stream-clone: disable gc for the initial section for the v3 format The number of small container created turn Python in a gc-frenzy that seriously impact performance. This significantly boost performance. The following number comes from a large private repository using perf::stream-locked-section: base-line: 35.04 seconds prev-change: 24.51 seconds (-30%) prev-change: 20.88 seconds (-40%) this-change: 14.22 seconds (-60% from baseline; -31% from prev)

from mercurial.i18n import _
from mercurial import changegroup, error, extensions


def abort(orig, *args, **kwargs):
    raise error.Abort(_('this is an exercise'))


def uisetup(ui):
    extensions.wrapfunction(changegroup, 'getbundler', abort)