mercurial/node.py

namespaces: record and expose whether namespace is built-in

Currently, the templating layer tends to treat each namespace
as a one-off, with explicit usage of {bookmarks}, {tags}, {branch},
etc instead of using {namespaces}. It would be really useful if
we could iterate over namespaces and operate on them generically.
However, some consumers may wish to differentiate namespaces by
whether they are built-in to core Mercurial or provided by extensions.
Expected use cases include ignoring non-built-in namespaces or
emitting a generic label for non-built-in namespaces.

This commit introduces an attribute on namespace instances
that says whether the namespace is "built-in" and then exposes
this to the templating layer.

As part of this, we implement a reusable extension for defining
custom names on each changeset for testing. A second consumer
will be introduced in a subsequent commit.

# 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
bin = binascii.unhexlify

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'

wdirnodes = {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])