view mercurial/node.py @ 27739:d6d3cf5fda6f

hooks: add HG_NODE_LAST to txnclose and changegroup hook environments

Sometimes a txnclose or changegroup hook wants to iterate through all
the changesets in transaction: in that situation usually the revset
`$HG_NODE:` is used to select the revisions. Unfortunately this revset
sometimes may contain too many changesets because we don't have the
write lock while the hook runs newer changes may be added to
repository in the meantime.

That's why there is a need for extra variable carrying the information about
the last change in the transaction.

# 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 = "\0" * 20
nullhex = hex(nullid)

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

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