annotate: simplify annotate parent function
The annotate algorithm used a custom parents() function to try to reuse
filectx and filelogs. I simplified it a bit to rely more heavily on the
self.parents() which makes it work well with alternative filectx
implementations. I tested performance on a file with 5000+ revisions
but no renames, and on a file with 500 revisions repeating a series of
4 edits+renames and saw zero performance hit. In fact, it was reliably a
couple milliseconds faster now.
Added the perfannotate command to contrib/perf.py for future use.
$ cat > engine.py << EOF
>
> from mercurial import templater
>
> class mytemplater(object):
> def __init__(self, loader, filters, defaults):
> self.loader = loader
>
> def process(self, t, map):
> tmpl = self.loader(t)
> for k, v in map.iteritems():
> if k in ('templ', 'ctx', 'repo', 'revcache', 'cache'):
> continue
> if hasattr(v, '__call__'):
> v = v(**map)
> v = templater.stringify(v)
> tmpl = tmpl.replace('{{%s}}' % k, v)
> yield tmpl
>
> templater.engines['my'] = mytemplater
> EOF
$ hg init test
$ echo '[extensions]' > test/.hg/hgrc
$ echo "engine = `pwd`/engine.py" >> test/.hg/hgrc
$ cd test
$ cat > mymap << EOF
> changeset = my:changeset.txt
> EOF
$ cat > changeset.txt << EOF
> {{rev}} {{node}} {{author}}
> EOF
$ hg ci -Ama
adding changeset.txt
adding mymap
$ hg log --style=./mymap
0 97e5f848f0936960273bbf75be6388cd0350a32b test
$ cat > changeset.txt << EOF
> {{p1rev}} {{p1node}} {{p2rev}} {{p2node}}
> EOF
$ hg ci -Ama
$ hg log --style=./mymap
0 97e5f848f0936960273bbf75be6388cd0350a32b -1 0000000000000000000000000000000000000000
-1 0000000000000000000000000000000000000000 -1 0000000000000000000000000000000000000000
$ cd ..