This change makes it so we aren't doing a directory traversal every time
we ask for completions from a module. Specifically, submodules that
aren't attributes of their parent module can only be discovered by
looking at the directory tree. But we want to avoid doing a directory
scan unless we think there are changes.
To make this work, this change does a little bit of surgery to
`FileRoot`. Previously, a `FileRoot` was only used for library search
paths. Its revision was bumped whenever a file in that tree was added,
deleted or even modified (to support the discovery of `pth` files and
changes to its contents). This generally seems fine since these are
presumably dependency paths that shouldn't change frequently.
In this change, we add a `FileRoot` for the project. But having the
`FileRoot`'s revision bumped for every change in the project makes
caching based on that `FileRoot` rather ineffective. That is, cache
invalidation will occur too aggressively. To the point that there is
little point in adding caching in the first place. To mitigate this, a
`FileRoot`'s revision is only bumped on a change to a child file's
contents when the `FileRoot` is a `LibrarySearchPath`. Otherwise, we
only bump the revision when a file is created or added.
The effect is that, at least in VS Code, when a new module is added or
removed, this change is picked up and the cache is properly invalidated.
Other LSP clients with worse support for file watching (which seems to
be the case for the CoC vim plugin that I use) don't work as well. Here,
the cache is less likely to be invalidated which might cause completions
to have stale results. Unless there's an obvious way to fix or improve
this, I propose punting on improvements here for now.
## Summary
Another salsa upgrade.
The main motivation is to stay on a recent salsa version because there
are still a lot of breaking changes happening.
The most significant changes in this update:
* Salsa no longer derives `Debug` by default. It now requires
`interned(debug)` (or similar)
* This version ships the foundation for garbage collecting interned
values. However, this comes at the cost that queries now track which
interned values they created (or read). The micro benchmarks in the
salsa repo showed a significant perf regression. Will see if this also
visible in our benchmarks.
## Test Plan
`cargo test`
## Summary
This PR adds support for untitled files in the Red Knot project.
Refer to the [design
discussion](https://github.com/astral-sh/ruff/discussions/12336) for
more details.
### Changes
* The `parsed_module` always assumes that the `SystemVirtual` path is of
`PySourceType::Python`.
* For the module resolver, as suggested, I went ahead by adding a new
`SystemOrVendoredPath` enum and renamed `FilePathRef` to
`SystemOrVendoredPathRef` (happy to consider better names here).
* The `file_to_module` query would return if it's a
`FilePath::SystemVirtual` variant because a virtual file doesn't belong
to any module.
* The sync implementation for the system virtual path is basically the
same as that of system path except that it uses the
`virtual_path_metadata`. The reason for this is that the system
(language server) would provide the metadata on whether it still exists
or not and if it exists, the corresponding metadata.
For point (1), VS Code would use `Untitled-1` for Python files and
`Untitled-1.ipynb` for Jupyter Notebooks. We could use this distinction
to determine whether the source type is `Python` or `Ipynb`.
## Test Plan
Added test cases in #12526