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.
# revset.py - asv revset benchmarks
#
# Copyright 2016 Logilab SA <contact@logilab.fr>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''ASV revset benchmarks generated from contrib/base-revsets.txt
Each revset benchmark is parameterized with variants (first, last, sort, ...)
'''
from __future__ import absolute_import
import os
import string
import sys
from . import basedir, perfbench
def createrevsetbenchmark(baseset, variants=None):
if variants is None:
# Default variants
variants = ["plain", "first", "last", "sort", "sort+first",
"sort+last"]
fname = "track_" + "_".join("".join([
c if c in string.digits + string.letters else " "
for c in baseset
]).split())
def wrap(fname, baseset):
@perfbench(name=baseset, params=[("variant", variants)])
def f(perf, variant):
revset = baseset
if variant != "plain":
for var in variant.split("+"):
revset = "%s(%s)" % (var, revset)
return perf("perfrevset", revset)
f.__name__ = fname
return f
return wrap(fname, baseset)
def initializerevsetbenchmarks():
mod = sys.modules[__name__]
with open(os.path.join(basedir, 'contrib', 'base-revsets.txt'),
'rb') as fh:
for line in fh:
baseset = line.strip()
if baseset and not baseset.startswith('#'):
func = createrevsetbenchmark(baseset)
setattr(mod, func.__name__, func)
initializerevsetbenchmarks()