mirrors/arti.git/crates/tor-persist, branch derive-traits

Merge branch 'clippy-allow-arc-clone' into 'main'

2022-03-01T20:38:05Z

Disable clippy::clone_on_ref_ptr See merge request tpo/core/arti!352

Bump all crates to 0.1.0

2022-03-01T13:59:34Z

arti-client: Unlock the state manager on failure to bootstrap

2022-02-24T19:55:59Z

`StateMgr` got a new `unlock()` method that does what it says on the tin. We now call it from `bootstrap()` using the new `util::StateMgrUnlockGuard`, which works in a manner similar to the `BoolResetter` from `tor_dirmgr`. (A decent small little task in future might be to unify these types in some sort of general arti utility crate?) closes arti#335

Disable clippy::clone_on_ref_ptr

2022-02-24T18:15:44Z

This lint is IMO inherently ill-conceived. I have looked for the reasons why this might be thought to be a good idea and there were basically two (and they are sort of contradictory): I. "Calling ‘.clone()` on an Rc, Arc, or Weak can obscure the fact that only the pointer is being cloned, not the underlying data." This is the wording from https://rust-lang.github.io/rust-clippy/v0.0.212/#clone_on_ref_ptr It is a bit terse; we are left to infer why it is a bad idea to obscure this fact. It seems to me that if it is bad to obscure some fact, that must be because the fact is a hazard. But why would it be a hazard to not copy the underlying data ? In other languages, faliing to copy the underlying data is a serious correctness hazard. There is a whose class of bugs where things were not copied, and then mutated and/or reused in multiple places in ways that were not what the programmer intended. In my experience, this is a very common bug when writing Python and Javascript. I'm told it's common in golang too. But in Rust this bug is much much harder to write. The data inside an Arc is immutable. To have this bug you'd have use interior mutability - ie mess around with Mutex or RefCell. That provides a good barrier to these kind of accidents. II. "The reason for writing Rc::clone and Arc::clone [is] to make it clear that only the pointer is being cloned, as opposed to the underlying data. The former is always fast, while the latter can be very expensive depending on what is being cloned." This is the reasoning found here https://github.com/rust-lang/rust-clippy/issues/2048 This is saying that *not* using Arc::clone is hazardous. Specifically, that a deep clone is a performance hazard. But for this argument, the lint is precisely backwards. It's linting the "good" case and asking for it to be written in a more explicit way; while the supposedly bad case can be written conveniently. Also, many objects (in our codebase, and in all the libraries we use) that are Clone are in fact simply handles. They contain Arc(s) (or similar) and are cheap to clone. Indeed, that is the usual case. It does not make sense to distinguish in the syntax we use to clone such a handle, whether the handle is a transparent Arc, or an opaque struct containing one or more other handles. Forcing Arc::clone to be written as such makes for code churn when a type is changed from Arc to Something: Clone, or vice versa.

Merge remote-tracking branch 'origin/mr/340'

2022-02-23T14:29:40Z

Make NoLock into BadApiUsage.

2022-02-22T21:13:37Z

To implement this, we had to refactor the tor_circmgr api for flushing state changes to disk, so that it checks if it has the lock, and only then tries to store.

Remove clippy::needless_borrow exception in CI.

2022-02-20T14:09:38Z

This exception is no longer necessary now that the underlying CI bug is fixed.

Change deny(clippy::all) to warn(clippy::all).

2022-02-14T14:24:06Z

Closes #338.

errors: Drop "Error" and "Failed" from various enum variants

2022-02-04T14:42:37Z

tor_persist::Error: impl HasKind and adjust comments

2022-02-04T14:42:37Z

And change the comments to slightly reinterpret these errors, to relate to the circumstances rather than error generation site.