annotate tests/test-addremove-similar.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.

  $ hg init rep; cd rep

  $ touch empty-file
  $ $PYTHON -c 'for x in range(10000): print(x)' > large-file

  $ hg addremove
  adding empty-file
  adding large-file

  $ hg commit -m A

  $ rm large-file empty-file
  $ $PYTHON -c 'for x in range(10,10000): print(x)' > another-file

  $ hg addremove -s50
  adding another-file
  removing empty-file
  removing large-file
  recording removal of large-file as rename to another-file (99% similar)

  $ hg commit -m B

comparing two empty files caused ZeroDivisionError in the past

  $ hg update -C 0
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ rm empty-file
  $ touch another-empty-file
  $ hg addremove -s50
  adding another-empty-file
  removing empty-file

  $ cd ..

  $ hg init rep2; cd rep2

  $ $PYTHON -c 'for x in range(10000): print(x)' > large-file
  $ $PYTHON -c 'for x in range(50): print(x)' > tiny-file

  $ hg addremove
  adding large-file
  adding tiny-file

  $ hg commit -m A

  $ $PYTHON -c 'for x in range(70): print(x)' > small-file
  $ rm tiny-file
  $ rm large-file

  $ hg addremove -s50
  removing large-file
  adding small-file
  removing tiny-file
  recording removal of tiny-file as rename to small-file (82% similar)

  $ hg commit -m B

should be sorted by path for stable result

  $ for i in `$PYTHON $TESTDIR/seq.py 0 9`; do
  >     cp small-file $i
  > done
  $ rm small-file
  $ hg addremove
  adding 0
  adding 1
  adding 2
  adding 3
  adding 4
  adding 5
  adding 6
  adding 7
  adding 8
  adding 9
  removing small-file
  recording removal of small-file as rename to 0 (100% similar)
  recording removal of small-file as rename to 1 (100% similar)
  recording removal of small-file as rename to 2 (100% similar)
  recording removal of small-file as rename to 3 (100% similar)
  recording removal of small-file as rename to 4 (100% similar)
  recording removal of small-file as rename to 5 (100% similar)
  recording removal of small-file as rename to 6 (100% similar)
  recording removal of small-file as rename to 7 (100% similar)
  recording removal of small-file as rename to 8 (100% similar)
  recording removal of small-file as rename to 9 (100% similar)
  $ hg commit -m '10 same files'

pick one from many identical files

  $ cp 0 a
  $ rm `$PYTHON $TESTDIR/seq.py 0 9`
  $ hg addremove
  removing 0
  removing 1
  removing 2
  removing 3
  removing 4
  removing 5
  removing 6
  removing 7
  removing 8
  removing 9
  adding a
  recording removal of 0 as rename to a (100% similar)
  $ hg revert -aq

pick one from many similar files

  $ cp 0 a
  $ for i in `$PYTHON $TESTDIR/seq.py 0 9`; do
  >     echo $i >> $i
  > done
  $ hg commit -m 'make them slightly different'
  $ rm `$PYTHON $TESTDIR/seq.py 0 9`
  $ hg addremove -s50
  removing 0
  removing 1
  removing 2
  removing 3
  removing 4
  removing 5
  removing 6
  removing 7
  removing 8
  removing 9
  adding a
  recording removal of 0 as rename to a (99% similar)
  $ hg commit -m 'always the same file should be selected'

should all fail

  $ hg addremove -s foo
  abort: similarity must be a number
  [255]
  $ hg addremove -s -1
  abort: similarity must be between 0 and 100
  [255]
  $ hg addremove -s 1e6
  abort: similarity must be between 0 and 100
  [255]

  $ cd ..

Issue1527: repeated addremove causes Abort

  $ hg init rep3; cd rep3
  $ mkdir d
  $ echo a > d/a
  $ hg add d/a
  $ hg commit -m 1

  $ mv d/a d/b
  $ hg addremove -s80
  removing d/a
  adding d/b
  recording removal of d/a as rename to d/b (100% similar) (glob)
  $ hg debugstate
  r   0          0 1970-01-01 00:00:00 d/a
  a   0         -1 unset               d/b
  copy: d/a -> d/b
  $ mv d/b c

no copies found here (since the target isn't in d

  $ hg addremove -s80 d
  removing d/b (glob)

copies here

  $ hg addremove -s80
  adding c
  recording removal of d/a as rename to c (100% similar) (glob)

  $ cd ..