bdiff: don't check border condition in loop
This is pretty much a copy of d500ddae7494, just to a different loop.
The condition `p == plast` (`plast == a + len - 1`) was only true on
the final iteration of the loop. So it was wasteful to check for it
on every iteration. We decrease the iteration count by 1 and add an
explicit check for `p == plast` after the loop.
Again, we see modest wins.
From the mozilla-unified repository:
$ perfbdiff -m 3041e4d59df2
! wall 0.035502 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
! wall 0.030480 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)
$ perfbdiff 0e9928989e9c --alldata --count 100
! wall 4.097394 comb 4.100000 user 4.100000 sys 0.000000 (best of 3)
! wall 3.597798 comb 3.600000 user 3.600000 sys 0.000000 (best of 3)
The 2nd example throws a total of ~3.3GB of data at bdiff. This
change increases the throughput from ~811 MB/s to ~924 MB/s.
from __future__ import absolute_import, print_function
import os
from mercurial import (
ui as uimod,
)
hgrc = os.environ['HGRCPATH']
f = open(hgrc)
basehgrc = f.read()
f.close()
print(' hgrc settings command line options final result ')
print(' quiet verbo debug quiet verbo debug quiet verbo debug')
for i in xrange(64):
hgrc_quiet = bool(i & 1<<0)
hgrc_verbose = bool(i & 1<<1)
hgrc_debug = bool(i & 1<<2)
cmd_quiet = bool(i & 1<<3)
cmd_verbose = bool(i & 1<<4)
cmd_debug = bool(i & 1<<5)
f = open(hgrc, 'w')
f.write(basehgrc)
f.write('\n[ui]\n')
if hgrc_quiet:
f.write('quiet = True\n')
if hgrc_verbose:
f.write('verbose = True\n')
if hgrc_debug:
f.write('debug = True\n')
f.close()
u = uimod.ui()
if cmd_quiet or cmd_debug or cmd_verbose:
u.setconfig('ui', 'quiet', str(bool(cmd_quiet)))
u.setconfig('ui', 'verbose', str(bool(cmd_verbose)))
u.setconfig('ui', 'debug', str(bool(cmd_debug)))
check = ''
if u.debugflag:
if not u.verbose or u.quiet:
check = ' *'
elif u.verbose and u.quiet:
check = ' +'
print(('%2d %5s %5s %5s %5s %5s %5s -> %5s %5s %5s%s'
% (i, hgrc_quiet, hgrc_verbose, hgrc_debug,
cmd_quiet, cmd_verbose, cmd_debug,
u.quiet, u.verbose, u.debugflag, check)))