view tests/test-mq-qdelete.t @ 33289:abd7dedbaa36

sparse: vendor Facebook-developed extension

Facebook has developed an extension to enable "sparse" checkouts -
a working directory with a subset of files. This feature is a critical
component in enabling repositories to scale to infinite number of
files while retaining reasonable performance. It's worth noting
that sparse checkout is only one possible solution to this problem:
another is virtual filesystems that realize files on first access.
But given that virtual filesystems may not be accessible to all
users, sparse checkout is necessary as a fallback.

Per mailing list discussion at
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095868.html
we want to add sparse checkout to the Mercurial distribution via
roughly the following mechanism:

1. Vendor extension as-is with minimal modifications (this patch)
2. Refactor extension so it is more clearly experimental and inline
   with Mercurial practices
3. Move code from extension into core where possible
4. Drop experimental labeling and/or move feature into core
   after sign-off from narrow clone feature owners

This commit essentially copies the sparse extension and tests
from revision 71e0a2aeca92a4078fe1b8c76e32c88ff1929737 of the
https://bitbucket.org/facebook/hg-experimental repository.

A list of modifications made as part of vendoring is as follows:

* "EXPERIMENTAL" added to module docstring
* Imports were changed to match Mercurial style conventions
* "testedwith" value was updated to core Mercurial special value and
  comment boilerplate was inserted
* A "clone_sparse" function was renamed to "clonesparse" to appease
  the style checker
* Paths to the sparse extension in tests reflect built-in location
* test-sparse-extensions.t was renamed to test-sparse-fsmonitor.t
  and references to "simplecache" were removed. The test always skips
  because it isn't trivial to run it given the way we currently run
  fsmonitor tests
* A double empty line was removed from test-sparse-profiles.t

There are aspects of the added code that are obviously not ideal.
The goal is to make a minimal number of modifications as part of
the vendoring to make it easier to track changes from the original
implementation. Refactoring will occur in subsequent patches.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init a
  $ cd a

  $ echo 'base' > base
  $ hg ci -Ambase -d '1 0'
  adding base

  $ hg qnew -d '1 0' pa
  $ hg qnew -d '1 0' pb
  $ hg qnew -d '1 0' pc

  $ hg qdel
  abort: qdelete requires at least one revision or patch name
  [255]

  $ hg qdel pc
  abort: cannot delete applied patch pc
  [255]

  $ hg qpop
  popping pc
  now at: pb

Delete the same patch twice in one command (issue2427)

  $ hg qdel pc pc

  $ hg qseries
  pa
  pb

  $ ls .hg/patches
  pa
  pb
  series
  status

  $ hg qpop
  popping pb
  now at: pa

  $ hg qdel -k 1

  $ ls .hg/patches
  pa
  pb
  series
  status

  $ hg qdel -r pa
  patch pa finalized without changeset message

  $ hg qapplied

  $ hg log --template '{rev} {desc}\n'
  1 [mq]: pa
  0 base

  $ hg qnew pd
  $ hg qnew pe
  $ hg qnew pf

  $ hg qdel -r pe
  abort: cannot delete revision 3 above applied patches
  [255]

  $ hg qdel -r qbase:pe
  patch pd finalized without changeset message
  patch pe finalized without changeset message

  $ hg qapplied
  pf

  $ hg log --template '{rev} {desc}\n'
  4 [mq]: pf
  3 [mq]: pe
  2 [mq]: pd
  1 [mq]: pa
  0 base

  $ cd ..

  $ hg init b
  $ cd b

  $ echo 'base' > base
  $ hg ci -Ambase -d '1 0'
  adding base

  $ hg qfinish
  abort: no revisions specified
  [255]

  $ hg qfinish -a
  no patches applied

  $ hg qnew -d '1 0' pa
  $ hg qnew -d '1 0' pb
  $ hg qnew pc # XXX fails to apply by /usr/bin/patch if we put a date

  $ hg qfinish 0
  abort: revision 0 is not managed
  [255]

  $ hg qfinish pb
  abort: cannot delete revision 2 above applied patches
  [255]

  $ hg qpop
  popping pc
  now at: pb

  $ hg qfinish -a pc
  abort: unknown revision 'pc'!
  [255]

  $ hg qpush
  applying pc
  patch pc is empty
  now at: pc

  $ hg qfinish qbase:pb
  patch pa finalized without changeset message
  patch pb finalized without changeset message

  $ hg qapplied
  pc

  $ hg log --template '{rev} {desc}\n'
  3 imported patch pc
  2 [mq]: pb
  1 [mq]: pa
  0 base

  $ hg qfinish -a pc
  patch pc finalized without changeset message

  $ hg qapplied

  $ hg log --template '{rev} {desc}\n'
  3 imported patch pc
  2 [mq]: pb
  1 [mq]: pa
  0 base

  $ ls .hg/patches
  series
  status

qdel -k X && hg qimp -e X used to trigger spurious output with versioned queues

  $ hg init --mq
  $ hg qimport -r 3
  $ hg qpop
  popping imported_patch_pc
  patch queue now empty
  $ hg qdel -k imported_patch_pc
  $ hg qimp -e imported_patch_pc
  adding imported_patch_pc to series file
  $ hg qfinish -a
  no patches applied


resilience to inconsistency: qfinish -a with applied patches not in series

  $ hg qser
  imported_patch_pc
  $ hg qapplied
  $ hg qpush
  applying imported_patch_pc
  patch imported_patch_pc is empty
  now at: imported_patch_pc
  $ echo next >>  base
  $ hg qrefresh -d '1 0'
  $ echo > .hg/patches/series # remove 3.diff from series to confuse mq
  $ hg qfinish -a
  revision 47dfa8501675 refers to unknown patches: imported_patch_pc

more complex state 'both known and unknown patches

  $ echo hip >>  base
  $ hg qnew -f -d '1 0' -m 4 4.diff
  $ echo hop >>  base
  $ hg qnew -f -d '1 0' -m 5 5.diff
  $ echo > .hg/patches/series # remove 4.diff and 5.diff from series to confuse mq
  $ echo hup >>  base
  $ hg qnew -f -d '1 0' -m 6 6.diff
  $ echo pup > base
  $ hg qfinish -a
  warning: uncommitted changes in the working directory
  revision 2b1c98802260 refers to unknown patches: 5.diff
  revision 33a6861311c0 refers to unknown patches: 4.diff

  $ cd ..