view tests/test-rebase-obsolete3.t @ 49777:e1953a34c110

bundle: emit full snapshot as is, without doing a redelta

With the new `forced` delta-reused policy, it become important to be able to
send full snapshot where full snapshot are needed. Otherwise, the fallback delta
will simply be used on the client side… creating monstrous delta chain, since
revision that are meant as a reset of delta-chain chain becoming too complex are
simply adding a new full delta-tree on the leaf of another one.

In the `non-forced` cases, client process full snapshot from the bundle
differently from deltas, so client will still try to convert the full snapshot
into a delta if possible. So this will no lead to pathological storage
explosion.

I have considered making this configurable, but the impact seems limited enough
that it does not seems to be worth it. Especially with the current
sparse-revlog format that use "delta-tree" with multiple level snapshots, full
snapshot are much less frequent and not that different from other intermediate
snapshot that we are already sending over the wire anyway.

CPU wise, this will help the bundling side a little as it will not need to
reconstruct revisions and compute deltas. The unbundling side might save a tiny
amount of CPU as it won't need to reconstruct the delta-base to reconstruct the
revision full text. This only slightly visible in some of the benchmarks. And
have no real impact on most of them.

### data-env-vars.name      = pypy-2018-08-01-zstd-sparse-revlog
  # benchmark.name          = perf-bundle
  # benchmark.variants.revs = last-40000
before:          11.467186 seconds
just-emit-full:  11.190576 seconds   (-2.41%)
with-pull-force: 11.041091 seconds   (-3.72%)
  # benchmark.name          = perf-unbundle
  # benchmark.variants.revs = last-40000
before:     16.744862
just-emit-full:: 16.561036 seconds   (-1.10%)
with-pull-force: 16.389344 seconds   (-2.12%)
  # benchmark.name          = pull
  # benchmark.variants.revs = last-40000
before:     26.870569
just-emit-full:  26.391188 seconds   (-1.78%)
with-pull-force: 25.633184 seconds   (-4.60%)


Space wise (so network-wise) the impact is fairly small. When taking compression into
account.

Below are tests the size of `hg bundle --all` for a handful of benchmark repositories
(with bzip, zstd compression and without it)

This show a small increase in the bundle size, but nothing really significant
except maybe for mozilla-try (+12%) that nobody really pulls large chunk of anyway.
Mozilla-try is also the repository that benefit the most for not having to
recompute deltas client size.

### mercurial:
bzip-before:     26 406 342 bytes
bzip-after:      26 691 543 bytes  +1.08%

zstd-before:     27 918 645 bytes
zstd-after:      28 075 896 bytes  +0.56%

none-before:     98 675 601 bytes
none-after:     100 411 237 bytes  +1.76%


### pypy
bzip-before:    201 295 752 bytes
bzip-after:     209 780 282 bytes  +4.21%

zstd-before:    202 974 795 bytes
zstd-after:     205 165 780 bytes  +1.08%

none-before:    871 070 261 bytes
none-after:     993 595 057 bytes +14.07%


### netbeans
bzip-before:    601 314 330 bytes
bzip-after:     614 246 241 bytes  +2.15%

zstd-before:    604 745 136 bytes
zstd-after:     615 497 705 bytes  +1.78%

none-before:  3 338 238 571 bytes
none-after:   3 439 422 535 bytes  +3.03%


### mozilla-central
bzip-before:  1 493 006 921 bytes
bzip-after:   1 549 650 570 bytes  +3.79%

zstd-before:  1 481 910 102 bytes
zstd-after:   1 513 052 415 bytes  +2.10%

none-before:  6 535 929 910 bytes
none-after:   7 010 191 342 bytes  +7.26%


### mozilla-try
bzip-before:  6 583 425 999 bytes
bzip-after:   7 423 536 928 bytes +12.76%

zstd-before:  6 021 009 212 bytes
zstd-after:   6 674 922 420 bytes +10.86%

none-before: 22 954 739 558 bytes
none-after:  26 013 854 771 bytes +13.32%

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

Enable obsolete

  $ cat >> $HGRCPATH << EOF
  > [command-templates]
  > log= {rev}:{node|short} {desc|firstline}{if(obsolete,' ({obsfate})')}
  > [experimental]
  > evolution.createmarkers=True
  > evolution.allowunstable=True
  > [phases]
  > publish=False
  > [extensions]
  > rebase=
  > drawdag=$TESTDIR/drawdag.py
  > strip=
  > EOF

Divergence cases due to obsolete changesets
-------------------------------------------

We should ignore branches with unstable changesets when they are based on an
obsolete changeset which successor is in rebase set.

