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<Something> to Something: Clone, or vice
versa.
This patch removes the EventStream associated type and the Runtime
parameter. The Runtime parameter wasn't actually used for anything,
and the EventStream was easy enough to replace with a BoxStream in
this case.
Also replaced DirBootstrapEvents with a BoxStream to avoid tying
anything to our backend.
It had too many possible Kinds depending on what kind of string had
failed to parse.
I decided to use #[source] here instead of #[from], so that we
would have to explicitly convert these errors where they show up.
The new `BootstrapBehavior` enum controls whether an unbootstrapped
`TorClient` will bootstrap itself automatically (`Ondemand`) when an
attempt is made to use it, or whether the user must perform
bootstrapping themselves (`Manual`).
The `lazy-init` example shows how you could write a simple
`get_tor_client()` function that used a global `OnceCell` to share
a Tor client across an entire application with this API.
closes arti#278
This commit changes how the `TorClient` type works, enabling it to be
constructed synchronously without initiating the bootstrapping process.
Daemon tasks are still started on construction (although some of them
won't do anything if the client isn't bootstrapped).
The old bootstrap() methods are now reimplemented in terms of the new
create_unbootstrapped() and bootstrap_existing() methods.
This required refactoring how the `DirMgr` works to enable the same sort
of thing there.
closes#293
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.
This failure occurred because our tests use canned data to exercise
the directory state functionality, and the canned consensus has
suddenly become very expired.
There are better fixes possible, but this is a minimal one that
should get CI working on main again.
This commit puts the native-tls crate behind a feature. The feature
is off-by-default in the tor-rtcompat crate, but can be enabled
either from arti or arti-client.
There is an included script that I used to test that tor-rtcompat
could build and run its tests with all subsets of its features.
Closes#300
The interface is similar to the one exposed by `arti-client`: it
internally uses postage::watch to give a series of events showing
when a bootstrap status is changing.
Thanks to the existing state/driver separation in the DirMgr design
we don't need much new logic: each download state needs to expose
(internally) how far along it is in its download, which the
bootstrap code passes to the DirMgr if it has changed.
I believe that in the long run, we'll probably want to expose more
(or different) information here, and we'll want to process it
differently. With that in mind, I've made the API for
`DirBootstrapStatus` deliberately narrow, so that we can change its
of its internal later on without breaking code that depends on it.
(The information exposed by this commit is not yet summarized in
`arti-client`.)
Part of #96.
I found these versions empirically, by using the following process:
First, I used `cargo tree --depth 1 --kind all` to get a list of
every immediate dependency we had.
Then, I used `cargo upgrade --workspace package@version` to change
each dependency to the earliest version with which (in theory) the
current version is semver-compatible. IOW, if the current version
was 3.2.3, I picked "3". If the current version was 0.12.8, I
picked "0.12".
Then, I used `cargo +nightly upgrade -Z minimal-versions` to
downgrade Cargo.lock to the minimal listed version for each
dependency. (I had to override a few packages; see .gitlab-ci.yml
for details).
Finally, I repeatedly increased the version of each of our
dependencies until our code compiled and the tests passed. Here's
what I found that we need:
anyhow >= 1.0.5: Earlier versions break our hyper example.
async-broadcast >= 0.3.2: Earlier versions fail our tests.
async-compression 0.3.5: Earlier versions handled futures and tokio
differently.
async-trait >= 0.1.2: Earlier versions are too buggy to compile our
code.
clap 2.33.0: For Arg::default_value_os().
coarsetime >= 0.1.20: exposed as_ticks() function.
curve25519-dalek >= 3.2: For is_identity().
generic-array 0.14.3: Earlier versions don't implement
From<&[T; 32]>
httparse >= 1.2: Earlier versions didn't implement Error.
itertools at 0.10.1: For at_most_once.
rusqlite >= 0.26.3: for backward compatibility with older rustc.
serde 1.0.103: Older versions break our code.
serde_json >= 1.0.50: Since we need its Value type to implement Eq.
shellexpand >= 2.1: To avoid a broken dirs crate version.
tokio >= 1.4: For Handle::block_on().
tracing >= 0.1.18: Previously, tracing_core and tracing had separate
LevelFilter types.
typenum >= 1.12: Compatibility with rust-crypto crates
x25519-dalek >= 1.2.0: For was_contributory().
Closes#275.
When our current consensus is getting close to being invalid (but
it isn't invalid yet), we try to get a new one. So far, so good.
But we had a bug: when we went to get a new consensus, we'd see that we
had a perfectly fine not-yet-invalid consensus in our cache, reload it,
find that it was ready, and continue!
This patch fixes our behavior: If we have a usable consensus, then
when we reset the bootstrapping process, we ignore any cached consensus.
Fixes bug #274.
This prevents a security-failure condition that could happen if our
directory caches don't give us these microdescriptors, but we
nevertheless decide that the directory is usable.
Closes#178
This warning occurs if we ask for microdescriptors from our local
cache, and our cache gives us something we didn't ask for. It
shouldn't be possible, so let's warn when it occurs.
This patch resolves an XXXX.
This approach tries to preserve the current interface, but uses a
counter-based event backend to implement a coalescing stream of
events that can be represented as small integers. The advantage
here is that publishing events no longer needs to be a blocking
operation, since there is no queue to fill up.
We can't change the authorities while in-flight: that would be pretty
miserable to implement.
Similarly we can't change the cache while in-flight.
Everything else should be fair game, though there are a couple of tricky
bits. I've tried to document those.
This patch doesn't actually make anything reconfigurable, but it
does create an API that will tell you "you can't change the value of
that!" If the API looks reasonable, I can start making it possible
to change the values of individual items.
We want to only use TODO in the codebase for non-blockers, and open
tickets for anything that is a bigger blocker than a TODO. These
XXXXs seem like definite non-blockers to me.
Part of arti#231.
To do this at all neatly, I had to split out `tor-config` from
`arti-config` again, and putting the lower level stuff (paths,
builder errors) into tor-config. I also changed our use of
derive_builder to always use a common error type, to avoid
error type proliferation.
It requires tracing-subscriber 0.2, which is a lower version than we
want, and which causes trouble with our minimal-versions CI test.
There is a pending issue to fix this; we can reinstate tracing-test
once it is merged: https://github.com/dbrgn/tracing-test/pull/11
This test uses a consensus that I've copied from
tor-netdoc/testdata. I would include it directly, but I think that
will cause trouble when it comes time to run "cargo package".
Previously we'd say that we were "waiting for the other process to
bootstrap" even if it was already bootstrapped: and we wouldn't
actually declare success when it was done.
For now, this avoids having to separately handle
AuthorityBuilderError, DirMgrConfigBuilderError, DownloadScheduleConfigBuilderError,
NetworkConfigBuilderError and FallbackDirBuilderError when anyhow is not
used.
Turn off a clippy warning.