fastannotate: initial import from Facebook's hg-experimental
I made as few changes as I could to get the tests to pass, but this
was a bit involved due to some churn in the blame code since someone
last gave fastannotate any TLC.
There's still follow-up work here to rip out support for old versions
of hg and to integrate the protocol with modern standards.
Some performance numbers (all on my 2016 MacBook Pro with a 2.6Ghz i7):
Mercurial mercurial/manifest.py
traditional blame
time: real 1.050 secs (user 0.990+0.000 sys 0.060+0.000)
build cache
time: real 5.900 secs (user 5.720+0.000 sys 0.110+0.000)
fastannotate
time: real 0.120 secs (user 0.100+0.000 sys 0.020+0.000)
Mercurial mercurial/localrepo.py
traditional blame
time: real 3.330 secs (user 3.220+0.000 sys 0.070+0.000)
build cache
time: real 30.610 secs (user 30.190+0.000 sys 0.230+0.000)
fastannotate
time: real 0.180 secs (user 0.160+0.000 sys 0.020+0.000)
mozilla-central dom/ipc/ContentParent.cpp
traditional blame
time: real 7.640 secs (user 7.210+0.000 sys 0.380+0.000)
build cache
time: real 98.650 secs (user 97.000+0.000 sys 0.950+0.000)
fastannotate
time: real 1.580 secs (user 1.340+0.000 sys 0.240+0.000)
mozilla-central dom/base/nsDocument.cpp
traditional blame
time: real 17.110 secs (user 16.490+0.000 sys 0.500+0.000)
build cache
time: real 399.750 secs (user 394.520+0.000 sys 2.610+0.000)
fastannotate
time: real 1.780 secs (user 1.530+0.000 sys 0.240+0.000)
So building the cache is expensive (but might be faster with xdiff
enabled), but the blame results are *way* faster.
Differential Revision: https://phab.mercurial-scm.org/D3994
https://bz.mercurial-scm.org/619
$ hg init
$ echo a > a
$ hg ci -Ama
adding a
$ echo b > b
$ hg branch b
marked working directory as branch b
(branches are permanent and global, did you want a bookmark?)
$ hg ci -Amb
adding b
$ hg co -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
Fast-forward:
$ hg merge b
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -Ammerge
Bogus fast-forward should fail:
$ hg merge b
abort: merging with a working directory ancestor has no effect
[255]
Even with strange revset (issue4465)
$ hg merge ::.
abort: merging with a working directory ancestor has no effect
[255]