view tests/test-rebase-obsolete.t @ 18040:fe8caf28d580

strip: make query to get new bookmark target cheaper

The current query to get the new bookmark target for stripped revisions
involves multiple walks up the DAG, and is really expensive, taking over 2.5
seconds on a repository with over 400,000 changesets even if just one
changeset is being stripped.

A slightly simplified version of the current query is

max(heads(::<tostrip> - <tostrip>))

We make two observations here.

1. For any set s, max(heads(s)) == max(s). That is because revision numbers
   define a topological order, so that the element with the highest revision
   number in s will not have any children in s.

2. For any set s, max(::s - s) == max(parents(s) - s). In other words, the
   ancestor of s with the highest revision number not in s is a parent of one
   of the revs in s. Why? Because if it were an ancestor but not a parent of s,
   it would have a descendant that would be a parent of s. This descendant
   would have a higher revision number, leading to a contradiction.

Combining these two observations, we rewrite the revset query as

max(parents(<tostrip>) - <tostrip>)

The time complexity is now linear in the number of changesets being stripped.
For the above repository, the query now takes 0.1 seconds when one changeset
is stripped. This speeds up operations that use repair.strip, like the rebase
and strip commands.

==========================
Test rebase with obsolete
==========================

Enable obsolete

  $ cat > ${TESTTMP}/obs.py << EOF
  > import mercurial.obsolete
  > mercurial.obsolete._enabled = True
  > EOF
  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} {desc|firstline}
  > [phases]
  > publish=False
  > [extensions]'
  > rebase=
  > 
  > obs=${TESTTMP}/obs.py
  > EOF

Setup rebase canonical repo

  $ hg init base
  $ cd base
  $ hg unbundle "$TESTDIR/bundles/rebase.hg"
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up tip
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg log -G
  @  7:02de42196ebe H
  |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  | o  3:32af7686d403 D
  | |
  | o  2:5fddd98957c8 C
  | |
  | o  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ cd ..

simple rebase
---------------------------------

  $ hg clone base simple
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd simple
  $ hg up 32af7686d403
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg rebase -d eea13746799a
  $ hg log -G
  @  10:8eeb3c33ad33 D
  |
  o  9:2327fea05063 C
  |
  o  8:e4e5be0395b2 B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  @  10:8eeb3c33ad33 D
  |
  o  9:2327fea05063 C
  |
  o  8:e4e5be0395b2 B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 e4e5be0395b2cbd471ed22a26b1b6a1a0658a794 0 {'date': '*', 'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 2327fea05063f39961b14cb69435a9898dc9a245 0 {'date': '*', 'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 8eeb3c33ad33d452c89e5dcf611c347f978fb42b 0 {'date': '*', 'user': 'test'} (glob)


  $ cd ..

empty changeset
---------------------------------

  $ hg clone base empty
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd empty
  $ hg up eea13746799a
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

We make a copy of both the first changeset in the rebased and some other in the
set.

  $ hg graft 42ccdea3bb16 32af7686d403
  grafting revision 1
  grafting revision 3
  $ hg rebase  -s 42ccdea3bb16 -d .
  $ hg log -G
  @  10:5ae4c968c6ac C
  |
  o  9:08483444fef9 D
  |
  o  8:8877864f1edb B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  @  10:5ae4c968c6ac C
  |
  o  9:08483444fef9 D
  |
  o  8:8877864f1edb B
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 08483444fef91d6224f6655ee586a65d263ad34c 0 {'date': '*', 'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 5ae4c968c6aca831df823664e706c9d4aa34473d 0 {'date': '*', 'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 5ae4c968c6aca831df823664e706c9d4aa34473d 0 {'date': '*', 'user': 'test'} (glob)


  $ cd ..

collapse rebase
---------------------------------

  $ hg clone base collapse
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd collapse
  $ hg rebase  -s 42ccdea3bb16 -d eea13746799a --collapse
  $ hg log -G
  @  8:4dc2197e807b Collapsed revision
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  @  8:4dc2197e807b Collapsed revision
  |
  | o  7:02de42196ebe H
  | |
  o |  6:eea13746799a G
  |\|
  | o  5:24b6387c8c8c F
  | |
  o |  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg id --debug
  4dc2197e807bae9817f09905b50ab288be2dbbcf tip
  $ hg debugobsolete
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 4dc2197e807bae9817f09905b50ab288be2dbbcf 0 {'date': '*', 'user': 'test'} (glob)
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b 4dc2197e807bae9817f09905b50ab288be2dbbcf 0 {'date': '*', 'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a 4dc2197e807bae9817f09905b50ab288be2dbbcf 0 {'date': '*', 'user': 'test'} (glob)

  $ cd ..

Rebase set has hidden descendants
---------------------------------

We rebase a changeset which has a hidden changeset. The hidden changeset must
not be rebased.

  $ hg clone base hidden
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd hidden
  $ hg rebase -s 5fddd98957c8 -d eea13746799a
  $ hg rebase -s 42ccdea3bb16 -d 02de42196ebe
  $ hg log -G
  @  10:7c6027df6a99 B
  |
  | o  9:cf44d2f5a9f4 D
  | |
  | o  8:e273c5e7d2d2 C
  | |
  o |  7:02de42196ebe H
  | |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  o  0:cd010b8cd998 A
  
  $ hg log --hidden -G
  @  10:7c6027df6a99 B
  |
  | o  9:cf44d2f5a9f4 D
  | |
  | o  8:e273c5e7d2d2 C
  | |
  o |  7:02de42196ebe H
  | |
  | o  6:eea13746799a G
  |/|
  o |  5:24b6387c8c8c F
  | |
  | o  4:9520eea781bc E
  |/
  | x  3:32af7686d403 D
  | |
  | x  2:5fddd98957c8 C
  | |
  | x  1:42ccdea3bb16 B
  |/
  o  0:cd010b8cd998 A
  
  $ hg debugobsolete
  5fddd98957c8a54a4d436dfe1da9d87f21a1b97b e273c5e7d2d29df783dce9f9eaa3ac4adc69c15d 0 {'date': '*', 'user': 'test'} (glob)
  32af7686d403cf45b5d95f2d70cebea587ac806a cf44d2f5a9f4297a62be94cbdd3dff7c7dc54258 0 {'date': '*', 'user': 'test'} (glob)
  42ccdea3bb16d28e1848c95fe2e44c000f3f21b1 7c6027df6a99d93f461868e5433f63bde20b6dfb 0 {'date': '*', 'user': 'test'} (glob)

  $ cd ..