tests/test-fastannotate-renames.t

obsolete: explicitly track folds inside the markers

We now record information to be able to recognize "fold" event from
obsolescence markers. To do so, we track the following pieces of information:

a) a fold ID. Unique to that fold (per successor),
b) the number of predecessors,
c) the index of the predecessor in that fold.

We will now be able to create an algorithm able to find "predecessorssets".

We now store this data in the generic "metadata" field of the markers.
Updating the format to have a more compact storage for this would be useful.

This way of tracking a fold through multiple markers could be applied to split
too. This would have two advantages:

1) We get a simpler format, since number of successors is limited to [0-1].
2) We can better deal with situations where only some of the split successors
   are pushed to a remote repository.

We should look into the relevance of such a change before updating the on-disk
format.

note: unlike splits, folds do not have to deal with cases where only some of
the markers have been synchronized. As they all share the same successor
changesets, they are all relevant to the same nodes.

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > fastannotate=
  > [fastannotate]
  > mainbranch=main
  > EOF

  $ hg init repo
  $ cd repo

add or rename files on top of the master branch

  $ echo a1 > a
  $ echo b1 > b
  $ hg commit -qAm 1
  $ hg bookmark -i main
  $ hg fastannotate --debug -nf b
  fastannotate: b: 1 new changesets in the main branch
  0 b: b1
  $ hg fastannotate --debug -nf a
  fastannotate: a: 1 new changesets in the main branch
  0 a: a1
  $ echo a2 >> a
  $ cat > b << EOF
  > b0
  > b1
  > EOF
  $ hg mv a t
  $ hg mv b a
  $ hg mv t b
  $ hg commit -m 'swap names'

existing linelogs are not helpful with such renames in side branches

  $ hg fastannotate --debug -nf a
  fastannotate: a: linelog cannot help in annotating this revision
  1 a: b0
  0 b: b1
  $ hg fastannotate --debug -nf b
  fastannotate: b: linelog cannot help in annotating this revision
  0 a: a1
  1 b: a2

move main branch forward, rebuild should happen

  $ hg bookmark -i main -r . -q
  $ hg fastannotate --debug -nf b
  fastannotate: b: cache broken and deleted
  fastannotate: b: 2 new changesets in the main branch
  0 a: a1
  1 b: a2
  $ hg fastannotate --debug -nf b
  fastannotate: b: using fast path (resolved fctx: True)
  0 a: a1
  1 b: a2

for rev 0, the existing linelog is still useful for a, but not for b

  $ hg fastannotate --debug -nf a -r 0
  fastannotate: a: using fast path (resolved fctx: True)
  0 a: a1
  $ hg fastannotate --debug -nf b -r 0
  fastannotate: b: linelog cannot help in annotating this revision
  0 b: b1

a rebuild can also be triggered if "the main branch last time" mismatches

  $ echo a3 >> a
  $ hg commit -m a3
  $ cat >> b << EOF
  > b3
  > b4
  > EOF
  $ hg commit -m b4
  $ hg bookmark -i main -q
  $ hg fastannotate --debug -nf a
  fastannotate: a: cache broken and deleted
  fastannotate: a: 3 new changesets in the main branch
  1 a: b0
  0 b: b1
  2 a: a3
  $ hg fastannotate --debug -nf a
  fastannotate: a: using fast path (resolved fctx: True)
  1 a: b0
  0 b: b1
  2 a: a3

linelog can be updated without being helpful

  $ hg mv a t
  $ hg mv b a
  $ hg mv t b
  $ hg commit -m 'swap names again'
  $ hg fastannotate --debug -nf b
  fastannotate: b: 1 new changesets in the main branch
  1 a: b0
  0 b: b1
  2 a: a3
  $ hg fastannotate --debug -nf b
  fastannotate: b: linelog cannot help in annotating this revision
  1 a: b0
  0 b: b1
  2 a: a3

move main branch forward again, rebuilds are one-time

  $ hg bookmark -i main -q
  $ hg fastannotate --debug -nf a
  fastannotate: a: cache broken and deleted
  fastannotate: a: 4 new changesets in the main branch
  0 a: a1
  1 b: a2
  3 b: b3
  3 b: b4
  $ hg fastannotate --debug -nf b
  fastannotate: b: cache broken and deleted
  fastannotate: b: 4 new changesets in the main branch
  1 a: b0
  0 b: b1
  2 a: a3
  $ hg fastannotate --debug -nf a
  fastannotate: a: using fast path (resolved fctx: True)
  0 a: a1
  1 b: a2
  3 b: b3
  3 b: b4
  $ hg fastannotate --debug -nf b
  fastannotate: b: using fast path (resolved fctx: True)
  1 a: b0
  0 b: b1
  2 a: a3

list changeset hashes to improve readability

  $ hg log -T '{rev}:{node}\n'
  4:980e1ab8c516350172928fba95b49ede3b643dca
  3:14e123fedad9f491f5dde0beca2a767625a0a93a
  2:96495c41e4c12218766f78cdf244e768d7718b0f
  1:35c2b781234c994896aba36bd3245d3104e023df
  0:653e95416ebb5dbcc25bbc7f75568c9e01f7bd2f

annotate a revision not in the linelog. linelog cannot be used, but does not get rebuilt either

  $ hg fastannotate --debug -nf a -r 96495c41e4c12218766f78cdf244e768d7718b0f
  fastannotate: a: linelog cannot help in annotating this revision
  1 a: b0
  0 b: b1
  2 a: a3
  $ hg fastannotate --debug -nf a -r 2
  fastannotate: a: linelog cannot help in annotating this revision
  1 a: b0
  0 b: b1
  2 a: a3
  $ hg fastannotate --debug -nf a -r .
  fastannotate: a: using fast path (resolved fctx: True)
  0 a: a1
  1 b: a2
  3 b: b3
  3 b: b4

annotate an ancient revision where the path matches. linelog can be used

  $ hg fastannotate --debug -nf a -r 0
  fastannotate: a: using fast path (resolved fctx: True)
  0 a: a1
  $ hg fastannotate --debug -nf a -r 653e95416ebb5dbcc25bbc7f75568c9e01f7bd2f
  fastannotate: a: using fast path (resolved fctx: False)
  0 a: a1