rebase, revlog: use set(x) instead of set(x.keys())

The latter is both unnecessary and slower.

hgext/rebase.py

@@ -1,473 +1,472
 # rebase.py - rebasing feature for mercurial
 #
 # Copyright 2008 Stefano Tortarolo <stefano.tortarolo at gmail dot com>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 '''move sets of revisions to a different ancestor
 
 This extension lets you rebase changesets in an existing Mercurial
 repository.
 
 For more information:
 http://www.selenic.com/mercurial/wiki/index.cgi/RebaseProject
 '''
 
 from mercurial import util, repair, merge, cmdutil, commands, error
 from mercurial import extensions, ancestor, copies, patch
 from mercurial.commands import templateopts
 from mercurial.node import nullrev
 from mercurial.lock import release
 from mercurial.i18n import _
 import os, errno
 
 def rebasemerge(repo, rev, first=False):
     'return the correct ancestor'
     oldancestor = ancestor.ancestor
 
     def newancestor(a, b, pfunc):
         ancestor.ancestor = oldancestor
         if b == rev:
             return repo[rev].parents()[0].rev()
         return ancestor.ancestor(a, b, pfunc)
 
     if not first:
         ancestor.ancestor = newancestor
     else:
         repo.ui.debug(_("first revision, do not change ancestor\n"))
     stats = merge.update(repo, rev, True, True, False)
     return stats
 
 def rebase(ui, repo, **opts):
     """move changeset (and descendants) to a different branch
 
     Rebase uses repeated merging to graft changesets from one part of
     history onto another. This can be useful for linearizing local
     changes relative to a master development tree.
 
     If a rebase is interrupted to manually resolve a merge, it can be
     continued with --continue/-c or aborted with --abort/-a.
     """
     originalwd = target = None
     external = nullrev
     state = skipped = {}
 
     lock = wlock = None
     try:
         lock = repo.lock()
         wlock = repo.wlock()
 
         # Validate input and define rebasing points
         destf = opts.get('dest', None)
         srcf = opts.get('source', None)
         basef = opts.get('base', None)
         contf = opts.get('continue')
         abortf = opts.get('abort')
         collapsef = opts.get('collapse', False)
         extrafn = opts.get('extrafn')
         keepf = opts.get('keep', False)
         keepbranchesf = opts.get('keepbranches', False)
 
         if contf or abortf:
             if contf and abortf:
                 raise error.ParseError('rebase',
                                        _('cannot use both abort and continue'))
             if collapsef:
                 raise error.ParseError(
                     'rebase', _('cannot use collapse with continue or abort'))
 
             if srcf or basef or destf:
                 raise error.ParseError('rebase',
                     _('abort and continue do not allow specifying revisions'))
 
             (originalwd, target, state, collapsef, keepf,
                                 keepbranchesf, external) = restorestatus(repo)
             if abortf:
                 abort(repo, originalwd, target, state)
                 return
         else:
             if srcf and basef:
                 raise error.ParseError('rebase', _('cannot specify both a '
                                                    'revision and a base'))
             cmdutil.bail_if_changed(repo)
             result = buildstate(repo, destf, srcf, basef, collapsef)
             if result:
                 originalwd, target, state, external = result
             else: # Empty state built, nothing to rebase
                 repo.ui.status(_('nothing to rebase\n'))
                 return
 
         if keepbranchesf:
             if extrafn:
                 raise error.ParseError(
                     'rebase', _('cannot use both keepbranches and extrafn'))
             def extrafn(ctx, extra):
                 extra['branch'] = ctx.branch()
 
         # Rebase
         targetancestors = list(repo.changelog.ancestors(target))
         targetancestors.append(target)
 
         for rev in util.sort(state):
             if state[rev] == -1:
                 storestatus(repo, originalwd, target, state, collapsef, keepf,
                                                     keepbranchesf, external)
                 rebasenode(repo, rev, target, state, skipped, targetancestors,
                                                        collapsef, extrafn)
         ui.note(_('rebase merging completed\n'))
 
         if collapsef:
             p1, p2 = defineparents(repo, min(state), target,
                                                         state, targetancestors)
             concludenode(repo, rev, p1, external, state, collapsef,
                          last=True, skipped=skipped, extrafn=extrafn)
 
         if 'qtip' in repo.tags():
             updatemq(repo, state, skipped, **opts)
 
         if not keepf:
             # Remove no more useful revisions
-            if (set(repo.changelog.descendants(min(state)))
-                                                    - set(state.keys())):
+            if set(repo.changelog.descendants(min(state))) - set(state):
                 ui.warn(_("warning: new changesets detected on source branch, "
                                                         "not stripping\n"))
             else:
                 repair.strip(repo.ui, repo, repo[min(state)].node(), "strip")
 
         clearstatus(repo)
         ui.status(_("rebase completed\n"))
         if os.path.exists(repo.sjoin('undo')):
             util.unlink(repo.sjoin('undo'))
         if skipped:
             ui.note(_("%d revisions have been skipped\n") % len(skipped))
     finally:
         release(lock, wlock)
 
 def concludenode(repo, rev, p1, p2, state, collapse, last=False, skipped={},
                  extrafn=None):
     """Skip commit if collapsing has been required and rev is not the last
     revision, commit otherwise
     """
     repo.ui.debug(_(" set parents\n"))
     if collapse and not last:
         repo.dirstate.setparents(repo[p1].node())
         return None
 
     repo.dirstate.setparents(repo[p1].node(), repo[p2].node())
 
     # Commit, record the old nodeid
     m, a, r = repo.status()[:3]
     newrev = nullrev
     try:
         if last:
             commitmsg = 'Collapsed revision'
             for rebased in state:
                 if rebased not in skipped:
                     commitmsg += '\n* %s' % repo[rebased].description()
             commitmsg = repo.ui.edit(commitmsg, repo.ui.username())
         else:
             commitmsg = repo[rev].description()
         # Commit might fail if unresolved files exist
         extra = {'rebase_source': repo[rev].hex()}
         if extrafn:
             extrafn(repo[rev], extra)
         newrev = repo.commit(m+a+r,
                             text=commitmsg,
                             user=repo[rev].user(),
                             date=repo[rev].date(),
                             extra=extra)
         return newrev
     except util.Abort:
         # Invalidate the previous setparents
         repo.dirstate.invalidate()
         raise
 
 def rebasenode(repo, rev, target, state, skipped, targetancestors, collapse,
                extrafn):
     'Rebase a single revision'
     repo.ui.debug(_("rebasing %d:%s\n") % (rev, repo[rev]))
 
     p1, p2 = defineparents(repo, rev, target, state, targetancestors)
 
     repo.ui.debug(_(" future parents are %d and %d\n") % (repo[p1].rev(),
                                                             repo[p2].rev()))
 
     # Merge phase
     if len(repo.parents()) != 2:
         # Update to target and merge it with local
         if repo['.'].rev() != repo[p1].rev():
             repo.ui.debug(_(" update to %d:%s\n") % (repo[p1].rev(), repo[p1]))
             merge.update(repo, p1, False, True, False)
         else:
             repo.ui.debug(_(" already in target\n"))
         repo.dirstate.write()
         repo.ui.debug(_(" merge against %d:%s\n") % (repo[rev].rev(), repo[rev]))
         first = repo[rev].rev() == repo[min(state)].rev()
         stats = rebasemerge(repo, rev, first)
 
         if stats[3] > 0:
             raise util.Abort(_('fix unresolved conflicts with hg resolve then '
                                                 'run hg rebase --continue'))
     else: # we have an interrupted rebase
         repo.ui.debug(_('resuming interrupted rebase\n'))
 
