tests/test-fastannotate-perfhack.t

revlog: add a C implementation of `headrevsdiff`

Python implementation of `headrevsdiff` can be very slow in the worst
case compared with the `heads` computation it replaces, since the
latter is done in C.

Even the average case of this Python implementation is still
noticeable in the profiles.

This patch makes the computation much much faster by doing it in C.

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > fastannotate=
  > [fastannotate]
  > perfhack=1
  > EOF

  $ hg init repo
  $ cd repo

a simple merge case

  $ echo 1 > a
  $ hg commit -qAm 'append 1'
  $ echo 2 >> a
  $ hg commit -m 'append 2'
  $ echo 3 >> a
  $ hg commit -m 'append 3'
  $ hg up 1 -q
  $ cat > a << EOF
  > 0
  > 1
  > 2
  > EOF
  $ hg commit -qm 'insert 0'
  $ hg merge 2 -q
  $ echo 4 >> a
  $ hg commit -m merge
  $ hg log -G -T '{rev}: {desc}'
  @    4: merge
  |\
  | o  3: insert 0
  | |
  o |  2: append 3
  |/
  o  1: append 2
  |
  o  0: append 1
  
  $ hg fastannotate a
  3: 0
  0: 1
  1: 2
  2: 3
  4: 4
  $ hg fastannotate -r 0 a
  0: 1
  $ hg fastannotate -r 1 a
  0: 1
  1: 2
  $ hg fastannotate -udnclf a
  test 3 d641cb51f61e Thu Jan 01 00:00:00 1970 +0000 a:1: 0
  test 0 4994017376d3 Thu Jan 01 00:00:00 1970 +0000 a:1: 1
  test 1 e940cb6d9a06 Thu Jan 01 00:00:00 1970 +0000 a:2: 2
  test 2 26162a884ba6 Thu Jan 01 00:00:00 1970 +0000 a:3: 3
  test 4 3ad7bcd2815f Thu Jan 01 00:00:00 1970 +0000 a:5: 4
  $ hg fastannotate --linear a
  3: 0
  0: 1
  1: 2
  4: 3
  4: 4

incrementally updating

  $ hg fastannotate -r 0 a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  $ hg fastannotate -r 0 a --debug --rebuild
  fastannotate: a: 1 new changesets in the main branch
  0: 1
  $ hg fastannotate -r 1 a --debug
  fastannotate: a: 1 new changesets in the main branch
  0: 1
  1: 2
  $ hg fastannotate -r 3 a --debug
  fastannotate: a: 1 new changesets in the main branch
  3: 0
  0: 1
  1: 2
  $ hg fastannotate -r 4 a --debug
  fastannotate: a: 1 new changesets in the main branch
  3: 0
  0: 1
  1: 2
  2: 3
  4: 4
  $ hg fastannotate -r 1 a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  1: 2

rebuild happens automatically if unable to update

  $ hg fastannotate -r 2 a --debug
  fastannotate: a: cache broken and deleted
  fastannotate: a: 3 new changesets in the main branch
  0: 1
  1: 2
  2: 3

config option "fastannotate.mainbranch"

  $ hg fastannotate -r 1 --rebuild --config fastannotate.mainbranch=tip a --debug
  fastannotate: a: 4 new changesets in the main branch
  0: 1
  1: 2
  $ hg fastannotate -r 4 a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  3: 0
  0: 1
  1: 2
  2: 3
  4: 4

rename

  $ hg mv a b
  $ cat > b << EOF
  > 0
  > 11
  > 3
  > 44
  > EOF
  $ hg commit -m b -q
  $ hg fastannotate -ncf --long-hash b
  3 d641cb51f61e331c44654104301f8154d7865c89 a: 0
  5 d44dade239915bc82b91e4556b1257323f8e5824 b: 11
  2 26162a884ba60e8c87bf4e0d6bb8efcc6f711a4e a: 3
  5 d44dade239915bc82b91e4556b1257323f8e5824 b: 44
  $ hg fastannotate -r 26162a884ba60e8c87bf4e0d6bb8efcc6f711a4e a
  0: 1
  1: 2
  2: 3

fastannotate --deleted

  $ hg fastannotate --deleted -nf b
  3 a:  0
  5 b:  11
  0 a: -1
  1 a: -2
  2 a:  3
  5 b:  44
  4 a: -4
  $ hg fastannotate --deleted -r 3 -nf a
  3 a:  0
  0 a:  1
  1 a:  2

file and directories with ".l", ".m" suffixes

  $ cd ..
  $ hg init repo2
  $ cd repo2

  $ mkdir a.l b.m c.lock a.l.hg b.hg
  $ for i in a b c d d.l d.m a.l/a b.m/a c.lock/a a.l.hg/a b.hg/a; do
  >   echo $i > $i
  > done
  $ hg add . -q
  $ hg commit -m init
  $ hg fastannotate a.l/a b.m/a c.lock/a a.l.hg/a b.hg/a d.l d.m a b c d
  0: a
  0: a.l.hg/a
  0: a.l/a
  0: b
  0: b.hg/a
  0: b.m/a
  0: c
  0: c.lock/a
  0: d
  0: d.l
  0: d.m

empty file

  $ touch empty
  $ hg commit -A empty -m empty
  $ hg fastannotate empty