view tests/test-rebase-collapse.t @ 34824:e2ad93bcc084

revlog: introduce an experimental flag to slice chunks reads when too sparse

Delta chains can become quite sparse if there is a lot of unrelated data between
relevant pieces. Right now, revlog always reads all the necessary data for the
delta chain in one single read. This can lead to a lot of unrelated data to be
read (see issue5482 for more details).
One can use the `experimental.maxdeltachainspan` option with a large value
(or -1) to easily produce a very sparse delta chain.

This change introduces the ability to slice the chunks retrieval into  multiple
reads, skipping large sections of unrelated data. Preliminary testing shows
interesting results. For example the peak memory consumption to read a manifest
on a large repository is reduced from 600MB to 250MB (200MB without
maxdeltachainspan). However, the slicing itself and the multiple reads can have
an negative impact on performance. This is why the new feature is hidden behind
an experimental flag.

Future changesets will add various parameters to control the slicing heuristics.
We hope to experiment a wide variety of repositories during 4.4 and hopefully
turn the feature on by default in 4.5.
As a first try, the algorithm itself is prone to deep changes. However, we wish
to define APIs and have a baseline to work on.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > mq=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: '{desc}' {branches}\n"
  > tglogp = log -G --template "{rev}:{phase} '{desc}' {branches}\n"
  > EOF

Create repo a:

  $ hg init a
  $ cd a
  $ hg unbundle "$TESTDIR/bundles/rebase.hg"
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  (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 tglog
  @  7: 'H'
  |
  | o  6: 'G'
  |/|
  o |  5: 'F'
  | |
  | o  4: 'E'
  |/
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebasing B onto H and collapsing changesets with different phases:


  $ hg clone -q -u 3 a a1
  $ cd a1

  $ hg phase --force --secret 3

  $ cat > $TESTTMP/editor.sh <<EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > echo "edited manually" >> \$1
  > EOF
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg rebase --collapse --keepbranches -e --dest 7
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  ==== before editing
  Collapsed revision
  * B
  * C
  * D
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: Nicolas Dumazet <[e-mail]>
  HG: branch 'default'
  HG: added B
  HG: added C
  HG: added D
  ====
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/42ccdea3bb16-3cb021d3-rebase.hg (glob)

  $ hg tglogp
  @  5:secret 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |
  |
  |  edited manually'
  o  4:draft 'H'
  |
  | o  3:draft 'G'
  |/|
  o |  2:draft 'F'
  | |
  | o  1:draft 'E'
  |/
  o  0:draft 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  F
  H

  $ cd ..


Rebasing E onto H:

  $ hg clone -q -u . a a2
  $ cd a2

  $ hg phase --force --secret 6
  $ hg rebase --source 4 --collapse --dest 7
  rebasing 4:9520eea781bc "E"
  rebasing 6:eea13746799a "G"
  saved backup bundle to $TESTTMP/a2/.hg/strip-backup/9520eea781bc-fcd8edd4-rebase.hg (glob)

  $ hg tglog
  o  6: 'Collapsed revision
  |  * E
  |  * G'
  @  5: 'H'
  |
  o  4: 'F'
  |
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  E
  F
  H

  $ cd ..

Rebasing G onto H with custom message:

  $ hg clone -q -u . a a3
  $ cd a3

  $ hg rebase --base 6 -m 'custom message'
  abort: message can only be specified with collapse
  [255]

  $ cat > $TESTTMP/checkeditform.sh <<EOF
  > env | grep HGEDITFORM
  > true
  > EOF
  $ HGEDITOR="sh $TESTTMP/checkeditform.sh" hg rebase --source 4 --collapse -m 'custom message' -e --dest 7
  rebasing 4:9520eea781bc "E"
  rebasing 6:eea13746799a "G"
  HGEDITFORM=rebase.collapse
  saved backup bundle to $TESTTMP/a3/.hg/strip-backup/9520eea781bc-fcd8edd4-rebase.hg (glob)

  $ hg tglog
  o  6: 'custom message'
  |
  @  5: 'H'
  |
  o  4: 'F'
  |
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  E
  F
  H

  $ cd ..