     # Keep track of renamed files in the revision that is going to be rebased
     # Here we simulate the copies and renames in the source changeset
     cop, diver = copies.copies(repo, repo[rev], repo[target], repo[p2], True)
     m1 = repo[rev].manifest()
     m2 = repo[target].manifest()
     for k, v in cop.iteritems():
         if k in m1:
             if v in m1 or v in m2:
                 repo.dirstate.copy(v, k)
                 if v in m2 and v not in m1:
                     repo.dirstate.remove(v)
                 
     newrev = concludenode(repo, rev, p1, p2, state, collapse,
                           extrafn=extrafn)
 
     # Update the state
     if newrev is not None:
         state[rev] = repo[newrev].rev()
     else:
         if not collapse:
             repo.ui.note(_('no changes, revision %d skipped\n') % rev)
             repo.ui.debug(_('next revision set to %s\n') % p1)
             skipped[rev] = True
         state[rev] = p1
 
 def defineparents(repo, rev, target, state, targetancestors):
     'Return the new parent relationship of the revision that will be rebased'
     parents = repo[rev].parents()
     p1 = p2 = nullrev
 
     P1n = parents[0].rev()
     if P1n in targetancestors:
         p1 = target
     elif P1n in state:
         p1 = state[P1n]
     else: # P1n external
         p1 = target
         p2 = P1n
 
     if len(parents) == 2 and parents[1].rev() not in targetancestors:
         P2n = parents[1].rev()
         # interesting second parent
         if P2n in state:
             if p1 == target: # P1n in targetancestors or external
                 p1 = state[P2n]
             else:
                 p2 = state[P2n]
         else: # P2n external
             if p2 != nullrev: # P1n external too => rev is a merged revision
                 raise util.Abort(_('cannot use revision %d as base, result '
                         'would have 3 parents') % rev)
             p2 = P2n
     return p1, p2
 
 def isagitpatch(repo, patchname):
     'Return true if the given patch is in git format'
     mqpatch = os.path.join(repo.mq.path, patchname)
     for line in patch.linereader(file(mqpatch, 'rb')):
         if line.startswith('diff --git'):
             return True
     return False
 
 def updatemq(repo, state, skipped, **opts):
     'Update rebased mq patches - finalize and then import them'
     mqrebase = {}
     for p in repo.mq.applied:
         if repo[p.rev].rev() in state:
             repo.ui.debug(_('revision %d is an mq patch (%s), finalize it.\n') %
                                         (repo[p.rev].rev(), p.name))
             mqrebase[repo[p.rev].rev()] = (p.name, isagitpatch(repo, p.name))
 
     if mqrebase:
         repo.mq.finish(repo, mqrebase.keys())
 
         # We must start import from the newest revision
         mq = mqrebase.keys()
         mq.sort()
         mq.reverse()
         for rev in mq:
             if rev not in skipped:
                 repo.ui.debug(_('import mq patch %d (%s)\n')
                               % (state[rev], mqrebase[rev][0]))
                 repo.mq.qimport(repo, (), patchname=mqrebase[rev][0],
                             git=mqrebase[rev][1],rev=[str(state[rev])])
         repo.mq.save_dirty()
 
 def storestatus(repo, originalwd, target, state, collapse, keep, keepbranches,
                                                                 external):
     'Store the current status to allow recovery'
     f = repo.opener("rebasestate", "w")
     f.write(repo[originalwd].hex() + '\n')
     f.write(repo[target].hex() + '\n')
     f.write(repo[external].hex() + '\n')
     f.write('%d\n' % int(collapse))
     f.write('%d\n' % int(keep))
     f.write('%d\n' % int(keepbranches))
     for d, v in state.iteritems():
         oldrev = repo[d].hex()
         newrev = repo[v].hex()
         f.write("%s:%s\n" % (oldrev, newrev))
     f.close()
     repo.ui.debug(_('rebase status stored\n'))
 
 def clearstatus(repo):
     'Remove the status files'
     if os.path.exists(repo.join("rebasestate")):
         util.unlink(repo.join("rebasestate"))
 
 def restorestatus(repo):
     'Restore a previously stored status'
     try:
         target = None
         collapse = False
         external = nullrev
         state = {}
         f = repo.opener("rebasestate")
         for i, l in enumerate(f.read().splitlines()):
             if i == 0:
                 originalwd = repo[l].rev()
             elif i == 1:
                 target = repo[l].rev()
             elif i == 2:
                 external = repo[l].rev()
             elif i == 3:
                 collapse = bool(int(l))
             elif i == 4:
                 keep = bool(int(l))
             elif i == 5:
                 keepbranches = bool(int(l))
             else:
                 oldrev, newrev = l.split(':')
                 state[repo[oldrev].rev()] = repo[newrev].rev()
         repo.ui.debug(_('rebase status resumed\n'))
         return originalwd, target, state, collapse, keep, keepbranches, external
     except IOError, err:
         if err.errno != errno.ENOENT:
             raise
         raise util.Abort(_('no rebase in progress'))
 
 def abort(repo, originalwd, target, state):
     'Restore the repository to its original state'
     if set(repo.changelog.descendants(target)) - set(state.values()):
         repo.ui.warn(_("warning: new changesets detected on target branch, "
                                                     "not stripping\n"))
     else:
         # Strip from the first rebased revision
         merge.update(repo, repo[originalwd].rev(), False, True, False)
         rebased = filter(lambda x: x > -1, state.values())
         if rebased:
             strippoint = min(rebased)
             repair.strip(repo.ui, repo, repo[strippoint].node(), "strip")
         clearstatus(repo)
         repo.ui.status(_('rebase aborted\n'))
 
 def buildstate(repo, dest, src, base, collapse):
     'Define which revisions are going to be rebased and where'
     targetancestors = set()
 
     if not dest:
         # Destination defaults to the latest revision in the current branch
         branch = repo[None].branch()
         dest = repo[branch].rev()
     else:
         if 'qtip' in repo.tags() and (repo[dest].hex() in
                                 [s.rev for s in repo.mq.applied]):
             raise util.Abort(_('cannot rebase onto an applied mq patch'))
         dest = repo[dest].rev()
 
     if src:
         commonbase = repo[src].ancestor(repo[dest])
         if commonbase == repo[src]:
             raise util.Abort(_('cannot rebase an ancestor'))
         if commonbase == repo[dest]:
             raise util.Abort(_('cannot rebase a descendant'))
         source = repo[src].rev()
     else:
         if base:
             cwd = repo[base].rev()
         else:
             cwd = repo['.'].rev()
 
         if cwd == dest:
             repo.ui.debug(_('already working on current\n'))
             return None
 
         targetancestors = set(repo.changelog.ancestors(dest))
         if cwd in targetancestors:
             repo.ui.debug(_('already working on the current branch\n'))
             return None
 
         cwdancestors = set(repo.changelog.ancestors(cwd))
         cwdancestors.add(cwd)
         rebasingbranch = cwdancestors - targetancestors
         source = min(rebasingbranch)
 
