`Transport::listen_on` is an asynchronous operation. It returns immediately but the actual process of establishing a listening socket happens as part of `Transport::poll` which will return one or more `TransportEvent`s related to a particular `listen_on` call.
Currently, `listen_on` returns a `ListenerId` which allows the user of the `Transport` interface to correlate the events with a particular `listen_on` call. This "user" is the `Swarm` runtime. Currently, a user of libp2p establishes a new listening socket by talking to the `Swarm::listen_on` interface and it is not possible to do the same thing via the `NetworkBehaviour` trait.
Within the `NetworkBehaviour` trait, we emit _commands_ to the `Swarm` like `ToSwarm::Dial`. These commands don't have a "return value" like a synchronous function does and thus, if we were to add a `ToSwarm::ListenOn` command, it could not receive the `ListenerId` from the `Transport`.
To fix this and to be consistent with our [coding guidelines](https://github.com/libp2p/rust-libp2p/blob/master/docs/coding-guidelines.md#allow-correlating-asynchronous-responses-to-their-requests) we change the interface of `Transport::listen_on` to require the user to pass in a `ListenerId`. This will allow us to construct a command in a `NetworkBehaviour` that remembers this ID which enables precise tracking of which events containing a `ListenerId` correlate which a particular `listen_on` command.
This is especially important in the context of listening on wildcard addresses like `0.0.0.0` because we end up binding to multiple network interfaces and thus emit multiple events for a single `listen_on` call.
Pull-Request: #3567.
Previously, a protocol could be any sequence of bytes as long as it started with `/`. Now, we directly parse a protocol as `String` which enforces it to be valid UTF8.
To notify users of this change, we delete the `ProtocolName` trait. The new requirement is that users need to provide a type that implements `AsRef<str>`.
We also add a `StreamProtocol` newtype in `libp2p-swarm` which provides an easy way for users to ensure their protocol strings are compliant. The newtype enforces that protocol strings start with `/`. `StreamProtocol` also implements `AsRef<str>`, meaning users can directly use it in their upgrades.
`multistream-select` by itself only changes marginally with this patch. The only thing we enforce in the type-system is that protocols must implement `AsRef<str>`.
Resolves: #2831.
Pull-Request: #3746.
Previously, we would specify the version and path of our workspace dependencies in each of our crates. This is error prone as https://github.com/libp2p/rust-libp2p/pull/3658#discussion_r1153278072 for example shows. Problems like these happened in the past too.
There is no need for us to ever depend on a earlier version than the most current one in our crates. It thus makes sense that we manage this version in a single place.
Cargo supports a feature called "workspace inheritance" which allows us to share a dependency declaration across a workspace and inherit it with `{ workspace = true }`.
We do this for all our workspace dependencies and for the MSRV.
Resolves#3787.
Pull-Request: #3715.
Instead of relying on the `MemoryTransport` to provide us with a duplex stream, we use the `futures_ringbuf` crate. This saves us several lines of code and removes the dependency on `libp2p_core::upgrade::apply`.
Related #3748.
Pull-Request: #3772.
The `unreachable_pub` lint makes us aware of uses of `pub` that are not actually reachable from the crate root. This is considered good because it means reading a `pub` somewhere means it is actually public API. Some of our crates are quite large and keeping their entire API surface in your head is difficult.
We should strive for most items being `pub(crate)`. This lint helps us enforce that.
Pull-Request: #3735.
A large release with lots of changes I am looking forward to. Sorry for the long release cadence.
Anything folks would like to see included that is not yet in `master`? As usual I would like to only block on bug fixes.
Pull-Request: #3491.
Most of this is trivial, apart from the rename of the `clippy::derive_hash_xor_eq` lint to `clippy::derived_hash_with_manual_eq`.
Instead of allowing that lint, we manually implement `PartialEq` and add a comment why the difference between the `PartialEq` and `Hash` implementations are okay.
As I do frequently, I corrected for the latest clippy warnings. This will make sure the CI won't complain in the future. We could automate this btw and maybe run the nightly version of clippy.
We refactor our continuous integration workflow with the following goals in mind:
- Run as few jobs as possible
- Have the jobs finish as fast as possible
- Have the jobs redo as little work as possible
There are only so many jobs that GitHub Actions will run in parallel.
Thus, it makes sense to not create massive matrices but instead group
things together meaningfully.
The new `test` job will:
- Run once for each crate
- Ensure that the crate compiles on its specified MSRV
- Ensure that the tests pass
- Ensure that there are no semver violations
This is an improvement to before because we are running all of these
in parallel which speeds up execution and highlights more errors at
once. Previously, tests run later in the pipeline would not get run
at all until you make sure the "first" one passes.
We also previously did not verify the MSRV of each crate, making the
setting in the `Cargo.toml` rather pointless.
The new `cross` job supersedes the existing `wasm` job.
This is an improvement because we now also compile the crate for
windows and MacOS. Something that wasn't checked before.
We assume that checking MSRV and the tests under Linux is good enough.
Hence, this job only checks for compile-errors.
The new `feature_matrix` ensures we compile correctly with certain feature combinations.
`libp2p` exposes a fair few feature-flags. Some of the combinations
are worth checking independently. For the moment, this concerns only
the executor related transports together with the executor flags but
this list can easily be extended.
The new `clippy` job runs for `stable` and `beta` rust.
Clippy gets continuously extended with new lints. Up until now, we would only
learn about those as soon as a new version of Rust is released and CI would
run the new lints. This leads to unrelated failures in CI. Running clippy on with `beta`
Rust gives us a heads-up of 6 weeks before these lints land on stable.
Fixes#2951.
Various muxer implementations struggle to fulfill this test. In practice, it doesn't matter much because we always run `multistream-select` on top of a newly negotiated stream so we never end up actually reading from a stream that we have never written to.
Relevant discussion: https://github.com/kpp/rust-libp2p/pull/27#discussion_r1012128418
Remove default features. You need to enable required features
explicitly now. As a quick workaround, you may want to use the
new `full` feature which activates all features.
Instead of having a mix of `poll_event`, `poll_outbound` and `poll_close`, we
flatten the entire interface of `StreamMuxer` into 4 individual functions:
- `poll_inbound`
- `poll_outbound`
- `poll_address_change`
- `poll_close`
This design is closer to the design of other async traits like `AsyncRead` and
`AsyncWrite`. It also allows us to delete the `StreamMuxerEvent`.
Remove the concept of individual `Transport::Listener` streams from `Transport`.
Instead the `Transport` is polled directly via `Transport::poll`. The
`Transport` is now responsible for driving its listeners.
This aligns the public API of the `libp2p-mplex` module with the one
from `libp2p-yamux`. This change has two benefits:
1. For standalone users of `libp2p-mplex`, the substreams itself are
now useful, similar to `libp2p-yamux` and don't necessarily need to
be polled via the `StreamMuxer`. The `StreamMuxer` only forwards to
the `Async{Read,Write}` implementations.
2. This will reduce the diff of #2648 because we can chunk the one
giant commit into smaller atomic ones.
`libp2p-core` provides the `StreamMuxer` abstraction so it can provide
functionality that abstracts over this trait.
We never use the `flush_all` function as part of our abstractions.
No one else is going to use it so we can remove it from the abstraction.
