view tests/test-rebase-detach.t @ 30418:1156ec81f709

util: improve iterfile so it chooses code path wisely

We have performance concerns on "iterfile" as it is 4X slower on normal
files. While modern systems have the nice property that reading a "fast"
(on-disk) file cannot be interrupted and should be made use of.

This patch dumps the related knowledge in comments. And "iterfile" chooses
code paths wisely:

  1. If it's CPython 3, or PyPY, use the fast path.
  2. If fp is a normal file, use the fast path.
  3. If fp is not a normal file and CPython version >= 2.7.4, use the same
     workaround (4x slower) as before.
  4. If fp is not a normal file and CPython version < 2.7.4, use another
     workaround (2x slower but may block longer then necessary) which
     basically re-invents the buffer + readline logic in Python.

This will give us good confidence on both correctness and performance
dealing with EINTR in iterfile(fp) for all known supported Python versions.

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


  $ 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)
  (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

  $ cd ..


Rebasing D onto H detaching from C:

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

  $ 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'
  
  $ hg phase --force --secret 3
  $ hg rebase -s 3 -d 7
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a1/.hg/strip-backup/32af7686d403-6f7dface-backup.hg (glob)

  $ hg log -G --template "{rev}:{phase} '{desc}' {branches}\n"
  o  7:secret 'D'
  |
  @  6:draft 'H'
  |
  | o  5:draft 'G'
  |/|
  o |  4:draft 'F'
  | |
  | o  3:draft 'E'
  |/
  | o  2:draft 'C'
  | |
  | o  1:draft 'B'
  |/
  o  0:draft 'A'
  
  $ hg manifest --rev tip
  A
  D
  F
  H

  $ cd ..


Rebasing C onto H detaching from B:

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

  $ 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'
  
  $ hg rebase -s 2 -d 7
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a2/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)

  $ hg tglog
  o  7: 'D'
  |
  o  6: 'C'
  |
  @  5: 'H'
  |
  | o  4: 'G'
  |/|
  o |  3: 'F'
  | |
  | o  2: 'E'
  |/
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  C
  D
  F
  H

  $ cd ..


Rebasing B onto H using detach (same as not using it):

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

  $ 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'
  
  $ hg rebase -s 1 -d 7
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a3/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)

  $ hg tglog
  o  7: 'D'
  |
  o  6: 'C'
  |
  o  5: 'B'
  |
  @  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
  $ hg manifest --rev tip
  A
  B
  C
  D
  F
  H

  $ cd ..


Rebasing C onto H detaching from B and collapsing:

  $ hg clone -q -u . a a4
  $ cd a4
  $ hg phase --force --secret 3

  $ 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'
  
  $ hg rebase --collapse -s 2 -d 7
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a4/.hg/strip-backup/5fddd98957c8-f9244fa1-backup.hg (glob)

  $ hg  log -G --template "{rev}:{phase} '{desc}' {branches}\n"
  o  6:secret 'Collapsed revision
  |  * C
  |  * D'
  @  5:draft 'H'
  |
  | o  4:draft 'G'
  |/|
  o |  3:draft 'F'
  | |
  | o  2:draft 'E'
  |/
  | o  1:draft 'B'
  |/
  o  0:draft 'A'
  
  $ hg manifest --rev tip
  A
  C
  D
  F
  H

  $ cd ..

Rebasing across null as ancestor
  $ hg clone -q -U a a5

  $ cd a5

  $ echo x > x

  $ hg add x

  $ hg ci -m "extra branch"
  created new head

  $ hg tglog
  @  8: 'extra branch'
  
  o  7: 'H'
  |
  | o  6: 'G'
  |/|
  o |  5: 'F'
  | |
  | o  4: 'E'
  |/
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  
  $ hg rebase -s 1 -d tip
  rebasing 1:42ccdea3bb16 "B"
  rebasing 2:5fddd98957c8 "C"
  rebasing 3:32af7686d403 "D"
  saved backup bundle to $TESTTMP/a5/.hg/strip-backup/42ccdea3bb16-3cb021d3-backup.hg (glob)

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

  $ hg rebase -d 5 -s 7
  rebasing 7:13547172c9c0 "C"
  rebasing 8:4e27a76c371a "D" (tip)
  saved backup bundle to $TESTTMP/a5/.hg/strip-backup/13547172c9c0-35685ded-backup.hg (glob)
  $ hg tglog
  o  8: 'D'
  |
  o  7: 'C'
  |
  | o  6: 'B'
  |/
  @  5: 'extra branch'
  
  o  4: 'H'
  |
  | o  3: 'G'
  |/|
  o |  2: 'F'
  | |
  | o  1: 'E'
  |/
  o  0: 'A'
  
  $ cd ..

Verify that target is not selected as external rev (issue3085)

  $ hg clone -q -U a a6
  $ cd a6
  $ hg up -q 6

  $ echo "I" >> E
  $ hg ci -m "I"
  $ hg merge 7
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m "Merge"
  $ echo "J" >> F
  $ hg ci -m "J"

  $ hg rebase -s 8 -d 7 --collapse --config ui.merge=internal:other
  rebasing 8:9790e768172d "I"
  rebasing 9:5d7b11f5fb97 "Merge"
  rebasing 10:9427d4d5af81 "J" (tip)
  saved backup bundle to $TESTTMP/a6/.hg/strip-backup/9790e768172d-c2111e9d-backup.hg (glob)

  $ hg tglog
  @  8: 'Collapsed revision
  |  * I
  |  * Merge
  |  * J'
  o  7: 'H'
  |
  | o  6: 'G'
  |/|
  o |  5: 'F'
  | |
  | o  4: 'E'
  |/
  | o  3: 'D'
  | |
  | o  2: 'C'
  | |
  | o  1: 'B'
  |/
  o  0: 'A'
  

  $ hg log --rev tip
  changeset:   8:9472f4b1d736
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Collapsed revision
  

  $ cd ..

Ensure --continue restores a correct state (issue3046) and phase:
  $ hg clone -q a a7
  $ cd a7
  $ hg up -q 3
  $ echo 'H2' > H
  $ hg ci -A -m 'H2'
  adding H
  $ hg phase --force --secret 8
  $ hg rebase -s 8 -d 7 --config ui.merge=internal:fail
  rebasing 8:6215fafa5447 "H2" (tip)
  merging H
  warning: conflicts while merging H! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ hg resolve --all -t internal:local
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase -c
  rebasing 8:6215fafa5447 "H2" (tip)
  note: rebase of 8:6215fafa5447 created no changes to commit
  saved backup bundle to $TESTTMP/a7/.hg/strip-backup/6215fafa5447-5804ebd5-backup.hg (glob)
  $ hg  log -G --template "{rev}:{phase} '{desc}' {branches}\n"
  @  7:draft 'H'
  |
  | o  6:draft 'G'
  |/|
  o |  5:draft 'F'
  | |
  | o  4:draft 'E'
  |/
  | o  3:draft 'D'
  | |
  | o  2:draft 'C'
  | |
  | o  1:draft 'B'
  |/
  o  0:draft 'A'
  

  $ cd ..