137
class _SFTPReadvHelper(object):
138
"""A class to help with managing the state of a readv request."""
140
# See _get_requests for an explanation.
141
_max_request_size = 32768
143
def __init__(self, original_offsets, relpath, _report_activity):
144
"""Create a new readv helper.
146
:param original_offsets: The original requests given by the caller of
148
:param relpath: The name of the file (if known)
149
:param _report_activity: A Transport._report_activity bound method,
150
to be called as data arrives.
152
self.original_offsets = list(original_offsets)
153
self.relpath = relpath
154
self._report_activity = _report_activity
156
def _get_requests(self):
157
"""Break up the offsets into individual requests over sftp.
159
The SFTP spec only requires implementers to support 32kB requests. We
160
could try something larger (openssh supports 64kB), but then we have to
161
handle requests that fail.
162
So instead, we just break up our maximum chunks into 32kB chunks, and
163
asyncronously requests them.
164
Newer versions of paramiko would do the chunking for us, but we want to
165
start processing results right away, so we do it ourselves.
167
# TODO: Because we issue async requests, we don't 'fudge' any extra
168
# data. I'm not 100% sure that is the best choice.
170
# The first thing we do, is to collapse the individual requests as much
171
# as possible, so we don't issues requests <32kB
172
sorted_offsets = sorted(self.original_offsets)
173
coalesced = list(ConnectedTransport._coalesce_offsets(sorted_offsets,
174
limit=0, fudge_factor=0))
176
for c_offset in coalesced:
177
start = c_offset.start
178
size = c_offset.length
180
# Break this up into 32kB requests
182
next_size = min(size, self._max_request_size)
183
requests.append((start, next_size))
186
if 'sftp' in debug.debug_flags:
187
mutter('SFTP.readv(%s) %s offsets => %s coalesced => %s requests',
188
self.relpath, len(sorted_offsets), len(coalesced),
192
def request_and_yield_offsets(self, fp):
193
"""Request the data from the remote machine, yielding the results.
195
:param fp: A Paramiko SFTPFile object that supports readv.
196
:return: Yield the data requested by the original readv caller, one by
199
requests = self._get_requests()
200
offset_iter = iter(self.original_offsets)
201
cur_offset, cur_size = offset_iter.next()
202
# paramiko .readv() yields strings that are in the order of the requests
203
# So we track the current request to know where the next data is
204
# being returned from.
210
# This is used to buffer chunks which we couldn't process yet
211
# It is (start, end, data) tuples.
213
# Create an 'unlimited' data stream, so we stop based on requests,
214
# rather than just because the data stream ended. This lets us detect
216
data_stream = itertools.chain(fp.readv(requests),
217
itertools.repeat(None))
218
for (start, length), data in itertools.izip(requests, data_stream):
220
if cur_coalesced is not None:
221
raise errors.ShortReadvError(self.relpath,
222
start, length, len(data))
223
if len(data) != length:
224
raise errors.ShortReadvError(self.relpath,
225
start, length, len(data))
226
self._report_activity(length, 'read')
228
# This is the first request, just buffer it
229
buffered_data = [data]
230
buffered_len = length
232
elif start == last_end:
233
# The data we are reading fits neatly on the previous
234
# buffer, so this is all part of a larger coalesced range.
235
buffered_data.append(data)
