view tests/test-mq-qpush-exact.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

make a test repository that looks like this:

o    2:28bc7b1afd6a
|
| @  1:d7fe2034f71b
|/
o    0/62ecad8b70e5

  $ hg init r0
  $ cd r0
  $ touch f0
  $ hg ci -m0 -Aq
  $ touch f1
  $ hg ci -m1 -Aq

  $ hg update 0 -q
  $ touch f2
  $ hg ci -m2 -Aq
  $ hg update 1 -q

make some patches with a parent: 1:d7fe2034f71b -> p0 -> p1

  $ echo cp0 >> fp0
  $ hg add fp0
  $ hg ci -m p0 -d "0 0"
  $ hg export -r. > p0
  $ hg strip -qn .
  $ hg qimport p0
  adding p0 to series file
  $ hg qpush
  applying p0
  now at: p0

  $ echo cp1 >> fp1
  $ hg add fp1
  $ hg qnew p1 -d "0 0"

  $ hg qpop -aq
  patch queue now empty

qpush --exact when at the parent

  $ hg update 1 -q
  $ hg qpush -e
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg qpush -e p0
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg qpush -e p1
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

qpush --exact when at another rev

  $ hg update 0 -q
  $ hg qpush -e
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 0 -q
  $ hg qpush -e p0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 0 -q
  $ hg qpush -e p1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 0 -q
  $ hg qpush -ea
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

qpush --exact while crossing branches

  $ hg update 2 -q
  $ hg qpush -e
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 2 -q
  $ hg qpush -e p0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 2 -q
  $ hg qpush -e p1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 2 -q
  $ hg qpush -ea
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

qpush --exact --force with changes to an unpatched file

  $ hg update 1 -q
  $ echo c0 >> f0
  $ hg qpush -e
  abort: local changes found
  [255]
  $ hg qpush -ef
  applying p0
  now at: p0
  $ cat f0
  c0
  $ rm f0
  $ touch f0
  $ hg qpop -aq
  patch queue now empty

  $ hg update 1 -q
  $ echo c0 >> f0
  $ hg qpush -e p1
  abort: local changes found
  [255]
  $ hg qpush -e p1 -f
  applying p0
  applying p1
  now at: p1
  $ cat f0
  c0
  $ rm f0
  $ touch f0
  $ hg qpop -aq
  patch queue now empty

qpush --exact --force with changes to a patched file

  $ hg update 1 -q
  $ echo cp0-bad >> fp0
  $ hg add fp0
  $ hg qpush -e
  abort: local changes found
  [255]
  $ hg qpush -ef
  applying p0
  file fp0 already exists
  1 out of 1 hunks FAILED -- saving rejects to file fp0.rej
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh p0
  [2]
  $ cat fp0
  cp0-bad
  $ cat fp0.rej
  --- fp0
  +++ fp0
  @@ -0,0 +1,1 @@
  +cp0
  $ hg qpop -aqf
  patch queue now empty
  $ rm fp0
  $ rm fp0.rej

  $ hg update 1 -q
  $ echo cp1-bad >> fp1
  $ hg add fp1
  $ hg qpush -e p1
  abort: local changes found
  [255]
  $ hg qpush -e p1 -f
  applying p0
  applying p1
  file fp1 already exists
  1 out of 1 hunks FAILED -- saving rejects to file fp1.rej
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh p1
  [2]
  $ cat fp1
  cp1-bad
  $ cat fp1.rej
  --- fp1
  +++ fp1
  @@ -0,0 +1,1 @@
  +cp1
  $ hg qpop -aqf
  patch queue now empty
  $ hg forget fp1
  $ rm fp1
  $ rm fp1.rej

qpush --exact when already at a patch

  $ hg update 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg qpush -e p0
  applying p0
  now at: p0
  $ hg qpush -e p1
  abort: cannot push --exact with applied patches
  [255]
  $ hg qpop -aq
  patch queue now empty

qpush --exact --move should fail

  $ hg qpush -e --move p1
  abort: cannot use --exact and --move together
  [255]

qpush --exact a patch without a parent recorded

  $ hg qpush -q
  now at: p0
  $ grep -v '# Parent' .hg/patches/p0 > p0.new
  $ mv p0.new .hg/patches/p0
  $ hg qpop -aq
  patch queue now empty
  $ hg qpush -e
  abort: p0 does not have a parent recorded
  [255]
  $ hg qpush -e p0
  abort: p0 does not have a parent recorded
  [255]
  $ hg qpush -e p1
  abort: p0 does not have a parent recorded
  [255]
  $ hg qpush -ea
  abort: p0 does not have a parent recorded
  [255]

  $ cd ..