  $ hg init divergence
  $ cd divergence
  $ cat >> .hg/hgrc << EOF
  > [extensions]
  > strip =
  > [alias]
  > strip = strip --no-backup --quiet
  > [templates]
  > instabilities = '{rev}:{node|short} {desc|firstline}{if(instabilities," ({instabilities})")}\n'
  > EOF

  $ hg debugdrawdag <<EOF
  >   e   f
  >   |   |
  >   d'  d # replace: d -> d'
  >    \ /
  >     c
  >     |
  >   x b
  >    \|
  >     a
  > EOF
  1 new orphan changesets
  $ hg log -G -r 'a'::
  *  7:1143e9adc121 f
  |
  | o  6:d60ebfa0f1cb e
  | |
  | o  5:027ad6c5830d d'
  | |
  x |  4:76be324c128b d (rewritten using replace as 5:027ad6c5830d)
  |/
  o  3:a82ac2b38757 c
  |
  | o  2:630d7c95eff7 x
  | |
  o |  1:488e1b7e7341 b
  |/
  o  0:b173517d0057 a
  

Changeset d and its descendants are excluded to avoid divergence of d, which
would occur because the successor of d (d') is also in rebaseset. As a
consequence f (descendant of d) is left behind.

  $ hg rebase -b 'e' -d 'x'
  rebasing 1:488e1b7e7341 b "b"
  rebasing 3:a82ac2b38757 c "c"
  note: not rebasing 4:76be324c128b d "d" and its descendants as this would cause divergence
  rebasing 5:027ad6c5830d d' "d'"
  rebasing 6:d60ebfa0f1cb e "e"
  $ hg log -G -r 'a'::
  o  11:eb6d63fc4ed5 e
  |
  o  10:44d8c724a70c d'
  |
  o  9:d008e6b4d3fd c
  |
  o  8:67e8f4a16c49 b
  |
  | *  7:1143e9adc121 f
  | |
  | | x  6:d60ebfa0f1cb e (rewritten using rebase as 11:eb6d63fc4ed5)
  | | |
  | | x  5:027ad6c5830d d' (rewritten using rebase as 10:44d8c724a70c)
  | | |
  | x |  4:76be324c128b d (rewritten using replace as 5:027ad6c5830d)
  | |/
  | x  3:a82ac2b38757 c (rewritten using rebase as 9:d008e6b4d3fd)
  | |
  o |  2:630d7c95eff7 x
  | |
  | x  1:488e1b7e7341 b (rewritten using rebase as 8:67e8f4a16c49)
  |/
  o  0:b173517d0057 a
  
  $ hg strip -r 8:
  $ hg log -G -r 'a'::
  *  7:1143e9adc121 f
  |
  | o  6:d60ebfa0f1cb e
  | |
  | o  5:027ad6c5830d d'
  | |
  x |  4:76be324c128b d (rewritten using replace as 5:027ad6c5830d)
  |/
  o  3:a82ac2b38757 c
  |
  | o  2:630d7c95eff7 x
  | |
  o |  1:488e1b7e7341 b
  |/
  o  0:b173517d0057 a
  

If the rebase set has an obsolete (d) with a successor (d') outside the rebase
set and none in destination, we still get the divergence warning.
By allowing divergence, we can perform the rebase.

