verify: recover lost freeing of memory

In df8973e1fb45 (verify: move file cross checking to its own function,
2016-01-05), "mflinkrevs = None" was moved into function, so the
reference was cleared there, but the calling function now held on to
the variable. The point of clearing it was presumably to free up
memory, so let's move the clearing to the calling function where it
makes a difference. Also change "mflinkrevs = None" to "del
mflinkrevs", since the comment about scope now surely is obsolete.

mercurial/verify.py

@@ -1,384 +1,384 b''
 # verify.py - repository integrity checking for Mercurial
 #
 # Copyright 2006, 2007 Matt Mackall <[e-mail]>
 #
 # 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,
     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
 
 def _validpath(repo, path):
     """Returns False if a path should NOT be treated as part of a repo.
 
     For all in-core cases, this returns True, as we have no way for a
     path to be mentioned in the history but not actually be
     relevant. For narrow clones, this is important because many
     filelogs will be missing, and changelog entries may mention
     modified files that are outside the narrow scope.
     """
     return True
 
 class verifier(object):
     def __init__(self, repo):
         self.repo = repo.unfiltered()
         self.ui = repo.ui
         self.badrevs = set()
         self.errors = 0
         self.warnings = 0
         self.havecl = len(repo.changelog) > 0
         self.havemf = len(repo.manifest) > 0
         self.revlogv1 = repo.changelog.version != revlog.REVLOGV0
         self.lrugetctx = util.lrucachefunc(repo.changectx)
         self.refersmf = False
         self.fncachewarned = False
 
     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)
 
         self._crosscheckfiles(mflinkrevs, filelinkrevs, filenodes)
+        del mflinkrevs
 
         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
         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 _validpath(repo, 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):
         repo = self.repo
         ui = self.ui
         mf = self.repo.manifest
 
         ui.status(_("checking manifests\n"))
         filenodes = {}
         seen = {}
         if self.refersmf:
             # Do not check manifest if there are only changelog entries with
             # null manifests.
             self.checklog(mf, "manifest", 0)
         total = len(mf)
         for i in mf:
             ui.progress(_('checking'), i, total=total, unit=_('manifests'))
             n = mf.node(i)
             lr = self.checkentry(mf, i, n, seen, mflinkrevs.get(n, []),
                                  "manifest")
             if n in mflinkrevs:
                 del mflinkrevs[n]
             else:
                 self.err(lr, _("%s not in changesets") % short(n), "manifest")
 
             try:
                 for f, fn in mf.readdelta(n).iteritems():
                     if not f:
                         self.err(lr, _("file without name in manifest"))
                     elif f != "/dev/null": # ignore this in very old repos
                         if _validpath(repo, f):
                             filenodes.setdefault(
                                 _normpath(f), {}).setdefault(fn, lr)
             except Exception as inst:
                 self.exc(lr, _("reading manifest delta %s") % short(n), inst)
         ui.progress(_('checking'), None)
 
         return filenodes
 
     def _crosscheckfiles(self, mflinkrevs, filelinkrevs, filenodes):
         repo = self.repo
         ui = self.ui
         ui.status(_("crosschecking files in changesets and manifests\n"))
 
         total = len(mflinkrevs) + len(filelinkrevs) + len(filenodes)
         count = 0
         if self.havemf:
             for c, m in sorted([(c, m) for m in mflinkrevs
                                 for c in mflinkrevs[m]]):
                 count += 1
                 if m == nullid:
                     continue
                 ui.progress(_('crosschecking'), count, total=total)
                 self.err(c, _("changeset refers to unknown manifest %s") %
                          short(m))
-            mflinkrevs = None # del is bad here due to scope issues
 
             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:
                 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)
             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
                 try:
                     l = len(fl.read(n))
                     rp = fl.renamed(n)
                     if l != fl.size(i):
                         if len(fl.revision(n)) != fl.size(i):
                             self.err(lr, _("unpacked size is %s, %s expected") %
                                      (l, fl.size(i)), f)
                 except error.CensoredNodeError:
                     # experimental config: censor.policy
                     if ui.config("censor", "policy", "abort") == "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 = [(lr, n) for n, lr in filenodes[f].iteritems()]
                 for lr, node in sorted(fns):
                     self.err(lr, _("%s in manifests not found") % short(node),
                              f)
         ui.progress(_('checking'), None)
 
         for f in storefiles:
             self.warn(_("warning: orphan revlog '%s'") % f)
 
         return len(files), revisions