very easy for people not very intimate with the concept to end up in intricate

concept and provide feedback

"""

from mercurial import localrepo

from mercurial import obsolete

from mercurial import extensions

from mercurial import cmdutil

from mercurial import scmutil

from mercurial import commands

from mercurial import lock as lockmod

from mercurial import bookmarks

from mercurial.i18n import _

cmdtable = {}

command = cmdutil.command(cmdtable)

def reposetup(ui, repo):

    class obsinhibitedrepo(repo.__class__):

        @localrepo.storecache('obsinhibit')

        def _obsinhibit(self):

            # XXX we should make sure it is invalidated by transaction failure

            obsinhibit = set()

            raw = self.sopener.tryread('obsinhibit')

            for i in xrange(0, len(raw), 20):

                obsinhibit.add(raw[i:i+20])

            return obsinhibit

        def commit(self, *args, **kwargs):

            newnode = super(obsinhibitedrepo, self).commit(*args, **kwargs)

            _inhibitmarkers(repo, [newnode])

            return newnode

    repo.__class__ = obsinhibitedrepo

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

    """

    When moving to a commit we want to inhibit any obsolete commit affecting

    the changeset we are updating to. In other words we don't want any visible

    commit to be obsolete.

    """

    wlock = None

    try:

        # Evolve is running a hook on lock release to display a warning message 

        # if the workind dir's parent is obsolete.

        # We take the lock here to make sure that we inhibit the parent before

        # that hook get a chance to run.

        wlock = repo.wlock()

        res = orig(ui, repo, *args, **kwargs)

        newhead = repo['.'].node()

        _inhibitmarkers(repo, [newhead])

        return res

    finally:

        lockmod.release(wlock)

def _bookmarkchanged(orig, bkmstoreinst, *args, **kwargs):

    """ Add inhibition markers to every obsolete bookmarks """

    repo = bkmstoreinst._repo

    bkmstorenodes = [repo[v].node() for v in bkmstoreinst.values()]

    _inhibitmarkers(repo, bkmstorenodes)

    return orig(bkmstoreinst, *args, **kwargs)

def _bookmark(orig, ui, repo, *bookmarks, **opts):

    """ Add a -D option to the bookmark command, map it to prune -B """

    haspruneopt = opts.get('prune', False)

    if not haspruneopt:

        return orig(ui, repo, *bookmarks, **opts)

    # Call prune -B

    evolve = extensions.find('evolve')

    optsdict = {

        'new': [],

        'succ': [],

        'rev': [],

        'bookmark': bookmarks[0],

        'keep': None,

        'biject': False,

    }

    evolve.cmdprune(ui, repo, **optsdict)

# obsolescence inhibitor

########################

def _schedulewrite(tr, obsinhibit):

    """Make sure on disk content will be updated on transaction commit"""

    def writer(fp):

        """Serialize the inhibited list to disk.

        """

        raw = ''.join(obsinhibit)

        fp.write(raw)

    tr.addfilegenerator('obsinhibit', ('obsinhibit',), writer)

    tr.hookargs['obs_inbihited'] = '1'

def _filterpublic(repo, nodes):

    """filter out inhibitor on public changeset

    Public changesets are already immune to obsolescence"""

    getrev = repo.changelog.nodemap.get

    getphase = repo._phasecache.phase

    return (n for n in repo._obsinhibit

            if getrev(n) is not None and getphase(repo, getrev(n)))

def _inhibitmarkers(repo, nodes):

    """add marker inhibitor for all obsolete revision under <nodes>

    Content of <nodes> and all mutable ancestors are considered. Marker for

    obsolete revision only are created.

    """

    newinhibit = repo.set('::%ln and obsolete()', nodes)

    if newinhibit:

        lock = tr = None

        try:

            lock = repo.lock()

            tr = repo.transaction('obsinhibit')

            repo._obsinhibit.update(c.node() for c in newinhibit)

            _schedulewrite(tr, _filterpublic(repo, repo._obsinhibit))

            repo.invalidatevolatilesets()

            tr.close()

        finally:

            lockmod.release(tr, lock)

def _deinhibitmarkers(repo, nodes):

    """lift obsolescence inhibition on a set of nodes

    This will be triggered when inhibited nodes received new obsolescence

    markers. Otherwise the new obsolescence markers would also be inhibited.

    """

    deinhibited = repo._obsinhibit & set(nodes)

    if deinhibited:

        tr = repo.transaction('obsinhibit')

        try:

            repo._obsinhibit -= deinhibited

            _schedulewrite(tr, _filterpublic(repo, repo._obsinhibit))

            repo.invalidatevolatilesets()

            tr.close()

        finally:

            tr.release()

def _createmarkers(orig, repo, relations, flag=0, date=None, metadata=None):

    """wrap markers create to make sure we de-inhibit target nodes"""

    # wrapping transactio to unify the one in each function

    tr = repo.transaction('add-obsolescence-marker')

    try:

        orig(repo, relations, flag, date, metadata)

        precs = (r[0].node() for r in relations)

        _deinhibitmarkers(repo, precs)

        tr.close()

    finally:

        tr.release()

def transactioncallback(orig, repo, *args, **kwargs):

    """ Wrap localrepo.transaction to inhibit new obsolete changes """

    def inhibitposttransaction(transaction):

        # At the end of the transaction we catch all the new visible and

        # obsolete commit to inhibit them

        visibleobsolete = repo.revs('(not hidden()) and obsolete()')

        ignoreset = set(getattr(repo, '_rebaseset', []))

        visibleobsolete = list(r for r in visibleobsolete if r not in ignoreset)

        if visibleobsolete:

            _inhibitmarkers(repo, [repo[r].node() for r in visibleobsolete])

    transaction = orig(repo, *args, **kwargs)

    transaction.addpostclose('inhibitposttransaction', inhibitposttransaction)

    return transaction

def extsetup(ui):

    # lets wrap the computation of the obsolete set

    # We apply inhibition there

    obsfunc = obsolete.cachefuncs['obsolete']

    def _computeobsoleteset(repo):

        """remove any inhibited nodes from the obsolete set

        This will trickle down to other part of mercurial (hidden, log, etc)"""

        obs = obsfunc(repo)

        getrev = repo.changelog.nodemap.get

        for n in repo._obsinhibit:

            obs.discard(getrev(n))

        return obs

    obsolete.cachefuncs['obsolete'] = _computeobsoleteset

    # wrap create marker to make it able to lift the inhibition

    extensions.wrapfunction(obsolete, 'createmarkers', _createmarkers)

@command('debugobsinhibit', [], '')

def cmddebugobsinhibit(ui, repo, *revs):

    """inhibit obsolescence markers effect on a set of revs"""

    nodes = (repo[r].node() for r in scmutil.revrange(repo, revs))

    _inhibitmarkers(repo, nodes)