annotate hgext/obsolete.py @ 405:b5b1bf5166a2

obsolete: enable obsolete feature

The feature is now disabled by default in core.

# obsolete.py - introduce the obsolete concept in mercurial.
#
# Copyright 2011 Pierre-Yves David <[e-mail]>
#                Logilab SA        <[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.
"""Introduce the Obsolete concept to mercurial

General concept
===============

This extension introduces the *obsolete* concept. It adds a new *obsolete*
relation between two changesets. A relation ``<changeset B> obsolete <changeset
A>`` is set to denote that ``<changeset B>`` is new version of ``<changeset
A>``.

The *obsolete* relation act as a **perpendicular history** to the standard
changeset history. Standard changeset history versions files. The *obsolete*
relation versions changesets.

:obsolete:     a changeset that has been replaced by another one.
:unstable:     a changeset that is not obsolete but has an obsolete ancestor.
:suspended:    an obsolete changeset with unstable descendant.
:extinct:      an obsolete changeset without unstable descendant.
               (subject to garbage collection)

Another name for unstable could be out of sync.


Usage and Feature
=================


New commands
------------

Note that rebased changesets are not marked obsolete rather than being stripped
In this experimental extensions, this is done forcing the --keep option. Trying
to use the --keep option of rebase with this extensionn this experimental
extension will cause such a call to abort. Until better releasen please use
graft command to rebase and copy changesets.

"""

import os, sys
try:
    from cStringIO import StringIO
except ImportError:
    from StringIO import StringIO

from mercurial.i18n import _

import json

import struct
from mercurial import util, base85

_pack = struct.pack
_unpack = struct.unpack

from mercurial import util
from mercurial import context
from mercurial import revset
from mercurial import scmutil
from mercurial import extensions
from mercurial import pushkey
from mercurial import discovery
from mercurial import error
from mercurial import commands
from mercurial import changelog
from mercurial import phases
from mercurial.node import hex, bin, short, nullid
from mercurial.lock import release
from mercurial import localrepo
from mercurial import cmdutil
from mercurial import templatekw
from mercurial import obsolete
setattr(obsolete, '_enabled', True)

try:
    from mercurial.localrepo import storecache
    storecache('babar') # to trigger import
except (TypeError, ImportError):
    def storecache(*args):
        return scmutil.filecache(*args, instore=True)


### Patch changectx
#############################

def unstable(ctx):
    """is the changeset unstable (have obsolete ancestor)"""
    if ctx.node() is None:
        return False
    return ctx.rev() in ctx._repo._unstableset

context.changectx.unstable = unstable

def extinct(ctx):
    """is the changeset extinct by other"""
    if ctx.node() is None:
        return False
    return ctx.rev() in ctx._repo._extinctset

context.changectx.extinct = extinct

def latecomer(ctx):
    """is the changeset latecomer (Try to succeed to public change)"""
    if ctx.node() is None:
        return False
    return ctx.rev() in ctx._repo._latecomerset

context.changectx.latecomer = latecomer

def conflicting(ctx):
    """is the changeset conflicting (Try to succeed to public change)"""
    if ctx.node() is None:
        return False
    return ctx.rev() in ctx._repo._conflictingset

context.changectx.conflicting = conflicting


### revset
#############################

def revsethidden(repo, subset, x):
    """``hidden()``
    Changeset is hidden.
    """
    args = revset.getargs(x, 0, 0, 'hidden takes no argument')
    return [r for r in subset if r in repo.hiddenrevs]

def revsetobsolete(repo, subset, x):
    """``obsolete()``
    Changeset is obsolete.
    """
    args = revset.getargs(x, 0, 0, 'obsolete takes no argument')
    return [r for r in subset if r in repo._obsoleteset and repo._phasecache.phase(repo, r) > 0]

