"""Small extension altering some push behavior

- Add a new wire protocol command to exchange obsolescence markers. Sending the

  raw file as a binary instead of using pushkey hack.

- Add a "push done" notification

- Push obsolescence marker before anything else (This works around the lack of global transaction)

"""

import errno

from StringIO import StringIO

from mercurial.i18n import _

from mercurial import extensions

from mercurial import wireproto

from mercurial import obsolete

from mercurial import localrepo

def client_pushobsmarkers(self, obsfile):

    """wireprotocol peer method"""

    self.requirecap('_push_experiment_pushobsmarkers_0',

                    _('push obsolete markers faster'))

    ret, output = self._callpush('push_experiment_pushobsmarkers_0', obsfile)

    for l in output.splitlines(True):

        self.ui.status(_('remote: '), l)

    return ret

def srv_pushobsmarkers(repo, proto):

    """wireprotocol command"""

    fp = StringIO()

    proto.redirect()

    proto.getfile(fp)

    data = fp.getvalue()

    fp.close()

    lock = repo.lock()

    try:

        tr = repo.transaction('pushkey: obsolete markers')

        try:

            repo.obsstore.mergemarkers(tr, data)

            tr.close()

        finally:

            tr.release()

    finally:

        lock.release()

    return wireproto.pushres(0)

def syncpush(orig, repo, remote):

    """wraper for obsolete.syncpush to use the fast way if possible"""

    if not (obsolete.isenabled(repo, obsolete.exchangeopt) and

            repo.obsstore):

        return

    if remote.capable('_push_experiment_pushobsmarkers_0'):

        return # already pushed before changeset

        remote.push_experiment_pushobsmarkers_0(obsfp)

        return

    return orig(repo, remote)

def client_notifypushend(self):

    """wire peer  command to notify a push is done"""

    self.requirecap('_push_experiment_notifypushend_0', _('hook once push is all done'))

    return self._call('push_experiment_notifypushend_0')

def srv_notifypushend(repo, proto):

    """wire protocol command to notify a push is done"""

    proto.redirect()

    repo.hook('notifypushend')

    return wireproto.pushres(0)

def augmented_push(orig, repo, remote, *args, **kwargs):

    """push wrapped that call the wire protocol command"""

    if not remote.canpush():

        raise util.Abort(_("destination does not support push"))

    if (obsolete.isenabled(repo, obsolete.exchangeopt) and repo.obsstore

        and remote.capable('_push_experiment_pushobsmarkers_0')):

        # push marker early to limit damage of pushing too early.

        try:

            obsfp = repo.svfs('obsstore')

        except IOError as e:

            if e.errno != errno.ENOENT:

                raise

        else:

            remote.push_experiment_pushobsmarkers_0(obsfp)

    ret = orig(repo, remote, *args, **kwargs)

    if remote.capable('_push_experiment_notifypushend_0'):

        remote.push_experiment_notifypushend_0()

    return ret

def capabilities(orig, repo, proto):

    """wrapper to advertise new capability"""

    caps = orig(repo, proto)

    if obsolete.isenabled(repo, obsolete.exchangeopt):

        caps += ' _push_experiment_pushobsmarkers_0'

    caps += ' _push_experiment_notifypushend_0'

    return caps

def extsetup(ui):

    wireproto.wirepeer.push_experiment_pushobsmarkers_0 = client_pushobsmarkers

    wireproto.wirepeer.push_experiment_notifypushend_0 = client_notifypushend

    wireproto.commands['push_experiment_pushobsmarkers_0'] = (srv_pushobsmarkers, '')

    wireproto.commands['push_experiment_notifypushend_0'] = (srv_notifypushend, '')

    extensions.wrapfunction(wireproto, 'capabilities', capabilities)

    extensions.wrapfunction(obsolete, 'syncpush', syncpush)

    extensions.wrapfunction(localrepo.localrepository, 'push', augmented_push)