback, args=(s,)).start()
769
except socket.error, x:
770
sys.excepthook(*sys.exc_info())
771
warning('Socket error during accept() within unit test server'
774
# probably a failed test; unit test thread will log the
776
sys.excepthook(*sys.exc_info())
777
warning('Exception from within unit test server thread: %r' %
781
class SocketDelay(object):
782
"""A socket decorator to make TCP appear slower.
784
This changes recv, send, and sendall to add a fixed latency to each python
785
call if a new roundtrip is detected. That is, when a recv is called and the
786
flag new_roundtrip is set, latency is charged. Every send and send_all
789
In addition every send, sendall and recv sleeps a bit per character send to
792
Not all methods are implemented, this is deliberate as this class is not a
793
replacement for the builtin sockets layer. fileno is not implemented to
794
prevent the proxy being bypassed.
798
_proxied_arguments = dict.fromkeys([
799
"close", "getpeername", "getsockname", "getsockopt", "gettimeout",
800
"setblocking", "setsockopt", "settimeout", "shutdown"])
802
def __init__(self, sock, latency, bandwidth=1.0,
805
:param bandwith: simulated bandwith (MegaBit)
806
:param really_sleep: If set to false, the SocketDelay will just
807
increase a counter, instead of calling time.sleep. This is useful for
808
unittesting the SocketDelay.
811
self.latency = latency
812
self.really_sleep = really_sleep
813
self.time_per_byte = 1 / (bandwidth / 8.0 * 1024 * 1024)
814
self.new_roundtrip = False
817
if self.really_sleep:
820
SocketDelay.simulated_time += s
822
def __getattr__(self, attr):
823
if attr in SocketDelay._proxied_arguments:
824
return getattr(self.sock, attr)
825
raise AttributeError("'SocketDelay' object has no attribute %r" %
829
return SocketDelay(self.sock.dup(), self.latency, self.time_per_byte,
832
def recv(self, *args):
833
data = self.sock.recv(*args)
834
if data and self.new_roundtrip:
835
self.new_roundtrip = False
836
self.sleep(self.latency)
837
self.sleep(len(data) * self.time_per_byte)
840
def sendall(self, data, flags=0):
841
if not self.new_roundtrip:
842
self.new_roundtrip = True
843
self.sleep(self.latency)
844
self.sleep(len(data) * self.time_per_byte)
845
return self.sock.sendall(data, flags)
847
def send(self, data, flags=0):
848
if not self.new_roundtrip:
849
self.new_roundtrip = True
850
self.sleep(self.latency)
851
bytes_sent = self.sock.send(data, flags)
852
self.sleep(bytes_sent * self.time_per_byte)
856
class SFTPServer(Server):
857
"""Common code for SFTP server facilities."""
859
def __init__(self, server_interface=StubServer):
860
self._original_vendor = None
862
self._server_homedir = None
863
self._listener = None
865
self._vendor = ssh.ParamikoVendor()
866
self._server_interface = server_interface
871
def _get_sftp_url(self, path):
872
"""Calculate an sftp url to this server for path."""
873
return 'sftp://foo:bar@localhost:%d/%s' % (self._listener.port, path)
875
def log(self, message):
876
"""StubServer uses this to log when a new server is created."""
877
self.logs.append(message)
879
def _run_server_entry(self, sock):
880
"""Entry point for all implementations of _run_server.
882
If self.add_latency is > 0.000001 then sock is given a latency adding
885
if self.add_latency > 0.000001:
886
sock = SocketDelay(sock, self.add_latency)
887
return self._run_server(sock)
889
def _run_server(self, s):
890
ssh_server = paramiko.Transport(s)
891
key_file = pathjoin(self._homedir, 'test_rsa.key')
892
f = open(key_file, 'w')
893
f.write(STUB_SERVER_KEY)
895
host_key = paramiko.RSAKey.from_private_key_file(key_file)
896
ssh_server.add_server_key(host_key)
897
server = self._server_interface(self)
898
ssh_server.set_subsystem_handler('sftp', paramiko.SFTPServer,
899
StubSFTPServer, root=self._root,
900
home=self._server_homedir)
901
event = threading.Event()
902
ssh_server.start_server(event, server)
905
def setUp(self, backing_server=None):
906
# XXX: TODO: make sftpserver back onto backing_server rather than local
908
assert (backing_server is None or
909
isinstance(backing_server, local.LocalURLServer)), (
910
"backing_server should not be %r, because this can only serve the "
911
"local current working directory." % (backing_server,))
912
self._original_vendor = ssh._ssh_vendor_manager._cached_ssh_vendor
913
ssh._ssh_vendor_manager._cached_ssh_vendor = self._vendor
914
if sys.platform == 'win32':
915
# Win32 needs to use the UNICODE api
916
self._homedir = getcwd()
918
# But Linux SFTP servers should just deal in bytestreams
919
self._homedir = os.getcwd()
920
if self._server_homedir is None:
921
self._server_homedir = self._homedir
923
if sys.platform == 'win32':
925
self._listener = SocketListener(self._run_server_entry)
926
self._listener.setDaemon(True)
927
self._listener.start()
930
"""See bzrlib.transport.Server.tearDown."""
