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.
# extension to emulate invoking 'patch.internalpatch()' at the time
# specified by '[fakepatchtime] fakenow'
from __future__ import absolute_import
from mercurial import (
extensions,
patch as patchmod,
util,
)
def internalpatch(orig, ui, repo, patchobj, strip,
prefix='', files=None,
eolmode='strict', similarity=0):
if files is None:
files = set()
r = orig(ui, repo, patchobj, strip,
prefix=prefix, files=files,
eolmode=eolmode, similarity=similarity)
fakenow = ui.config('fakepatchtime', 'fakenow')
if fakenow:
# parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
# 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
fakenow = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
for f in files:
repo.wvfs.utime(f, (fakenow, fakenow))
return r
def extsetup(ui):
extensions.wrapfunction(patchmod, 'internalpatch', internalpatch)