1.66 release speeds up compile times for over 10% according to tests.
Also its Clippy finds plenty of old nits in our code:
* useless conversion, `foo as u8` where `foo: u8` and similar, removed
`as u8` and similar
* useless references and dereferenced (that were automatically adjusted
by the compiler), removed various `&` and `*`
* bool -> u8 conversion via `if/else`, changed to `u8::from`
* Map `.iter()` calls where only values were used, changed to
`.values()` instead
Standing out lints:
* `Eq` is missing in our protoc generated structs. Silenced, does not
seem crucial for us.
* `fn default` looks like the one from `Default` trait, so I've
implemented that instead and replaced the `dummy_*` method in tests with
`::default()` invocation
* Clippy detected that
```
if retry_attempt < u32::MAX {
retry_attempt += 1;
}
```
is a saturating add and proposed to replace it.
refactor: use new type LayerFileName when referring to layer file names in PathBuf/RemotePath
Before this patch, we would sometimes carry around plain file names in
`Path` types and/or awkwardly "rebase" paths to have a unified
representation of the layer file name between local and remote.
This patch introduces a new type `LayerFileName` which replaces the use
of `Path` / `PathBuf` / `RemotePath` in the `storage_sync2` APIs.
Instead of holding a string, it contains the parsed representation of
the image and delta file name.
When we need the file name, e.g., to construct a local path or
remote object key, we construct the name ad-hoc.
`LayerFileName` is also serde {Dese,Se}rializable, and in an initial
version of this patch, it was supposed to be used directly inside
`IndexPart`, replacing `RemotePath`.
However,
commit 3122f3282f
Ignore backup files (ones with .n.old suffix) in download_missing
fixed handling of `*.old` backup file names in IndexPart, and we need
to carry that behavior forward.
The solution is to remove `*.old` backup files names during
deserialization. When we re-serialize the IndexPart, the `*.old` file
will be gone.
This leaks the `.old` file in the remote storage, but makes it safe
to clean it up later.
There is additional churn by a preliminary refactoring that got squashed
into this change:
split off LayerMap's needs from trait Layer into super trait
That refactoring renames `Layer` to `PersistentLayer` and splits off a subset
of the functions into a super-trait called `Layer`.
The upser trait implements just the functions needed by `LayerMap`, whereas
`PersisentLayer` adds the context of the pageserver.
The naming is imperfect as some functions that reside in `PersistentLayer`
have nothing persistence-specific to it. But it's a step in the right direction.
