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.
#!/usr/bin/env python
from mercurial import demandimport
demandimport.enable()
import sys
from mercurial.i18n import _
from mercurial import error, simplemerge, fancyopts, util, ui
options = [('L', 'label', [], _('labels to use on conflict markers')),
('a', 'text', None, _('treat all files as text')),
('p', 'print', None,
_('print results instead of overwriting LOCAL')),
('', 'no-minimal', None, _('no effect (DEPRECATED)')),
('h', 'help', None, _('display help and exit')),
('q', 'quiet', None, _('suppress output'))]
usage = _('''simplemerge [OPTS] LOCAL BASE OTHER
Simple three-way file merge utility with a minimal feature set.
Apply to LOCAL the changes necessary to go from BASE to OTHER.
By default, LOCAL is overwritten with the results of this operation.
''')
class ParseError(Exception):
"""Exception raised on errors in parsing the command line."""
def showhelp():
sys.stdout.write(usage)
sys.stdout.write('\noptions:\n')
out_opts = []
for shortopt, longopt, default, desc in options:
out_opts.append(('%2s%s' % (shortopt and '-%s' % shortopt,
longopt and ' --%s' % longopt),
'%s' % desc))
opts_len = max([len(opt[0]) for opt in out_opts])
for first, second in out_opts:
sys.stdout.write(' %-*s %s\n' % (opts_len, first, second))
try:
for fp in (sys.stdin, sys.stdout, sys.stderr):
util.setbinary(fp)
opts = {}
try:
args = fancyopts.fancyopts(sys.argv[1:], options, opts)
except fancyopts.getopt.GetoptError as e:
raise ParseError(e)
if opts['help']:
showhelp()
sys.exit(0)
if len(args) != 3:
raise ParseError(_('wrong number of arguments'))
sys.exit(simplemerge.simplemerge(ui.ui(), *args, **opts))
except ParseError as e:
sys.stdout.write("%s: %s\n" % (sys.argv[0], e))
showhelp()
sys.exit(1)
except error.Abort as e:
sys.stderr.write("abort: %s\n" % e)
sys.exit(255)
except KeyboardInterrupt:
sys.exit(255)