revlog: ignore empty trailing chunks when reading segments
When a merge commit creates an empty diff in the revlog, its offset may still
be quite far from the end of the previous chunk.
Skipping these empty chunks may reduce read size significantly.
In most cases, there is no gain, and in some cases, little gain.
On my clone of pypy, `hg manifest` reads 65% less bytes (96140 i/o 275943) for
revision 4260 by ignoring the only empty trailing diff.
For revision 2229, 35% (34557 i/o 53435)
Sadly, this is difficult to reproduce, as hg clone can make its own different
structure every time.
# 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,
revlog,
scmutil,
util,
)
def verify(repo):
with repo.lock():
return verifier(repo).verify()
def _normpath(f):
# under hg < 2.4, convert didn't sanitize paths properly, so a
# converted repo may contain repeated slashes
while '//' in f:
f = f.replace('//', '/')
return f
class verifier(object):
# The match argument is always None in hg core, but e.g. the narrowhg
# extension will pass in a matcher here.
def __init__(self, repo, match=None):
self.repo = repo.unfiltered()
self.ui = repo.ui
self.match = match or scmutil.matchall(repo)
self.badrevs = set()
self.errors = 0
self.warnings = 0
self.havecl = len(repo.changelog) > 0
self.havemf = len(repo.manifestlog._revlog) > 0
self.revlogv1 = repo.changelog.version != revlog.REVLOGV0
self.lrugetctx = util.lrucachefunc(repo.changectx)
self.refersmf = False
self.fncachewarned = False
# developer config: verify.skipflags
self.skipflags = repo.ui.configint('verify', 'skipflags')
def warn(self, msg):
self.ui.warn(msg + "\n")
self.warnings += 1
def err(self, linkrev, msg, filename=None):
if linkrev is not None:
self.badrevs.add(linkrev)
else:
linkrev = '?'
msg = "%s: %s" % (linkrev, msg)
if filename:
msg = "%s@%s" % (filename, msg)
self.ui.warn(" " + msg + "\n")
self.errors += 1
def exc(self, linkrev, msg, inst, filename=None):
if not str(inst):
inst = repr(inst)
self.err(linkrev, "%s: %s" % (msg, inst), filename)
def checklog(self, obj, name, linkrev):
if not len(obj) and (self.havecl or self.havemf):
self.err(linkrev, _("empty or missing %s") % name)
return
d = obj.checksize()
if d[0]:
self.err(None, _("data length off by %d bytes") % d[0], name)
if d[1]:
self.err(None, _("index contains %d extra bytes") % d[1], name)
if obj.version != revlog.REVLOGV0:
if not self.revlogv1:
self.warn(_("warning: `%s' uses revlog format 1") % name)
elif self.revlogv1:
self.warn(_("warning: `%s' uses revlog format 0") % name)
def checkentry(self, obj, i, node, seen, linkrevs, f):
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 = _("rev %d points to nonexistent changeset %d")
else:
msg = _("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(_(" (expected %s)") % " ".join(map(str, linkrevs)))
lr = None # can't be trusted
try:
p1, p2 = obj.parents(node)
if p1 not in seen and p1 != nullid:
self.err(lr, _("unknown parent 1 %s of %s") %
(short(p1), short(node)), f)
if p2 not in seen and p2 != nullid:
self.err(lr, _("unknown parent 2 %s of %s") %
(short(p2), short(node)), f)
except Exception as inst:
self.exc(lr, _("checking parents of %s") % short(node), inst, f)
if node in seen:
self.err(lr, _("duplicate revision %d (%d)") % (i, seen[node]), f)
seen[node] = i
return lr
def verify(self):
repo = self.repo
ui = repo.ui
if not repo.url().startswith('file:'):
raise error.Abort(_("cannot verify bundle or remote repos"))
if os.path.exists(repo.sjoin("journal")):
ui.warn(_("abandoned transaction found - run hg recover\n"))
if ui.verbose or not self.revlogv1:
ui.status(_("repository uses revlog format %d\n") %
(self.revlogv1 and 1 or 0))
mflinkrevs, filelinkrevs = self._verifychangelog()
filenodes = self._verifymanifest(mflinkrevs)
del mflinkrevs
self._crosscheckfiles(filelinkrevs, filenodes)
totalfiles, filerevisions = self._verifyfiles(filenodes, filelinkrevs)
ui.status(_("%d files, %d changesets, %d total revisions\n") %
(totalfiles, len(repo.changelog), filerevisions))
if self.warnings:
ui.warn(_("%d warnings encountered!\n") % self.warnings)