# XXX Backward compatibility, to be removed once stabilized
if '_phasecache' not in vars(localrepo.localrepository): # new api
    def revsetobsolete(repo, subset, x):
        """``obsolete()``
        Changeset is obsolete.
        """
        args = revset.getargs(x, 0, 0, 'obsolete takes no argument')
        return [r for r in subset if r in repo._obsoleteset and repo._phaserev[r] > 0]

def revsetunstable(repo, subset, x):
    """``unstable()``
    Unstable changesets are non-obsolete with obsolete ancestors.
    """
    args = revset.getargs(x, 0, 0, 'unstable takes no arguments')
    return [r for r in subset if r in repo._unstableset]

def revsetsuspended(repo, subset, x):
    """``suspended()``
    Obsolete changesets with non-obsolete descendants.
    """
    args = revset.getargs(x, 0, 0, 'suspended takes no arguments')
    return [r for r in subset if r in repo._suspendedset]

def revsetextinct(repo, subset, x):
    """``extinct()``
    Obsolete changesets with obsolete descendants only.
    """
    args = revset.getargs(x, 0, 0, 'extinct takes no arguments')
    return [r for r in subset if r in repo._extinctset]

def revsetlatecomer(repo, subset, x):
    """``latecomer()``
    Changesets marked as successors of public changesets.
    """
    args = revset.getargs(x, 0, 0, 'latecomer takes no arguments')
    return [r for r in subset if r in repo._latecomerset]

def revsetconflicting(repo, subset, x):
    """``conflicting()``
    Changesets marked as successors of a same changeset.
    """
    args = revset.getargs(x, 0, 0, 'conflicting takes no arguments')
    return [r for r in subset if r in repo._conflictingset]

def _precursors(repo, s):
    """Precursor of a changeset"""
    cs = set()
    nm = repo.changelog.nodemap
    markerbysubj = repo.obsstore.successors
    for r in s:
        for p in markerbysubj.get(repo[r].node(), ()):
            pr = nm.get(p[0])
            if pr is not None:
                cs.add(pr)
    return cs

def revsetprecursors(repo, subset, x):
    """``precursors(set)``
    Immediate precursors of changesets in set.
    """
    s = revset.getset(repo, range(len(repo)), x)
    cs = _precursors(repo, s)
    return [r for r in subset if r in cs]

def _allprecursors(repo, s):  # XXX we need a better naming
    """transitive precursors of a subset"""
    toproceed = [repo[r].node() for r in s]
    seen = set()
    allsubjects = repo.obsstore.successors
    while toproceed:
        nc = toproceed.pop()
        for mark in allsubjects.get(nc, ()):
            np = mark[0]
            if np not in seen:
                seen.add(np)
                toproceed.append(np)
    nm = repo.changelog.nodemap
    cs = set()
    for p in seen:
        pr = nm.get(p)
        if pr is not None:
            cs.add(pr)
    return cs

def revsetallprecursors(repo, subset, x):
    """``allprecursors(set)``
    Transitive precursors of changesets in set.
    """
    s = revset.getset(repo, range(len(repo)), x)
    cs = _allprecursors(repo, s)
    return [r for r in subset if r in cs]

def _successors(repo, s):
    """Successors of a changeset"""
    cs = set()
    nm = repo.changelog.nodemap
    markerbyobj = repo.obsstore.precursors
    for r in s:
        for p in markerbyobj.get(repo[r].node(), ()):
            for sub in p[1]:
                sr = nm.get(sub)
                if sr is not None:
                    cs.add(sr)
    return cs

def revsetsuccessors(repo, subset, x):
    """``successors(set)``
    Immediate successors of changesets in set.
    """
    s = revset.getset(repo, range(len(repo)), x)
    cs = _successors(repo, s)
    return [r for r in subset if r in cs]

def _allsuccessors(repo, s):  # XXX we need a better naming
    """transitive successors of a subset"""
    toproceed = [repo[r].node() for r in s]
    seen = set()
    allobjects = repo.obsstore.precursors
    while toproceed:
        nc = toproceed.pop()
        for mark in allobjects.get(nc, ()):
            for sub in mark[1]:
                if sub not in seen:
                    seen.add(sub)
                    toproceed.append(sub)
    nm = repo.changelog.nodemap
    cs = set()
    for s in seen:
        sr = nm.get(s)
        if sr is not None:
            cs.add(sr)
    return cs

def revsetallsuccessors(repo, subset, x):
    """``allsuccessors(set)``
    Transitive successors of changesets in set.
    """
    s = revset.getset(repo, range(len(repo)), x)
    cs = _allsuccessors(repo, s)
    return [r for r in subset if r in cs]


