tests/test-rebase-interruptions.t

bundle2: implement consume() API on unbundlepart

We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.

A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.

In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.

The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:

! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)

Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.

Differential Revision: https://phab.mercurial-scm.org/D1388

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


  $ hg init a
  $ cd a

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

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

  $ echo C >> A
  $ hg ci -m C

  $ hg up -q -C 0

  $ echo D >> A
  $ hg ci -m D
  created new head

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

  $ cd ..


Changes during an interruption - continue:

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

  $ hg tglog
  @  4: 'E'
  |
  o  3: 'D'
  |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
Rebasing B onto E:

  $ hg rebase -s 1 -d 4
  rebasing 1:27547f69f254 "B"
  rebasing 2:965c486023db "C"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Force a commit on C during the interruption:

  $ hg up -q -C 2 --config 'extensions.rebase=!'

  $ echo 'Extra' > Extra
  $ hg add Extra
  $ hg ci -m 'Extra' --config 'extensions.rebase=!'

Force this commit onto secret phase

  $ hg phase --force --secret 6

  $ hg tglogp
  @  6:secret 'Extra'
  |
  | o  5:draft 'B'
  | |
  | o  4:draft 'E'
  | |
  | o  3:draft 'D'
  | |
  o |  2:draft 'C'
  | |
  o |  1:draft 'B'
  |/
  o  0:draft 'A'
  
Resume the rebasing:

  $ hg rebase --continue
  already rebased 1:27547f69f254 "B" as 45396c49d53b
  rebasing 2:965c486023db "C"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Solve the conflict and go on:

  $ echo 'conflict solved' > A
  $ rm A.orig
  $ hg resolve -m A
  (no more unresolved files)
  continue: hg rebase --continue

  $ hg rebase --continue
  already rebased 1:27547f69f254 "B" as 45396c49d53b
  rebasing 2:965c486023db "C"
  warning: orphaned descendants detected, not stripping 27547f69f254, 965c486023db

  $ hg tglogp
  o  7:draft 'C'
  |
  | o  6:secret 'Extra'
  | |
  o |  5:draft 'B'
  | |
  @ |  4:draft 'E'
  | |
  o |  3:draft 'D'
  | |
  | o  2:draft 'C'
  | |
  | o  1:draft 'B'
  |/
  o  0:draft 'A'
  
  $ cd ..


Changes during an interruption - abort:

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

  $ hg tglog
  @  4: 'E'
  |
  o  3: 'D'
  |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
Rebasing B onto E:

  $ hg rebase -s 1 -d 4
  rebasing 1:27547f69f254 "B"
  rebasing 2:965c486023db "C"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Force a commit on B' during the interruption:

  $ hg up -q -C 5 --config 'extensions.rebase=!'

  $ echo 'Extra' > Extra
  $ hg add Extra
  $ hg ci -m 'Extra' --config 'extensions.rebase=!'

  $ hg tglog
  @  6: 'Extra'
  |
  o  5: 'B'
  |
  o  4: 'E'
  |
  o  3: 'D'
  |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
Abort the rebasing:

  $ hg rebase --abort
  warning: new changesets detected on destination branch, can't strip
  rebase aborted

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

Changes during an interruption - abort (again):

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

  $ hg tglogp
  @  4:draft 'E'
  |
  o  3:draft 'D'
  |
  | o  2:draft 'C'
  | |
  | o  1:draft 'B'
  |/
  o  0:draft 'A'
  
Rebasing B onto E:

  $ hg rebase -s 1 -d 4
  rebasing 1:27547f69f254 "B"
  rebasing 2:965c486023db "C"
  merging A
  warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

Change phase on B and B'

  $ hg up -q -C 5 --config 'extensions.rebase=!'
  $ hg phase --public 1
  $ hg phase --public 5
  $ hg phase --secret -f 2

  $ hg tglogp
  @  5:public 'B'
  |
  o  4:public 'E'
  |
  o  3:public 'D'
  |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
Abort the rebasing:

  $ hg rebase --abort
  warning: can't clean up public changesets 45396c49d53b
  rebase aborted

  $ hg tglogp
  @  5:public 'B'
  |
  o  4:public 'E'
  |
  o  3:public 'D'
  |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
Test rebase interrupted by hooks

  $ hg up 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo F > F
  $ hg add F
  $ hg ci -m F

  $ cd ..