if self.fncachewarned:
ui.warn(_('hint: run "hg debugrebuildfncache" to recover from '
'corrupt fncache\n'))
if self.errors:
ui.warn(_("%d integrity errors encountered!\n") % self.errors)
if self.badrevs:
ui.warn(_("(first damaged changeset appears to be %d)\n")
% min(self.badrevs))
return 1
def _verifychangelog(self):
ui = self.ui
repo = self.repo
match = self.match
cl = repo.changelog
ui.status(_("checking changesets\n"))
mflinkrevs = {}
filelinkrevs = {}
seen = {}
self.checklog(cl, "changelog", 0)
total = len(repo)
for i in repo:
ui.progress(_('checking'), i, total=total, unit=_('changesets'))
n = cl.node(i)
self.checkentry(cl, i, n, seen, [i], "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, _("unpacking changeset %s") % short(n), inst)
ui.progress(_('checking'), None)
return mflinkrevs, filelinkrevs
def _verifymanifest(self, mflinkrevs, dir="", storefiles=None,
progress=None):
repo = self.repo
ui = self.ui
match = self.match
mfl = self.repo.manifestlog
mf = mfl._revlog.dirlog(dir)
if not dir:
self.ui.status(_("checking manifests\n"))
filenodes = {}
subdirnodes = {}
seen = {}
label = "manifest"
if dir:
label = dir
revlogfiles = mf.files()
storefiles.difference_update(revlogfiles)
if progress: # should be true since we're in a subdirectory
progress()
if self.refersmf:
# Do not check manifest if there are only changelog entries with
# null manifests.
self.checklog(mf, label, 0)
total = len(mf)
for i in mf:
if not dir:
ui.progress(_('checking'), i, total=total, unit=_('manifests'))
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, _("%s not in parent-directory manifest") %
short(n), label)
else:
self.err(lr, _("%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, _("entry without name in manifest"))
elif f == "/dev/null": # ignore this in very old repos
continue
fullpath = dir + _normpath(f)
if fl == 't':
if not match.visitdir(fullpath):
continue
subdirnodes.setdefault(fullpath + '/', {}).setdefault(
fn, []).append(lr)
else:
if not match(fullpath):
continue
filenodes.setdefault(fullpath, {}).setdefault(fn, lr)
except Exception as inst:
self.exc(lr, _("reading delta %s") % short(n), inst, label)
if not dir:
ui.progress(_('checking'), None)
if self.havemf:
for c, m in sorted([(c, m) for m in mflinkrevs
for c in mflinkrevs[m]]):
if dir:
self.err(c, _("parent-directory manifest refers to unknown "
"revision %s") % short(m), label)
else:
self.err(c, _("changeset refers to unknown revision %s") %
short(m), label)
if not dir and subdirnodes:
self.ui.status(_("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, _("cannot decode filename '%s'") % f2)
elif (size > 0 or not revlogv1) and f.startswith('meta/'):
storefiles.add(_normpath(f))
subdirs.add(os.path.dirname(f))
subdircount = len(subdirs)
currentsubdir = [0]
def progress():
currentsubdir[0] += 1
ui.progress(_('checking'), currentsubdir[0], total=subdircount,
unit=_('manifests'))
for subdir, linkrevs in subdirnodes.iteritems():
subdirfilenodes = self._verifymanifest(linkrevs, subdir, storefiles,
progress)
for f, onefilenodes in subdirfilenodes.iteritems():
filenodes.setdefault(f, {}).update(onefilenodes)
if not dir and subdirnodes:
ui.progress(_('checking'), None)
for f in sorted(storefiles):
self.warn(_("warning: orphan revlog '%s'") % f)
return filenodes
def _crosscheckfiles(self, filelinkrevs, filenodes):
repo = self.repo
ui = self.ui
ui.status(_("crosschecking files in changesets and manifests\n"))
total = len(filelinkrevs) + len(filenodes)
count = 0
if self.havemf:
for f in sorted(filelinkrevs):
count += 1
ui.progress(_('crosschecking'), count, total=total)
if f not in filenodes:
lr = filelinkrevs[f][0]
self.err(lr, _("in changeset but not in manifest"), f)
if self.havecl:
for f in sorted(filenodes):
count += 1
ui.progress(_('crosschecking'), count, total=total)
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, _("in manifest but not in changeset"), f)
ui.progress(_('crosschecking'), None)
def _verifyfiles(self, filenodes, filelinkrevs):
repo = self.repo
ui = self.ui
lrugetctx = self.lrugetctx
