tests/test-contrib.t

log: speed up single file log with hidden revs (issue4747)

On repos with lots of heads, the filelog() code could spend several
minutes decompressing manifests. This change instead tries to
efficiently scan the changelog for candidates and decompress as few
manifests as possible. This is a regression introduced in 3.3 by the
linkrev adjustment code. Prior to that, filelog was nearly instant.

For the repo in the bug report, this improves time of a simple log
command from ~3 minutes to ~.5 seconds, a 360x speedup.

For the main Mercurial repo, a log of commands.py slows down from
1.14s to 1.45s, a 27% slowdown. This is still faster than the file()
revset, which takes 2.1 seconds.

Set vars:

  $ CONTRIBDIR="$TESTDIR/../contrib"

Prepare repo-a:

  $ hg init repo-a
  $ cd repo-a

  $ echo this is file a > a
  $ hg add a
  $ hg commit -m first

  $ echo adding to file a >> a
  $ hg commit -m second

  $ echo adding more to file a >> a
  $ hg commit -m third

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 3 changesets, 3 total revisions

Dumping revlog of file a to stdout:

  $ python "$CONTRIBDIR/dumprevlog" .hg/store/data/a.i
  file: .hg/store/data/a.i
  node: 183d2312b35066fb6b3b449b84efc370d50993d0
  linkrev: 0
  parents: 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000
  length: 15
  -start-
  this is file a
  
  -end-
  node: b1047953b6e6b633c0d8197eaa5116fbdfd3095b
  linkrev: 1
  parents: 183d2312b35066fb6b3b449b84efc370d50993d0 0000000000000000000000000000000000000000
  length: 32
  -start-
  this is file a
  adding to file a
  
  -end-
  node: 8c4fd1f7129b8cdec6c7f58bf48fb5237a4030c1
  linkrev: 2
  parents: b1047953b6e6b633c0d8197eaa5116fbdfd3095b 0000000000000000000000000000000000000000
  length: 54
  -start-
  this is file a
  adding to file a
  adding more to file a
  
  -end-

Dump all revlogs to file repo.dump:

  $ find .hg/store -name "*.i" | sort | xargs python "$CONTRIBDIR/dumprevlog" > ../repo.dump
  $ cd ..

Undumping into repo-b:

  $ hg init repo-b
  $ cd repo-b
  $ python "$CONTRIBDIR/undumprevlog" < ../repo.dump
  .hg/store/00changelog.i
  .hg/store/00manifest.i
  .hg/store/data/a.i
  $ cd ..

Rebuild fncache with clone --pull:

  $ hg clone --pull -U repo-b repo-c
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 1 files

Verify:

  $ hg -R repo-c verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 3 changesets, 3 total revisions

Compare repos:

  $ hg -R repo-c incoming repo-a
  comparing with repo-a
  searching for changes
  no changes found
  [1]

  $ hg -R repo-a incoming repo-c
  comparing with repo-c
  searching for changes
  no changes found
  [1]

Test simplemerge command:

  $ cp "$CONTRIBDIR/simplemerge" .
  $ echo base > base
  $ echo local > local
  $ cat base >> local
  $ cp local orig
  $ cat base > other
  $ echo other >> other

changing local directly

  $ python simplemerge local base other && echo "merge succeeded"
  merge succeeded
  $ cat local
  local
  base
  other
  $ cp orig local

printing to stdout

  $ python simplemerge -p local base other
  local
  base
  other

local:

  $ cat local
  local
  base

conflicts

  $ cp base conflict-local
  $ cp other conflict-other
  $ echo not other >> conflict-local
  $ echo end >> conflict-local
  $ echo end >> conflict-other

  $ python simplemerge -p conflict-local base conflict-other
  base
  <<<<<<< conflict-local
  not other
  end
  =======
  other
  end
  >>>>>>> conflict-other
  [1]

1 label

  $ python simplemerge -p -L foo conflict-local base conflict-other
  base
  <<<<<<< foo
  not other
  end
  =======
  other
  end
  >>>>>>> conflict-other
  [1]

2 labels

  $ python simplemerge -p -L foo -L bar conflict-local base conflict-other
  base
  <<<<<<< foo
  not other
  end
  =======
  other
  end
  >>>>>>> bar
  [1]

3 labels

  $ python simplemerge -p -L foo -L bar -L base conflict-local base conflict-other
  base
  <<<<<<< foo
  not other
  end
  ||||||| base
  =======
  other
  end
  >>>>>>> bar
  [1]

too many labels

  $ python simplemerge -p -L foo -L bar -L baz -L buz conflict-local base conflict-other
  abort: can only specify three labels.
  [255]

binary file

  $ $PYTHON -c "f = file('binary-local', 'w'); f.write('\x00'); f.close()"
  $ cat orig >> binary-local
  $ python simplemerge -p binary-local base other
  warning: binary-local looks like a binary file.
  [1]

binary file --text

  $ python simplemerge -a -p binary-local base other 2>&1
  warning: binary-local looks like a binary file.
  \x00local (esc)
  base
  other

help

  $ python simplemerge --help
  simplemerge [OPTS] LOCAL BASE OTHER
  
      Simple three-way file merge utility with a minimal feature set.
  
      Apply to LOCAL the changes necessary to go from BASE to OTHER.
  
      By default, LOCAL is overwritten with the results of this operation.
  
  options:
   -L --label       labels to use on conflict markers
   -a --text        treat all files as text
   -p --print       print results instead of overwriting LOCAL
      --no-minimal  no effect (DEPRECATED)
   -h --help        display help and exit
   -q --quiet       suppress output

wrong number of arguments

  $ python simplemerge
  simplemerge: wrong number of arguments
  simplemerge [OPTS] LOCAL BASE OTHER
  
      Simple three-way file merge utility with a minimal feature set.
  
      Apply to LOCAL the changes necessary to go from BASE to OTHER.
  
      By default, LOCAL is overwritten with the results of this operation.
  
  options:
   -L --label       labels to use on conflict markers
   -a --text        treat all files as text
   -p --print       print results instead of overwriting LOCAL
      --no-minimal  no effect (DEPRECATED)
   -h --help        display help and exit
   -q --quiet       suppress output
  [1]

bad option

  $ python simplemerge --foo -p local base other
  simplemerge: option --foo not recognized
  simplemerge [OPTS] LOCAL BASE OTHER
  
      Simple three-way file merge utility with a minimal feature set.
  
      Apply to LOCAL the changes necessary to go from BASE to OTHER.
  
      By default, LOCAL is overwritten with the results of this operation.
  
  options:
   -L --label       labels to use on conflict markers
   -a --text        treat all files as text
   -p --print       print results instead of overwriting LOCAL
      --no-minimal  no effect (DEPRECATED)
   -h --help        display help and exit
   -q --quiet       suppress output
  [1]