mergetools: add new conflict marker format with diffs in
I use 3-way conflict markers. Often when I resolve them, I manually
compare one the base with one side and apply the differences to the
other side. That can be hard when the conflict marker is large. This
patch introduces a new type of conflict marker, which I'm hoping will
make it easier to resolve conflicts.
The new format uses `<<<<<<<` and `>>>>>>>` to open and close the
markers, just like our existing 2-way and 3-way conflict
markers. Instead of having 2 or 3 snapshots (left+right or
left+base+right), it has a sequence of diffs. A diff looks like this:
```
------- base
+++++++ left
a
-b
+c
d
```
A diff that adds one side ("diff from nothing") has a `=======` header
instead and does not have have `+` prefixed on its lines. A regular
3-way merge can be viewed as adding one side plus a diff between the
base and the other side. It thus has two ways of being represented,
depending on which side is being diffed:
```
<<<<<<<
======= left
contents
on
left
------- base
+++++++ right
contents
on
-left
+right
>>>>>>>
```
or
```
<<<<<<<
------- base
+++++++ left
contents
on
-right
+left
======= right
contents
on
right
>>>>>>>
```
I've made it so the new merge tool tries to pick a version that has
the most common lines (no difference in the example above).
I've called the new tool "mergediff" to stick to the convention of
starting with "merge" if the tool tries a regular 3-way merge.
The idea came from my pet VCS (placeholder name `jj`), which has
support for octopus merges and other ways of ending up with merges of
more than 3 versions. I wanted to be able to represent such conflicts
in the working copy and therefore thought of this format (although I
have not yet implemented it in my VCS). I then attended a meeting with
Larry McVoy, who said BitKeeper has an option (`bk smerge -g`) for
showing a similar format, which reminded me to actually attempt this
in Mercurial.
Differential Revision: https://phab.mercurial-scm.org/D9551
# verify.py - repository integrity checking for Mercurial
#
# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
#
# 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 os
from .i18n import _
from .node import (
nullid,
short,
)
from . import (
error,
pycompat,
revlog,
util,
)
VERIFY_DEFAULT = 0
VERIFY_FULL = 1
def verify(repo, level=None):
with repo.lock():
v = verifier(repo, level)
return v.verify()
def _normpath(f):
# under hg < 2.4, convert didn't sanitize paths properly, so a
# converted repo may contain repeated slashes
while b'//' in f:
f = f.replace(b'//', b'/')
return f
class verifier(object):
def __init__(self, repo, level=None):
self.repo = repo.unfiltered()
self.ui = repo.ui
self.match = repo.narrowmatch()
if level is None:
level = VERIFY_DEFAULT
self._level = level
self.badrevs = set()
self.errors = 0
self.warnings = 0
self.havecl = len(repo.changelog) > 0
self.havemf = len(repo.manifestlog.getstorage(b'')) > 0
self.revlogv1 = repo.changelog.version != revlog.REVLOGV0
self.lrugetctx = util.lrucachefunc(repo.unfiltered().__getitem__)
self.refersmf = False
self.fncachewarned = False
# developer config: verify.skipflags
self.skipflags = repo.ui.configint(b'verify', b'skipflags')
self.warnorphanstorefiles = True
def _warn(self, msg):
"""record a "warning" level issue"""
self.ui.warn(msg + b"\n")
self.warnings += 1
def _err(self, linkrev, msg, filename=None):
"""record a "error" level issue"""
if linkrev is not None:
self.badrevs.add(linkrev)
linkrev = b"%d" % linkrev
else:
linkrev = b'?'
msg = b"%s: %s" % (linkrev, msg)
if filename:
msg = b"%s@%s" % (filename, msg)
self.ui.warn(b" " + msg + b"\n")
self.errors += 1
def _exc(self, linkrev, msg, inst, filename=None):
"""record exception raised during the verify process"""
fmsg = pycompat.bytestr(inst)
if not fmsg:
fmsg = pycompat.byterepr(inst)
self._err(linkrev, b"%s: %s" % (msg, fmsg), filename)
def _checkrevlog(self, obj, name, linkrev):
"""verify high level property of a revlog
- revlog is present,
- revlog is non-empty,
- sizes (index and data) are correct,
- revlog's format version is correct.