     repo.ui.debug(_('rebase onto %d starting from %d\n') % (dest, source))
     state = dict.fromkeys(repo.changelog.descendants(source), nullrev)
     external = nullrev
     if collapse:
         if not targetancestors:
             targetancestors = set(repo.changelog.ancestors(dest))
         for rev in state:
             # Check externals and fail if there are more than one
             for p in repo[rev].parents():
                 if (p.rev() not in state and p.rev() != source
                             and p.rev() not in targetancestors):
                     if external != nullrev:
                         raise util.Abort(_('unable to collapse, there is more '
                                 'than one external parent'))
                     external = p.rev()
 
     state[source] = nullrev
     return repo['.'].rev(), repo[dest].rev(), state, external
 
 def pullrebase(orig, ui, repo, *args, **opts):
     'Call rebase after pull if the latter has been invoked with --rebase'
     if opts.get('rebase'):
         if opts.get('update'):
             del opts.get['update']
             ui.debug(_('--update and --rebase are not compatible, ignoring '
                                         'the update flag\n'))
 
         cmdutil.bail_if_changed(repo)
         revsprepull = len(repo)
         orig(ui, repo, *args, **opts)
         revspostpull = len(repo)
         if revspostpull > revsprepull:
             rebase(ui, repo, **opts)
             branch = repo[None].branch()
             dest = repo[branch].rev()
             if dest != repo['.'].rev():
                 # there was nothing to rebase we force an update
                 merge.update(repo, dest, False, False, False)
     else:
         orig(ui, repo, *args, **opts)
 
 def uisetup(ui):
     'Replace pull with a decorator to provide --rebase option'
     entry = extensions.wrapcommand(commands.table, 'pull', pullrebase)
     entry[1].append(('', 'rebase', None,
                      _("rebase working directory to branch head"))
 )
 
 cmdtable = {
 "rebase":
         (rebase,
         [
         ('s', 'source', '', _('rebase from a given revision')),
         ('b', 'base', '', _('rebase from the base of a given revision')),
         ('d', 'dest', '', _('rebase onto a given revision')),
         ('', 'collapse', False, _('collapse the rebased revisions')),
         ('', 'keep', False, _('keep original revisions')),
         ('', 'keepbranches', False, _('keep original branches')),
         ('c', 'continue', False, _('continue an interrupted rebase')),
         ('a', 'abort', False, _('abort an interrupted rebase')),] +
          templateopts,
         _('hg rebase [-s REV | -b REV] [-d REV] [--collapse] [--keep] '
                             '[--keepbranches] | [-c] | [-a]')),
 }

mercurial/revlog.py

@@ -1,1369 +1,1369
 """
 revlog.py - storage back-end for mercurial
 
 This provides efficient delta storage with O(1) retrieve and append
 and O(changes) merge between branches
 
 Copyright 2005-2007 Matt Mackall <[e-mail]>
 
 This software may be used and distributed according to the terms
 of the GNU General Public License, incorporated herein by reference.
 """
 
 # import stuff from node for others to import from revlog
 from node import bin, hex, nullid, nullrev, short #@UnusedImport
 from i18n import _
 import changegroup, errno, ancestor, mdiff, parsers
 import struct, util, zlib, error
 
 _pack = struct.pack
 _unpack = struct.unpack
 _compress = zlib.compress
 _decompress = zlib.decompress
 _sha = util.sha1
 
 # revlog flags
 REVLOGV0 = 0
 REVLOGNG = 1
 REVLOGNGINLINEDATA = (1 << 16)
 REVLOG_DEFAULT_FLAGS = REVLOGNGINLINEDATA
 REVLOG_DEFAULT_FORMAT = REVLOGNG
 REVLOG_DEFAULT_VERSION = REVLOG_DEFAULT_FORMAT | REVLOG_DEFAULT_FLAGS
 
 RevlogError = error.RevlogError
 LookupError = error.LookupError
 
 def getoffset(q):
     return int(q >> 16)
 
 def gettype(q):
     return int(q & 0xFFFF)
 
 def offset_type(offset, type):
     return long(long(offset) << 16 | type)
 
 nullhash = _sha(nullid)
 
 def hash(text, p1, p2):
     """generate a hash from the given text and its parent hashes
 
     This hash combines both the current file contents and its history
     in a manner that makes it easy to distinguish nodes with the same
     content in the revision graph.
     """
     # As of now, if one of the parent node is null, p2 is null
     if p2 == nullid:
         # deep copy of a hash is faster than creating one
         s = nullhash.copy()
         s.update(p1)
     else:
         # none of the parent nodes are nullid
         l = [p1, p2]
         l.sort()
         s = _sha(l[0])
         s.update(l[1])
     s.update(text)
     return s.digest()
 
 def compress(text):
     """ generate a possibly-compressed representation of text """
     if not text:
         return ("", text)
     l = len(text)
     bin = None
     if l < 44:
         pass
     elif l > 1000000:
         # zlib makes an internal copy, thus doubling memory usage for
         # large files, so lets do this in pieces
         z = zlib.compressobj()
         p = []
         pos = 0
         while pos < l:
             pos2 = pos + 2**20
             p.append(z.compress(text[pos:pos2]))
             pos = pos2
         p.append(z.flush())
         if sum(map(len, p)) < l:
             bin = "".join(p)
     else:
         bin = _compress(text)
     if bin is None or len(bin) > l:
         if text[0] == '\0':
             return ("", text)
         return ('u', text)
     return ("", bin)
 
 def decompress(bin):
     """ decompress the given input """
     if not bin:
         return bin
     t = bin[0]
     if t == '\0':
         return bin
     if t == 'x':
         return _decompress(bin)
     if t == 'u':
         return bin[1:]
     raise RevlogError(_("unknown compression type %r") % t)
 
 class lazyparser(object):
     """
     this class avoids the need to parse the entirety of large indices
     """
 
     # lazyparser is not safe to use on windows if win32 extensions not
     # available. it keeps file handle open, which make it not possible
     # to break hardlinks on local cloned repos.
 
     def __init__(self, dataf, size):
         self.dataf = dataf
         self.s = struct.calcsize(indexformatng)
         self.datasize = size
         self.l = size/self.s
         self.index = [None] * self.l
         self.map = {nullid: nullrev}
         self.allmap = 0
         self.all = 0
         self.mapfind_count = 0
 
     def loadmap(self):
         """
         during a commit, we need to make sure the rev being added is
         not a duplicate.  This requires loading the entire index,
         which is fairly slow.  loadmap can load up just the node map,
         which takes much less time.
         """
         if self.allmap:
             return
         end = self.datasize
         self.allmap = 1
         cur = 0
         count = 0
         blocksize = self.s * 256
         self.dataf.seek(0)
         while cur < end:
             data = self.dataf.read(blocksize)
             off = 0
             for x in xrange(256):
                 n = data[off + ngshaoffset:off + ngshaoffset + 20]
                 self.map[n] = count
                 count += 1
                 if count >= self.l:
                     break
                 off += self.s
             cur += blocksize
 
     def loadblock(self, blockstart, blocksize, data=None):
         if self.all:
             return
         if data is None:
             self.dataf.seek(blockstart)
             if blockstart + blocksize > self.datasize:
                 # the revlog may have grown since we've started running,
                 # but we don't have space in self.index for more entries.
                 # limit blocksize so that we don't get too much data.
                 blocksize = max(self.datasize - blockstart, 0)
             data = self.dataf.read(blocksize)
         lend = len(data) / self.s
         i = blockstart / self.s
         off = 0
         # lazyindex supports __delitem__
         if lend > len(self.index) - i:
             lend = len(self.index) - i
         for x in xrange(lend):
             if self.index[i + x] == None:
                 b = data[off : off + self.s]
                 self.index[i + x] = b
                 n = b[ngshaoffset:ngshaoffset + 20]
                 self.map[n] = i + x
             off += self.s
 
     def findnode(self, node):
         """search backwards through the index file for a specific node"""
         if self.allmap:
             return None
 