  $ hg rebase -r 'c'::'f' -d 'x'
  abort: this rebase will cause divergences from: 76be324c128b
  (to force the rebase please set experimental.evolution.allowdivergence=True)
  [20]
  $ hg rebase --config experimental.evolution.allowdivergence=true -r 'c'::'f' -d 'x'
  rebasing 3:a82ac2b38757 c "c"
  rebasing 4:76be324c128b d "d"
  rebasing 7:1143e9adc121 f tip "f"
  1 new orphan changesets
  2 new content-divergent changesets
  $ hg log -G -r 'a':: -T instabilities
  o  10:e1744ea07510 f
  |
  *  9:e2b36ea9a0a0 d (content-divergent)
  |
  o  8:6a0376de376e c
  |
  | x  7:1143e9adc121 f
  | |
  | | *  6:d60ebfa0f1cb e (orphan)
  | | |
  | | *  5:027ad6c5830d d' (orphan content-divergent)
  | | |
  | x |  4:76be324c128b d
  | |/
  | x  3:a82ac2b38757 c
  | |
  o |  2:630d7c95eff7 x
  | |
  | o  1:488e1b7e7341 b
  |/
  o  0:b173517d0057 a
  
  $ hg strip -r 8:

(Not skipping obsoletes means that divergence is allowed.)

  $ hg rebase --config experimental.rebaseskipobsolete=false -r 'c'::'f' -d 'x'
  rebasing 3:a82ac2b38757 c "c"
  rebasing 4:76be324c128b d "d"
  rebasing 7:1143e9adc121 f tip "f"
  1 new orphan changesets
  2 new content-divergent changesets

  $ hg strip -r 0:

Similar test on a more complex graph

  $ hg debugdrawdag <<EOF
  >       g
  >       |
  >   f   e
  >   |   |
  >   e'  d # replace: e -> e'
  >    \ /
  >     c
  >     |
  >   x b
  >    \|
  >     a
  > EOF
  1 new orphan changesets
  $ hg log -G -r 'a':
  *  8:2876ce66c6eb g
  |
  | o  7:3ffec603ab53 f
  | |
  x |  6:e36fae928aec e (rewritten using replace as 5:63324dc512ea)
  | |
  | o  5:63324dc512ea e'
  | |
  o |  4:76be324c128b d
  |/
  o  3:a82ac2b38757 c
  |
  | o  2:630d7c95eff7 x
  | |
  o |  1:488e1b7e7341 b
  |/
  o  0:b173517d0057 a
  
  $ hg rebase -b 'f' -d 'x'
  rebasing 1:488e1b7e7341 b "b"
  rebasing 3:a82ac2b38757 c "c"
  rebasing 4:76be324c128b d "d"
  note: not rebasing 6:e36fae928aec e "e" and its descendants as this would cause divergence
  rebasing 5:63324dc512ea e' "e'"
  rebasing 7:3ffec603ab53 f "f"
  $ hg log -G -r 'a':
  o  13:ef6251596616 f
  |
  o  12:b6f172e64af9 e'
  |
  | o  11:a1707a5b7c2c d
  |/
  o  10:d008e6b4d3fd c
  |
  o  9:67e8f4a16c49 b
  |
  | *  8:2876ce66c6eb g
  | |
  | | x  7:3ffec603ab53 f (rewritten using rebase as 13:ef6251596616)
  | | |
  | x |  6:e36fae928aec e (rewritten using replace as 5:63324dc512ea)
  | | |
  | | x  5:63324dc512ea e' (rewritten using rebase as 12:b6f172e64af9)
  | | |
  | x |  4:76be324c128b d (rewritten using rebase as 11:a1707a5b7c2c)
  | |/
  | x  3:a82ac2b38757 c (rewritten using rebase as 10:d008e6b4d3fd)
  | |
  o |  2:630d7c95eff7 x
  | |
  | x  1:488e1b7e7341 b (rewritten using rebase as 9:67e8f4a16c49)
  |/
  o  0:b173517d0057 a
  

issue5782
  $ hg strip -r 0:
  $ hg debugdrawdag <<EOF
  >       d
  >       |
  >   c1  c # replace: c -> c1
  >    \ /
  >     b
  >     |
  >     a
  > EOF
  1 new orphan changesets
  $ hg debugobsolete `hg log -T "{node}" --hidden -r 'desc("c1")'`
  1 new obsolescence markers
  obsoleted 1 changesets
  $ hg log -G -r 'a': --hidden
  *  4:76be324c128b d
  |
  | x  3:ef8a456de8fa c1 (pruned)
  | |
  x |  2:a82ac2b38757 c (rewritten using replace as 3:ef8a456de8fa)
  |/
  o  1:488e1b7e7341 b
  |
  o  0:b173517d0057 a
  