"""
if not len(obj) and (self.havecl or self.havemf):
self._err(linkrev, _(b"empty or missing %s") % name)
return
d = obj.checksize()
if d[0]:
self._err(None, _(b"data length off by %d bytes") % d[0], name)
if d[1]:
self._err(None, _(b"index contains %d extra bytes") % d[1], name)
if obj.version != revlog.REVLOGV0:
if not self.revlogv1:
self._warn(_(b"warning: `%s' uses revlog format 1") % name)
elif self.revlogv1:
self._warn(_(b"warning: `%s' uses revlog format 0") % name)
def _checkentry(self, obj, i, node, seen, linkrevs, f):
"""verify a single revlog entry
arguments are:
- obj: the source revlog
- i: the revision number
- node: the revision node id
- seen: nodes previously seen for this revlog
- linkrevs: [changelog-revisions] introducing "node"
- f: string label ("changelog", "manifest", or filename)
Performs the following checks:
- linkrev points to an existing changelog revision,
- linkrev points to a changelog revision that introduces this revision,
- linkrev points to the lowest of these changesets,
- both parents exist in the revlog,
- the revision is not duplicated.
Return the linkrev of the revision (or None for changelog's revisions).
"""
lr = obj.linkrev(obj.rev(node))
if lr < 0 or (self.havecl and lr not in linkrevs):
if lr < 0 or lr >= len(self.repo.changelog):
msg = _(b"rev %d points to nonexistent changeset %d")
else:
msg = _(b"rev %d points to unexpected changeset %d")
self._err(None, msg % (i, lr), f)
if linkrevs:
if f and len(linkrevs) > 1:
try:
# attempt to filter down to real linkrevs
linkrevs = [
l
for l in linkrevs
if self.lrugetctx(l)[f].filenode() == node
]
except Exception:
pass
self._warn(
_(b" (expected %s)")
% b" ".join(map(pycompat.bytestr, linkrevs))
)
lr = None # can't be trusted
try:
p1, p2 = obj.parents(node)
if p1 not in seen and p1 != nullid:
self._err(
lr,
_(b"unknown parent 1 %s of %s") % (short(p1), short(node)),
f,
)
if p2 not in seen and p2 != nullid:
self._err(
lr,
_(b"unknown parent 2 %s of %s") % (short(p2), short(node)),
f,
)
except Exception as inst:
self._exc(lr, _(b"checking parents of %s") % short(node), inst, f)
if node in seen:
self._err(lr, _(b"duplicate revision %d (%d)") % (i, seen[node]), f)
seen[node] = i
return lr
def verify(self):
"""verify the content of the Mercurial repository
This method run all verifications, displaying issues as they are found.
return 1 if any error have been encountered, 0 otherwise."""
# initial validation and generic report
repo = self.repo
ui = repo.ui
if not repo.url().startswith(b'file:'):
raise error.Abort(_(b"cannot verify bundle or remote repos"))
if os.path.exists(repo.sjoin(b"journal")):
ui.warn(_(b"abandoned transaction found - run hg recover\n"))
if ui.verbose or not self.revlogv1:
ui.status(
_(b"repository uses revlog format %d\n")
% (self.revlogv1 and 1 or 0)
)
# data verification
mflinkrevs, filelinkrevs = self._verifychangelog()
filenodes = self._verifymanifest(mflinkrevs)
del mflinkrevs
self._crosscheckfiles(filelinkrevs, filenodes)
totalfiles, filerevisions = self._verifyfiles(filenodes, filelinkrevs)
# final report
ui.status(
_(b"checked %d changesets with %d changes to %d files\n")
% (len(repo.changelog), filerevisions, totalfiles)
)
if self.warnings:
ui.warn(_(b"%d warnings encountered!\n") % self.warnings)
if self.fncachewarned:
ui.warn(
_(
b'hint: run "hg debugrebuildfncache" to recover from '
b'corrupt fncache\n'
)
)
if self.errors:
ui.warn(_(b"%d integrity errors encountered!\n") % self.errors)
if self.badrevs:
ui.warn(
_(b"(first damaged changeset appears to be %d)\n")
% min(self.badrevs)
)
return 1
return 0
def _verifychangelog(self):
"""verify the changelog of a repository
The following checks are performed:
- all of `_checkrevlog` checks,
- all of `_checkentry` checks (for each revisions),
- each revision can be read.