931
self._listener.stop()
932
ssh._ssh_vendor_manager._cached_ssh_vendor = self._original_vendor
934
def get_bogus_url(self):
935
"""See bzrlib.transport.Server.get_bogus_url."""
936
# this is chosen to try to prevent trouble with proxies, wierd dns, etc
937
# we bind a random socket, so that we get a guaranteed unused port
938
# we just never listen on that port
940
s.bind(('localhost', 0))
941
return 'sftp://%s:%s/' % s.getsockname()
944
class SFTPFullAbsoluteServer(SFTPServer):
945
"""A test server for sftp transports, using absolute urls and ssh."""
948
"""See bzrlib.transport.Server.get_url."""
949
homedir = self._homedir
950
if sys.platform != 'win32':
951
# Remove the initial '/' on all platforms but win32
952
homedir = homedir[1:]
953
return self._get_sftp_url(urlutils.escape(homedir))
956
class SFTPServerWithoutSSH(SFTPServer):
957
"""An SFTP server that uses a simple TCP socket pair rather than SSH."""
960
super(SFTPServerWithoutSSH, self).__init__()
961
self._vendor = ssh.LoopbackVendor()
963
def _run_server(self, sock):
964
# Re-import these as locals, so that they're still accessible during
965
# interpreter shutdown (when all module globals get set to None, leading
966
# to confusing errors like "'NoneType' object has no attribute 'error'".
967
class FakeChannel(object):
968
def get_transport(self):
970
def get_log_channel(self):
974
def get_hexdump(self):
979
server = paramiko.SFTPServer(FakeChannel(), 'sftp', StubServer(self), StubSFTPServer,
980
root=self._root, home=self._server_homedir)
982
server.start_subsystem('sftp', None, sock)
983
except socket.error, e:
984
if (len(e.args) > 0) and (e.args[0] == errno.EPIPE):
985
# it's okay for the client to disconnect abruptly
986
# (bug in paramiko 1.6: it should absorb this exception)
991
# This typically seems to happen during interpreter shutdown, so
992
# most of the useful ways to report this error are won't work.
993
# Writing the exception type, and then the text of the exception,
994
# seems to be the best we can do.
996
sys.stderr.write('\nEXCEPTION %r: ' % (e.__class__,))
997
sys.stderr.write('%s\n\n' % (e,))
998
server.finish_subsystem()
1001
class SFTPAbsoluteServer(SFTPServerWithoutSSH):
1002
"""A test server for sftp transports, using absolute urls."""
1005
"""See bzrlib.transport.Server.get_url."""
1006
homedir = self._homedir
1007
if sys.platform != 'win32':
1008
# Remove the initial '/' on all platforms but win32
1009
homedir = homedir[1:]
1010
return self._get_sftp_url(urlutils.escape(homedir))
1013
class SFTPHomeDirServer(SFTPServerWithoutSSH):
1014
"""A test server for sftp transports, using homedir relative urls."""
1017
"""See bzrlib.transport.Server.get_url."""
1018
return self._get_sftp_url("~/")
1021
class SFTPSiblingAbsoluteServer(SFTPAbsoluteServer):
1022
"""A test server for sftp transports where only absolute paths will work.
1024
It does this by serving from a deeply-nested directory that doesn't exist.
1027
def setUp(self, backing_server=None):
1028
self._server_homedir = '/dev/noone/runs/tests/here'
1029
super(SFTPSiblingAbsoluteServer, self).setUp(backing_server)
908
1032
def get_test_permutations():
909
1033
"""Return the permutations to be used in testing."""
910
from bzrlib.tests import stub_sftp
911
return [(SFTPTransport, stub_sftp.SFTPAbsoluteServer),
912
(SFTPTransport, stub_sftp.SFTPHomeDirServer),
913
(SFTPTransport, stub_sftp.SFTPSiblingAbsoluteServer),
1034
return [(SFTPTransport, SFTPAbsoluteServer),
1035
(SFTPTransport, SFTPHomeDirServer),
1036
(SFTPTransport, SFTPSiblingAbsoluteServer),
added
removed
bzrlib/transport/sftp.py