  $ hg rebase -d 0 -r 2
  note: not rebasing 2:a82ac2b38757 c "c", it has no successor
  $ hg log -G -r 'a': --hidden
  *  4:76be324c128b d
  |
  | x  3:ef8a456de8fa c1 (pruned)
  | |
  x |  2:a82ac2b38757 c (rewritten using replace as 3:ef8a456de8fa)
  |/
  o  1:488e1b7e7341 b
  |
  o  0:b173517d0057 a
  
  $ cd ..

Start a normal rebase. When it runs into conflicts, rewrite one of the
commits in the rebase set, causing divergence when the rebase continues.

  $ hg init $TESTTMP/new-divergence-after-conflict
  $ cd $TESTTMP/new-divergence-after-conflict
  $ hg debugdrawdag <<'EOS'
  >  C2
  >  | C1
  >  |/
  >  B # B/D=B
  >  | D
  >  |/
  >  A
  > EOS
  $ hg rebase -r B::C1 -d D
  rebasing 1:2ec65233581b B "B"
  merging D
  warning: conflicts while merging D! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]
  $ hg debugobsolete $(hg log -r C1 -T '{node}') $(hg log -r C2 -T '{node}')
  1 new obsolescence markers
  obsoleted 1 changesets
  $ hg log -G
  o  4:fdb9df6b130c C2
  |
  | x  3:7e5bfd3c08f0 C1 (rewritten as 4:fdb9df6b130c)
  |/
  | @  2:b18e25de2cf5 D
  | |
  % |  1:2ec65233581b B
  |/
  o  0:426bada5c675 A
  
  $ echo resolved > D
  $ hg resolve -m D
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase -c
  rebasing 1:2ec65233581b B "B"
  note: not rebasing 3:7e5bfd3c08f0 C1 "C1" and its descendants as this would cause divergence
  1 new orphan changesets

Rebase merge where successor of one parent is equal to destination (issue5198)

  $ hg init p1-succ-is-dest
  $ cd p1-succ-is-dest

  $ hg debugdrawdag <<EOF
  >   F
  >  /|
  > E D B # replace: D -> B
  >  \|/
  >   A
  > EOF
  1 new orphan changesets

  $ hg rebase -d B -s D
  note: not rebasing 2:b18e25de2cf5 D "D", already in destination as 1:112478962961 B "B"
  rebasing 4:66f1a38021c9 F tip "F"
  $ hg log -G
  o    5:50e9d60b99c6 F
  |\
  | | x  4:66f1a38021c9 F (rewritten using rebase as 5:50e9d60b99c6)
  | |/|
  | o |  3:7fb047a69f22 E
  | | |
  | | x  2:b18e25de2cf5 D (rewritten using replace as 1:112478962961)
  | |/
  o |  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
  $ cd ..

Rebase merge where successor of other parent is equal to destination

  $ hg init p2-succ-is-dest
  $ cd p2-succ-is-dest

  $ hg debugdrawdag <<EOF
  >   F
  >  /|
  > E D B # replace: E -> B
  >  \|/
  >   A
  > EOF
  1 new orphan changesets

  $ hg rebase -d B -s E
  note: not rebasing 3:7fb047a69f22 E "E", already in destination as 1:112478962961 B "B"
  rebasing 4:66f1a38021c9 F tip "F"
  $ hg log -G
  o    5:aae1787dacee F
  |\
  | | x  4:66f1a38021c9 F (rewritten using rebase as 5:aae1787dacee)
  | |/|
  | | x  3:7fb047a69f22 E (rewritten using replace as 1:112478962961)
  | | |
  | o |  2:b18e25de2cf5 D
  | |/
  o /  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
  $ cd ..

