lfs: verify lfs object content when transferring to and from the remote store
This avoids inserting corrupt files into the usercache, and local and remote
stores. One down side is that the bad file won't be available locally for
forensic purposes after a remote download. I'm thinking about adding an
'incoming' directory to the local lfs store to handle the download, and then
move it to the 'objects' directory after it passes verification. That would
have the additional benefit of not concatenating each transfer chunk in memory
until the full file is transferred.
Verification isn't needed when the data is passed back through the revlog
interface or when the oid was just calculated, but otherwise it is on by
default. The additional overhead should be well worth avoiding problems with
file based remote stores, or buggy lfs servers.
Having two different verify functions is a little sad, but the full data of the
blob is mostly passed around in memory, because that's what the revlog interface
wants. The upload function, however, chunks up the data. It would be ideal if
that was how the content is always handled, but that's probably a huge project.
I don't really like printing the long hash, but `hg debugdata` isn't a public
interface, and is the only way to get it. The filelog and revision info is
nowhere near this area, so recommending `hg verify` is the easiest thing to do.
# automv.py
#
# Copyright 2013-2016 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.
"""check for unrecorded moves at commit time (EXPERIMENTAL)
This extension checks at commit/amend time if any of the committed files
comes from an unrecorded mv.
The threshold at which a file is considered a move can be set with the
``automv.similarity`` config option. This option takes a percentage between 0
(disabled) and 100 (files must be identical), the default is 95.
"""
# Using 95 as a default similarity is based on an analysis of the mercurial
# repositories of the cpython, mozilla-central & mercurial repositories, as
# well as 2 very large facebook repositories. At 95 50% of all potential
# missed moves would be caught, as well as correspond with 87% of all
# explicitly marked moves. Together, 80% of moved files are 95% similar or
# more.
#
# See http://markmail.org/thread/5pxnljesvufvom57 for context.
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial import (
commands,
copies,
error,
extensions,
pycompat,
registrar,
scmutil,
similar
)
configtable = {}
configitem = registrar.configitem(configtable)
configitem('automv', 'similarity',
default=95,
)
def extsetup(ui):
entry = extensions.wrapcommand(
commands.table, 'commit', mvcheck)
entry[1].append(
('', 'no-automv', None,
_('disable automatic file move detection')))
def mvcheck(orig, ui, repo, *pats, **opts):
"""Hook to check for moves at commit time"""
opts = pycompat.byteskwargs(opts)
renames = None
disabled = opts.pop('no_automv', False)
if not disabled:
threshold = ui.configint('automv', 'similarity')
if not 0 <= threshold <= 100:
raise error.Abort(_('automv.similarity must be between 0 and 100'))
if threshold > 0:
match = scmutil.match(repo[None], pats, opts)
added, removed = _interestingfiles(repo, match)
renames = _findrenames(repo, match, added, removed,
threshold / 100.0)
with repo.wlock():
if renames is not None:
scmutil._markchanges(repo, (), (), renames)
return orig(ui, repo, *pats, **pycompat.strkwargs(opts))
def _interestingfiles(repo, matcher):
"""Find what files were added or removed in this commit.
Returns a tuple of two lists: (added, removed). Only files not *already*
marked as moved are included in the added list.
"""
stat = repo.status(match=matcher)
added = stat[1]
removed = stat[2]
copy = copies._forwardcopies(repo['.'], repo[None], matcher)
# remove the copy files for which we already have copy info
added = [f for f in added if f not in copy]
return added, removed
def _findrenames(repo, matcher, added, removed, similarity):
"""Find what files in added are really moved files.
Any file named in removed that is at least similarity% similar to a file
in added is seen as a rename.
"""
renames = {}
if similarity > 0:
for src, dst, score in similar.findrenames(
repo, added, removed, similarity):
if repo.ui.verbose:
repo.ui.status(
_('detected move of %s as %s (%d%% similar)\n') % (
matcher.rel(src), matcher.rel(dst), score * 100))
renames[dst] = src
if renames:
repo.ui.status(_('detected move of %d files\n') % len(renames))
return renames