annotate hgext/obsolete.py @ 381:3a161a89d65d

obsolete: rely on core to filter extinct changeset out

# 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:obsolete:     a changeset that has been replaced by another one.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
=================

Display and Exchange
--------------------

obsolete changesets are hidden. (except if they have non obsolete changeset)

obsolete changesets are not exchanged. This will probably change later but it
was the simpler solution for now.

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.

Context object
--------------

Context gains a ``obsolete`` method that will return True if a changeset is
obsolete False otherwise.

revset
------

Add an ``obsolete()`` entry.

repo extension
--------------

To Do
~~~~~

- refuse to obsolete published changesets

- handle split

- handle conflict

- handle unstable // out of sync

"""

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

from mercurial.i18n import _

import base64
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 import store
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

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

### temporary core fix
#############################
getattr(store, '_load', lambda:None)()
if 'obsstore' not in vars(store)['_data']:
    store._data = vars(store)['_data'] + ' obsstore'

def wrapcopylist(orig, *args, **kwargs):
    l = orig(*args, **kwargs)
    if 'store/obsstore' not in l:
        l.append('store/obsstore')
    return l


### 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 changesets"""
    args = revset.getargs(x, 0, 0, 'hidden takes no argument')
    return [r for r in subset if r in repo.changelog.hiddenrevs]

def revsetobsolete(repo, subset, x):
    """obsolete changesets"""
    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 changesets"""
        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):
    """non obsolete changesets descendant of obsolete one"""
    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):
    """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):
    """obsolete changesets without obsolete descendants"""
    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, Try to succeed to public change"""
    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, Try to succeed to public change"""
    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 of a subset"""
    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):
    """obsolete parents"""
    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 of a subset"""
    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):
    """obsolete parents"""
    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 only is enought because any thing base on obsolete
        # changeset is either obsolete or unstable.
        ctx =  repo[h]
        if ctx.unstable():
            raise util.Abort(_("push includes an unstable changeset: %s!")
                             % ctx)
        if ctx.obsolete():
            raise util.Abort(_("push includes an  obsolete changeset: %s!")
                             % ctx)
        if ctx.latecomer():
            raise util.Abort(_("push includes an latecomer changeset: %s!")
                             % ctx)
        if ctx.conflicting():
            raise util.Abort(_("push includes conflicting changeset: %s!")
                             % ctx)
    ### patch remote branch map
    # do not read it this burn eyes
    try:
        if 'oldbranchmap' not in vars(remote):
            remote.oldbranchmap = remote.branchmap
            def branchmap():
                newbm = {}
                oldbm = None
                if (util.safehasattr(discovery, 'visiblebranchmap')
                    and not util.safehasattr(remote, 'ignorevisiblebranchmap')
                   ):
                    remote.ignorevisiblebranchmap = False
                    remote.branchmap = remote.oldbranchmap
                    oldbm = phases.visiblebranchmap(remote)
                    remote.branchmap = remote.newbranchmap
                    remote.ignorevisiblebranchmap = True
                if oldbm is None:
                    oldbm = remote.oldbranchmap()
                for branch, nodes in oldbm.iteritems():
                    nodes = list(nodes)
                    new = set()
                    while nodes:
                        n = nodes.pop()
                        if n in repo.obsstore.precursors:
                            markers = repo.obsstore.precursors[n]
                            for mark in markers:
                                for newernode in mark[1]:
                                    if newernode is not None:
                                        nodes.append(newernode)
                        else:
                            new.add(n)
                    if new:
                        newbm[branch] = list(new)
                return newbm
            remote.ignorevisiblebranchmap = True
            remote.branchmap = branchmap
            remote.newbranchmap = branchmap
        return orig(repo, remote, outgoing, *args, **kwargs)
    finally:
        remote.__dict__.pop('branchmap', None) # restore class one
        remote.__dict__.pop('oldbranchmap', None)
        remote.__dict__.pop('newbranchmap', None)
        remote.__dict__.pop('ignorevisiblebranchmap', None)

# eye are still burning
def wrapvisiblebranchmap(orig, repo):
    ignore = getattr(repo, 'ignorevisiblebranchmap', None)
    if ignore is None:
        return orig(repo)
    elif ignore:
        return repo.branchmap()
    else:
        return None # break recursion

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 wrapmaycreateobsmarker(origfn, ui, repo, *args, **opts):
    lock = repo.lock()
    try:
        res = origfn(ui, repo, *args, **opts)
        repo._turn_extinct_secret()
    finally:
        lock.release()
    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 noextinctsvisibleheads(orig, repo):
    repo._turn_extinct_secret()
    return orig(repo)

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()
                repo._turn_extinct_secret()
            finally:
                tr.release()
        finally:
            lock.release()
    return new

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

### 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)')
    opull = repo.pull
    opush = repo.push
    olock = repo.lock
    o_rollback = repo._rollback
    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()
                    self._turn_extinct_secret()
                    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)

        def _turn_extinct_secret(self):
            """ensure all extinct changeset are secret"""
            self._clearobsoletecache()
            # this is mainly for safety purpose
            # both pull and push
            query = '(obsolete() - obsolete()::(unstable() - secret())) - secret()'
            expobs = [c.node() for c in repo.set(query)]
            phases.retractboundary(repo, 2, expobs)

        ### pull // push support

        def pull(self, remote, *args, **kwargs):
            """wrapper around push that push obsolete relation"""
            l = repo.lock()
            try:
                result = opull(remote, *args, **kwargs)
                self._turn_extinct_secret()
                return result
            finally:
                l.release()

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


        ### rollback support

        # /!\ api change in  Hg 2.2 (97efd26eb9576f39590812ea9) /!\
        def _journalfiles(self):
            return o_journalfiles() + (self.sjoin('journal.obsstore'),) 

        def _writejournal(self, desc):
            """wrapped version of _writejournal that save obsolete data"""
            o_writejournal(desc)
            filename = 'obsstore'
            filepath = self.sjoin(filename)
            if os.path.exists(filepath):
                journalname = 'journal.' + filename
                journalpath = self.sjoin(journalname)
                util.copyfile(filepath, journalpath)


        def _rollback(self, dryrun, force):
            """wrapped version of _rollback that restore obsolete data"""
            ret = o_rollback(dryrun, force)
            if not (ret or dryrun): #rollback did not failed
                src = self.sjoin('undo.obsstore')
                dst = self.sjoin('obsstore')
                if os.path.exists(src):
                    util.rename(src, dst)
                elif os.path.exists(dst):
                    # If no state was saved because the file did not existed before.
                    os.unlink(dst)
                # invalidate cache
                self.__dict__.pop('obsstore', None)
            return ret

        @storecache('00changelog.i')
        def changelog(self):
            # << copy pasted from mercurial source
            c = changelog.changelog(self.sopener)
            if 'HG_PENDING' in os.environ:
                p = os.environ['HG_PENDING']
                if p.startswith(self.root):
                    c.readpending('00changelog.i.a')
            # >> end of the copy paste
            old = c.__dict__.pop('hiddenrevs', ())
            if old:
                ui.warn("old wasn't empty ? %r" % old)
            def _sethidden(c, value):
                assert not value


            class hchangelog(c.__class__):
                @util.propertycache
                def hiddenrevs(c):
                    shown = ['not obsolete()', '.', 'bookmark()', 'tagged()',
                             'public()']
                    basicquery = 'obsolete() - (::(%s))' % (' or '.join(shown))
                    # !!! self is repo not changelog
                    result = set(scmutil.revrange(self, [basicquery]))
                    return result
            c.__class__ = hchangelog
            return c

    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.')