236
buffered_len += length
238
# We have an 'interrupt' in the data stream. So we know we are
239
# at a request boundary.
241
# We haven't consumed the buffer so far, so put it into
242
# data_chunks, and continue.
243
buffered = ''.join(buffered_data)
244
data_chunks.append((input_start, buffered))
246
buffered_data = [data]
247
buffered_len = length
248
last_end = start + length
249
if input_start == cur_offset and cur_size <= buffered_len:
250
# Simplify the next steps a bit by transforming buffered_data
251
# into a single string. We also have the nice property that
252
# when there is only one string ''.join([x]) == x, so there is
254
buffered = ''.join(buffered_data)
255
# Clean out buffered data so that we keep memory
259
# TODO: We *could* also consider the case where cur_offset is in
260
# in the buffered range, even though it doesn't *start*
261
# the buffered range. But for packs we pretty much always
262
# read in order, so you won't get any extra data in the
264
while (input_start == cur_offset
265
and (buffered_offset + cur_size) <= buffered_len):
266
# We've buffered enough data to process this request, spit it
268
cur_data = buffered[buffered_offset:buffered_offset + cur_size]
269
# move the direct pointer into our buffered data
270
buffered_offset += cur_size
271
# Move the start-of-buffer pointer
272
input_start += cur_size
273
# Yield the requested data
274
yield cur_offset, cur_data
275
cur_offset, cur_size = offset_iter.next()
276
# at this point, we've consumed as much of buffered as we can,
277
# so break off the portion that we consumed
278
if buffered_offset == len(buffered_data):
279
# No tail to leave behind
283
buffered = buffered[buffered_offset:]
284
buffered_data = [buffered]
285
buffered_len = len(buffered)
287
buffered = ''.join(buffered_data)
289
data_chunks.append((input_start, buffered))
291
if 'sftp' in debug.debug_flags:
292
mutter('SFTP readv left with %d out-of-order bytes',
293
sum(map(lambda x: len(x[1]), data_chunks)))
294
# We've processed all the readv data, at this point, anything we
295
# couldn't process is in data_chunks. This doesn't happen often, so
296
# this code path isn't optimized
297
# We use an interesting process for data_chunks
298
# Specifically if we have "bisect_left([(start, len, entries)],
300
# If start == qstart, then we get the specific node. Otherwise we
301
# get the previous node
303
idx = bisect.bisect_left(data_chunks, (cur_offset,))
304
if idx < len(data_chunks) and data_chunks[idx][0] == cur_offset:
305
# The data starts here
306
data = data_chunks[idx][1][:cur_size]
308
# The data is in a portion of a previous page
310
sub_offset = cur_offset - data_chunks[idx][0]
311
data = data_chunks[idx][1]
312
data = data[sub_offset:sub_offset + cur_size]
314
# We are missing the page where the data should be found,
317
if len(data) != cur_size:
318
raise AssertionError('We must have miscalulated.'
319
' We expected %d bytes, but only found %d'
320
% (cur_size, len(data)))
321
yield cur_offset, data
322
cur_offset, cur_size = offset_iter.next()
325
class SFTPTransport(ConnectedTransport):
137
class SFTPUrlHandling(Transport):
138
"""Mix-in that does common handling of SSH/SFTP URLs."""
140
def __init__(self, base):
141
self._parse_url(base)
142
base = self._unparse_url(self._path)
145
super(SFTPUrlHandling, self).__init__(base)
147
def _parse_url(self, url):
149
self._username, self._password,
150
self._host, self._port, self._path) = self._split_url(url)
152
def _unparse_url(self, path):
153
"""Return a URL for a path relative to this transport.
155
path = urllib.quote(path)
156
# handle homedir paths
157
if not path.startswith('/'):
159
netloc = urllib.quote(self._host)
160
if self._username is not None:
161
netloc = '%s@%s' % (urllib.quote(self._username), netloc)
162
if self._port is not None:
163
netloc = '%s:%d' % (netloc, self._port)
164
return urlparse.urlunparse((self._scheme, netloc, path, '', '', ''))
166
def _split_url(self, url):
167
(scheme, username, password, host, port, path) = split_url(url)
168
## assert scheme == 'sftp'
170
# the initial slash should be removed from the path, and treated
171
# as a homedir relative path (the path begins with a double slash
172
# if it is absolute).
173
# see draft-ietf-secsh-scp-sftp-ssh-uri-03.txt
174
# RBC 20060118 we are not using this as its too user hostile. instead
175
# we are following lftp and using /~/foo to mean '~/foo'.
176
# handle homedir paths
177
if path.startswith('/~/'):
181
return (scheme, username, password, host, port, path)
183
def abspath(self, relpath):
184
"""Return the full url to the given relative path.
186
@param relpath: the relative path or path components
187
@type relpath: str or list
189
return self._unparse_url(self._remote_path(relpath))
191
def _remote_path(self, relpath):
192
"""Return the path to be passed along the sftp protocol for relpath.
194
:param relpath: is a urlencoded string.
196
return self._combine_paths(self._path, relpath)
199
class SFTPTransport(SFTPUrlHandling):
326
200
"""Transport implementation for SFTP access."""
