sparse: remove reference to hgwatchman
This is a legacy extension. Now that the extension is in core,
we only need to support what's in core, which is fsmonitor.
sparse: expand module docstring
Clarify lack of BC guarantees. And say a bit more about the extension.
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.
contrib: widen "direct use of `python`" net again
I think I've now caught all of them.
Differential Revision: https://phab.mercurial-scm.org/D15
tests: clean up a newly-introduced instance of `python`
Differential Revision: https://phab.mercurial-scm.org/D16
tests: clean up even more direct `python` calls with $PYTHON
This time ones that are prefixed with =, ", ', or `. This appears to
be the last of them.
Differential Revision: https://phab.mercurial-scm.org/D14
contrib: widen the "don't use `python`" net a little
I'm still cleaning this up, but it's easier to do in bite-size chunks
like this than all at once. The negative lookahead avoids one false
positive category from some output related to finding Subversion
bindings.
Differential Revision: https://phab.mercurial-scm.org/D13
followlines: join merge parents line ranges in blockdescendants() (
issue5595)
In blockdescendants(), we had an assertion when line range of a merge
changeset was not consistent depending on which parent was considered for
computation. For instance, this might occur when file content (in lookup
range) is significantly different between parent branches of the merge as
demonstrated in added tests (where we almost completely rewrite the "baz" file
while also introducing similarities with its content in the other branch we
later merge to).
Now, in such case, we combine line ranges from all parents by storing the
envelope of both line ranges. This is conservative (the line range is
extended, possibly unnecessarily) but at least this should avoid missing
descendants with changes in a range that would fall in that of one parent but
not in another one (the case of "baz: narrow change (2->2+)" changeset in
tests).
workingfilectx: add exists, lexists
Switch the lone call in merge.py to use it.
As with past refactors, the goal is to make wctx hot-swappable with an
in-memory context in the future. This change should be a no-op today.