mirrors/arti.git/crates/tor-dirclient/src/lib.rs, branch derive-traits

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.

dirclient: Remove HttpStatus error variant

2022-02-17T20:12:00Z

Getting a non-200 status is no longer a failure condition; it's just a different kind of answer. Closes #349.

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

2022-02-14T14:24:06Z

Closes #338.

Merge branch 'dirclient-testing' into 'main'

2022-02-03T15:09:06Z

dir-client: bug fix and more tests See merge request tpo/core/arti!271

Explain a testing oddity in tor-dirclient.

2022-02-03T14:17:34Z

Fix a stale comment in tor-dirclient.

2022-02-03T14:17:10Z

Untangle two needless Ok(r?) into just r

2022-02-02T18:35:28Z

Prompted by clippy::needless_question_mark. Sometimes Ok(r?) is needed to do automatic error conversion. I assume the lint checks for that. Anyway, in these cases it's not needed.

dirclient: refactor and test "should-i-retire-the-circuit" code.

2022-02-01T14:54:47Z

dirclient: Add tests for a number of failing cases.

2022-02-01T14:54:47Z

These bring the case a tiny improvement in test coverage, and also manage to turn up a few bugs.

dirclient: don't return too-long responses on decompression failure

2022-02-01T14:54:47Z

There are a couple of places where we forgot to truncate our return-buffer to its actual size, and instead returned a big bunch of zeros. Found while writing the tests in the next commit. Someday, we'll have ReadBuf and won't have to worry about these things.