phases: use revision number in `_pushdiscoveryphase`
We now reach our target checkpoint in terms of rev-num conversion. The
`_pushdiscoveryphase` function is now performing graph computation based on
revision number only. Avoiding repeated conversion from node-id to rev-num.
See previous changeset updated `new_heads` for rationnal.
Again, time saved in the 100 milliseconds order of magnitude for the mozilla-try
benchmark I have been using.
However, wow that the logic is done using revision number, we can look into having
better logic in the next changesets, which will provide a much bigger speedup.
# __init__.py - Startup and module loading logic for Mercurial.
#
# Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
# Allow 'from mercurial import demandimport' to keep working.
import hgdemandimport
demandimport = hgdemandimport