         # hg log will cause many many searches for the manifest
         # nodes.  After we get called a few times, just load the whole
         # thing.
         if self.mapfind_count > 8:
             self.loadmap()
             if node in self.map:
                 return node
             return None
         self.mapfind_count += 1
         last = self.l - 1
         while self.index[last] != None:
             if last == 0:
                 self.all = 1
                 self.allmap = 1
                 return None
             last -= 1
         end = (last + 1) * self.s
         blocksize = self.s * 256
         while end >= 0:
             start = max(end - blocksize, 0)
             self.dataf.seek(start)
             data = self.dataf.read(end - start)
             findend = end - start
             while True:
                 # we're searching backwards, so we have to make sure
                 # we don't find a changeset where this node is a parent
                 off = data.find(node, 0, findend)
                 findend = off
                 if off >= 0:
                     i = off / self.s
                     off = i * self.s
                     n = data[off + ngshaoffset:off + ngshaoffset + 20]
                     if n == node:
                         self.map[n] = i + start / self.s
                         return node
                 else:
                     break
             end -= blocksize
         return None
 
     def loadindex(self, i=None, end=None):
         if self.all:
             return
         all = False
         if i == None:
             blockstart = 0
             blocksize = (65536 / self.s) * self.s
             end = self.datasize
             all = True
         else:
             if end:
                 blockstart = i * self.s
                 end = end * self.s
                 blocksize = end - blockstart
             else:
                 blockstart = (i & ~1023) * self.s
                 blocksize = self.s * 1024
                 end = blockstart + blocksize
         while blockstart < end:
             self.loadblock(blockstart, blocksize)
             blockstart += blocksize
         if all:
             self.all = True
 
 class lazyindex(object):
     """a lazy version of the index array"""
     def __init__(self, parser):
         self.p = parser
     def __len__(self):
         return len(self.p.index)
     def load(self, pos):
         if pos < 0:
             pos += len(self.p.index)
         self.p.loadindex(pos)
         return self.p.index[pos]
     def __getitem__(self, pos):
         return _unpack(indexformatng, self.p.index[pos] or self.load(pos))
     def __setitem__(self, pos, item):
         self.p.index[pos] = _pack(indexformatng, *item)
     def __delitem__(self, pos):
         del self.p.index[pos]
     def insert(self, pos, e):
         self.p.index.insert(pos, _pack(indexformatng, *e))
     def append(self, e):
         self.p.index.append(_pack(indexformatng, *e))
 
 class lazymap(object):
     """a lazy version of the node map"""
     def __init__(self, parser):
         self.p = parser
     def load(self, key):
         n = self.p.findnode(key)
         if n == None:
             raise KeyError(key)
     def __contains__(self, key):
         if key in self.p.map:
             return True
         self.p.loadmap()
         return key in self.p.map
     def __iter__(self):
         yield nullid
         for i in xrange(self.p.l):
             ret = self.p.index[i]
             if not ret:
                 self.p.loadindex(i)
                 ret = self.p.index[i]
             if isinstance(ret, str):
                 ret = _unpack(indexformatng, ret)
             yield ret[7]
     def __getitem__(self, key):
         try:
             return self.p.map[key]
         except KeyError:
             try:
                 self.load(key)
                 return self.p.map[key]
             except KeyError:
                 raise KeyError("node " + hex(key))
     def __setitem__(self, key, val):
         self.p.map[key] = val
     def __delitem__(self, key):
         del self.p.map[key]
 
 indexformatv0 = ">4l20s20s20s"
 v0shaoffset = 56
 
 class revlogoldio(object):
     def __init__(self):
         self.size = struct.calcsize(indexformatv0)
 
     def parseindex(self, fp, inline):
         s = self.size
         index = []
         nodemap =  {nullid: nullrev}
         n = off = 0
         data = fp.read()
         l = len(data)
         while off + s <= l:
             cur = data[off:off + s]
             off += s
             e = _unpack(indexformatv0, cur)
             # transform to revlogv1 format
             e2 = (offset_type(e[0], 0), e[1], -1, e[2], e[3],
                   nodemap.get(e[4], nullrev), nodemap.get(e[5], nullrev), e[6])
             index.append(e2)
             nodemap[e[6]] = n
             n += 1
 
         return index, nodemap, None
 
     def packentry(self, entry, node, version, rev):
         e2 = (getoffset(entry[0]), entry[1], entry[3], entry[4],
               node(entry[5]), node(entry[6]), entry[7])
         return _pack(indexformatv0, *e2)
 
 # index ng:
 # 6 bytes offset
 # 2 bytes flags
 # 4 bytes compressed length
 # 4 bytes uncompressed length
 # 4 bytes: base rev
 # 4 bytes link rev
 # 4 bytes parent 1 rev
 # 4 bytes parent 2 rev
 # 32 bytes: nodeid
 indexformatng = ">Qiiiiii20s12x"
 ngshaoffset = 32
 versionformat = ">I"
 
 class revlogio(object):
     def __init__(self):
         self.size = struct.calcsize(indexformatng)
 
     def parseindex(self, fp, inline):
         try:
             size = util.fstat(fp).st_size
         except AttributeError:
             size = 0
 
         if util.openhardlinks() and not inline and size > 1000000:
             # big index, let's parse it on demand
             parser = lazyparser(fp, size)
             index = lazyindex(parser)
             nodemap = lazymap(parser)
             e = list(index[0])
             type = gettype(e[0])
             e[0] = offset_type(0, type)
             index[0] = e
             return index, nodemap, None
 
         data = fp.read()
         # call the C implementation to parse the index data
         index, nodemap, cache = parsers.parse_index(data, inline)
         return index, nodemap, cache
 
     def packentry(self, entry, node, version, rev):
         p = _pack(indexformatng, *entry)
         if rev == 0:
             p = _pack(versionformat, version) + p[4:]
         return p
 
 class revlog(object):
     """
     the underlying revision storage object
 
     A revlog consists of two parts, an index and the revision data.
 
     The index is a file with a fixed record size containing
     information on each revision, including its nodeid (hash), the
     nodeids of its parents, the position and offset of its data within
     the data file, and the revision it's based on. Finally, each entry
     contains a linkrev entry that can serve as a pointer to external
     data.
 
     The revision data itself is a linear collection of data chunks.
     Each chunk represents a revision and is usually represented as a
     delta against the previous chunk. To bound lookup time, runs of
     deltas are limited to about 2 times the length of the original
     version data. This makes retrieval of a version proportional to
     its size, or O(1) relative to the number of revisions.
 