### template keywords
#####################

def obsoletekw(repo, ctx, templ, **args):
    """:obsolete: String. The obsolescence level of the node, could be
    ``stable``, ``unstable``, ``suspended`` or ``extinct``.
    """
    rev = ctx.rev()
    if rev in repo._extinctset:
        return 'extinct'
    if rev in repo._suspendedset:
        return 'suspended'
    if rev in repo._unstableset:
        return 'unstable'
    return 'stable'

### Other Extension compat
############################


def buildstate(orig, repo, dest, rebaseset, *ags, **kws):
    """wrapper for rebase 's buildstate that exclude obsolete changeset"""
    rebaseset = repo.revs('%ld - extinct()', rebaseset)
    return orig(repo, dest, rebaseset, *ags, **kws)

def defineparents(orig, repo, rev, target, state, *args, **kwargs):
    rebasestate = getattr(repo, '_rebasestate', None)
    if rebasestate is not None:
        repo._rebasestate = dict(state)
        repo._rebasetarget = target
    return orig(repo, rev, target, state, *args, **kwargs)

def concludenode(orig, repo, rev, p1, *args, **kwargs):
    """wrapper for rebase 's concludenode that set obsolete relation"""
    newrev = orig(repo, rev, p1, *args, **kwargs)
    rebasestate = getattr(repo, '_rebasestate', None)
    if rebasestate is not None:
        if newrev is not None:
            nrev = repo[newrev].rev()
        else:
            nrev = p1
        repo._rebasestate[rev] = nrev
    return newrev

def cmdrebase(orig, ui, repo, *args, **kwargs):

    reallykeep = kwargs.get('keep', False)
    kwargs = dict(kwargs)
    kwargs['keep'] = True

    # We want to mark rebased revision as obsolete and set their
    # replacements if any. Doing it in concludenode() prevents
    # aborting the rebase, and is not called with all relevant
    # revisions in --collapse case. Instead, we try to track the
    # rebase state structure by sampling/updating it in
    # defineparents() and concludenode(). The obsolete markers are
    # added from this state after a successful call.
    repo._rebasestate = {}
    repo._rebasetarget = None
    try:
        res = orig(ui, repo, *args, **kwargs)
        if not reallykeep:
            # Filter nullmerge or unrebased entries
            repo._rebasestate = dict(p for p in repo._rebasestate.iteritems()
                                     if p[1] >= 0)
            if not res and not kwargs.get('abort') and repo._rebasestate:
                # Rebased revisions are assumed to be descendants of
                # targetrev. If a source revision is mapped to targetrev
                # or to another rebased revision, it must have been
                # removed.
                targetrev = repo[repo._rebasetarget].rev()
                newrevs = set([targetrev])
                replacements = {}
                for rev, newrev in sorted(repo._rebasestate.items()):
                    oldnode = repo[rev].node()
                    if newrev not in newrevs:
                        newnode = repo[newrev].node()
                        newrevs.add(newrev)
                    else:
                        newnode = nullid
                    replacements[oldnode] = newnode

                if kwargs.get('collapse'):
                    newnodes = set(n for n in replacements.values() if n != nullid)
                    if newnodes:
                        # Collapsing into more than one revision?
                        assert len(newnodes) == 1, newnodes
                        newnode = newnodes.pop()
                    else:
                        newnode = nullid
                    repo.addcollapsedobsolete(replacements, newnode)
                else:
                    for oldnode, newnode in replacements.iteritems():
                        repo.addobsolete(newnode, oldnode)
        return res
    finally:
        delattr(repo, '_rebasestate')
        delattr(repo, '_rebasetarget')


