##// 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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hgk.py
389 lines | 11.9 KiB | text/x-python | PythonLexer
# Minimal support for git commands on an hg repository
#
# Copyright 2005, 2006 Chris Mason <mason@suse.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''browse the repository in a graphical way
The hgk extension allows browsing the history of a repository in a
graphical way. It requires Tcl/Tk version 8.4 or later. (Tcl/Tk is not
distributed with Mercurial.)
hgk consists of two parts: a Tcl script that does the displaying and
querying of information, and an extension to Mercurial named hgk.py,
which provides hooks for hgk to get information. hgk can be found in
the contrib directory, and the extension is shipped in the hgext
repository, and needs to be enabled.
The :hg:`view` command will launch the hgk Tcl script. For this command
to work, hgk must be in your search path. Alternately, you can specify
the path to hgk in your configuration file::
[hgk]
path = /location/of/hgk
hgk can make use of the extdiff extension to visualize revisions.
Assuming you had already configured extdiff vdiff command, just add::
[hgk]
vdiff=vdiff
Revisions context menu will now display additional entries to fire
vdiff on hovered and selected revisions.
'''
from __future__ import absolute_import
import os
from mercurial.i18n import _
from mercurial.node import (
nullid,
nullrev,
short,
)
from mercurial import (
commands,
obsolete,
patch,
pycompat,
registrar,
scmutil,
)
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'
configtable = {}
configitem = registrar.configitem(configtable)
configitem(
b'hgk',
b'path',
default=b'hgk',
)
@command(
b'debug-diff-tree',
[
(b'p', b'patch', None, _(b'generate patch')),
(b'r', b'recursive', None, _(b'recursive')),
(b'P', b'pretty', None, _(b'pretty')),
(b's', b'stdin', None, _(b'stdin')),
(b'C', b'copy', None, _(b'detect copies')),
(b'S', b'search', b"", _(b'search')),
],
b'[OPTION]... NODE1 NODE2 [FILE]...',
inferrepo=True,
)
def difftree(ui, repo, node1=None, node2=None, *files, **opts):
"""diff trees from two commits"""
def __difftree(repo, node1, node2, files=None):
assert node2 is not None
if files is None:
files = []
mmap = repo[node1].manifest()
mmap2 = repo[node2].manifest()
m = scmutil.match(repo[node1], files)
st = repo.status(node1, node2, m)
empty = short(nullid)
for f in st.modified:
# TODO get file permissions
ui.writenoi18n(
b":100664 100664 %s %s M\t%s\t%s\n"
% (short(mmap[f]), short(mmap2[f]), f, f)
)
for f in st.added:
ui.writenoi18n(
b":000000 100664 %s %s N\t%s\t%s\n"
% (empty, short(mmap2[f]), f, f)
)
for f in st.removed:
ui.writenoi18n(
b":100664 000000 %s %s D\t%s\t%s\n"
% (short(mmap[f]), empty, f, f)
)
##
while True:
if opts['stdin']:
line = ui.fin.readline()
if not line:
break
line = line.rstrip(pycompat.oslinesep).split(b' ')
node1 = line[0]
if len(line) > 1:
node2 = line[1]
else:
node2 = None
node1 = repo.lookup(node1)
if node2:
node2 = repo.lookup(node2)
else:
node2 = node1
node1 = repo.changelog.parents(node1)[0]
if opts['patch']:
if opts['pretty']:
catcommit(ui, repo, node2, b"")
m = scmutil.match(repo[node1], files)
diffopts = patch.difffeatureopts(ui)
diffopts.git = True
chunks = patch.diff(repo, node1, node2, match=m, opts=diffopts)
for chunk in chunks:
ui.write(chunk)
else:
__difftree(repo, node1, node2, files=files)
if not opts['stdin']:
break
def catcommit(ui, repo, n, prefix, ctx=None):
nlprefix = b'\n' + prefix
if ctx is None:
ctx = repo[n]
# use ctx.node() instead ??
ui.write((b"tree %s\n" % short(ctx.changeset()[0])))
for p in ctx.parents():
ui.write((b"parent %s\n" % p))
date = ctx.date()
description = ctx.description().replace(b"\0", b"")
ui.write((b"author %s %d %d\n" % (ctx.user(), int(date[0]), date[1])))
if b'committer' in ctx.extra():
ui.write((b"committer %s\n" % ctx.extra()[b'committer']))
ui.write((b"revision %d\n" % ctx.rev()))
ui.write((b"branch %s\n" % ctx.branch()))
if obsolete.isenabled(repo, obsolete.createmarkersopt):
if ctx.obsolete():
ui.writenoi18n(b"obsolete\n")
ui.write((b"phase %s\n\n" % ctx.phasestr()))
if prefix != b"":
ui.write(
b"%s%s\n" % (prefix, description.replace(b'\n', nlprefix).strip())
)
else:
ui.write(description + b"\n")
if prefix:
ui.write(b'\0')
@command(b'debug-merge-base', [], _(b'REV REV'))
def base(ui, repo, node1, node2):
"""output common ancestor information"""
node1 = repo.lookup(node1)
node2 = repo.lookup(node2)
n = repo.changelog.ancestor(node1, node2)
ui.write(short(n) + b"\n")
@command(
b'debug-cat-file',
[(b's', b'stdin', None, _(b'stdin'))],
_(b'[OPTION]... TYPE FILE'),
inferrepo=True,
)
def catfile(ui, repo, type=None, r=None, **opts):
"""cat a specific revision"""
# in stdin mode, every line except the commit is prefixed with two
# spaces. This way the our caller can find the commit without magic
# strings
#
prefix = b""
if opts['stdin']:
line = ui.fin.readline()
if not line:
return
(type, r) = line.rstrip(pycompat.oslinesep).split(b' ')
prefix = b" "
else:
if not type or not r:
ui.warn(_(b"cat-file: type or revision not supplied\n"))
commands.help_(ui, b'cat-file')
while r:
if type != b"commit":
ui.warn(_(b"aborting hg cat-file only understands commits\n"))
return 1
n = repo.lookup(r)
catcommit(ui, repo, n, prefix)
if opts['stdin']:
line = ui.fin.readline()
if not line:
break
(type, r) = line.rstrip(pycompat.oslinesep).split(b' ')
else:
break
# git rev-tree is a confusing thing. You can supply a number of
# commit sha1s on the command line, and it walks the commit history
# telling you which commits are reachable from the supplied ones via
# a bitmask based on arg position.
# you can specify a commit to stop at by starting the sha1 with ^
def revtree(ui, args, repo, full=b"tree", maxnr=0, parents=False):
def chlogwalk():
count = len(repo)
i = count
l = [0] * 100
chunk = 100
while True:
if chunk > i:
chunk = i
i = 0
else:
i -= chunk
for x in pycompat.xrange(chunk):
if i + x >= count:
l[chunk - x :] = [0] * (chunk - x)
break
if full is not None:
if (i + x) in repo:
l[x] = repo[i + x]
l[x].changeset() # force reading
else:
if (i + x) in repo:
l[x] = 1
for x in pycompat.xrange(chunk - 1, -1, -1):
if l[x] != 0:
yield (i + x, full is not None and l[x] or None)
if i == 0:
break
# calculate and return the reachability bitmask for sha
def is_reachable(ar, reachable, sha):
if len(ar) == 0:
return 1
mask = 0
for i in pycompat.xrange(len(ar)):
if sha in reachable[i]:
mask |= 1 << i
return mask
reachable = []
stop_sha1 = []
want_sha1 = []
count = 0
# figure out which commits they are asking for and which ones they
# want us to stop on
for i, arg in enumerate(args):
if arg.startswith(b'^'):
s = repo.lookup(arg[1:])
stop_sha1.append(s)
want_sha1.append(s)
elif arg != b'HEAD':
want_sha1.append(repo.lookup(arg))
# calculate the graph for the supplied commits
for i, n in enumerate(want_sha1):
reachable.append(set())
visit = [n]
reachable[i].add(n)
while visit:
n = visit.pop(0)
if n in stop_sha1:
continue
for p in repo.changelog.parents(n):
if p not in reachable[i]:
reachable[i].add(p)
visit.append(p)
if p in stop_sha1:
continue
# walk the repository looking for commits that are in our
# reachability graph
for i, ctx in chlogwalk():
if i not in repo:
continue
n = repo.changelog.node(i)
mask = is_reachable(want_sha1, reachable, n)
if mask:
parentstr = b""
if parents:
pp = repo.changelog.parents(n)
if pp[0] != nullid:
parentstr += b" " + short(pp[0])
if pp[1] != nullid:
parentstr += b" " + short(pp[1])
if not full:
ui.write(b"%s%s\n" % (short(n), parentstr))
elif full == b"commit":
ui.write(b"%s%s\n" % (short(n), parentstr))
catcommit(ui, repo, n, b' ', ctx)
else:
(p1, p2) = repo.changelog.parents(n)
(h, h1, h2) = map(short, (n, p1, p2))
(i1, i2) = map(repo.changelog.rev, (p1, p2))
date = ctx.date()[0]
ui.write(b"%s %s:%s" % (date, h, mask))
mask = is_reachable(want_sha1, reachable, p1)
if i1 != nullrev and mask > 0:
ui.write(b"%s:%s " % (h1, mask)),
mask = is_reachable(want_sha1, reachable, p2)
if i2 != nullrev and mask > 0:
ui.write(b"%s:%s " % (h2, mask))
ui.write(b"\n")
if maxnr and count >= maxnr:
break
count += 1
# git rev-list tries to order things by date, and has the ability to stop
# at a given commit without walking the whole repo. TODO add the stop
# parameter
@command(
b'debug-rev-list',
[
(b'H', b'header', None, _(b'header')),
(b't', b'topo-order', None, _(b'topo-order')),
(b'p', b'parents', None, _(b'parents')),
(b'n', b'max-count', 0, _(b'max-count')),
],
b'[OPTION]... REV...',
)
def revlist(ui, repo, *revs, **opts):
"""print revisions"""
if opts['header']:
full = b"commit"
else:
full = None
copy = [x for x in revs]
revtree(ui, copy, repo, full, opts['max_count'], opts[r'parents'])
@command(
b'view',
[(b'l', b'limit', b'', _(b'limit number of changes displayed'), _(b'NUM'))],
_(b'[-l LIMIT] [REVRANGE]'),
helpcategory=command.CATEGORY_CHANGE_NAVIGATION,
)
def view(ui, repo, *etc, **opts):
"""start interactive history viewer"""
opts = pycompat.byteskwargs(opts)
os.chdir(repo.root)
optstr = b' '.join(
[b'--%s %s' % (k, v) for k, v in pycompat.iteritems(opts) if v]
)
if repo.filtername is None:
optstr += b'--hidden'
cmd = ui.config(b"hgk", b"path") + b" %s %s" % (optstr, b" ".join(etc))
ui.debug(b"running %s\n" % cmd)
ui.system(cmd, blockedtag=b'hgk_view')