This makes it clear that RevsetExpression::Present node is noop at the
evaluation stage.
RevsetEvaluationError::StoreError is unused right now, but I'm not sure if
it should be removed. It makes some sense that evaluate() can propagate
StoreError as it has access to the store.
The `Repo` is a higher-level type that the index shouldn't have to
know about. With this change, a custom revset implementation should be
able evaluate the revset on a server without knowing which repo it
refers to.
This replaces the direct use of `IdIndex` in `ReadonlyRepo` by use of
`Revset::change_id_index()`.
I made the `Index` trait require `Send` and `Sync` in order to be able
to store an instance of it in `ReadonlyRepo` (via `ChangeIdIndex`) and
still have that be `Send` and `Sync`. We could alternatively store the
`ChangeIdIndex` in a `Mutex`. Now that will be up to the
`ChangeIdIndex` instead.
This commit adds an `evaluate_revset()` function to the `Index`
trait. It will require some further cleanup, but it already achieves
the goal of letting the index implementation decide which revset
engine to use.
I broke `jj debug reindex` in a27da7d8d5. From that commit, we no
longer delete the pointer to the old index, so nothing happens when we
reload the index. This commit fixes that, and also makes the command
error out if run on a repo with a non-default index type.
This is yet another step towards making the index pluggable. The
`IndexStore` trait seems reasonable after this commit. There's still a
lot of work to remove `IndexPosition` from the `Index` trait.
I didn't make `ReadonlyIndex` extend `Index` because it needed an
`as_index()` to convert to `&dyn Index` trait object
anyway. Separating the types also gives us flexibility to implement
the two traits on different types.
Not all index implementations may want to store the readonly index
implementation in an Arc. Exposing the Arc in the interface is also
problematic because `Arc<IndexImpl>` cannot be cast to `Arc<dyn
Index>`.
These two files are closely related, and `Index` and `IndexStore` are
expected to be customized together, so it seems better to keep them in
a single file.
Even though we don't know the details yet, we know that we want to
make the index pluggable like the commit and opstore
backends. Defining a trait for it should be a good step. We can refine
the trait later.
The function is currently only about the length of commit IDs, so
let's clarify that. I'm going to add another function for the length
of change IDs next. I don't know if we're going to care about lengths
of other hashes in the future. We might even be able to remove the
current restriction that all commit IDs and all change IDs have the
same length.
This iterator will be used to merge neighbor commit ids across segments.
resolve_prefix() is simplified to non-short-circuiting loop. I think that's
fine because visiting parents is cheap, and the costly operation here is
segment_resolve_prefix().
entry_by_pos() could also be migrated to iterator, but I leave the unsafe
bits there.
ReadonlyIndex implementation leverages the existing binary search
function. MutableIndex one is basically the same as repo::IdIndex.
Shortest prefix length could be calculated for each segment, but I think
returning neighbors is better for testing.
If commit_id[..prefix_len] < prefix, commit_id < prefix is obviously true.
If commit_id[..prefix_len] == prefix, commit_id < prefix returns false. So
slicing isn't needed.
This makes commit_id_byte_prefix_to_pos() basically the same as
segment_commit_id_to_pos(), and these two functions can be merged.
matches() is called from resolve_change_id() loop right now, so it's better to
not allocate String there. Regarding new IdIndex integration, I'll probably make
IdIndex store raw byte ids instead of hexes, and use HexPrefix to look up
range and test prefixes. I think this is basically the same as prefix lookup
in MutableIndex, but I have no idea if we can factor out a common interface.
I made HexPrefix store (Vec<u8>, bool) instead of (Vec<u8>, Option<u8>) so
both min/partial prefixes can be borrowed as slice.
I ran an upgraded Clippy on the codebase. All the changes seem to be
about using variables directly in format strings instead of passing
them as separate arguments.
This will be a building block of 'parents(base)' revset. 'base---' will
be .filter_by_generation(3..4) for example. I think 'ancestors(base)' can
also have an optional generation parameter, but I haven't considered any
particular syntax yet.
Even though I couldn't determine if RevWalkGenerationRange has a measurable
cost compared to RevWalk, I'm not comfortable with enabling generation
tracking by default. So this patch adds a separate struct. I duplicated
Iterator::next() method as it seemed rather complicated to extract a common
iterator wrapper.
Actual filtering function and tests will be added by the next commit.