     Both pieces of the revlog are written to in an append-only
     fashion, which means we never need to rewrite a file to insert or
     remove data, and can use some simple techniques to avoid the need
     for locking while reading.
     """
     def __init__(self, opener, indexfile):
         """
         create a revlog object
 
         opener is a function that abstracts the file opening operation
         and can be used to implement COW semantics or the like.
         """
         self.indexfile = indexfile
         self.datafile = indexfile[:-2] + ".d"
         self.opener = opener
         self._cache = None
         self._chunkcache = None
         self.nodemap = {nullid: nullrev}
         self.index = []
 
         v = REVLOG_DEFAULT_VERSION
         if hasattr(opener, "defversion"):
             v = opener.defversion
             if v & REVLOGNG:
                 v |= REVLOGNGINLINEDATA
 
         i = ""
         try:
             f = self.opener(self.indexfile)
             i = f.read(4)
             f.seek(0)
             if len(i) > 0:
                 v = struct.unpack(versionformat, i)[0]
         except IOError, inst:
             if inst.errno != errno.ENOENT:
                 raise
 
         self.version = v
         self._inline = v & REVLOGNGINLINEDATA
         flags = v & ~0xFFFF
         fmt = v & 0xFFFF
         if fmt == REVLOGV0 and flags:
             raise RevlogError(_("index %s unknown flags %#04x for format v0")
                               % (self.indexfile, flags >> 16))
         elif fmt == REVLOGNG and flags & ~REVLOGNGINLINEDATA:
             raise RevlogError(_("index %s unknown flags %#04x for revlogng")
                               % (self.indexfile, flags >> 16))
         elif fmt > REVLOGNG:
             raise RevlogError(_("index %s unknown format %d")
                               % (self.indexfile, fmt))
 
         self._io = revlogio()
         if self.version == REVLOGV0:
             self._io = revlogoldio()
         if i:
             try:
                 d = self._io.parseindex(f, self._inline)
             except (ValueError, IndexError), e:
                 raise RevlogError(_("index %s is corrupted") % (self.indexfile))
             self.index, self.nodemap, self._chunkcache = d
 
         # add the magic null revision at -1 (if it hasn't been done already)
         if (self.index == [] or isinstance(self.index, lazyindex) or
             self.index[-1][7] != nullid) :
             self.index.append((0, 0, 0, -1, -1, -1, -1, nullid))
 
     def _loadindex(self, start, end):
         """load a block of indexes all at once from the lazy parser"""
         if isinstance(self.index, lazyindex):
             self.index.p.loadindex(start, end)
 
     def _loadindexmap(self):
         """loads both the map and the index from the lazy parser"""
         if isinstance(self.index, lazyindex):
             p = self.index.p
             p.loadindex()
             self.nodemap = p.map
 
     def _loadmap(self):
         """loads the map from the lazy parser"""
         if isinstance(self.nodemap, lazymap):
             self.nodemap.p.loadmap()
             self.nodemap = self.nodemap.p.map
 
     def tip(self):
         return self.node(len(self.index) - 2)
     def __len__(self):
         return len(self.index) - 1
     def __iter__(self):
         for i in xrange(len(self)):
             yield i
     def rev(self, node):
         try:
             return self.nodemap[node]
         except KeyError:
             raise LookupError(node, self.indexfile, _('no node'))
     def node(self, rev):
         return self.index[rev][7]
     def linkrev(self, rev):
         return self.index[rev][4]
     def parents(self, node):
         i = self.index
         d = i[self.rev(node)]
         return i[d[5]][7], i[d[6]][7] # map revisions to nodes inline
     def parentrevs(self, rev):
         return self.index[rev][5:7]
     def start(self, rev):
         return int(self.index[rev][0] >> 16)
     def end(self, rev):
         return self.start(rev) + self.length(rev)
     def length(self, rev):
         return self.index[rev][1]
     def base(self, rev):
         return self.index[rev][3]
 
     def size(self, rev):
         """return the length of the uncompressed text for a given revision"""
         l = self.index[rev][2]
         if l >= 0:
             return l
 
         t = self.revision(self.node(rev))
         return len(t)
 
         # alternate implementation, The advantage to this code is it
         # will be faster for a single revision.  But, the results are not
         # cached, so finding the size of every revision will be slower.
         """
         if self.cache and self.cache[1] == rev:
             return len(self.cache[2])
 
         base = self.base(rev)
         if self.cache and self.cache[1] >= base and self.cache[1] < rev:
             base = self.cache[1]
             text = self.cache[2]
         else:
             text = self.revision(self.node(base))
 
         l = len(text)
         for x in xrange(base + 1, rev + 1):
             l = mdiff.patchedsize(l, self.chunk(x))
         return l
         """
 
     def reachable(self, node, stop=None):
         """return a hash of all nodes ancestral to a given node, including
          the node itself, stopping when stop is matched"""
         reachable = {}
         visit = [node]
         reachable[node] = 1
         if stop:
             stopn = self.rev(stop)
         else:
             stopn = 0
         while visit:
             n = visit.pop(0)
             if n == stop:
                 continue
             if n == nullid:
                 continue
             for p in self.parents(n):
                 if self.rev(p) < stopn:
                     continue
                 if p not in reachable:
                     reachable[p] = 1
                     visit.append(p)
         return reachable
 
     def ancestors(self, *revs):
         'Generate the ancestors of revs using a breadth-first visit'
         visit = list(revs)
         seen = set([nullrev])
         while visit:
             for parent in self.parentrevs(visit.pop(0)):
                 if parent not in seen:
                     visit.append(parent)
                     seen.add(parent)
                     yield parent
 
     def descendants(self, *revs):
         'Generate the descendants of revs in topological order'
         seen = set(revs)
         for i in xrange(min(revs) + 1, len(self)):
             for x in self.parentrevs(i):
                 if x != nullrev and x in seen:
                     seen.add(i)
                     yield i
                     break
 
     def findmissing(self, common=None, heads=None):
         '''
         returns the topologically sorted list of nodes from the set:
         missing = (ancestors(heads) \ ancestors(common))
 
         where ancestors() is the set of ancestors from heads, heads included
 
         if heads is None, the heads of the revlog are used
         if common is None, nullid is assumed to be a common node
         '''
         if common is None:
             common = [nullid]
         if heads is None:
             heads = self.heads()
 
         common = [self.rev(n) for n in common]
         heads = [self.rev(n) for n in heads]
 
         # we want the ancestors, but inclusive
         has = set(self.ancestors(*common))
         has.add(nullrev)
         has.update(common)
 
         # take all ancestors from heads that aren't in has
         missing = {}
         visit = [r for r in heads if r not in has]
         while visit:
             r = visit.pop(0)
             if r in missing:
                 continue
             else:
                 missing[r] = None
                 for p in self.parentrevs(r):
                     if p not in has:
                         visit.append(p)
         missing = missing.keys()
         missing.sort()
         return [self.node(r) for r in missing]
 
     def nodesbetween(self, roots=None, heads=None):
         """Return a tuple containing three elements. Elements 1 and 2 contain
         a final list bases and heads after all the unreachable ones have been
         pruned.  Element 0 contains a topologically sorted list of all
 
         nodes that satisfy these constraints:
         1. All nodes must be descended from a node in roots (the nodes on
            roots are considered descended from themselves).
         2. All nodes must also be ancestors of a node in heads (the nodes in
            heads are considered to be their own ancestors).
 
