view mercurial/node.py @ 17013:c8eda7bbdcab

strip: incrementally update the branchheads cache after a strip

This function augments strip to incrementally update the branchheads cache
rather than recompute it from scratch.  This speeds up the performance of strip
and rebase on repos with long history.  The performance optimization only
happens if the revisions stripped are all on the same branch and the parents of
the stripped revisions are also on that same branch.

This adds a few test cases, particularly one that reproduces the extra heads
that mpm observed.

# node.py - basic nodeid manipulation for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import binascii

nullrev = -1
nullid = "\0" * 20

# This ugly style has a noticeable effect in manifest parsing
hex = binascii.hexlify
bin = binascii.unhexlify

def short(node):
    return hex(node[:6])