dirstate-guard: remove the feature
The dirstate guard duplicated some of the logic already implemented in the
transaction (and now the changing_* context).
However the feature was incomplete, for example, living only in memory meant we
could not recover from the hardest crash. In addition this duplicated with the
transaction logic meant things could go out of sync or step on each other.
Removing the feature now that we no longer needs it seems the safest.
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):
> ui.write(b"mmapping %s\n" % pycompat.bytestr(fp.name))
> ui.flush()
> return orig(fp)
>
> 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
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
100
99
98
97
96
$ cd ..