         If roots is unspecified, nullid is assumed as the only root.
         If heads is unspecified, it is taken to be the output of the
         heads method (i.e. a list of all nodes in the repository that
         have no children)."""
         nonodes = ([], [], [])
         if roots is not None:
             roots = list(roots)
             if not roots:
                 return nonodes
             lowestrev = min([self.rev(n) for n in roots])
         else:
             roots = [nullid] # Everybody's a descendent of nullid
             lowestrev = nullrev
         if (lowestrev == nullrev) and (heads is None):
             # We want _all_ the nodes!
             return ([self.node(r) for r in self], [nullid], list(self.heads()))
         if heads is None:
             # All nodes are ancestors, so the latest ancestor is the last
             # node.
             highestrev = len(self) - 1
             # Set ancestors to None to signal that every node is an ancestor.
             ancestors = None
             # Set heads to an empty dictionary for later discovery of heads
             heads = {}
         else:
             heads = list(heads)
             if not heads:
                 return nonodes
             ancestors = {}
             # Turn heads into a dictionary so we can remove 'fake' heads.
             # Also, later we will be using it to filter out the heads we can't
             # find from roots.
             heads = dict.fromkeys(heads, 0)
             # Start at the top and keep marking parents until we're done.
-            nodestotag = set(heads.keys())
+            nodestotag = set(heads)
             # Remember where the top was so we can use it as a limit later.
             highestrev = max([self.rev(n) for n in nodestotag])
             while nodestotag:
                 # grab a node to tag
                 n = nodestotag.pop()
                 # Never tag nullid
                 if n == nullid:
                     continue
                 # A node's revision number represents its place in a
                 # topologically sorted list of nodes.
                 r = self.rev(n)
                 if r >= lowestrev:
                     if n not in ancestors:
                         # If we are possibly a descendent of one of the roots
                         # and we haven't already been marked as an ancestor
                         ancestors[n] = 1 # Mark as ancestor
                         # Add non-nullid parents to list of nodes to tag.
                         nodestotag.update([p for p in self.parents(n) if
                                            p != nullid])
                     elif n in heads: # We've seen it before, is it a fake head?
                         # So it is, real heads should not be the ancestors of
                         # any other heads.
                         heads.pop(n)
             if not ancestors:
                 return nonodes
             # Now that we have our set of ancestors, we want to remove any
             # roots that are not ancestors.
 
             # If one of the roots was nullid, everything is included anyway.
             if lowestrev > nullrev:
                 # But, since we weren't, let's recompute the lowest rev to not
                 # include roots that aren't ancestors.
 
                 # Filter out roots that aren't ancestors of heads
                 roots = [n for n in roots if n in ancestors]
                 # Recompute the lowest revision
                 if roots:
                     lowestrev = min([self.rev(n) for n in roots])
                 else:
                     # No more roots?  Return empty list
                     return nonodes
             else:
                 # We are descending from nullid, and don't need to care about
                 # any other roots.
                 lowestrev = nullrev
                 roots = [nullid]
         # Transform our roots list into a set.
         descendents = set(roots)
         # Also, keep the original roots so we can filter out roots that aren't
         # 'real' roots (i.e. are descended from other roots).
         roots = descendents.copy()
         # Our topologically sorted list of output nodes.
         orderedout = []
         # Don't start at nullid since we don't want nullid in our output list,
         # and if nullid shows up in descedents, empty parents will look like
         # they're descendents.
         for r in xrange(max(lowestrev, 0), highestrev + 1):
             n = self.node(r)
             isdescendent = False
             if lowestrev == nullrev:  # Everybody is a descendent of nullid
                 isdescendent = True
             elif n in descendents:
                 # n is already a descendent
                 isdescendent = True
                 # This check only needs to be done here because all the roots
                 # will start being marked is descendents before the loop.
                 if n in roots:
                     # If n was a root, check if it's a 'real' root.
                     p = tuple(self.parents(n))
                     # If any of its parents are descendents, it's not a root.
                     if (p[0] in descendents) or (p[1] in descendents):
                         roots.remove(n)
             else:
                 p = tuple(self.parents(n))
                 # A node is a descendent if either of its parents are
                 # descendents.  (We seeded the dependents list with the roots
                 # up there, remember?)
                 if (p[0] in descendents) or (p[1] in descendents):
                     descendents.add(n)
                     isdescendent = True
             if isdescendent and ((ancestors is None) or (n in ancestors)):
                 # Only include nodes that are both descendents and ancestors.
                 orderedout.append(n)
                 if (ancestors is not None) and (n in heads):
                     # We're trying to figure out which heads are reachable
                     # from roots.
                     # Mark this head as having been reached
                     heads[n] = 1
                 elif ancestors is None:
                     # Otherwise, we're trying to discover the heads.
                     # Assume this is a head because if it isn't, the next step
                     # will eventually remove it.
                     heads[n] = 1
                     # But, obviously its parents aren't.
                     for p in self.parents(n):
                         heads.pop(p, None)
         heads = [n for n in heads.iterkeys() if heads[n] != 0]
         roots = list(roots)
         assert orderedout
         assert roots
         assert heads
         return (orderedout, roots, heads)
 
     def heads(self, start=None, stop=None):
         """return the list of all nodes that have no children
 
         if start is specified, only heads that are descendants of
         start will be returned
         if stop is specified, it will consider all the revs from stop
         as if they had no children
         """
         if start is None and stop is None:
             count = len(self)
             if not count:
                 return [nullid]
             ishead = [1] * (count + 1)
             index = self.index
             for r in xrange(count):
                 e = index[r]
                 ishead[e[5]] = ishead[e[6]] = 0
             return [self.node(r) for r in xrange(count) if ishead[r]]
 
         if start is None:
             start = nullid
         if stop is None:
             stop = []
         stoprevs = set([self.rev(n) for n in stop])
         startrev = self.rev(start)
         reachable = {startrev: 1}
         heads = {startrev: 1}
 
         parentrevs = self.parentrevs
         for r in xrange(startrev + 1, len(self)):
             for p in parentrevs(r):
                 if p in reachable:
                     if r not in stoprevs:
                         reachable[r] = 1
                     heads[r] = 1
                 if p in heads and p not in stoprevs:
                     del heads[p]
 
         return [self.node(r) for r in heads]
 
     def children(self, node):
         """find the children of a given node"""
         c = []
         p = self.rev(node)
         for r in range(p + 1, len(self)):
             prevs = [pr for pr in self.parentrevs(r) if pr != nullrev]
             if prevs:
                 for pr in prevs:
                     if pr == p:
                         c.append(self.node(r))
             elif p == nullrev:
                 c.append(self.node(r))
         return c
 
     def _match(self, id):
         if isinstance(id, (long, int)):
             # rev
             return self.node(id)
         if len(id) == 20:
             # possibly a binary node
             # odds of a binary node being all hex in ASCII are 1 in 10**25
             try:
                 node = id
                 self.rev(node) # quick search the index
                 return node
             except LookupError:
                 pass # may be partial hex id
         try:
             # str(rev)
             rev = int(id)
             if str(rev) != id:
                 raise ValueError
             if rev < 0:
                 rev = len(self) + rev
             if rev < 0 or rev >= len(self):
                 raise ValueError
             return self.node(rev)
         except (ValueError, OverflowError):
             pass
         if len(id) == 40:
             try:
                 # a full hex nodeid?
                 node = bin(id)
                 self.rev(node)
                 return node
             except (TypeError, LookupError):
                 pass
 