Create repo b:

  $ hg init b
  $ cd b

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B

  $ hg up -q 0

  $ echo C > C
  $ hg ci -Am C
  adding C
  created new head

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo D > D
  $ hg ci -Am D
  adding D

  $ hg up -q 1

  $ echo E > E
  $ hg ci -Am E
  adding E
  created new head

  $ echo F > F
  $ hg ci -Am F
  adding F

  $ hg merge
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m G

  $ hg up -q 0

  $ echo H > H
  $ hg ci -Am H
  adding H
  created new head

  $ hg tglog
  @  7: 'H'
  |
  | o    6: 'G'
  | |\
  | | o  5: 'F'
  | | |
  | | o  4: 'E'
  | | |
  | o |  3: 'D'
  | |\|
  | o |  2: 'C'
  |/ /
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase and collapse - more than one external (fail):

  $ hg clone -q -u . b b1
  $ cd b1

  $ hg rebase -s 2 --dest 7 --collapse
  abort: unable to collapse on top of 7, there is more than one external parent: 1, 5
  [255]

Rebase and collapse - E onto H:

  $ hg rebase -s 4 --dest 7 --collapse # root (4) is not a merge
  rebasing 4:8a5212ebc852 "E"
  rebasing 5:7f219660301f "F"
  rebasing 6:c772a8b2dc17 "G"
  saved backup bundle to $TESTTMP/b1/.hg/strip-backup/8a5212ebc852-75046b61-rebase.hg (glob)

  $ hg tglog
  o    5: 'Collapsed revision
  |\   * E
  | |  * F
  | |  * G'
  | @  4: 'H'
  | |
  o |    3: 'D'
  |\ \
  | o |  2: 'C'
  | |/
  o /  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  C
  D
  E
  F
  H

  $ cd ..




Test that branchheads cache is updated correctly when doing a strip in which
the parent of the ancestor node to be stripped does not become a head and also,
the parent of a node that is a child of the node stripped becomes a head (node
3). The code is now much simpler and we could just test a simpler scenario
We keep it the test this way in case new complexity is injected.

  $ hg clone -q -u . b b2
  $ cd b2

  $ hg heads --template="{rev}:{node} {branch}\n"
  7:c65502d4178782309ce0574c5ae6ee9485a9bafa default
  6:c772a8b2dc17629cec88a19d09c926c4814b12c7 default

  $ cat $TESTTMP/b2/.hg/cache/branch2-served
  c65502d4178782309ce0574c5ae6ee9485a9bafa 7
  c772a8b2dc17629cec88a19d09c926c4814b12c7 o default
  c65502d4178782309ce0574c5ae6ee9485a9bafa o default

  $ hg strip 4
  saved backup bundle to $TESTTMP/b2/.hg/strip-backup/8a5212ebc852-75046b61-backup.hg (glob)

  $ cat $TESTTMP/b2/.hg/cache/branch2-served
  c65502d4178782309ce0574c5ae6ee9485a9bafa 4
  2870ad076e541e714f3c2bc32826b5c6a6e5b040 o default
  c65502d4178782309ce0574c5ae6ee9485a9bafa o default

  $ hg heads --template="{rev}:{node} {branch}\n"
  4:c65502d4178782309ce0574c5ae6ee9485a9bafa default
  3:2870ad076e541e714f3c2bc32826b5c6a6e5b040 default

  $ cd ..






Create repo c:

  $ hg init c
  $ cd c

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B

  $ hg up -q 0

  $ echo C > C
  $ hg ci -Am C
  adding C
  created new head

  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo D > D
  $ hg ci -Am D
  adding D

  $ hg up -q 1

  $ echo E > E
  $ hg ci -Am E
  adding E
  created new head
  $ echo F > E
  $ hg ci -m 'F'

  $ echo G > G
  $ hg ci -Am G
  adding G

  $ hg merge
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg ci -m H

  $ hg up -q 0

  $ echo I > I
  $ hg ci -Am I
  adding I
  created new head

  $ hg tglog
  @  8: 'I'
  |
  | o    7: 'H'
  | |\
  | | o  6: 'G'
  | | |
  | | o  5: 'F'
  | | |
  | | o  4: 'E'
  | | |
  | o |  3: 'D'
  | |\|
  | o |  2: 'C'
  |/ /
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase and collapse - E onto I:

  $ hg clone -q -u . c c1
  $ cd c1

  $ hg rebase -s 4 --dest 8 --collapse # root (4) is not a merge
  rebasing 4:8a5212ebc852 "E"
  rebasing 5:dca5924bb570 "F"
  merging E
  rebasing 6:55a44ad28289 "G"
  rebasing 7:417d3b648079 "H"
  saved backup bundle to $TESTTMP/c1/.hg/strip-backup/8a5212ebc852-f95d0879-rebase.hg (glob)

  $ hg tglog
  o    5: 'Collapsed revision
  |\   * E
  | |  * F
  | |  * G
  | |  * H'
  | @  4: 'I'
  | |
  o |    3: 'D'
  |\ \
  | o |  2: 'C'
  | |/
  o /  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  C
  D
  E
  G
  I

  $ hg up tip -q
  $ cat E
  F

  $ cd ..