Rebase merge where successor of one parent is ancestor of destination

  $ hg init p1-succ-in-dest
  $ cd p1-succ-in-dest

  $ hg debugdrawdag <<EOF
  >   F C
  >  /| |
  > E D B # replace: D -> B
  >  \|/
  >   A
  > EOF
  1 new orphan changesets

  $ hg rebase -d C -s D
  note: not rebasing 2:b18e25de2cf5 D "D", already in destination as 1:112478962961 B "B"
  rebasing 5:66f1a38021c9 F tip "F"

  $ hg log -G
  o    6:0913febf6439 F
  |\
  +---x  5:66f1a38021c9 F (rewritten using rebase as 6:0913febf6439)
  | | |
  | o |  4:26805aba1e60 C
  | | |
  o | |  3:7fb047a69f22 E
  | | |
  +---x  2:b18e25de2cf5 D (rewritten using replace as 1:112478962961)
  | |
  | o  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
  $ cd ..

Rebase merge where successor of other parent is ancestor of destination

  $ hg init p2-succ-in-dest
  $ cd p2-succ-in-dest

  $ hg debugdrawdag <<EOF
  >   F C
  >  /| |
  > E D B # replace: E -> B
  >  \|/
  >   A
  > EOF
  1 new orphan changesets

  $ hg rebase -d C -s E
  note: not rebasing 3:7fb047a69f22 E "E", already in destination as 1:112478962961 B "B"
  rebasing 5:66f1a38021c9 F tip "F"
  $ hg log -G
  o    6:c6ab0cc6d220 F
  |\
  +---x  5:66f1a38021c9 F (rewritten using rebase as 6:c6ab0cc6d220)
  | | |
  | o |  4:26805aba1e60 C
  | | |
  | | x  3:7fb047a69f22 E (rewritten using replace as 1:112478962961)
  | | |
  o---+  2:b18e25de2cf5 D
   / /
  o /  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
  $ cd ..

Rebase merge where successor of one parent is ancestor of destination

  $ hg init p1-succ-in-dest-b
  $ cd p1-succ-in-dest-b

  $ hg debugdrawdag <<EOF
  >   F C
  >  /| |
  > E D B # replace: E -> B
  >  \|/
  >   A
  > EOF
  1 new orphan changesets

  $ hg rebase -d C -b F
  rebasing 2:b18e25de2cf5 D "D"
  note: not rebasing 3:7fb047a69f22 E "E", already in destination as 1:112478962961 B "B"
  rebasing 5:66f1a38021c9 F tip "F"
  note: not rebasing 5:66f1a38021c9 F tip "F", its destination already has all its changes
  $ hg log -G
  o  6:8f47515dda15 D
  |
  | x    5:66f1a38021c9 F (pruned using rebase)
  | |\
  o | |  4:26805aba1e60 C
  | | |
  | | x  3:7fb047a69f22 E (rewritten using replace as 1:112478962961)
  | | |
  | x |  2:b18e25de2cf5 D (rewritten using rebase as 6:8f47515dda15)
  | |/
  o /  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
  $ cd ..

Rebase merge where successor of other parent is ancestor of destination

  $ hg init p2-succ-in-dest-b
  $ cd p2-succ-in-dest-b

  $ hg debugdrawdag <<EOF
  >   F C
  >  /| |
  > E D B # replace: D -> B
  >  \|/
  >   A
  > EOF
  1 new orphan changesets

  $ hg rebase -d C -b F
  note: not rebasing 2:b18e25de2cf5 D "D", already in destination as 1:112478962961 B "B"
  rebasing 3:7fb047a69f22 E "E"
  rebasing 5:66f1a38021c9 F tip "F"
  note: not rebasing 5:66f1a38021c9 F tip "F", its destination already has all its changes

  $ hg log -G
  o  6:533690786a86 E
  |
  | x    5:66f1a38021c9 F (pruned using rebase)
  | |\
  o | |  4:26805aba1e60 C
  | | |
  | | x  3:7fb047a69f22 E (rewritten using rebase as 6:533690786a86)
  | | |
  | x |  2:b18e25de2cf5 D (rewritten using replace as 1:112478962961)
  | |/
  o /  1:112478962961 B
  |/
  o  0:426bada5c675 A
  
  $ cd ..

