Alternatively, we can wrap BTreeMap<String, Option<RefTarget>> to flatten
Option<&Option<..>> internally, but doing that would be tedious. It would
also be unclear if map.remove(name) should construct an absent RefTarget if
the ref doesn't exist.
Since RefTarget will be reimplemented on top of Conflict<Option<CommitId>>,
we won't be able to simply return a slice of type &[CommitId]. These functions
are also renamed in order to disambiguate from Conflict::adds()/removes().
If we migrate RefTarget to new Conflict-based type, it won't store
Conflict<CommitId>, but Conflict<Option<CommitId>>. As the Option will
be internalized, new RefTarget type will also represent an absent target.
The 'target: Option<RefTarget>' argument will be replaced with new RefTarget
type.
I've also renamed the function for consistency with the following changes.
It would be surprising if set_local_branch(name, target) could remove the
branch. I feel the name set_local_branch_target() is less confusing.
Errors that may occur while loading backend would vary per backends, and
it's unlikely that these errors could be mapped to BackendError variants
other than BackendError::Other. So let's extract Other(_) of that kind as
a separate type to clarify there would be no other error variants.
Perhaps, Backend/Error will be renamed to CommitBackend/Error or
CommitStore/Error?, whereas I think BackendInit/LoadError can be shared
among store factories.
This commit fixes#1305
Before this commit, running `jj init --git-repo=./` in a folder that
does not have a .git would cause jj to panick and leave an unfinished corrupted jj repo.
This commit fixes that by changing the call chain to return an error
instead of calling .unwrap() and panicking. This commit also adds logic to delete the unfinished jj
repository when the git backend initialization failed.
Before this commit, running the above command would result in the following
```
Running `jj/target/debug/jj init --git-repo=./`
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error { code: -3, klass: 2, message: "failed to resolve path '/Users/kevincliao/github/jj/test-repo/.jj/repo/store/../../../.git': No such file or directory" }', lib/src/git_backend.rs:83:75
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
After this commit, the result is the following and the jj repo is deleted:
```
Running `jj/target/debug/jj init --git-repo=./`
Error: Failed to access the repository: Error: Failed to open git repository: failed to resolve path '/Users/kevincliao/github/jj/test-repo/.jj/repo/store/../../../.git': No such file or directory; class=Os (2); code=NotFound (-3)
```
..and other assorted boilerplate. These are just stubs for now, but now
that we've reserved the `submodule_store` subdirectory, we can start
adding more functionality.
In colocated mid-size "linux" repo, this saves ~450ms needed to do
enforce_view_invariants(). We could instead make add_head() to return early,
but the condition would be a bit weird since HEAD@git is typically a parent
of known heads, not a head itself.
It might sound scary to add public .mutable_index() accessor, but I think
it's okay because immutable MutableIndex reference has no more power than
Index.
This allows us to implement Index for lifetime-bound type such as
CompositeIndex<'_>.
I've added a helper function because the construction of the range expression
is a bit noisy. It could be a Repo method, but I don't want to make it a
default implementation of the trait method.
revset::walk_revs() let the caller handle RevsetEvaluationError since the
evaluation engine may error out even with such a trivial query. For now, most
callers just .unwrap() the error as before.
I don't know if we ever resolve revsets in a mutable repo, but now
that we can get a change id index from a revset, it's easier to
implement this functionality that way.
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.
I'd like to be able to pass a `self` of `type `&ReadonlyRepo` to
functions that take a `&dyn Repo`. For that, we need `ReadonlyRepo`
itself to implement `Repo` instead of having `Arc<ReadonlyRepo>`
implement it. I could have solved it in a different way, but the `Arc`
requirement seems like an unnecessary constraint.
The functions resolving a change id to commits currently return a
`Vec<IndexEntry>`. We want to avoid depending on `IndexEntry` and we
only need the commit ids here.
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.
This is another step towards allowing a custom `jj` binary to have its
own index type. We're going to have a server-backed index
implementation at Google, for example.
This is a step towards making the index storage pluggable. The
interface will probably change a bit soon, but let's start with
functions that match the current implementation.
I called the current implementation the `DefaultIndexStore`. Calling
it `SimpleIndexStore` (like `SimpleOpStore` and `SimpleOpHeadsStore`)
didn't seem accurate.
It makes the APIs much simpler if we don't have to pass in information
about the initial operation when we create the `OpHeadsStore`. It also
makes the alternative `OpHeadsStore` implementations simpler since we
move some logic into a shared location (`ReadonlyRepo::init()`).
This effectively undoes ec071041268d. Maybe some further refactoring
made it possible to move it back as I'm doing in this commit?
I'm about to make `RepoLoader::init()` return a `Result`, and I don't
want to have to wrap that in a new error in
`ReadonlyRepo::load_at_head()` since that's only used in tests.
This is just a little preparation for extracting a `Repo` trait that's
implemented by both `ReadonlyRepo` and `MutableRepo`. The `index()`
function in that trait will of course have to return the same type in
both implementations, and that type will be `&dyn Index`.