(precommit version)

  $ cp -R a3 hook-precommit
  $ cd hook-precommit
  $ hg rebase --source 2 --dest 5 --tool internal:other --config 'hooks.precommit=hg status | grep "M A"'
  rebasing 2:965c486023db "C"
  M A
  rebasing 6:a0b2430ebfb8 "F" (tip)
  abort: precommit hook exited with status 1
  [255]
  $ hg tglogp
  @  7:secret 'C'
  |
  | @  6:secret 'F'
  | |
  o |  5:public 'B'
  | |
  o |  4:public 'E'
  | |
  o |  3:public 'D'
  | |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ hg rebase --continue
  already rebased 2:965c486023db "C" as 401ccec5e39f
  rebasing 6:a0b2430ebfb8 "F"
  saved backup bundle to $TESTTMP/hook-precommit/.hg/strip-backup/965c486023db-aa6250e7-rebase.hg (glob)
  $ hg tglogp
  @  6:secret 'F'
  |
  o  5:secret 'C'
  |
  o  4:public 'B'
  |
  o  3:public 'E'
  |
  o  2:public 'D'
  |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ cd ..

(pretxncommit version)

  $ cp -R a3 hook-pretxncommit
  $ cd hook-pretxncommit
#if windows
  $ NODE="%HG_NODE%"
#else
  $ NODE="\$HG_NODE"
#endif
  $ hg rebase --source 2 --dest 5 --tool internal:other --config "hooks.pretxncommit=hg log -r $NODE | grep \"summary:     C\""
  rebasing 2:965c486023db "C"
  summary:     C
  rebasing 6:a0b2430ebfb8 "F" (tip)
  transaction abort!
  rollback completed
  abort: pretxncommit hook exited with status 1
  [255]
  $ hg tglogp
  @  7:secret 'C'
  |
  | @  6:secret 'F'
  | |
  o |  5:public 'B'
  | |
  o |  4:public 'E'
  | |
  o |  3:public 'D'
  | |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ hg rebase --continue
  already rebased 2:965c486023db "C" as 401ccec5e39f
  rebasing 6:a0b2430ebfb8 "F"
  saved backup bundle to $TESTTMP/hook-pretxncommit/.hg/strip-backup/965c486023db-aa6250e7-rebase.hg (glob)
  $ hg tglogp
  @  6:secret 'F'
  |
  o  5:secret 'C'
  |
  o  4:public 'B'
  |
  o  3:public 'E'
  |
  o  2:public 'D'
  |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ cd ..

(pretxnclose version)

  $ cp -R a3 hook-pretxnclose
  $ cd hook-pretxnclose
  $ hg rebase --source 2 --dest 5 --tool internal:other --config 'hooks.pretxnclose=hg log -r tip | grep "summary:     C"'
  rebasing 2:965c486023db "C"
  summary:     C
  rebasing 6:a0b2430ebfb8 "F" (tip)
  transaction abort!
  rollback completed
  abort: pretxnclose hook exited with status 1
  [255]
  $ hg tglogp
  @  7:secret 'C'
  |
  | @  6:secret 'F'
  | |
  o |  5:public 'B'
  | |
  o |  4:public 'E'
  | |
  o |  3:public 'D'
  | |
  | o  2:secret 'C'
  | |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ hg rebase --continue
  already rebased 2:965c486023db "C" as 401ccec5e39f
  rebasing 6:a0b2430ebfb8 "F"
  saved backup bundle to $TESTTMP/hook-pretxnclose/.hg/strip-backup/965c486023db-aa6250e7-rebase.hg (glob)
  $ hg tglogp
  @  6:secret 'F'
  |
  o  5:secret 'C'
  |
  o  4:public 'B'
  |
  o  3:public 'E'
  |
  o  2:public 'D'
  |
  | o  1:public 'B'
  |/
  o  0:public 'A'
  
  $ cd ..

Make sure merge state is cleaned up after a no-op rebase merge (issue5494)
  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg commit -qAm base
  $ echo b >> a
  $ hg commit -qm b
  $ hg up '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo c >> a
  $ hg commit -qm c
  $ hg rebase -s 1 -d 2 --noninteractive
  rebasing 1:fdaca8533b86 "b"
  merging a
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ echo a > a
  $ echo c >> a
  $ hg resolve --mark a
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 1:fdaca8533b86 "b"
  note: rebase of 1:fdaca8533b86 created no changes to commit
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/fdaca8533b86-7fd70513-rebase.hg (glob)
  $ hg resolve --list
  $ test -f .hg/merge
  [1]