view tests/test-rebase-mq.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%

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > mq=
  > 
  > [mq]
  > plain=true
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' tags: {tags}\n"
  > EOF


  $ hg init a
  $ cd a
  $ hg qinit -c

  $ echo c1 > f
  $ hg add f
  $ hg ci -m C1

  $ echo r1 > f
  $ hg ci -m R1

  $ hg up -q 0

  $ hg qnew f.patch -d '1 0'
  $ echo mq1 > f
  $ hg qref -m P0

  $ hg qnew f2.patch
  $ echo mq2 > f
  $ hg qref -m P1 -d '2 0'

  $ hg tglog
  @  3: 929394423cd3 'P1' tags: f2.patch qtip tip
  |
  o  2: 3504f44bffc0 'P0' tags: f.patch qbase
  |
  | o  1: bac9ed9960d8 'R1' tags:
  |/
  o  0: 36f36ddbca61 'C1' tags: qparent
  

Rebase - try to rebase on an applied mq patch:

  $ hg rebase -s 1 -d 3
  abort: cannot rebase onto an applied mq patch
  [20]

Rebase - same thing, but mq patch is default dest:

  $ hg up -q 1
  $ hg rebase
  abort: cannot rebase onto an applied mq patch
  [20]
  $ hg up -q qtip

Rebase - generate a conflict:

  $ hg rebase -s 2 -d 1
  rebasing 2:3504f44bffc0 f.patch qbase "P0"
  merging f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

Fix the 1st conflict:

  $ echo mq1r1 > f
  $ hg resolve -m f
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase -c
  rebasing 2:3504f44bffc0 f.patch qbase "P0"
  rebasing 3:929394423cd3 f2.patch qtip tip "P1"
  merging f
  warning: conflicts while merging f! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
  [240]

Fix the 2nd conflict:

  $ echo mq1r1mq2 > f
  $ hg resolve -m f
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase -c
  already rebased 2:3504f44bffc0 f.patch qbase "P0" as ebe9914c0d1c
  rebasing 3:929394423cd3 f2.patch qtip "P1"
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/3504f44bffc0-30595b40-rebase.hg

  $ hg tglog
  @  3: 462012cf340c 'P1' tags: f2.patch qtip tip
  |
  o  2: ebe9914c0d1c 'P0' tags: f.patch qbase
  |
  o  1: bac9ed9960d8 'R1' tags: qparent
  |
  o  0: 36f36ddbca61 'C1' tags:
  
  $ hg up -q qbase

  $ cat f
  mq1r1

  $ cat .hg/patches/f.patch
  # HG changeset patch
  # User test
  # Date 1 0
  #      Thu Jan 01 00:00:01 1970 +0000
  # Node ID ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
  # Parent  bac9ed9960d8992bcad75864a879fa76cadaf1b0
  P0
  
  diff -r bac9ed9960d8 -r ebe9914c0d1c f
  --- a/f	Thu Jan 01 00:00:00 1970 +0000
  +++ b/f	Thu Jan 01 00:00:01 1970 +0000
  @@ -1,1 +1,1 @@
  -r1
  +mq1r1

Update to qtip:

  $ hg up -q qtip

  $ cat f
  mq1r1mq2

  $ cat .hg/patches/f2.patch
  # HG changeset patch
  # User test
  # Date 2 0
  #      Thu Jan 01 00:00:02 1970 +0000
  # Node ID 462012cf340c97d44d62377c985a423f6bb82f07
  # Parent  ebe9914c0d1c3f60096e952fa4dbb3d377dea3ab
  P1
  
  diff -r ebe9914c0d1c -r 462012cf340c f
  --- a/f	Thu Jan 01 00:00:01 1970 +0000
  +++ b/f	Thu Jan 01 00:00:02 1970 +0000
  @@ -1,1 +1,1 @@
  -mq1r1
  +mq1r1mq2

Adding one git-style patch and one normal:

  $ hg qpop -a
  popping f2.patch
  popping f.patch
  patch queue now empty

  $ rm -fr .hg/patches
  $ hg qinit -c

  $ hg up -q 0

  $ hg qnew --git f_git.patch -d '3 0'
  $ echo mq1 > p
  $ hg add p
  $ hg qref --git -m 'P0 (git)'

  $ hg qnew f.patch -d '4 0'
  $ echo mq2 > p
  $ hg qref -m P1
  $ hg qci -m 'save patch state'

  $ hg qseries -s
  f_git.patch: P0 (git)
  f.patch: P1

  $ hg -R .hg/patches manifest
  .hgignore
  f.patch
  f_git.patch
  series

  $ cat .hg/patches/f_git.patch
  Date: 3 0
  
  P0 (git)
  
  diff --git a/p b/p
  new file mode 100644
  --- /dev/null
  +++ b/p
  @@ -0,0 +1,1 @@
  +mq1

