branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
#!/usr/bin/env python3
# Copyright 2010 Intevation GmbH
# Author(s):
# Thomas Arendsen Hein <thomas@intevation.de>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Create a Mercurial repository in revlog format 0
changeset: 0:a1ef0b125355
tag: tip
user: user
date: Thu Jan 01 00:00:00 1970 +0000
files: empty
description:
empty file
"""
import binascii
import os
import sys
files = [
(
b'formatv0/.hg/00changelog.i',
b'000000000000004400000000000000000000000000000000000000'
b'000000000000000000000000000000000000000000000000000000'
b'0000a1ef0b125355d27765928be600cfe85784284ab3',
),
(
b'formatv0/.hg/00changelog.d',
b'756163613935613961356635353036303562366138343738336237'
b'61623536363738616436356635380a757365720a3020300a656d70'
b'74790a0a656d7074792066696c65',
),
(
b'formatv0/.hg/00manifest.i',
b'000000000000003000000000000000000000000000000000000000'
b'000000000000000000000000000000000000000000000000000000'
b'0000aca95a9a5f550605b6a84783b7ab56678ad65f58',
),
(
b'formatv0/.hg/00manifest.d',
b'75656d707479006238306465356431333837353835343163356630'
b'35323635616431343461623966613836643164620a',
),
(
b'formatv0/.hg/data/empty.i',
b'000000000000000000000000000000000000000000000000000000'
b'000000000000000000000000000000000000000000000000000000'
b'0000b80de5d138758541c5f05265ad144ab9fa86d1db',
),
(b'formatv0/.hg/data/empty.d', b''),
]
def makedirs(name):
"""recursive directory creation"""
parent = os.path.dirname(name)
if parent:
makedirs(parent)
os.mkdir(name)
makedirs(os.path.join(*'formatv0/.hg/data'.split('/')))
for name, data in files:
f = open(name, 'wb')
f.write(binascii.unhexlify(data))
f.close()
sys.exit(0)