Rebase merge where extinct node has successor that is not an ancestor of
destination

  $ hg init extinct-with-succ-not-in-dest
  $ cd extinct-with-succ-not-in-dest

  $ hg debugdrawdag <<EOF
  > E C # replace: C -> E
  > | |
  > D B
  > |/
  > A
  > EOF

  $ hg rebase -d D -s B
  rebasing 1:112478962961 B "B"
  note: not rebasing 3:26805aba1e60 C "C" and its descendants as this would cause divergence

  $ cd ..

  $ hg init p2-succ-in-dest-c
  $ cd p2-succ-in-dest-c

The scenario here was that B::D were developed on default.  B was queued on
stable, but amended before being push to hg-committed.  C was queued on default,
along with unrelated J.

  $ hg debugdrawdag <<EOF
  > J
  > |
  > F
  > |
  > E
  > | D
  > | |
  > | C      # replace: C -> F
  > | |  H I # replace: B -> H -> I
  > | B  |/
  > |/   G
  > A
  > EOF
  1 new orphan changesets

This strip seems to be the key to avoid an early divergence warning.
  $ hg --config extensions.strip= --hidden strip -qr H
  1 new orphan changesets

  $ hg rebase -b 'desc("D")' -d 'desc("J")'
  abort: this rebase will cause divergences from: 112478962961
  (to force the rebase please set experimental.evolution.allowdivergence=True)
  [20]

Rebase merge where both parents have successors in destination

  $ hg init p12-succ-in-dest
  $ cd p12-succ-in-dest
  $ hg debugdrawdag <<'EOS'
  >   E   F
  >  /|  /|  # replace: A -> C
  > A B C D  # replace: B -> D
  > | |
  > X Y
  > EOS
  1 new orphan changesets
  $ hg rebase -r A+B+E -d F
  note: not rebasing 4:a3d17304151f A "A", already in destination as 0:96cc3511f894 C "C"
  note: not rebasing 5:b23a2cc00842 B "B", already in destination as 1:058c1e1fb10a D "D"
  rebasing 7:dac5d11c5a7d E tip "E"
  abort: rebasing 7:dac5d11c5a7d will include unwanted changes from 3:59c792af609c, 5:b23a2cc00842 or 2:ba2b7fa7166d, 4:a3d17304151f
  [10]
  $ cd ..

Rebase a non-clean merge. One parent has successor in destination, the other
parent moves as requested.

  $ hg init p1-succ-p2-move
  $ cd p1-succ-p2-move
  $ hg debugdrawdag <<'EOS'
  >   D Z
  >  /| | # replace: A -> C
  > A B C # D/D = D
  > EOS
  1 new orphan changesets
  $ hg rebase -r A+B+D -d Z
  note: not rebasing 0:426bada5c675 A "A", already in destination as 2:96cc3511f894 C "C"
  rebasing 1:fc2b737bb2e5 B "B"
  rebasing 3:b8ed089c80ad D "D"

  $ rm .hg/localtags
  $ hg log -G
  o  6:e4f78693cc88 D
  |
  o  5:76840d832e98 B
  |
  o  4:50e41c1f3950 Z
  |
  o  2:96cc3511f894 C
  
  $ hg files -r tip
  B
  C
  D
  Z

  $ cd ..

  $ hg init p1-move-p2-succ
  $ cd p1-move-p2-succ
  $ hg debugdrawdag <<'EOS'
  >   D Z
  >  /| |  # replace: B -> C
  > A B C  # D/D = D
  > EOS
  1 new orphan changesets
  $ hg rebase -r B+A+D -d Z
  rebasing 0:426bada5c675 A "A"
  note: not rebasing 1:fc2b737bb2e5 B "B", already in destination as 2:96cc3511f894 C "C"
  rebasing 3:b8ed089c80ad D "D"

  $ rm .hg/localtags
  $ hg log -G
  o  6:1b355ed94d82 D
  |
  o  5:a81a74d764a6 A
  |
  o  4:50e41c1f3950 Z
  |
  o  2:96cc3511f894 C
  
  $ hg files -r tip
  A
  C
  D
  Z

  $ cd ..