Create repo d:

  $ hg init d
  $ cd d

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B
  $ echo C > C
  $ hg ci -Am C
  adding C

  $ hg up -q 1

  $ echo D > D
  $ hg ci -Am D
  adding D
  created new head
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg ci -m E

  $ hg up -q 0

  $ echo F > F
  $ hg ci -Am F
  adding F
  created new head

  $ hg tglog
  @  5: 'F'
  |
  | o    4: 'E'
  | |\
  | | o  3: 'D'
  | | |
  | o |  2: 'C'
  | |/
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ cd ..


Rebase and collapse - B onto F:

  $ hg clone -q -u . d d1
  $ cd d1

  $ hg rebase -s 1 --collapse --dest 5
  rebasing 1:27547f69f254 "B"
  rebasing 2:f838bfaca5c7 "C"
  rebasing 3:7bbcd6078bcc "D"
  rebasing 4:0a42590ed746 "E"
  saved backup bundle to $TESTTMP/d1/.hg/strip-backup/27547f69f254-9a3f7d92-rebase.hg (glob)

  $ hg tglog
  o  2: 'Collapsed revision
  |  * B
  |  * C
  |  * D
  |  * E'
  @  1: 'F'
  |
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  F

Interactions between collapse and keepbranches
  $ cd ..
  $ hg init e
  $ cd e
  $ echo 'a' > a
  $ hg ci -Am 'A'
  adding a

  $ hg branch 'one'
  marked working directory as branch one
  (branches are permanent and global, did you want a bookmark?)
  $ echo 'b' > b
  $ hg ci -Am 'B'
  adding b

  $ hg branch 'two'
  marked working directory as branch two
  $ echo 'c' > c
  $ hg ci -Am 'C'
  adding c

  $ hg up -q 0
  $ echo 'd' > d
  $ hg ci -Am 'D'
  adding d

  $ hg tglog
  @  3: 'D'
  |
  | o  2: 'C' two
  | |
  | o  1: 'B' one
  |/
  o  0: 'A'
  
  $ hg rebase --keepbranches --collapse -s 1 -d 3
  abort: cannot collapse multiple named branches
  [255]

  $ repeatchange() {
  >   hg checkout $1
  >   hg cp d z
  >   echo blah >> z
  >   hg commit -Am "$2" --user "$3"
  > }
  $ repeatchange 3 "E" "user1"
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ repeatchange 3 "E" "user2"
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  created new head
  $ hg tglog
  @  5: 'E'
  |
  | o  4: 'E'
  |/
  o  3: 'D'
  |
  | o  2: 'C' two
  | |
  | o  1: 'B' one
  |/
  o  0: 'A'
  
  $ hg rebase -s 5 -d 4
  rebasing 5:fbfb97b1089a "E" (tip)
  note: rebase of 5:fbfb97b1089a created no changes to commit
  saved backup bundle to $TESTTMP/e/.hg/strip-backup/fbfb97b1089a-553e1d85-rebase.hg (glob)
  $ hg tglog
  @  4: 'E'
  |
  o  3: 'D'
  |
  | o  2: 'C' two
  | |
  | o  1: 'B' one
  |/
  o  0: 'A'
  
  $ hg export tip
  # HG changeset patch
  # User user1
  # Date 0 0
  #      Thu Jan 01 00:00:00 1970 +0000
  # Node ID f338eb3c2c7cc5b5915676a2376ba7ac558c5213
  # Parent  41acb9dca9eb976e84cd21fcb756b4afa5a35c09
  E
  
  diff -r 41acb9dca9eb -r f338eb3c2c7c z
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/z	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,2 @@
  +d
  +blah

  $ cd ..

Rebase, collapse and copies

  $ hg init copies
  $ cd copies
  $ hg unbundle "$TESTDIR/bundles/renames.hg"
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 11 changes to 7 files (+1 heads)
  new changesets f447d5abf5ea:338e84e2e558
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg up -q tip
  $ hg tglog
  @  3: 'move2'
  |
  o  2: 'move1'
  |
  | o  1: 'change'
  |/
  o  0: 'add'
  
