view mercurial/node.py @ 18100:3a6ddacb7198

clfilter: add actual repo filtering mechanism

We add a `filtered` method on repo. This method return an instance of `repoview`
that behaves exactly as the original repository but with a filtered changelog
attribute. Filters are identified by a "name". Planned filter are `unserved`,
`hidden` and `mutable`. Filtering the repository in place what out of question
as it wont not allows multiple thread to share the same repo. It would makes
control of the filtering scope harder too. See the `repoview` docstring for
details.

A mechanism to compute filtered revision is also installed. Some caches will be
installed in later 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.

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])