The function returns some of the data observed in the changesets as a
(mflinkrevs, filelinkrevs) tuples:
- mflinkrevs: is a { manifest-node -> [changelog-rev] } mapping
- filelinkrevs: is a { file-path -> [changelog-rev] } mapping
If a matcher was specified, filelinkrevs will only contains matched
files.
"""
ui = self.ui
repo = self.repo
match = self.match
cl = repo.changelog
ui.status(_(b"checking changesets\n"))
mflinkrevs = {}
filelinkrevs = {}
seen = {}
self._checkrevlog(cl, b"changelog", 0)
progress = ui.makeprogress(
_(b'checking'), unit=_(b'changesets'), total=len(repo)
)
for i in repo:
progress.update(i)
n = cl.node(i)
self._checkentry(cl, i, n, seen, [i], b"changelog")
try:
changes = cl.read(n)
if changes[0] != nullid:
mflinkrevs.setdefault(changes[0], []).append(i)
self.refersmf = True
for f in changes[3]:
if match(f):
filelinkrevs.setdefault(_normpath(f), []).append(i)
except Exception as inst:
self.refersmf = True
self._exc(i, _(b"unpacking changeset %s") % short(n), inst)
progress.complete()
return mflinkrevs, filelinkrevs
def _verifymanifest(
self, mflinkrevs, dir=b"", storefiles=None, subdirprogress=None
):
"""verify the manifestlog content
Inputs:
- mflinkrevs: a {manifest-node -> [changelog-revisions]} mapping
- dir: a subdirectory to check (for tree manifest repo)
- storefiles: set of currently "orphan" files.
- subdirprogress: a progress object
This function checks:
* all of `_checkrevlog` checks (for all manifest related revlogs)
* all of `_checkentry` checks (for all manifest related revisions)
* nodes for subdirectory exists in the sub-directory manifest
* each manifest entries have a file path
* each manifest node refered in mflinkrevs exist in the manifest log
If tree manifest is in use and a matchers is specified, only the
sub-directories matching it will be verified.
return a two level mapping:
{"path" -> { filenode -> changelog-revision}}
This mapping primarily contains entries for every files in the
repository. In addition, when tree-manifest is used, it also contains
sub-directory entries.
If a matcher is provided, only matching paths will be included.
"""
repo = self.repo
ui = self.ui
match = self.match
mfl = self.repo.manifestlog
mf = mfl.getstorage(dir)
if not dir:
self.ui.status(_(b"checking manifests\n"))
filenodes = {}
subdirnodes = {}
seen = {}
label = b"manifest"
if dir:
label = dir
revlogfiles = mf.files()
storefiles.difference_update(revlogfiles)
if subdirprogress: # should be true since we're in a subdirectory
subdirprogress.increment()
if self.refersmf:
# Do not check manifest if there are only changelog entries with
# null manifests.
self._checkrevlog(mf, label, 0)
progress = ui.makeprogress(
_(b'checking'), unit=_(b'manifests'), total=len(mf)
)
for i in mf:
if not dir:
progress.update(i)
n = mf.node(i)
lr = self._checkentry(mf, i, n, seen, mflinkrevs.get(n, []), label)
if n in mflinkrevs:
del mflinkrevs[n]
elif dir:
self._err(
lr,
_(b"%s not in parent-directory manifest") % short(n),
label,
)
else:
self._err(lr, _(b"%s not in changesets") % short(n), label)
try:
mfdelta = mfl.get(dir, n).readdelta(shallow=True)
for f, fn, fl in mfdelta.iterentries():
if not f:
self._err(lr, _(b"entry without name in manifest"))
elif f == b"/dev/null": # ignore this in very old repos
continue
fullpath = dir + _normpath(f)
if fl == b't':
if not match.visitdir(fullpath):
continue
subdirnodes.setdefault(fullpath + b'/', {}).setdefault(
fn, []
).append(lr)
else:
if not match(fullpath):
continue
filenodes.setdefault(fullpath, {}).setdefault(fn, lr)
except Exception as inst:
self._exc(lr, _(b"reading delta %s") % short(n), inst, label)
if self._level >= VERIFY_FULL:
try:
# Various issues can affect manifest. So we read each full
# text from storage. This triggers the checks from the core
# code (eg: hash verification, filename are ordered, etc.)
mfdelta = mfl.get(dir, n).read()
except Exception as inst:
self._exc(
lr,
_(b"reading full manifest %s") % short(n),
inst,
label,
)
if not dir:
progress.complete()
if self.havemf:
# since we delete entry in `mflinkrevs` during iteration, any
# remaining entries are "missing". We need to issue errors for them.
changesetpairs = [(c, m) for m in mflinkrevs for c in mflinkrevs[m]]
for c, m in sorted(changesetpairs):
if dir:
self._err(
c,
_(
b"parent-directory manifest refers to unknown"
b" revision %s"
)
% short(m),
label,
)
else:
self._err(
c,
_(b"changeset refers to unknown revision %s")
% short(m),
label,
)
if not dir and subdirnodes:
self.ui.status(_(b"checking directory manifests\n"))
storefiles = set()
subdirs = set()
revlogv1 = self.revlogv1
for f, f2, size in repo.store.datafiles():
if not f:
self._err(None, _(b"cannot decode filename '%s'") % f2)
elif (size > 0 or not revlogv1) and f.startswith(b'meta/'):
storefiles.add(_normpath(f))
subdirs.add(os.path.dirname(f))
subdirprogress = ui.makeprogress(
_(b'checking'), unit=_(b'manifests'), total=len(subdirs)
)
for subdir, linkrevs in pycompat.iteritems(subdirnodes):
subdirfilenodes = self._verifymanifest(
linkrevs, subdir, storefiles, subdirprogress
)
for f, onefilenodes in pycompat.iteritems(subdirfilenodes):
filenodes.setdefault(f, {}).update(onefilenodes)
if not dir and subdirnodes:
subdirprogress.complete()
if self.warnorphanstorefiles:
for f in sorted(storefiles):
self._warn(_(b"warning: orphan data file '%s'") % f)
return filenodes
def _crosscheckfiles(self, filelinkrevs, filenodes):
repo = self.repo
ui = self.ui
ui.status(_(b"crosschecking files in changesets and manifests\n"))
total = len(filelinkrevs) + len(filenodes)
progress = ui.makeprogress(
_(b'crosschecking'), unit=_(b'files'), total=total
)
if self.havemf:
for f in sorted(filelinkrevs):
progress.increment()
if f not in filenodes:
lr = filelinkrevs[f][0]
self._err(lr, _(b"in changeset but not in manifest"), f)
if self.havecl:
for f in sorted(filenodes):
progress.increment()
if f not in filelinkrevs:
try:
fl = repo.file(f)
lr = min([fl.linkrev(fl.rev(n)) for n in filenodes[f]])
except Exception:
lr = None
self._err(lr, _(b"in manifest but not in changeset"), f)
progress.complete()
def _verifyfiles(self, filenodes, filelinkrevs):
repo = self.repo
ui = self.ui
lrugetctx = self.lrugetctx
revlogv1 = self.revlogv1
havemf = self.havemf
ui.status(_(b"checking files\n"))
storefiles = set()
for f, f2, size in repo.store.datafiles():
if not f:
self._err(None, _(b"cannot decode filename '%s'") % f2)
elif (size > 0 or not revlogv1) and f.startswith(b'data/'):
storefiles.add(_normpath(f))
