stream-clone: disable gc for the initial section for the v3 format
The number of small container created turn Python in a gc-frenzy that seriously
impact performance.
This significantly boost performance. The following number comes from a large
private repository using perf::stream-locked-section:
base-line: 35.04 seconds
prev-change: 24.51 seconds (-30%)
prev-change: 20.88 seconds (-40%)
this-change: 14.22 seconds (-60% from baseline; -31% from prev)
#testcases dirstate-v1 dirstate-v2
#if dirstate-v2
$ cat >> $HGRCPATH << EOF
> [format]
> use-dirstate-v2=1
> [storage]
> dirstate-v2.slow-path=allow
> EOF
#endif
$ rm -rf r
$ hg init r
$ cd r
$ mkdir d1
$ mkdir d2
$ touch d1/f d2/f
$ hg commit -Am '.'
adding d1/f
adding d2/f
$ echo 'syntax:re' >> .hgignore
$ echo '^d1$' >> .hgignore
$ hg commit -Am "ignore d1"
adding .hgignore
Now d1 is a directory that's both committed and ignored.
Untracked files in d2 are still shown, but ones in d1 are ignored:
$ touch d1/g
$ touch d2/g
$ RAYON_NUM_THREADS=1 hg status
? d2/g