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.
#require killdaemons
= Test the known() protocol function =
Create a test repository:
$ hg init repo
$ cd repo
$ touch a ; hg add a ; hg ci -ma
$ touch b ; hg add b ; hg ci -mb
$ touch c ; hg add c ; hg ci -mc
$ hg log --template '{node}\n'
991a3460af53952d10ec8a295d3d2cc2e5fa9690
0e067c57feba1a5694ca4844f05588bb1bf82342
3903775176ed42b1458a6281db4a0ccf4d9f287a
$ cd ..
Test locally:
$ hg debugknown repo 991a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 3903775176ed42b1458a6281db4a0ccf4d9f287a
111
$ hg debugknown repo 000a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 0003775176ed42b1458a6281db4a0ccf4d9f287a
010
$ hg debugknown repo
Test via HTTP:
$ hg serve -R repo -p $HGPORT -d --pid-file=hg.pid -E error.log -A access.log
$ cat hg.pid >> $DAEMON_PIDS
$ hg debugknown http://localhost:$HGPORT/ 991a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 3903775176ed42b1458a6281db4a0ccf4d9f287a
111
$ hg debugknown http://localhost:$HGPORT/ 000a3460af53952d10ec8a295d3d2cc2e5fa9690 0e067c57feba1a5694ca4844f05588bb1bf82342 0003775176ed42b1458a6281db4a0ccf4d9f287a
010
$ hg debugknown http://localhost:$HGPORT/
$ cat error.log
$ killdaemons.py