databendlabs / openraft / 18972411689

88%

push

github

change: storage traits return `io::Error`

Issue #1457: Simplify storage trait error API.

Benefits: Simpler trait implementation - Storage code doesn't need to
know about `StorageError<C>` or generic type parameters in error handling.

## Changes

Storage trait methods now return `io::Error` instead of `StorageError<C>`:
- `RaftLogStorage`: `append()`, `truncate()`, `purge()`, `save_vote()`, `save_committed()`
- `RaftLogReader`: `try_get_log_entries()`, `limited_get_log_entries()`, `read_vote()`, `get_key_log_ids()`
- `RaftStateMachine`: `applied_state()`, `apply()`, `get_current_snapshot()`, `begin_receiving_snapshot()`, `install_snapshot()`
- `RaftSnapshotBuilder`: `build_snapshot()`

Added internal `StorageIOResult` trait for error conversion:
- Provides 14 methods like `.sto_read_logs()`, `.sto_write_snapshot()`, etc.
- Converts `io::Error` to `StorageError<C>` with proper context at Openraft boundaries

- Fix: #1457

Upgrade tip:

Storage implementors should update trait methods to return `io::Error`:

```rust
// Before
async fn read_vote(&mut self) -> Result<Option<Vote>, StorageError<C>> {
    self.vote.read().map_err(|e| StorageError::read_vote(&e))
}

// After
async fn read_vote(&mut self) -> Result<Option<Vote>, io::Error> {
    self.vote.read()
}
```

Return `io::Error` directly - Openraft adds context automatically.
The method body may leave unchanged: `io::Error` can be converted to
`StorageError` with a simple `?`.

143 of 165 new or added lines in 13 files covered. (86.67%)

12405 of 13572 relevant lines covered (91.4%)

136635.12 hits per line