     def _partialmatch(self, id):
         if len(id) < 40:
             try:
                 # hex(node)[:...]
                 l = len(id) / 2  # grab an even number of digits
                 bin_id = bin(id[:l*2])
                 nl = [n for n in self.nodemap if n[:l] == bin_id]
                 nl = [n for n in nl if hex(n).startswith(id)]
                 if len(nl) > 0:
                     if len(nl) == 1:
                         return nl[0]
                     raise LookupError(id, self.indexfile,
                                       _('ambiguous identifier'))
                 return None
             except TypeError:
                 pass
 
     def lookup(self, id):
         """locate a node based on:
             - revision number or str(revision number)
             - nodeid or subset of hex nodeid
         """
         n = self._match(id)
         if n is not None:
             return n
         n = self._partialmatch(id)
         if n:
             return n
 
         raise LookupError(id, self.indexfile, _('no match found'))
 
     def cmp(self, node, text):
         """compare text with a given file revision"""
         p1, p2 = self.parents(node)
         return hash(text, p1, p2) != node
 
     def chunk(self, rev, df=None):
         def loadcache(df):
             if not df:
                 if self._inline:
                     df = self.opener(self.indexfile)
                 else:
                     df = self.opener(self.datafile)
             df.seek(start)
             self._chunkcache = (start, df.read(cache_length))
 
         start, length = self.start(rev), self.length(rev)
         if self._inline:
             start += (rev + 1) * self._io.size
         end = start + length
 
         offset = 0
         if not self._chunkcache:
             cache_length = max(65536, length)
             loadcache(df)
         else:
             cache_start = self._chunkcache[0]
             cache_length = len(self._chunkcache[1])
             cache_end = cache_start + cache_length
             if start >= cache_start and end <= cache_end:
                 # it is cached
                 offset = start - cache_start
             else:
                 cache_length = max(65536, length)
                 loadcache(df)
 
         # avoid copying large chunks
         c = self._chunkcache[1]
         if cache_length != length:
             c = c[offset:offset + length]
 
         return decompress(c)
 
     def revdiff(self, rev1, rev2):
         """return or calculate a delta between two revisions"""
         if rev1 + 1 == rev2 and self.base(rev1) == self.base(rev2):
             return self.chunk(rev2)
 
         return mdiff.textdiff(self.revision(self.node(rev1)),
                               self.revision(self.node(rev2)))
 
     def revision(self, node):
         """return an uncompressed revision of a given node"""
         if node == nullid:
             return ""
         if self._cache and self._cache[0] == node:
             return str(self._cache[2])
 
         # look up what we need to read
         text = None
         rev = self.rev(node)
         base = self.base(rev)
 
         # check rev flags
         if self.index[rev][0] & 0xFFFF:
             raise RevlogError(_('incompatible revision flag %x') %
                               (self.index[rev][0] & 0xFFFF))
 
         df = None
 
         # do we have useful data cached?
         if self._cache and self._cache[1] >= base and self._cache[1] < rev:
             base = self._cache[1]
             text = str(self._cache[2])
             self._loadindex(base, rev + 1)
             if not self._inline and rev > base + 1:
                 df = self.opener(self.datafile)
         else:
             self._loadindex(base, rev + 1)
             if not self._inline and rev > base:
                 df = self.opener(self.datafile)
             text = self.chunk(base, df=df)
 
         bins = [self.chunk(r, df) for r in xrange(base + 1, rev + 1)]
         text = mdiff.patches(text, bins)
         p1, p2 = self.parents(node)
         if node != hash(text, p1, p2):
             raise RevlogError(_("integrity check failed on %s:%d")
                               % (self.datafile, rev))
 
         self._cache = (node, rev, text)
         return text
 
     def checkinlinesize(self, tr, fp=None):
         if not self._inline:
             return
         if not fp:
             fp = self.opener(self.indexfile, 'r')
             fp.seek(0, 2)
         size = fp.tell()
         if size < 131072:
             return
         trinfo = tr.find(self.indexfile)
         if trinfo == None:
             raise RevlogError(_("%s not found in the transaction")
                               % self.indexfile)
 
         trindex = trinfo[2]
         dataoff = self.start(trindex)
 
         tr.add(self.datafile, dataoff)
         df = self.opener(self.datafile, 'w')
         try:
             calc = self._io.size
             for r in self:
                 start = self.start(r) + (r + 1) * calc
                 length = self.length(r)
                 fp.seek(start)
                 d = fp.read(length)
                 df.write(d)
         finally:
             df.close()
 
         fp.close()
         fp = self.opener(self.indexfile, 'w', atomictemp=True)
         self.version &= ~(REVLOGNGINLINEDATA)
         self._inline = False
         for i in self:
             e = self._io.packentry(self.index[i], self.node, self.version, i)
             fp.write(e)
 
         # if we don't call rename, the temp file will never replace the
         # real index
         fp.rename()
 
         tr.replace(self.indexfile, trindex * calc)
         self._chunkcache = None
 
     def addrevision(self, text, transaction, link, p1, p2, d=None):
         """add a revision to the log
 
         text - the revision data to add
         transaction - the transaction object used for rollback
         link - the linkrev data to add
         p1, p2 - the parent nodeids of the revision
         d - an optional precomputed delta
         """
         dfh = None
         if not self._inline:
             dfh = self.opener(self.datafile, "a")
         ifh = self.opener(self.indexfile, "a+")
         try:
             return self._addrevision(text, transaction, link, p1, p2, d, ifh, dfh)
         finally:
             if dfh:
                 dfh.close()
             ifh.close()
 
     def _addrevision(self, text, transaction, link, p1, p2, d, ifh, dfh):
         node = hash(text, p1, p2)
         if node in self.nodemap:
             return node
 
         curr = len(self)
         prev = curr - 1
         base = self.base(prev)
         offset = self.end(prev)
 
         if curr:
             if not d:
                 ptext = self.revision(self.node(prev))
                 d = mdiff.textdiff(ptext, text)
             data = compress(d)
             l = len(data[1]) + len(data[0])
             dist = l + offset - self.start(base)
 
         # full versions are inserted when the needed deltas
         # become comparable to the uncompressed text
         if not curr or dist > len(text) * 2:
             data = compress(text)
             l = len(data[1]) + len(data[0])
             base = curr
 
         e = (offset_type(offset, 0), l, len(text),
              base, link, self.rev(p1), self.rev(p2), node)
         self.index.insert(-1, e)
         self.nodemap[node] = curr
 
         entry = self._io.packentry(e, self.node, self.version, curr)
         if not self._inline:
             transaction.add(self.datafile, offset)
             transaction.add(self.indexfile, curr * len(entry))
             if data[0]:
                 dfh.write(data[0])
             dfh.write(data[1])
             dfh.flush()
             ifh.write(entry)
         else:
             offset += curr * self._io.size
             transaction.add(self.indexfile, offset, curr)
             ifh.write(entry)
             ifh.write(data[0])
             ifh.write(data[1])
             self.checkinlinesize(transaction, ifh)
 
         self._cache = (node, curr, text)
         return node
 
     def ancestor(self, a, b):
         """calculate the least common ancestor of nodes a and b"""
 
         def parents(rev):
             return [p for p in self.parentrevs(rev) if p != nullrev]
 
         c = ancestor.ancestor(self.rev(a), self.rev(b), parents)
         if c is None:
             return nullid
 
         return self.node(c)
 
     def group(self, nodelist, lookup, infocollect=None):
         """calculate a delta group
 
