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 (
hg,
merge,
ui as uimod,
)
u = uimod.ui()
repo = hg.repository(u, 'test1', create=1)
os.chdir('test1')
def commit(text, time):
repo.commit(text=text, date="%d 0" % time)
def addcommit(name, time):
f = open(name, 'w')
f.write('%s\n' % name)
f.close()
repo[None].add([name])
commit(name, time)
def update(rev):
merge.update(repo, rev, False, True)
def merge_(rev):
merge.update(repo, rev, True, False)
if __name__ == '__main__':
addcommit("A", 0)
addcommit("B", 1)
update(0)
addcommit("C", 2)
merge_(1)
commit("D", 3)
update(2)
addcommit("E", 4)
addcommit("F", 5)
update(3)
addcommit("G", 6)
merge_(5)
commit("H", 7)
update(5)
addcommit("I", 8)
# Ancestors
print('Ancestors of 5')
for r in repo.changelog.ancestors([5]):
print(r, end=' ')
print('\nAncestors of 6 and 5')
for r in repo.changelog.ancestors([6, 5]):
print(r, end=' ')
print('\nAncestors of 5 and 4')
for r in repo.changelog.ancestors([5, 4]):
print(r, end=' ')
print('\nAncestors of 7, stop at 6')
for r in repo.changelog.ancestors([7], 6):
print(r, end=' ')
print('\nAncestors of 7, including revs')
for r in repo.changelog.ancestors([7], inclusive=True):
print(r, end=' ')
print('\nAncestors of 7, 5 and 3, including revs')
for r in repo.changelog.ancestors([7, 5, 3], inclusive=True):
print(r, end=' ')
# Descendants
print('\n\nDescendants of 5')
for r in repo.changelog.descendants([5]):
print(r, end=' ')
print('\nDescendants of 5 and 3')
for r in repo.changelog.descendants([5, 3]):
print(r, end=' ')
print('\nDescendants of 5 and 4')
print(*repo.changelog.descendants([5, 4]), sep=' ')