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
import array
import errno
import fcntl
import os
import sys
from . import (
encoding,
osutil,
)
def _rcfiles(path):
rcs = [os.path.join(path, 'hgrc')]
rcdir = os.path.join(path, 'hgrc.d')
try:
rcs.extend([os.path.join(rcdir, f)
for f, kind in osutil.listdir(rcdir)
if f.endswith(".rc")])
except OSError:
pass
return rcs
def systemrcpath():
path = []
if sys.platform == 'plan9':
root = 'lib/mercurial'
else:
root = 'etc/mercurial'
# old mod_python does not set sys.argv
if len(getattr(sys, 'argv', [])) > 0:
p = os.path.dirname(os.path.dirname(sys.argv[0]))
if p != '/':
path.extend(_rcfiles(os.path.join(p, root)))
path.extend(_rcfiles('/' + root))
return path
def userrcpath():
if sys.platform == 'plan9':
return [encoding.environ['home'] + '/lib/hgrc']
else:
return [os.path.expanduser('~/.hgrc')]
def termsize(ui):
try:
import termios
TIOCGWINSZ = termios.TIOCGWINSZ # unavailable on IRIX (issue3449)
except (AttributeError, ImportError):
return 80, 24
for dev in (ui.ferr, ui.fout, ui.fin):
try:
try:
fd = dev.fileno()
except AttributeError:
continue
if not os.isatty(fd):
continue
arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8)
height, width = array.array('h', arri)[:2]
if width > 0 and height > 0:
return width, height
except ValueError:
pass
except IOError as e:
if e[0] == errno.EINVAL:
pass
else:
raise
return 80, 24