def extsetup(ui):

    revset.symbols["hidden"] = revsethidden
    revset.symbols["obsolete"] = revsetobsolete
    revset.symbols["unstable"] = revsetunstable
    revset.symbols["suspended"] = revsetsuspended
    revset.symbols["extinct"] = revsetextinct
    revset.symbols["latecomer"] = revsetlatecomer
    revset.symbols["conflicting"] = revsetconflicting
    revset.symbols["obsparents"] = revsetprecursors  # DEPR
    revset.symbols["precursors"] = revsetprecursors
    revset.symbols["obsancestors"] = revsetallprecursors  # DEPR
    revset.symbols["allprecursors"] = revsetallprecursors  # bad name
    revset.symbols["successors"] = revsetsuccessors
    revset.symbols["allsuccessors"] = revsetallsuccessors  # bad name

    templatekw.keywords['obsolete'] = obsoletekw

    # warning about more obsolete
    for cmd in ['commit', 'push', 'pull', 'graft', 'phase', 'unbundle']:
        entry = extensions.wrapcommand(commands.table, cmd, warnobserrors)
    try:
        rebase = extensions.find('rebase')
        if rebase:
            entry = extensions.wrapcommand(rebase.cmdtable, 'rebase', warnobserrors)
            extensions.wrapfunction(rebase, 'buildstate', buildstate)
            extensions.wrapfunction(rebase, 'defineparents', defineparents)
            extensions.wrapfunction(rebase, 'concludenode', concludenode)
            extensions.wrapcommand(rebase.cmdtable, "rebase", cmdrebase)
    except KeyError:
        pass  # rebase not found

### Discovery wrapping
#############################


def wrapcheckheads(orig, repo, remote, outgoing, *args, **kwargs):
    """wrap mercurial.discovery.checkheads

    * prevent unstability to be pushed
    * patch remote to ignore obsolete heads on remote
    """
    # do not push instability
    for h in outgoing.missingheads:
        # Checking heads is enough, obsolete descendants are either
        # obsolete or unstable.
        ctx = repo[h]
        if ctx.latecomer():
            raise util.Abort(_("push includes a latecomer changeset: %s!")
                             % ctx)
        if ctx.conflicting():
            raise util.Abort(_("push includes a conflicting changeset: %s!")
                             % ctx)
    return orig(repo, remote, outgoing, *args, **kwargs)

def wrapclearcache(orig, repo, *args, **kwargs):
    try:
        return orig(repo, *args, **kwargs)
    finally:
        repo._clearobsoletecache()


### New commands
#############################

cmdtable = {}
command = cmdutil.command(cmdtable)


@command('debugconvertobsolete', [], '')
def cmddebugconvertobsolete(ui, repo):
    """import markers from an .hg/obsolete-relations file"""
    cnt = 0
    err = 0
    l = repo.lock()
    some = False
    try:
        unlink = []
        tr = repo.transaction('convert-obsolete')
        try:
            repo._importoldobsolete = True
            store = repo.obsstore
            ### very first format
            try:
                f = repo.opener('obsolete-relations')
                try:
                    some = True
                    for line in f:
                        subhex, objhex = line.split()
                        suc = bin(subhex)
                        prec = bin(objhex)
                        sucs = (suc==nullid) and [] or [suc]
                        meta = {
                            'date':  '%i %i' % util.makedate(),
                            'user': ui.username(),
                            }
                        try:
                            store.create(tr, prec, sucs, 0, meta)
                            cnt += 1
                        except ValueError:
                            repo.ui.write_err("invalid old marker line: %s"
                                              % (line))
                            err += 1
                finally:
                    f.close()
                unlink.append(repo.join('obsolete-relations'))
            except IOError:
                pass
            ### second (json) format
            data = repo.sopener.tryread('obsoletemarkers')
            if data:
                some = True
                for oldmark in json.loads(data):
                    del oldmark['id']  # dropped for now
                    del oldmark['reason']  # unused until then
                    oldobject = str(oldmark.pop('object'))
                    oldsubjects = [str(s) for s in oldmark.pop('subjects', [])]
                    LOOKUP_ERRORS = (error.RepoLookupError, error.LookupError)
                    if len(oldobject) != 40:
                        try:
                            oldobject = repo[oldobject].node()
                        except LOOKUP_ERRORS:
                            pass
                    if any(len(s) != 40 for s in oldsubjects):
                        try:
                            oldsubjects = [repo[s].node() for s in oldsubjects]
                        except LOOKUP_ERRORS:
                            pass

