phases: stop using `repo.set` in `remotephasessummary`
The `repository.set` create changectx on the fly, an expensive operation. Using
`repo.revs` and a direct rev-num → node-id translation will be significantly
faster.
This is especially true as we prepare ourself to no longer do the rev-num →
node-id transalation there.
The speedup is a bit lost in the overall noisyness of the slow phase discovery algorithm, but it save a small amount of time in my benchmark.
create verbosemmap.py
$ cat << EOF > verbosemmap.py
> # extension to make util.mmapread verbose
>
>
> from mercurial import (
> extensions,
> pycompat,
> util,
> )
>
> def extsetup(ui):
> def mmapread(orig, fp, *args):
> ui.write(b"mmapping %s\n" % pycompat.bytestr(fp.name))
> ui.flush()
> return orig(fp, *args)
>
> extensions.wrapfunction(util, 'mmapread', mmapread)
> EOF
setting up base repo
$ hg init a
$ cd a
$ touch a
$ hg add a
$ hg commit -qm base
$ for i in `$TESTDIR/seq.py 1 100` ; do
> echo $i > a
> hg commit -qm $i
> done
set up verbosemmap extension
$ cat << EOF >> $HGRCPATH
> [extensions]
> verbosemmap=$TESTTMP/verbosemmap.py
> EOF
mmap index which is now more than 4k long
$ hg log -l 5 -T '{rev}\n' --config experimental.mmapindexthreshold=4k
mmapping $TESTTMP/a/.hg/store/00changelog.i
mmapping $TESTTMP/a/.hg/store/00changelog-????????.nd (glob) (rust !)
100
99
98
97
96
do not mmap index which is still less than 32k
$ hg log -l 5 -T '{rev}\n' --config experimental.mmapindexthreshold=32k
mmapping $TESTTMP/a/.hg/store/00changelog-????????.nd (glob) (rust !)
100
99
98
97
96
$ cd ..