rust-index: using the `hg::index::Index` in ancestors iterator and lazy set
Since there is no Rust implementation for REVLOGV2/CHANGELOGv2, we declare
them to be incompatible with Rust, hence indexes in these formats will use
the implementations from Python `mercurial.ancestor`. If this is an unacceptable
performance hit for current users of these formats, we can later on add Rust
implementations based on the C index for them or implement these formats for
the Rust indexes.
Among the challenges that we had to meet, we wanted to avoid taking the GIL each
time the inner (vcsgraph) iterator has to call the parents function. This would probably
still be acceptable in terms of performance with `AncestorsIterator`, but not with
`LazyAncestors` nor for the upcoming change in `MissingAncestors`.
Hence we enclose the reference to the index in a `PySharedRef`, leading to more
rigourous checking of mutations, which does pass now that there no logically immutable
methods of `hg::index::Index` that take a mutable reference as input.
== New Features ==
* `hg mv -A` can now be used with `--at-rev`. It behaves just like
`hg cp -A --at-rev`, i.e. it marks the destination as a copy of the
source whether or not the source still exists (but the source must
exist in the parent revision).
* New revset predicate `diffcontains(pattern)` for filtering revisions
in the same way as `hg grep --diff pattern`.
* The memory footprint per changeset and per file during pull/unbundle
operations has been significantly reduced.
== New Experimental Features ==
== Bug Fixes ==
== Backwards Compatibility Changes ==
== Internal API Changes ==
* `merge.update()` is now private (renamed to `_update()`). Hopefully
the higher-level functions available in the same module cover your
use cases.
* `phases.registernew` now takes a set of revisions instead of a list
of nodes. `phases.advanceboundary` takes an optional set of revisions
in addition to the list of nodes. The corresponeding members of the
`phasecache` class follow this change.
* The `addgroup` member of `revlog` classes no longer keeps a list of
all found nodes. It now returns True iff a node was found in the group.
An optional callback for duplicated nodes can be used by callers to keep
track of all nodes themselve.
* The `_chaininfocache` of `revlog` classes has been changed from a dict
to a LRU cache.