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.
#!/usr/bin/env python3
#
# A tool to help producing large and poorly compressible files
#
# Usage:
# $TESTDIR/seq.py 1000 | $TESTDIR/sha256line.py > my-file.txt
import hashlib
import sys
for line in sys.stdin:
print(hashlib.sha256(line.encode('utf8')).hexdigest())