                    oldmark['date'] = '%i %i' % tuple(oldmark['date'])
                    meta = dict((k.encode('utf-8'), v.encode('utf-8'))
                                 for k, v in oldmark.iteritems())
                    try:
                        succs = [bin(n) for n in oldsubjects]
                        succs = [n for n in succs if n != nullid]
                        store.create(tr, bin(oldobject), succs,
                                     0, meta)
                        cnt += 1
                    except ValueError:
                        repo.ui.write_err("invalid marker %s -> %s\n"
                                     % (oldobject, oldsubjects))
                        err += 1
                unlink.append(repo.sjoin('obsoletemarkers'))
            tr.close()
            for path in unlink:
                util.unlink(path)
        finally:
            tr.release()
    finally:
        del repo._importoldobsolete
        l.release()
    if not some:
            ui.warn('nothing to do\n')
    ui.status('%i obsolete marker converted\n' % cnt)
    if err:
        ui.write_err('%i conversion failed. check you graph!\n' % err)

@command('debugsuccessors', [], '')
def cmddebugsuccessors(ui, repo):
    """dump obsolete changesets and their successors

    Each line matches an existing marker, the first identifier is the
    obsolete changeset identifier, followed by it successors.
    """
    lock = repo.lock()
    try:
        allsuccessors = repo.obsstore.precursors
        for old in sorted(allsuccessors):
            successors = [sorted(m[1]) for m in allsuccessors[old]]
            for i, group in enumerate(sorted(successors)):
                ui.write('%s' % short(old))
                for new in group:
                    ui.write(' %s' % short(new))
                ui.write('\n')
    finally:
        lock.release()

### Altering existing command
#############################

def wrapmayobsoletewc(origfn, ui, repo, *args, **opts):
    res = origfn(ui, repo, *args, **opts)
    if repo['.'].obsolete():
        ui.warn(_('Working directory parent is obsolete\n'))
    return res

def warnobserrors(orig, ui, repo, *args, **kwargs):
    """display warning is the command resulted in more instable changeset"""
    priorunstables = len(repo.revs('unstable()'))
    priorlatecomers = len(repo.revs('latecomer()'))
    priorconflictings = len(repo.revs('conflicting()'))
    #print orig, priorunstables
    #print len(repo.revs('secret() - obsolete()'))
    try:
        return orig(ui, repo, *args, **kwargs)
    finally:
        newunstables = len(repo.revs('unstable()')) - priorunstables
        newlatecomers = len(repo.revs('latecomer()')) - priorlatecomers
        newconflictings = len(repo.revs('conflicting()')) - priorconflictings
        #print orig, newunstables
        #print len(repo.revs('secret() - obsolete()'))
        if newunstables > 0:
            ui.warn(_('%i new unstables changesets\n') % newunstables)
        if newlatecomers > 0:
            ui.warn(_('%i new latecomers changesets\n') % newlatecomers)
        if newconflictings > 0:
            ui.warn(_('%i new conflictings changesets\n') % newconflictings)

def wrapcmdutilamend(orig, ui, repo, commitfunc, old, *args, **kwargs):
    oldnode = old.node()
    new = orig(ui, repo, commitfunc, old, *args, **kwargs)
    if new != oldnode:
        lock = repo.lock()
        try:
            tr = repo.transaction('post-amend-obst')
            try:
                meta = {
                    'date':  '%i %i' % util.makedate(),
                    'user': ui.username(),
                    }
                repo.obsstore.create(tr, oldnode, [new], 0, meta)
                tr.close()
                repo._clearobsoletecache()
            finally:
                tr.release()
        finally:
            lock.release()
    return new

