view hgext/pushexperiment.py @ 1414:4198e2fad6ba

evolve: add an help topic about evolution

The text is probably bad, but this have been laying around for quite sometime
(with Mercurial core in mind) lets move forward and add this to evolve.

"""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.sopener('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)