328
202
_do_prefetch = _default_do_prefetch
343
217
# up the request itself, rather than us having to worry about it
344
218
_max_request_size = 32768
346
def __init__(self, base, _from_transport=None):
347
super(SFTPTransport, self).__init__(base,
348
_from_transport=_from_transport)
220
def __init__(self, base, clone_from=None):
221
super(SFTPTransport, self).__init__(base)
222
if clone_from is None:
225
# use the same ssh connection, etc
226
self._sftp = clone_from._sftp
227
# super saves 'self.base'
229
def should_cache(self):
231
Return True if the data pulled across should be cached locally.
235
def clone(self, offset=None):
237
Return a new SFTPTransport with root at self.base + offset.
238
We share the same SFTP session between such transports, because it's
239
fairly expensive to set them up.
242
return SFTPTransport(self.base, self)
244
return SFTPTransport(self.abspath(offset), self)
350
246
def _remote_path(self, relpath):
351
247
"""Return the path to be passed along the sftp protocol for relpath.
353
:param relpath: is a urlencoded string.
355
relative = urlutils.unescape(relpath).encode('utf-8')
356
remote_path = self._combine_paths(self._path, relative)
357
# the initial slash should be removed from the path, and treated as a
358
# homedir relative path (the path begins with a double slash if it is
359
# absolute). see draft-ietf-secsh-scp-sftp-ssh-uri-03.txt
360
# RBC 20060118 we are not using this as its too user hostile. instead
361
# we are following lftp and using /~/foo to mean '~/foo'
362
# vila--20070602 and leave absolute paths begin with a single slash.
363
if remote_path.startswith('/~/'):
364
remote_path = remote_path[3:]
365
elif remote_path == '/~':
369
def _create_connection(self, credentials=None):
370
"""Create a new connection with the provided credentials.
372
:param credentials: The credentials needed to establish the connection.
374
:return: The created connection and its associated credentials.
376
The credentials are only the password as it may have been entered
377
interactively by the user and may be different from the one provided
378
in base url at transport creation time.
380
if credentials is None:
381
password = self._password
249
relpath is a urlencoded string.
251
:return: a path prefixed with / for regular abspath-based urls, or a
252
path that does not begin with / for urls which begin with /~/.
254
# how does this work?
255
# it processes relpath with respect to
257
# firstly we create a path to evaluate:
258
# if relpath is an abspath or homedir path, its the entire thing
259
# otherwise we join our base with relpath
260
# then we eliminate all empty segments (double //'s) outside the first
261
# two elements of the list. This avoids problems with trailing
262
# slashes, or other abnormalities.
263
# finally we evaluate the entire path in a single pass
265
# '..' result in popping the left most already
266
# processed path (which can never be empty because of the check for
267
# abspath and homedir meaning that its not, or that we've used our
268
# path. If the pop would pop the root, we ignore it.
270
# Specific case examinations:
271
# remove the special casefor ~: if the current root is ~/ popping of it
272
# = / thus our seed for a ~ based path is ['', '~']
273
# and if we end up with [''] then we had basically ('', '..') (which is
274
# '/..' so we append '' if the length is one, and assert that the first
275
# element is still ''. Lastly, if we end with ['', '~'] as a prefix for
276
# the output, we've got a homedir path, so we strip that prefix before
277
# '/' joining the resulting list.
279
# case one: '/' -> ['', ''] cannot shrink
280
# case two: '/' + '../foo' -> ['', 'foo'] (take '', '', '..', 'foo')
281
# and pop the second '' for the '..', append 'foo'
282
# case three: '/~/' -> ['', '~', '']
283
# case four: '/~/' + '../foo' -> ['', '~', '', '..', 'foo'],
284
# and we want to get '/foo' - the empty path in the middle
285
# needs to be stripped, then normal path manipulation will
287
# case five: '/..' ['', '..'], we want ['', '']
288
# stripping '' outside the first two is ok
289
# ignore .. if its too high up
291
# lastly this code is possibly reusable by FTP, but not reusable by
292
# local paths: ~ is resolvable correctly, nor by HTTP or the smart
293
# server: ~ is resolved remotely.
295
# however, a version of this that acts on self.base is possible to be
296
# written which manipulates the URL in canonical form, and would be
297
# reusable for all transports, if a flag for allowing ~/ at all was
299
assert isinstance(relpath, basestring)
300
relpath = urlutils.unescape(relpath)
303
if relpath.startswith('/'):