def uisetup(ui):
    extensions.wrapcommand(commands.table, "update", wrapmayobsoletewc)
    extensions.wrapcommand(commands.table, "pull", wrapmayobsoletewc)
    if util.safehasattr(cmdutil, 'amend'):
        extensions.wrapfunction(cmdutil, 'amend', wrapcmdutilamend)
    extensions.wrapfunction(discovery, 'checkheads', wrapcheckheads)
    extensions.wrapfunction(phases, 'advanceboundary', wrapclearcache)

### serialisation
#############################

def _obsserialise(obssubrels, flike):
    """serialise an obsolete relation mapping in a plain text one

    this is for subject -> [objects] mapping

    format is::

        <subject-full-hex> <object-full-hex>\n"""
    for sub, objs in obssubrels.iteritems():
        for obj in objs:
            if sub is None:
                sub = nullid
            flike.write('%s %s\n' % (hex(sub), hex(obj)))

def _obsdeserialise(flike):
    """read a file like object serialised with _obsserialise

    this desierialize into a {subject -> objects} mapping"""
    rels = {}
    for line in flike:
        subhex, objhex = line.split()
        subnode = bin(subhex)
        if subnode == nullid:
            subnode = None
        rels.setdefault( subnode, set()).add(bin(objhex))
    return rels

### diagnostique tools
#############################

def unstables(repo):
    """Return all unstable changeset"""
    return scmutil.revrange(repo, ['obsolete():: and (not obsolete())'])

def newerversion(repo, obs):
    """Return the newer version of an obsolete changeset"""
    toproceed = set([(obs,)])
    # XXX known optimization available
    newer = set()
    objectrels = repo.obsstore.precursors
    while toproceed:
        current = toproceed.pop()
        assert len(current) <= 1, 'splitting not handled yet. %r' % current
        current = [n for n in current if n != nullid]
        if current:
            n, = current
            if n in objectrels:
                markers = objectrels[n]
                for mark in markers:
                    toproceed.add(tuple(mark[1]))
            else:
                newer.add(tuple(current))
        else:
            newer.add(())
    return sorted(newer)

### repo subclassing
#############################

def reposetup(ui, repo):
    if not repo.local():
        return

    if not util.safehasattr(repo.opener, 'tryread'):
        raise util.Abort('Obsolete extension require Mercurial 2.2 (or later)')
    opush = repo.push
    o_updatebranchcache = repo.updatebranchcache

    # /!\ api change in  Hg 2.2 (97efd26eb9576f39590812ea9) /!\
    if util.safehasattr(repo, '_journalfiles'): # Hg 2.2
        o_journalfiles = repo._journalfiles
    o_writejournal = repo._writejournal


    class obsoletingrepo(repo.__class__):

        ### Public method
        def obsoletedby(self, node):
            """return the set of node that make <node> obsolete (obj)"""
            others = set()
            for marker in self.obsstore.precursors.get(node, []):
                others.update(marker[1])
            return others

        def obsolete(self, node):
            """return the set of node that <node> make obsolete (sub)"""
            return set(marker[0] for marker in self.obsstore.successors.get(node, []))

        @util.propertycache
        def _obsoleteset(self):
            """the set of obsolete revision"""
            obs = set()
            nm = self.changelog.nodemap
            for prec in self.obsstore.precursors:
                rev = nm.get(prec)
                if rev is not None:
                    obs.add(rev)
            return obs

        @util.propertycache
        def _unstableset(self):
            """the set of non obsolete revision with obsolete parent"""
            return set(self.revs('(obsolete()::) - obsolete()'))

        @util.propertycache
        def _suspendedset(self):
            """the set of obsolete parent with non obsolete descendant"""
            return set(self.revs('obsolete() and obsolete()::unstable()'))