  $ hg rebase --collapse -d 1
  rebasing 2:6e7340ee38c0 "move1"
  merging a and d to d
  merging b and e to e
  merging c and f to f
  rebasing 3:338e84e2e558 "move2" (tip)
  merging f and c to c
  merging e and g to g
  saved backup bundle to $TESTTMP/copies/.hg/strip-backup/6e7340ee38c0-ef8ef003-rebase.hg (glob)
  $ hg st
  $ hg st --copies --change tip
  A d
    a
  A g
    b
  R b
  $ hg up tip -q
  $ cat c
  c
  c
  $ cat d
  a
  a
  $ cat g
  b
  b
  $ hg log -r . --template "{file_copies}\n"
  d (a)g (b)

Test collapsing a middle revision in-place

  $ hg tglog
  @  2: 'Collapsed revision
  |  * move1
  |  * move2'
  o  1: 'change'
  |
  o  0: 'add'
  
  $ hg rebase --collapse -r 1 -d 0
  abort: can't remove original changesets with unrebased descendants
  (use --keep to keep original changesets)
  [255]

Test collapsing in place

  $ hg rebase --collapse -b . -d 0
  rebasing 1:1352765a01d4 "change"
  rebasing 2:64b456429f67 "Collapsed revision" (tip)
  saved backup bundle to $TESTTMP/copies/.hg/strip-backup/1352765a01d4-45a352ea-rebase.hg (glob)
  $ hg st --change tip --copies
  M a
  M c
  A d
    a
  A g
    b
  R b
  $ hg up tip -q
  $ cat a
  a
  a
  $ cat c
  c
  c
  $ cat d
  a
  a
  $ cat g
  b
  b
  $ cd ..


Test stripping a revision with another child

  $ hg init f
  $ cd f

  $ echo A > A
  $ hg ci -Am A
  adding A
  $ echo B > B
  $ hg ci -Am B
  adding B

  $ hg up -q 0

  $ echo C > C
  $ hg ci -Am C
  adding C
  created new head

  $ hg tglog
  @  2: 'C'
  |
  | o  1: 'B'
  |/
  o  0: 'A'
  


  $ hg heads --template="{rev}:{node} {branch}: {desc}\n"
  2:c5cefa58fd557f84b72b87f970135984337acbc5 default: C
  1:27547f69f25460a52fff66ad004e58da7ad3fb56 default: B

  $ hg strip 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/f/.hg/strip-backup/c5cefa58fd55-629429f4-backup.hg (glob)

  $ hg tglog
  o  1: 'B'
  |
  @  0: 'A'
  


  $ hg heads --template="{rev}:{node} {branch}: {desc}\n"
  1:27547f69f25460a52fff66ad004e58da7ad3fb56 default: B

  $ cd ..

Test collapsing changes that add then remove a file

  $ hg init collapseaddremove
  $ cd collapseaddremove

  $ touch base
  $ hg commit -Am base
  adding base
  $ touch a
  $ hg commit -Am a
  adding a
  $ hg rm a
  $ touch b
  $ hg commit -Am b
  adding b
  $ hg book foo
  $ hg rebase -d 0 -r "1::2" --collapse -m collapsed
  rebasing 1:6d8d9f24eec3 "a"
  rebasing 2:1cc73eca5ecc "b" (foo tip)
  saved backup bundle to $TESTTMP/collapseaddremove/.hg/strip-backup/6d8d9f24eec3-77d3b6e2-rebase.hg (glob)
  $ hg log -G --template "{rev}: '{desc}' {bookmarks}"
  @  1: 'collapsed' foo
  |
  o  0: 'base'
  
  $ hg manifest --rev tip
  b
  base

  $ cd ..

Test that rebase --collapse will remember message after
running into merge conflict and invoking rebase --continue.

  $ hg init collapse_remember_message
  $ cd collapse_remember_message
  $ touch a
  $ hg add a
  $ hg commit -m "a"
  $ echo "a-default" > a
  $ hg commit -m "a-default"
  $ hg update -r 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch dev
  marked working directory as branch dev
  (branches are permanent and global, did you want a bookmark?)
  $ echo "a-dev" > a
  $ hg commit -m "a-dev"
  $ hg rebase --collapse -m "a-default-dev" -d 1
  rebasing 2:b8d8db2b242d "a-dev" (tip)
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ rm a.orig
  $ hg resolve --mark a
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 2:b8d8db2b242d "a-dev" (tip)
  saved backup bundle to $TESTTMP/collapse_remember_message/.hg/strip-backup/b8d8db2b242d-f474c19a-rebase.hg (glob)
  $ hg log
  changeset:   2:45ba1d1a8665
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a-default-dev
  
  changeset:   1:3c8db56a44bc
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a-default
  
  changeset:   0:3903775176ed
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  $ cd ..