state = {
# TODO this assumes revlog storage for changelog.
b'expectedversion': self.repo.changelog.version & 0xFFFF,
b'skipflags': self.skipflags,
# experimental config: censor.policy
b'erroroncensored': ui.config(b'censor', b'policy') == b'abort',
}
files = sorted(set(filenodes) | set(filelinkrevs))
revisions = 0
progress = ui.makeprogress(
_(b'checking'), unit=_(b'files'), total=len(files)
)
for i, f in enumerate(files):
progress.update(i, item=f)
try:
linkrevs = filelinkrevs[f]
except KeyError:
# in manifest but not in changelog
linkrevs = []
if linkrevs:
lr = linkrevs[0]
else:
lr = None
try:
fl = repo.file(f)
except error.StorageError as e:
self._err(lr, _(b"broken revlog! (%s)") % e, f)
continue
for ff in fl.files():
try:
storefiles.remove(ff)
except KeyError:
if self.warnorphanstorefiles:
self._warn(
_(b" warning: revlog '%s' not in fncache!") % ff
)
self.fncachewarned = True
if not len(fl) and (self.havecl or self.havemf):
self._err(lr, _(b"empty or missing %s") % f)
else:
# Guard against implementations not setting this.
state[b'skipread'] = set()
state[b'safe_renamed'] = set()
for problem in fl.verifyintegrity(state):
if problem.node is not None:
linkrev = fl.linkrev(fl.rev(problem.node))
else:
linkrev = None
if problem.warning:
self._warn(problem.warning)
elif problem.error:
self._err(
linkrev if linkrev is not None else lr,
problem.error,
f,
)
else:
raise error.ProgrammingError(
b'problem instance does not set warning or error '
b'attribute: %s' % problem.msg
)
seen = {}
for i in fl:
revisions += 1
n = fl.node(i)
lr = self._checkentry(fl, i, n, seen, linkrevs, f)
if f in filenodes:
if havemf and n not in filenodes[f]:
self._err(lr, _(b"%s not in manifests") % (short(n)), f)
else:
del filenodes[f][n]
if n in state[b'skipread'] and n not in state[b'safe_renamed']:
continue
# check renames
try:
# This requires resolving fulltext (at least on revlogs,
# though not with LFS revisions). We may want
# ``verifyintegrity()`` to pass a set of nodes with
# rename metadata as an optimization.
rp = fl.renamed(n)
if rp:
if lr is not None and ui.verbose:
ctx = lrugetctx(lr)
if not any(rp[0] in pctx for pctx in ctx.parents()):
self._warn(
_(
b"warning: copy source of '%s' not"
b" in parents of %s"
)
% (f, ctx)
)
fl2 = repo.file(rp[0])
if not len(fl2):
self._err(
lr,
_(
b"empty or missing copy source revlog "
b"%s:%s"
)
% (rp[0], short(rp[1])),
f,
)
elif rp[1] == nullid:
ui.note(
_(
b"warning: %s@%s: copy source"
b" revision is nullid %s:%s\n"
)
% (f, lr, rp[0], short(rp[1]))
)
else:
fl2.rev(rp[1])
except Exception as inst:
self._exc(
lr, _(b"checking rename of %s") % short(n), inst, f
)
# cross-check
if f in filenodes:
fns = [(v, k) for k, v in pycompat.iteritems(filenodes[f])]
for lr, node in sorted(fns):
self._err(
lr,
_(b"manifest refers to unknown revision %s")
% short(node),
f,
)
progress.complete()
if self.warnorphanstorefiles:
for f in sorted(storefiles):
self._warn(_(b"warning: orphan data file '%s'") % f)
return len(files), revisions