        @util.propertycache
        def _extinctset(self):
            """the set of obsolete parent without non obsolete descendant"""
            return set(self.revs('obsolete() - obsolete()::unstable()'))

        @util.propertycache
        def _latecomerset(self):
            """the set of rev trying to obsolete public revision"""
            query = 'allsuccessors(public()) - obsolete() - public()'
            return set(self.revs(query))

        @util.propertycache
        def _conflictingset(self):
            """the set of rev trying to obsolete public revision"""
            conflicting = set()
            obsstore = self.obsstore
            newermap = {}
            for ctx in self.set('(not public()) - obsolete()'):
                prec = obsstore.successors.get(ctx.node(), ())
                toprocess = set(prec)
                while toprocess:
                    prec = toprocess.pop()[0]
                    if prec not in newermap:
                        newermap[prec] = newerversion(self, prec)
                    newer = [n for n in newermap[prec] if n] # filter kill
                    if len(newer) > 1:
                        conflicting.add(ctx.rev())
                        break
                toprocess.update(obsstore.successors.get(prec, ()))
            return conflicting

        def _clearobsoletecache(self):
            if '_obsoleteset' in vars(self):
                del self._obsoleteset
            self._clearunstablecache()

        def updatebranchcache(self):
            o_updatebranchcache()
            self._clearunstablecache()

        def _clearunstablecache(self):
            if '_unstableset' in vars(self):
                del self._unstableset
            if '_suspendedset' in vars(self):
                del self._suspendedset
            if '_extinctset' in vars(self):
                del self._extinctset
            if '_latecomerset' in vars(self):
                del self._latecomerset
            if '_conflictingset' in vars(self):
                del self._conflictingset

        def addobsolete(self, sub, obj):
            """Add a relation marking that node <sub> is a new version of <obj>"""
            assert sub != obj
            if not repo[obj].phase():
                if sub is None:
                    self.ui.warn(
                        _("trying to kill immutable changeset %(obj)s\n")
                        % {'obj': short(obj)})
                if sub is not None:
                    self.ui.warn(
                        _("%(sub)s try to obsolete immutable changeset %(obj)s\n")
                        % {'sub': short(sub), 'obj': short(obj)})
            lock = self.lock()
            try:
                tr = self.transaction('add-obsolete')
                try:
                    meta = {
                        'date':  '%i %i' % util.makedate(),
                        'user': ui.username(),
                        }
                    subs = (sub == nullid) and [] or [sub]
                    mid = self.obsstore.create(tr, obj, subs, 0, meta)
                    tr.close()
                    self._clearobsoletecache()
                    return mid
                finally:
                    tr.release()
            finally:
                lock.release()

        def addcollapsedobsolete(self, oldnodes, newnode):
            """Mark oldnodes as collapsed into newnode."""
            # Assume oldnodes are all descendants of a single rev
            rootrevs = self.revs('roots(%ln)', oldnodes)
            assert len(rootrevs) == 1, rootrevs
            #rootnode = self[rootrevs[0]].node()
            for n in oldnodes:
                self.addobsolete(newnode, n)

        ### pull // push support

        def push(self, remote, *args, **opts):
            """wrapper around pull that pull obsolete relation"""
            try:
                result = opush(remote, *args, **opts)
            except util.Abort, ex:
                hint = _("use 'hg stabilize' to get a stable history "
                         "or --force to ignore warnings")
                if (len(ex.args) >= 1
                    and ex.args[0].startswith('push includes ')
                    and ex.hint is None):
                    ex.hint = hint
                raise
            return result


    repo.__class__ = obsoletingrepo
    for arg in sys.argv:
        if 'debugc' in arg:
            break
    else:
        data = repo.opener.tryread('obsolete-relations')
        if not data:
            data = repo.sopener.tryread('obsoletemarkers')
        if data:
            raise util.Abort('old format of obsolete marker detected!\n'
                             'run `hg debugconvertobsolete` once.')