revlogv1 = self.revlogv1
havemf = self.havemf
ui.status(_("checking files\n"))
storefiles = set()
for f, f2, size in repo.store.datafiles():
if not f:
self.err(None, _("cannot decode filename '%s'") % f2)
elif (size > 0 or not revlogv1) and f.startswith('data/'):
storefiles.add(_normpath(f))
files = sorted(set(filenodes) | set(filelinkrevs))
total = len(files)
revisions = 0
for i, f in enumerate(files):
ui.progress(_('checking'), i, item=f, total=total, unit=_('files'))
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.RevlogError as e:
self.err(lr, _("broken revlog! (%s)") % e, f)
continue
for ff in fl.files():
try:
storefiles.remove(ff)
except KeyError:
self.warn(_(" warning: revlog '%s' not in fncache!") % ff)
self.fncachewarned = True
self.checklog(fl, f, lr)
seen = {}
rp = None
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, _("%s not in manifests") % (short(n)), f)
else:
del filenodes[f][n]
# Verify contents. 4 cases to care about:
#
# common: the most common case
# rename: with a rename
# meta: file content starts with b'\1\n', the metadata
# header defined in filelog.py, but without a rename
# ext: content stored externally
#
# More formally, their differences are shown below:
#
# | common | rename | meta | ext
# -------------------------------------------------------
# flags() | 0 | 0 | 0 | not 0
# renamed() | False | True | False | ?
# rawtext[0:2]=='\1\n'| False | True | True | ?
#
# "rawtext" means the raw text stored in revlog data, which
# could be retrieved by "revision(rev, raw=True)". "text"
# mentioned below is "revision(rev, raw=False)".
#
# There are 3 different lengths stored physically:
# 1. L1: rawsize, stored in revlog index
# 2. L2: len(rawtext), stored in revlog data
# 3. L3: len(text), stored in revlog data if flags==0, or
# possibly somewhere else if flags!=0
#
# L1 should be equal to L2. L3 could be different from them.
# "text" may or may not affect commit hash depending on flag
# processors (see revlog.addflagprocessor).
#
# | common | rename | meta | ext
# -------------------------------------------------
# rawsize() | L1 | L1 | L1 | L1
# size() | L1 | L2-LM | L1(*) | L1 (?)
# len(rawtext) | L2 | L2 | L2 | L2
# len(text) | L2 | L2 | L2 | L3
# len(read()) | L2 | L2-LM | L2-LM | L3 (?)
#
# LM: length of metadata, depending on rawtext
# (*): not ideal, see comment in filelog.size
# (?): could be "- len(meta)" if the resolved content has
# rename metadata
#
# Checks needed to be done:
# 1. length check: L1 == L2, in all cases.
# 2. hash check: depending on flag processor, we may need to
# use either "text" (external), or "rawtext" (in revlog).
try:
skipflags = self.skipflags
if skipflags:
skipflags &= fl.flags(i)
if not skipflags:
fl.read(n) # side effect: read content and do checkhash
rp = fl.renamed(n)
# the "L1 == L2" check
l1 = fl.rawsize(i)
l2 = len(fl.revision(n, raw=True))
if l1 != l2:
self.err(lr, _("unpacked size is %s, %s expected") %
(l2, l1), f)
except error.CensoredNodeError:
# experimental config: censor.policy
if ui.config("censor", "policy") == "abort":
self.err(lr, _("censored file data"), f)
except Exception as inst:
self.exc(lr, _("unpacking %s") % short(n), inst, f)
# check renames
try:
if rp:
if lr is not None and ui.verbose:
ctx = lrugetctx(lr)
found = False
for pctx in ctx.parents():
if rp[0] in pctx:
found = True
break
if not found:
self.warn(_("warning: copy source of '%s' not"
" in parents of %s") % (f, ctx))
fl2 = repo.file(rp[0])
if not len(fl2):
self.err(lr, _("empty or missing copy source "
"revlog %s:%s") % (rp[0], short(rp[1])), f)
elif rp[1] == nullid:
ui.note(_("warning: %s@%s: copy source"
" 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, _("checking rename of %s") % short(n), inst, f)
# cross-check
if f in filenodes:
fns = [(v, k) for k, v in filenodes[f].iteritems()]
for lr, node in sorted(fns):
self.err(lr, _("manifest refers to unknown revision %s") %
short(node), f)
ui.progress(_('checking'), None)
for f in sorted(storefiles):
self.warn(_("warning: orphan revlog '%s'") % f)
return len(files), revisions