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<title>mirrors/arti.git/crates/tor-netdir, branch derive-traits</title>
<subtitle>mirror of https://gitlab.torproject.org/tpo/core/arti
</subtitle>
<id>http://git.dilluti0n.com/mirrors/arti.git/atom?h=derive-traits</id>
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<updated>2022-03-01T20:38:05Z</updated>
<entry>
<title>Merge branch 'clippy-allow-arc-clone' into 'main'</title>
<updated>2022-03-01T20:38:05Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-03-01T20:38:05Z</published>
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<id>urn:sha1:83c8b11c2c08a05928bdb0390922391d13261ef2</id>
<content type='text'>
Disable clippy::clone_on_ref_ptr

See merge request tpo/core/arti!352</content>
</entry>
<entry>
<title>Bump all crates to 0.1.0</title>
<updated>2022-03-01T13:59:34Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-03-01T13:59:34Z</published>
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<id>urn:sha1:e8e9791a9757a32779657c5284b380ae91ca7979</id>
<content type='text'>
</content>
</entry>
<entry>
<title>Disable clippy::clone_on_ref_ptr</title>
<updated>2022-02-24T18:15:44Z</updated>
<author>
<name>Ian Jackson</name>
<email>ijackson@chiark.greenend.org.uk</email>
</author>
<published>2022-02-24T18:15:44Z</published>
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<id>urn:sha1:afb50fe7354a8715290516e74e89679f0649568e</id>
<content type='text'>
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&lt;Something&gt; to Something: Clone, or vice
versa.
</content>
</entry>
<entry>
<title>tor-netdir: Split testnet errors into a new type</title>
<updated>2022-02-15T19:43:36Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-02-15T19:43:36Z</published>
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<id>urn:sha1:058e4d7705c09b9e5a9d45e10b84a409308235b2</id>
<content type='text'>
There's no reason to have the test-network-construction code share an
error enum with the main netdir code.
</content>
</entry>
<entry>
<title>tor-netdir: remove unused error variants</title>
<updated>2022-02-15T19:36:15Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-02-15T19:36:15Z</published>
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<id>urn:sha1:ceb8e8c1e2864fbd326cf59c814209cf67e10a07</id>
<content type='text'>
This turns out to have been most of them, which
simplifies matters a lot.
</content>
</entry>
<entry>
<title>Merge branch 'doc-errors' into 'main'</title>
<updated>2022-02-15T15:09:48Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-02-15T15:09:48Z</published>
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<id>urn:sha1:7b6a7a57d3dbd74aed17df6f1e088fcb401b21a8</id>
<content type='text'>
Refactor errors in tor-netdoc

See merge request tpo/core/arti!314</content>
</entry>
<entry>
<title>netdoc: Make doc-build errors a separate type</title>
<updated>2022-02-14T15:46:04Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-02-14T15:46:04Z</published>
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<id>urn:sha1:b27c51d3a2ad4a7b8ec00c2a06be55af9459507a</id>
<content type='text'>
Every other case of tor_netdoc::Error means a parse failure.  This one,
though, means a failure to construct  a document.
</content>
</entry>
<entry>
<title>Change deny(clippy::all) to warn(clippy::all).</title>
<updated>2022-02-14T14:24:06Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-02-14T14:24:06Z</published>
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<id>urn:sha1:1cecc7e45a9a432f87a8f11abb8cb86b35464a0b</id>
<content type='text'>
Closes #338.
</content>
</entry>
<entry>
<title>Bump tor-netdir and tor-guardmgr versions</title>
<updated>2022-01-31T16:05:34Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-01-31T16:05:34Z</published>
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<id>urn:sha1:329bde58ddc572cc6db198da279f180a1ac6895d</id>
<content type='text'>
tor-netdir needs to bump because tor-netdoc bumped, even though
there were no other changes in tor-netdir.  Whoops.

tor-guardmgr needs to bump because it already published, with the
older tor-netdir.
</content>
</entry>
<entry>
<title>Bump the patch version of every crate that changed since 0.0.3</title>
<updated>2022-01-31T15:30:52Z</updated>
<author>
<name>Nick Mathewson</name>
<email>nickm@torproject.org</email>
</author>
<published>2022-01-31T15:30:52Z</published>
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<id>urn:sha1:01d99373089f8131d1df9758fce45ffaa3fbf659</id>
<content type='text'>
</content>
</entry>
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