manifestmerge: use dicthelpers.diff and join
This patch improves manifestmerge performance significantly.
In a repository with 170,000 files, the following results were observed on a
clean working directory. Revision '.' adds one file.
hg perfmergecalculate -r .
- before: 0.41 seconds
- after: 0.13 seconds
hg perfmergecalculate -r .^
- before: 0.53 seconds
- after: 0.24 seconds
Comparing against '.' is much faster than comparing against '.^' because with
'.', the wctx and p2 manifest strings have the same identity, so comparisons
are simply pointer equality. With '.^', the strings have different identities
so we need to perform memcmps.
Any operation that uses manifestmerge benefits.
- hg update . goes from 2.04 seconds to 1.75
- hg update .^ goes from 2.52 seconds to 2.25
- hg rebase -r . -d .~6 (involves 4 merges) goes from 11.8 seconds to 10.8
#!/usr/bin/env python
#
# mercurial - scalable distributed SCM
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import os
import sys
libdir = '@LIBDIR@'
if libdir != '@' 'LIBDIR' '@':
if not os.path.isabs(libdir):
libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),
libdir)
libdir = os.path.abspath(libdir)
sys.path.insert(0, libdir)
# enable importing on demand to reduce startup time
try:
from mercurial import demandimport; demandimport.enable()
except ImportError:
import sys
sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
' '.join(sys.path))
sys.stderr.write("(check your install and PYTHONPATH)\n")
sys.exit(-1)
import mercurial.util
import mercurial.dispatch
for fp in (sys.stdin, sys.stdout, sys.stderr):
mercurial.util.setbinary(fp)
mercurial.dispatch.run()