comparison mercurial/exchange.py @ 33701:fda0867cfe03

exchange: drop support for lock-based unbundling (BC)

Locking over the wire protocol and the "addchangegroup" wire
protocol command has been deprecated since e8c4f3d3df8c, which was
first part of Mercurial 0.9.1.

Support for handling these commands from sshserver was dropped in
9f6e0e7ef828 in 2015, effectively locking out pre 0.9.1 clients
from new servers.

However, client-side code for calling lock and addchangegroup is
still present in exchange.py and the various peer classes to
facilitate pushing to pre 0.9.1 servers.

The lock-based pushing mechanism is extremely brittle. 0.9.1 was
released in July 2006 and I highly doubt anyone is still running
such an ancient version of Mercurial on a server. I'm about to
refactor the peer API and I don't think it is worth keeping
support for this ancient protocol feature. So, this commit removes
client support for the lock-based pushing mechanism. This means
modern clients will no longer be able to push to pre 0.9.1 servers.

Differential Revision: https://phab.mercurial-scm.org/D264

33700:970967e0a917

            msg = _("required features are not"
                    " supported in the destination:"
                    " %s") % (', '.join(sorted(missing)))
            raise error.Abort(msg)

    # there are two ways to push to remote repo:
    #
    # addchangegroup assumes local user can lock remote
    # repo (local filesystem, old ssh servers).
    #
    # unbundle assumes local user cannot lock remote repo (new ssh
    # servers, http servers).

    if not pushop.remote.canpush():
        raise error.Abort(_("destination does not support push"))
    # get local lock as we might write phase data
    localwlock = locallock = None
    try:
        # bundle2 push may receive a reply bundle touching bookmarks or other
        # things requiring the wlock. Take it now to ensure proper ordering.

        if pushop.locallocked:
            pushop.trmanager = transactionmanager(pushop.repo,
                                                  'push-response',
                                                  pushop.remote.url())
        pushop.repo.checkpush(pushop)
        lock = None
        unbundle = pushop.remote.capable('unbundle')
        if not unbundle:
            lock = pushop.remote.lock()
        try:
            _pushdiscovery(pushop)
            if not _forcebundle1(pushop):
                _pushbundle2(pushop)
            _pushchangeset(pushop)
            _pushsyncphase(pushop)
            _pushobsolete(pushop)
            _pushbookmark(pushop)
        finally:
            if lock is not None:
                lock.release()
        if pushop.trmanager:
            pushop.trmanager.close()
    finally:
        if pushop.trmanager:
            pushop.trmanager.release()

    if 'changesets' in pushop.stepsdone:
        return
    pushop.stepsdone.add('changesets')
    if not _pushcheckoutgoing(pushop):
        return
    pushop.repo.prepushoutgoinghooks(pushop)
    outgoing = pushop.outgoing
    unbundle = pushop.remote.capable('unbundle')
    # TODO: get bundlecaps from remote
    bundlecaps = None
    # create a changegroup from local
    if pushop.revs is None and not (outgoing.excluded
                            or pushop.repo.changelog.filteredrevs):

    else:
        cg = changegroup.getchangegroup(pushop.repo, 'push', outgoing,
                                        bundlecaps=bundlecaps)

    # apply changegroup to remote
    if unbundle:
        # local repo finds heads on server, finds out what
        # revs it must push. once revs transferred, if server
        # finds it has different heads (someone else won
        # commit/push race), server aborts.
        if pushop.force:
            remoteheads = ['force']
        else:
            remoteheads = pushop.remoteheads
        # ssh: return remote's addchangegroup()
        # http: return remote's addchangegroup() or 0 for error
        pushop.cgresult = pushop.remote.unbundle(cg, remoteheads,
                                            pushop.repo.url())
    else:
        # we return an integer indicating remote head count
        # change
        pushop.cgresult = pushop.remote.addchangegroup(cg, 'push',
                                                       pushop.repo.url())

def _pushsyncphase(pushop):
    """synchronise phase information locally and remotely"""
    cheads = pushop.commonheads
    # even when we don't push, exchanging phase data is useful

33701:fda0867cfe03

            msg = _("required features are not"
                    " supported in the destination:"
                    " %s") % (', '.join(sorted(missing)))
            raise error.Abort(msg)

    if not pushop.remote.canpush():
        raise error.Abort(_("destination does not support push"))

    if not pushop.remote.capable('unbundle'):
        raise error.Abort(_('cannot push: destination does not support the '
                            'unbundle wire protocol command'))

    # get local lock as we might write phase data
    localwlock = locallock = None
    try:
        # bundle2 push may receive a reply bundle touching bookmarks or other
        # things requiring the wlock. Take it now to ensure proper ordering.

        if pushop.locallocked:
            pushop.trmanager = transactionmanager(pushop.repo,
                                                  'push-response',
                                                  pushop.remote.url())
        pushop.repo.checkpush(pushop)
        _pushdiscovery(pushop)
        if not _forcebundle1(pushop):
            _pushbundle2(pushop)
        _pushchangeset(pushop)
        _pushsyncphase(pushop)
        _pushobsolete(pushop)
        _pushbookmark(pushop)

        if pushop.trmanager:
            pushop.trmanager.close()
    finally:
        if pushop.trmanager:
            pushop.trmanager.release()

    if 'changesets' in pushop.stepsdone:
        return
    pushop.stepsdone.add('changesets')
    if not _pushcheckoutgoing(pushop):
        return

    # Should have verified this in push().
    assert pushop.remote.capable('unbundle')

    pushop.repo.prepushoutgoinghooks(pushop)
    outgoing = pushop.outgoing
    # TODO: get bundlecaps from remote
    bundlecaps = None
    # create a changegroup from local
    if pushop.revs is None and not (outgoing.excluded
                            or pushop.repo.changelog.filteredrevs):

    else:
        cg = changegroup.getchangegroup(pushop.repo, 'push', outgoing,
                                        bundlecaps=bundlecaps)

    # apply changegroup to remote
    # local repo finds heads on server, finds out what
    # revs it must push. once revs transferred, if server
    # finds it has different heads (someone else won
    # commit/push race), server aborts.
    if pushop.force:
        remoteheads = ['force']
    else:
        remoteheads = pushop.remoteheads
    # ssh: return remote's addchangegroup()
    # http: return remote's addchangegroup() or 0 for error
    pushop.cgresult = pushop.remote.unbundle(cg, remoteheads,
                                        pushop.repo.url())

def _pushsyncphase(pushop):
    """synchronise phase information locally and remotely"""
    cheads = pushop.commonheads
    # even when we don't push, exchanging phase data is useful