  $ cat .hg/patches/f.patch
  Date: 4 0
  
  P1
  
  diff -r ???????????? p (glob)
  --- a/p	??? ??? ?? ??:??:?? ???? ????? (glob)
  +++ b/p	??? ??? ?? ??:??:?? ???? ????? (glob)
  @@ -1,1 +1,1 @@
  -mq1
  +mq2


Rebase the applied mq patches:

  $ hg rebase -s 2 -d 1
  rebasing 2:0c587ffcb480 f_git.patch qbase "P0 (git)"
  rebasing 3:c7f18665e4bc f.patch qtip tip "P1"
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/0c587ffcb480-0ea5695f-rebase.hg

  $ hg qci -m 'save patch state'

  $ hg qseries -s
  f_git.patch: P0 (git)
  f.patch: P1

  $ hg -R .hg/patches manifest
  .hgignore
  f.patch
  f_git.patch
  series

  $ cat .hg/patches/f_git.patch
  # HG changeset patch
  # User test
  # Date 3 0
  #      Thu Jan 01 00:00:03 1970 +0000
  # Node ID 12d9f6a3bbe560dee50c7c454d434add7fb8e837
  # Parent  bac9ed9960d8992bcad75864a879fa76cadaf1b0
  P0 (git)
  
  diff --git a/p b/p
  new file mode 100644
  --- /dev/null
  +++ b/p
  @@ -0,0 +1,1 @@
  +mq1

  $ cat .hg/patches/f.patch
  # HG changeset patch
  # User test
  # Date 4 0
  #      Thu Jan 01 00:00:04 1970 +0000
  # Node ID c77a2661c64c60d82f63c4f7aefd95b3a948a557
  # Parent  12d9f6a3bbe560dee50c7c454d434add7fb8e837
  P1
  
  diff -r 12d9f6a3bbe5 -r c77a2661c64c p
  --- a/p	Thu Jan 01 00:00:03 1970 +0000
  +++ b/p	Thu Jan 01 00:00:04 1970 +0000
  @@ -1,1 +1,1 @@
  -mq1
  +mq2

  $ cd ..

Rebase with guards

  $ hg init foo
  $ cd foo
  $ echo a > a
  $ hg ci -Am a
  adding a

Create mq repo with guarded patches foo and bar and empty patch:

  $ hg qinit
  $ echo guarded > guarded
  $ hg add guarded
  $ hg qnew guarded
  $ hg qnew empty-important -m 'important commit message' -d '1 0'
  $ echo bar > bar
  $ hg add bar
  $ hg qnew bar -d '2 0'
  $ echo foo > foo
  $ hg add foo
  $ hg qnew foo
  $ hg qpop -a
  popping foo
  popping bar
  popping empty-important
  popping guarded
  patch queue now empty
  $ hg qguard guarded +guarded
  $ hg qguard bar +baz
  $ hg qguard foo +baz
  $ hg qselect baz
  number of unguarded, unapplied patches has changed from 1 to 3
  $ hg qpush bar
  applying empty-important
  patch empty-important is empty
  applying bar
  now at: bar

  $ hg qguard -l
  guarded: +guarded
  empty-important: unguarded
  bar: +baz
  foo: +baz

  $ hg tglog
  @  2: 4f44b861d38c 'imported patch bar' tags: bar qtip tip
  |
  o  1: 0aaf4c3af7eb 'important commit message' tags: empty-important qbase
  |
  o  0: cb9a9f314b8b 'a' tags: qparent
  
Create new head to rebase bar onto:

  $ hg up -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo b > b
  $ hg add b
  $ hg ci -m b
  created new head
  $ hg up -C 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a >> a
  $ hg qref

  $ hg tglog
  @  3: d526d4536ed6 '[mq]: bar' tags: bar qtip tip
  |
  | o  2: d2ae7f538514 'b' tags:
  | |
  o |  1: 0aaf4c3af7eb 'important commit message' tags: empty-important qbase
  |/
  o  0: cb9a9f314b8b 'a' tags: qparent
  

Rebase bar (make sure series order is preserved and empty-important also is
removed from the series):

  $ hg qseries
  guarded
  empty-important
  bar
  foo
  $ [ -f .hg/patches/empty-important ]
  $ hg -q rebase -d 2
  note: not rebasing 1:0aaf4c3af7eb empty-important qbase "important commit message", its destination already has all its changes
  $ hg qseries
  guarded
  bar
  foo
  $ [ -f .hg/patches/empty-important ]
  [1]

  $ hg qguard -l
  guarded: +guarded
  bar: +baz
  foo: +baz

  $ hg tglog
  @  2: 477d948bb2af '[mq]: bar' tags: bar qbase qtip tip
  |
  o  1: d2ae7f538514 'b' tags: qparent
  |
  o  0: cb9a9f314b8b 'a' tags:
  
  $ cd ..