304
# abspath - normal split is fine.
305
current_path = relpath.split('/')
306
elif relpath.startswith('~/'):
307
# root is homedir based: normal split and prefix '' to remote the
309
current_path = [''].extend(relpath.split('/'))
383
password = credentials
385
vendor = ssh._get_ssh_vendor()
388
auth = config.AuthenticationConfig()
389
user = auth.get_user('ssh', self._host, self._port)
390
connection = vendor.connect_sftp(self._user, password,
391
self._host, self._port)
392
return connection, (user, password)
395
"""Ensures that a connection is established"""
396
connection = self._get_connection()
397
if connection is None:
398
# First connection ever
399
connection, credentials = self._create_connection()
400
self._set_connection(connection, credentials)
311
# root is from the current directory:
312
if self._path.startswith('/'):
313
# abspath, take the regular split
316
# homedir based, add the '', '~' not present in self._path
317
current_path = ['', '~']
318
# add our current dir
319
current_path.extend(self._path.split('/'))
320
# add the users relpath
321
current_path.extend(relpath.split('/'))
322
# strip '' segments that are not in the first one - the leading /.
323
to_process = current_path[:1]
324
for segment in current_path[1:]:
326
to_process.append(segment)
328
# process '.' and '..' segments into output_path.
330
for segment in to_process:
332
# directory pop. Remove a directory
333
# as long as we are not at the root
334
if len(output_path) > 1:
337
# cannot pop beyond the root, so do nothing
339
continue # strip the '.' from the output.
341
# this will append '' to output_path for the root elements,
342
# which is appropriate: its why we strip '' in the first pass.
343
output_path.append(segment)
345
# check output special cases:
346
if output_path == ['']:
348
output_path = ['', '']
349
elif output_path[:2] == ['', '~']:
350
# ['', '~', ...] -> ...
351
output_path = output_path[2:]
352
path = '/'.join(output_path)
355
def relpath(self, abspath):
356
scheme, username, password, host, port, path = self._split_url(abspath)
358
if (username != self._username):
359
error.append('username mismatch')
360
if (host != self._host):
361
error.append('host mismatch')
362
if (port != self._port):
363
error.append('port mismatch')
364
if (not path.startswith(self._path)):
365
error.append('path mismatch')
367
extra = ': ' + ', '.join(error)
368
raise PathNotChild(abspath, self.base, extra=extra)
370
return path[pl:].strip('/')
403
372
def has(self, relpath):
405
374
Does the target location exist?
408
self._get_sftp().stat(self._remote_path(relpath))
409
# stat result is about 20 bytes, let's say
410
self._report_activity(20, 'read')
377
self._sftp.stat(self._remote_path(relpath))
415
382
def get(self, relpath):
416
"""Get the file at the given relative path.
384
Get the file at the given relative path.
418
386
:param relpath: The relative path to the file
421
# FIXME: by returning the file directly, we don't pass this
422
# through to report_activity. We could try wrapping the object
423
# before it's returned. For readv and get_bytes it's handled in
424
# the higher-level function.
426
389
path = self._remote_path(relpath)
427
f = self._get_sftp().file(path, mode='rb')
390
f = self._sftp.file(path, mode='rb')
428
391
if self._do_prefetch and (getattr(f, 'prefetch', None) is not None):
431
394
except (IOError, paramiko.SSHException), e:
432
self._translate_io_exception(e, path, ': error retrieving',
433
failure_exc=errors.ReadError)
435
def get_bytes(self, relpath):
436
# reimplement this here so that we can report how many bytes came back
437
f = self.get(relpath)
440
self._report_activity(len(bytes), 'read')
445
def _readv(self, relpath, offsets):
395
self._translate_io_exception(e, path, ': error retrieving')
397
def readv(self, relpath, offsets):
446
398
"""See Transport.readv()"""
447
399
# We overload the default readv() because we want to use a file
448
400
# that does not have prefetch enabled.
454
406
path = self._remote_path(relpath)
455
fp = self._get_sftp().file(path, mode='rb')
407
fp = self._sftp.file(path, mode='rb')
456
408
readv = getattr(fp, 'readv', None)
458
410
return self._sftp_readv(fp, offsets, relpath)
459
if 'sftp' in debug.debug_flags:
460
mutter('seek and read %s offsets', len(offsets))
411
mutter('seek and read %s offsets', len(offsets))
461
412
return self._seek_and_read(fp, offsets, relpath)
462
413
except (IOError, paramiko.SSHException), e:
463
414
self._translate_io_exception(e, path, ': error retrieving')
465
def recommended_page_size(self):
466
"""See Transport.recommended_page_size().
