log: introduce struct that carries log traversal options
I tried to refactor logcmdutil.getrevs() without using an options struct,
but none of these attempts didn't work out. Since every stage of getrevs()
needs various log command options (e.g. both matcher and revset query need
file patterns), it isn't possible to cleanly split getrevs() into a command
layer and a core logic.
So, this patch introduces a named struct to carry command options in slightly
abstracted way, which will be later used by "hg grep" and "hg churn". More
fields will be added to the walkopt struct.
Type hints aren't verified. I couldn't figure out how to teach pytype to
load its own attr type stubs in place of our .thirdparty.attr. Conditional
import didn't work. s/^from \.thirdparty // is the only way I found pytype
could parse the @attr.ib decorator.
create verbosemmap.py
$ cat << EOF > verbosemmap.py
> # extension to make util.mmapread verbose
>
> from __future__ import absolute_import
>
> 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 ..