##// END OF EJS Templates
revlog: add a mechanism to verify expected file position before appending...
revlog: add a mechanism to verify expected file position before appending If someone uses `hg debuglocks`, or some non-hg process writes to the .hg directory without respecting the locks, or if the repo's on a networked filesystem, it's possible for the revlog code to write out corrupted data. The form of this corruption can vary depending on what data was written and how that happened. We are in the "networked filesystem" case (though I've had users also do this to themselves with the "`hg debuglocks`" scenario), and most often see this with the changelog. What ends up happening is we produce two items (let's call them rev1 and rev2) in the .i file that have the same linkrev, baserev, and offset into the .d file, while the data in the .d file is appended properly. rev2's compressed_size is accurate for rev2, but when we go to decompress the data in the .d file, we use the offset that's recorded in the index file, which is the same as rev1, and attempt to decompress rev2.compressed_size bytes of rev1's data. This usually does not succeed. :) When using inline data, this also fails, though I haven't investigated why too closely. This shows up as a "patch decode" error. I believe what's happening there is that we're basically ignoring the offset field, getting the data properly, but since baserev != rev, it thinks this is a delta based on rev (instead of a full text) and can't actually apply it as such. For now, I'm going to make this an optional component and default it to entirely off. I may increase the default severity of this in the future, once I've enabled it for my users and we gain more experience with it. Luckily, most of my users have a versioned filesystem and can roll back to before the corruption has been written, it's just a hassle to do so and not everyone knows how (so it's a support burden). Users on other filesystems will not have that luxury, and this can cause them to have a corrupted repository that they are unlikely to know how to resolve, and they'll see this as a data-loss event. Refusing to create the corruption is a much better user experience. This mechanism is not perfect. There may be false-negatives (racy writes that are not detected). There should not be any false-positives (non-racy writes that are detected as such). This is not a mechanism that makes putting a repo on a networked filesystem "safe" or "supported", just *less* likely to cause corruption. Differential Revision: https://phab.mercurial-scm.org/D9952

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graphlog.py
125 lines | 3.3 KiB | text/x-python | PythonLexer
# ASCII graph log extension for Mercurial
#
# Copyright 2007 Joel Rosdahl <joel@rosdahl.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''command to view revision graphs from a shell (DEPRECATED)
The functionality of this extension has been include in core Mercurial
since version 2.3. Please use :hg:`log -G ...` instead.
This extension adds a --graph option to the incoming, outgoing and log
commands. When this options is given, an ASCII representation of the
revision graph is also shown.
'''
from __future__ import absolute_import
from mercurial.i18n import _
from mercurial import (
cmdutil,
commands,
registrar,
)
cmdtable = {}
command = registrar.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'
@command(
b'glog',
[
(
b'f',
b'follow',
None,
_(
b'follow changeset history, or file history across copies and renames'
),
),
(
b'',
b'follow-first',
None,
_(b'only follow the first parent of merge changesets (DEPRECATED)'),
),
(
b'd',
b'date',
b'',
_(b'show revisions matching date spec'),
_(b'DATE'),
),
(b'C', b'copies', None, _(b'show copied files')),
(
b'k',
b'keyword',
[],
_(b'do case-insensitive search for a given text'),
_(b'TEXT'),
),
(
b'r',
b'rev',
[],
_(b'show the specified revision or revset'),
_(b'REV'),
),
(
b'',
b'removed',
None,
_(b'include revisions where files were removed'),
),
(b'm', b'only-merges', None, _(b'show only merges (DEPRECATED)')),
(b'u', b'user', [], _(b'revisions committed by user'), _(b'USER')),
(
b'',
b'only-branch',
[],
_(
b'show only changesets within the given named branch (DEPRECATED)'
),
_(b'BRANCH'),
),
(
b'b',
b'branch',
[],
_(b'show changesets within the given named branch'),
_(b'BRANCH'),
),
(
b'P',
b'prune',
[],
_(b'do not display revision or any of its ancestors'),
_(b'REV'),
),
]
+ cmdutil.logopts
+ cmdutil.walkopts,
_(b'[OPTION]... [FILE]'),
helpcategory=command.CATEGORY_CHANGE_NAVIGATION,
inferrepo=True,
)
def glog(ui, repo, *pats, **opts):
"""show revision history alongside an ASCII revision graph
Print a revision history alongside a revision graph drawn with
ASCII characters.
Nodes printed as an @ character are parents of the working
directory.
This is an alias to :hg:`log -G`.
"""
opts['graph'] = True
return commands.log(ui, repo, *pats, **opts)