         Given a list of changeset revs, return a set of deltas and
         metadata corresponding to nodes. the first delta is
         parent(nodes[0]) -> nodes[0] the receiver is guaranteed to
         have this parent as it has all history before these
         changesets. parent is parent[0]
         """
         revs = [self.rev(n) for n in nodelist]
 
         # if we don't have any revisions touched by these changesets, bail
         if not revs:
             yield changegroup.closechunk()
             return
 
         # add the parent of the first rev
         p = self.parents(self.node(revs[0]))[0]
         revs.insert(0, self.rev(p))
 
         # build deltas
         for d in xrange(0, len(revs) - 1):
             a, b = revs[d], revs[d + 1]
             nb = self.node(b)
 
             if infocollect is not None:
                 infocollect(nb)
 
             p = self.parents(nb)
             meta = nb + p[0] + p[1] + lookup(nb)
             if a == -1:
                 d = self.revision(nb)
                 meta += mdiff.trivialdiffheader(len(d))
             else:
                 d = self.revdiff(a, b)
             yield changegroup.chunkheader(len(meta) + len(d))
             yield meta
             if len(d) > 2**20:
                 pos = 0
                 while pos < len(d):
                     pos2 = pos + 2 ** 18
                     yield d[pos:pos2]
                     pos = pos2
             else:
                 yield d
 
         yield changegroup.closechunk()
 
     def addgroup(self, revs, linkmapper, transaction):
         """
         add a delta group
 
         given a set of deltas, add them to the revision log. the
         first delta is against its parent, which should be in our
         log, the rest are against the previous delta.
         """
 
         #track the base of the current delta log
         r = len(self)
         t = r - 1
         node = None
 
         base = prev = nullrev
         start = end = textlen = 0
         if r:
             end = self.end(t)
 
         ifh = self.opener(self.indexfile, "a+")
         isize = r * self._io.size
         if self._inline:
             transaction.add(self.indexfile, end + isize, r)
             dfh = None
         else:
             transaction.add(self.indexfile, isize, r)
             transaction.add(self.datafile, end)
             dfh = self.opener(self.datafile, "a")
 
         try:
             # loop through our set of deltas
             chain = None
             for chunk in revs:
                 node, p1, p2, cs = struct.unpack("20s20s20s20s", chunk[:80])
                 link = linkmapper(cs)
                 if node in self.nodemap:
                     # this can happen if two branches make the same change
                     chain = node
                     continue
                 delta = buffer(chunk, 80)
                 del chunk
 
                 for p in (p1, p2):
                     if not p in self.nodemap:
                         raise LookupError(p, self.indexfile, _('unknown parent'))
 
                 if not chain:
                     # retrieve the parent revision of the delta chain
                     chain = p1
                     if not chain in self.nodemap:
                         raise LookupError(chain, self.indexfile, _('unknown base'))
 
                 # full versions are inserted when the needed deltas become
                 # comparable to the uncompressed text or when the previous
                 # version is not the one we have a delta against. We use
                 # the size of the previous full rev as a proxy for the
                 # current size.
 
                 if chain == prev:
                     cdelta = compress(delta)
                     cdeltalen = len(cdelta[0]) + len(cdelta[1])
                     textlen = mdiff.patchedsize(textlen, delta)
 
                 if chain != prev or (end - start + cdeltalen) > textlen * 2:
                     # flush our writes here so we can read it in revision
                     if dfh:
                         dfh.flush()
                     ifh.flush()
                     text = self.revision(chain)
                     if len(text) == 0:
                         # skip over trivial delta header
                         text = buffer(delta, 12)
                     else:
                         text = mdiff.patches(text, [delta])
                     del delta
                     chk = self._addrevision(text, transaction, link, p1, p2, None,
                                             ifh, dfh)
                     if not dfh and not self._inline:
                         # addrevision switched from inline to conventional
                         # reopen the index
                         dfh = self.opener(self.datafile, "a")
                         ifh = self.opener(self.indexfile, "a")
                     if chk != node:
                         raise RevlogError(_("consistency error adding group"))
                     textlen = len(text)
                 else:
                     e = (offset_type(end, 0), cdeltalen, textlen, base,
                          link, self.rev(p1), self.rev(p2), node)
                     self.index.insert(-1, e)
                     self.nodemap[node] = r
                     entry = self._io.packentry(e, self.node, self.version, r)
                     if self._inline:
                         ifh.write(entry)
                         ifh.write(cdelta[0])
                         ifh.write(cdelta[1])
                         self.checkinlinesize(transaction, ifh)
                         if not self._inline:
                             dfh = self.opener(self.datafile, "a")
                             ifh = self.opener(self.indexfile, "a")
                     else:
                         dfh.write(cdelta[0])
                         dfh.write(cdelta[1])
                         ifh.write(entry)
 
                 t, r, chain, prev = r, r + 1, node, node
                 base = self.base(t)
                 start = self.start(base)
                 end = self.end(t)
         finally:
             if dfh:
                 dfh.close()
             ifh.close()
 
         return node
 
     def strip(self, minlink, transaction):
         """truncate the revlog on the first revision with a linkrev >= minlink
 
         This function is called when we're stripping revision minlink and
         its descendants from the repository.
 
         We have to remove all revisions with linkrev >= minlink, because
         the equivalent changelog revisions will be renumbered after the
         strip.
 
         So we truncate the revlog on the first of these revisions, and
         trust that the caller has saved the revisions that shouldn't be
         removed and that it'll readd them after this truncation.
         """
         if len(self) == 0:
             return
 
         if isinstance(self.index, lazyindex):
             self._loadindexmap()
 
         for rev in self:
             if self.index[rev][4] >= minlink:
                 break
         else:
             return
 
         # first truncate the files on disk
         end = self.start(rev)
         if not self._inline:
             transaction.add(self.datafile, end)
             end = rev * self._io.size
         else:
             end += rev * self._io.size
 
         transaction.add(self.indexfile, end)
 
         # then reset internal state in memory to forget those revisions
         self._cache = None
         self._chunkcache = None
         for x in xrange(rev, len(self)):
             del self.nodemap[self.node(x)]
 
         del self.index[rev:-1]
 
     def checksize(self):
         expected = 0
         if len(self):
             expected = max(0, self.end(len(self) - 1))
 
         try:
             f = self.opener(self.datafile)
             f.seek(0, 2)
             actual = f.tell()
             dd = actual - expected
         except IOError, inst:
             if inst.errno != errno.ENOENT:
                 raise
             dd = 0
 
         try:
             f = self.opener(self.indexfile)
             f.seek(0, 2)
             actual = f.tell()
             s = self._io.size
             i = max(0, actual / s)
             di = actual - (i * s)
             if self._inline:
                 databytes = 0
                 for r in self:
                     databytes += max(0, self.length(r))
                 dd = 0
                 di = actual - len(self) * s - databytes
         except IOError, inst:
             if inst.errno != errno.ENOENT:
                 raise
             di = 0
 
         return (dd, di)
 
     def files(self):
         res = [ self.indexfile ]
         if not self._inline:
             res.append(self.datafile)
         return res