mercurial/node.py

ui: remove commands.status.terse=u from ui.tweakdefaults

commands.status.terse=u can add significant overhead when operating
on large repositories. Using the Firefox repository:

HGRCPATH= hg --time status
time: real 1.340 secs (user 0.960+0.000 sys 0.380+0.000)

HGRCPATH= hg --time --config commands.status.terse=u status
time: real 2.420 secs (user 2.070+0.000 sys 0.360+0.000)

HGRCPATH= hg --time --config extensions.fsmonitor= status
time: real 0.080 secs (user 0.050+0.010 sys 0.040+0.000)

HGRCPATH= ~/src/hg/hg --time --config extensions.fsmonitor= --config commands.status.terse=u status
time: real 2.470 secs (user 2.080+0.000 sys 0.390+0.000)

The performance regression - especially when fsmonitor is being
used - is too much to stomach for the 4.7 release. We've decided
to remove commands.status.terse=u from ui.tweakdefaults until we
can improve its performance, hopefully in the 4.8 cycle.

This commit effectively backs out 6acf41bb8d40.

# 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.

from __future__ import absolute_import

import binascii

# This ugly style has a noticeable effect in manifest parsing
hex = binascii.hexlify
# Adapt to Python 3 API changes. If this ends up showing up in
# profiles, we can use this version only on Python 3, and forward
# binascii.unhexlify like we used to on Python 2.
def bin(s):
    try:
        return binascii.unhexlify(s)
    except binascii.Error as e:
        raise TypeError(e)

nullrev = -1
nullid = b"\0" * 20
nullhex = hex(nullid)

# Phony node value to stand-in for new files in some uses of
# manifests.
newnodeid = '!' * 20
addednodeid = ('0' * 15) + 'added'
modifiednodeid = ('0' * 12) + 'modified'

wdirfilenodeids = {newnodeid, addednodeid, modifiednodeid}

# pseudo identifiers for working directory
# (they are experimental, so don't add too many dependencies on them)
wdirrev = 0x7fffffff
wdirid = b"\xff" * 20
wdirhex = hex(wdirid)

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