##// END OF EJS Templates
ssh: avoid reading beyond the end of stream when using compression...
ssh: avoid reading beyond the end of stream when using compression Compressed streams can be used as part of getbundle. The normal read() operation of bufferedinputpipe will try to fulfill the request exactly and can deadlock if the server sends less as it is done. At the same time, the bundle2 logic will stop reading when it believes it has gotten all parts of the bundle, which can leave behind end of stream markers as used by bzip2 and zstd. To solve this, introduce a new optional unbufferedread interface and provided it in bufferedinputpipe and doublepipe. If there is buffered data left, it will be returned, otherwise it will issue a single read request and return whatever it obtains. Reorganize the decompression handlers to try harder to read until the end of stream, especially if the requested read can already be fulfilled. Check for end of stream is messy with Python 2, none of the standard compression modules properly exposes it. At least with zstd and bzip2, decompressing will remember EOS and fail for empty input after the EOS has been seen. For zlib, the only way to detect it with Python 2 is to duplicate the decompressobj and force some additional data into it. The common handler can be further optimized, but works as PoC. Differential Revision: https://phab.mercurial-scm.org/D3937

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pointer.py
83 lines | 2.8 KiB | text/x-python | PythonLexer
# pointer.py - Git-LFS pointer serialization
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import re
from mercurial.i18n import _
from mercurial import (
error,
pycompat,
)
from mercurial.utils import (
stringutil,
)
class InvalidPointer(error.RevlogError):
pass
class gitlfspointer(dict):
VERSION = 'https://git-lfs.github.com/spec/v1'
def __init__(self, *args, **kwargs):
self['version'] = self.VERSION
super(gitlfspointer, self).__init__(*args)
self.update(pycompat.byteskwargs(kwargs))
@classmethod
def deserialize(cls, text):
try:
return cls(l.split(' ', 1) for l in text.splitlines()).validate()
except ValueError: # l.split returns 1 item instead of 2
raise InvalidPointer(_('cannot parse git-lfs text: %s')
% stringutil.pprint(text))
def serialize(self):
sortkeyfunc = lambda x: (x[0] != 'version', x)
items = sorted(self.validate().iteritems(), key=sortkeyfunc)
return ''.join('%s %s\n' % (k, v) for k, v in items)
def oid(self):
return self['oid'].split(':')[-1]
def size(self):
return int(self['size'])
# regular expressions used by _validate
# see https://github.com/git-lfs/git-lfs/blob/master/docs/spec.md
_keyre = re.compile(br'\A[a-z0-9.-]+\Z')
_valuere = re.compile(br'\A[^\n]*\Z')
_requiredre = {
'size': re.compile(br'\A[0-9]+\Z'),
'oid': re.compile(br'\Asha256:[0-9a-f]{64}\Z'),
'version': re.compile(br'\A%s\Z' % stringutil.reescape(VERSION)),
}
def validate(self):
"""raise InvalidPointer on error. return self if there is no error"""
requiredcount = 0
for k, v in self.iteritems():
if k in self._requiredre:
if not self._requiredre[k].match(v):
raise InvalidPointer(
_('unexpected lfs pointer value: %s=%s')
% (k, stringutil.pprint(v)))
requiredcount += 1
elif not self._keyre.match(k):
raise InvalidPointer(_('unexpected lfs pointer key: %s') % k)
if not self._valuere.match(v):
raise InvalidPointer(_('unexpected lfs pointer value: %s=%s')
% (k, stringutil.pprint(v)))
if len(self._requiredre) != requiredcount:
miss = sorted(set(self._requiredre.keys()).difference(self.keys()))
raise InvalidPointer(_('missing lfs pointer keys: %s')
% ', '.join(miss))
return self
deserialize = gitlfspointer.deserialize