468
For SFTP we suggest a large page size to reduce the overhead
469
introduced by latency.
473
def _sftp_readv(self, fp, offsets, relpath):
416
def _sftp_readv(self, fp, offsets, relpath='<unknown>'):
474
417
"""Use the readv() member of fp to do async readv.
476
Then read them using paramiko.readv(). paramiko.readv()
419
And then read them using paramiko.readv(). paramiko.readv()
477
420
does not support ranges > 64K, so it caps the request size, and
478
just reads until it gets all the stuff it wants.
421
just reads until it gets all the stuff it wants
480
helper = _SFTPReadvHelper(offsets, relpath, self._report_activity)
481
return helper.request_and_yield_offsets(fp)
423
offsets = list(offsets)
424
sorted_offsets = sorted(offsets)
426
# The algorithm works as follows:
427
# 1) Coalesce nearby reads into a single chunk
428
# This generates a list of combined regions, the total size
429
# and the size of the sub regions. This coalescing step is limited
430
# in the number of nearby chunks to combine, and is allowed to
431
# skip small breaks in the requests. Limiting it makes sure that
432
# we can start yielding some data earlier, and skipping means we
433
# make fewer requests. (Beneficial even when using async)
434
# 2) Break up this combined regions into chunks that are smaller
435
# than 64KiB. Technically the limit is 65536, but we are a
436
# little bit conservative. This is because sftp has a maximum
437
# return chunk size of 64KiB (max size of an unsigned short)
438
# 3) Issue a readv() to paramiko to create an async request for
440
# 4) Read in the data as it comes back, until we've read one
441
# continuous section as determined in step 1
442
# 5) Break up the full sections into hunks for the original requested
443
# offsets. And put them in a cache
444
# 6) Check if the next request is in the cache, and if it is, remove
445
# it from the cache, and yield its data. Continue until no more
446
# entries are in the cache.
447
# 7) loop back to step 4 until all data has been read
449
# TODO: jam 20060725 This could be optimized one step further, by
450
# attempting to yield whatever data we have read, even before
451
# the first coallesced section has been fully processed.
453
# When coalescing for use with readv(), we don't really need to
454
# use any fudge factor, because the requests are made asynchronously
455
coalesced = list(self._coalesce_offsets(sorted_offsets,
456
limit=self._max_readv_combine,
460
for c_offset in coalesced:
461
start = c_offset.start
462
size = c_offset.length
464
# We need to break this up into multiple requests
466
next_size = min(size, self._max_request_size)
467
requests.append((start, next_size))
471
mutter('SFTP.readv() %s offsets => %s coalesced => %s requests',
472
len(offsets), len(coalesced), len(requests))
474
# Queue the current read until we have read the full coalesced section
477
cur_coalesced_stack = iter(coalesced)
478
cur_coalesced = cur_coalesced_stack.next()
480
# Cache the results, but only until they have been fulfilled
482
# turn the list of offsets into a stack
483
offset_stack = iter(offsets)
484
cur_offset_and_size = offset_stack.next()
486
for data in fp.readv(requests):
488
cur_data_len += len(data)
490
if cur_data_len < cur_coalesced.length:
492
assert cur_data_len == cur_coalesced.length, \
493
"Somehow we read too much: %s != %s" % (cur_data_len,
494
cur_coalesced.length)
495
all_data = ''.join(cur_data)
499
for suboffset, subsize in cur_coalesced.ranges:
500
key = (cur_coalesced.start+suboffset, subsize)
501
data_map[key] = all_data[suboffset:suboffset+subsize]
503
# Now that we've read some data, see if we can yield anything back
504
while cur_offset_and_size in data_map:
505
this_data = data_map.pop(cur_offset_and_size)
506
yield cur_offset_and_size[0], this_data
507
cur_offset_and_size = offset_stack.next()
509
# We read a coalesced entry, so mark it as done
511
# Now that we've read all of the data for this coalesced section
513
cur_coalesced = cur_coalesced_stack.next()
515
if cur_coalesced is not None:
516
raise errors.ShortReadvError(relpath, cur_coalesced.start,
517
cur_coalesced.length, len(data))
483
519
def put_file(self, relpath, f, mode=None):
added
removed
bzrlib/transport/sftp.py
