bdiff: give slight preference to longest matches in the middle of the B side
We already have a slight preference for matches close to the middle on the A
side. Now, do the same on the B side.
j is iterating the b range backwards and we thus accept a new j if the previous
match was in the upper half.
This makes the test-bhalf diff "correct". It obviously also gives more
preference to balanced recursion than to appending to sequences. That is kind
of correct, but will also unfortunately make some bundles bigger. No doubt, we
can also create examples where it will make them smaller ...
The bundle size for 4.0 (hg bundle --base null -r 4.0 x.hg) happens to go from
22803824 to 22806817 bytes - an 0.01% increase.
#!/usr/bin/env python
#
# hgperf - measure performance of Mercurial commands
#
# Copyright 2014 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.
'''measure performance of Mercurial commands
Using ``hgperf`` instead of ``hg`` measures performance of the target
Mercurial command. For example, the execution below measures
performance of :hg:`heads --topo`::
$ hgperf heads --topo
All command output via ``ui`` is suppressed, and just measurement
result is displayed: see also "perf" extension in "contrib".
Costs of processing before dispatching to the command function like
below are not measured::
- parsing command line (e.g. option validity check)
- reading configuration files in
But ``pre-`` and ``post-`` hook invocation for the target command is
measured, even though these are invoked before or after dispatching to
the command function, because these may be required to repeat
execution of the target command correctly.
'''
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
import time
def timer(func, title=None):
results = []
begin = time.time()
count = 0
while True:
ostart = os.times()
cstart = time.time()
r = func()
cstop = time.time()
ostop = os.times()
count += 1
a, b = ostart, ostop
results.append((cstop - cstart, b[0] - a[0], b[1]-a[1]))
if cstop - begin > 3 and count >= 100:
break
if cstop - begin > 10 and count >= 3:
break
if title:
sys.stderr.write("! %s\n" % title)
if r:
sys.stderr.write("! result: %s\n" % r)
m = min(results)
sys.stderr.write("! wall %f comb %f user %f sys %f (best of %d)\n"
% (m[0], m[1] + m[2], m[1], m[2], count))
orgruncommand = mercurial.dispatch.runcommand
def runcommand(lui, repo, cmd, fullargs, ui, options, d, cmdpats, cmdoptions):
ui.pushbuffer()
lui.pushbuffer()
timer(lambda : orgruncommand(lui, repo, cmd, fullargs, ui,
options, d, cmdpats, cmdoptions))
ui.popbuffer()
lui.popbuffer()
mercurial.dispatch.runcommand = runcommand
for fp in (sys.stdin, sys.stdout, sys.stderr):
mercurial.util.setbinary(fp)
mercurial.dispatch.run()