refactor(iroh)!: rename ProtocolError to AcceptError (#3339)

## Description

To me, this reads much nicer in the examples etc. 

## Breaking Changes

- `iroh::endpoint::ProtocolError` -> `AcceptError`

## Notes & open questions

<!-- Any notes, remarks or open questions you have to make about the PR.
-->

## Change checklist
<!-- Remove any that are not relevant. -->
- [x] Self-review.
- [ ] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [x] All breaking changes documented.
- [x] List all breaking changes in the above "Breaking Changes" section.
- [ ] Open an issue or PR on any number0 repos that are affected by this
breaking change. Give guidance on how the updates should be handled or
do the actual updates themselves. The major ones are:
    - [ ] [`quic-rpc`](https://github.com/n0-computer/quic-rpc)
    - [ ] [`iroh-gossip`](https://github.com/n0-computer/iroh-gossip)
    - [ ] [`iroh-blobs`](https://github.com/n0-computer/iroh-blobs)
    - [ ] [`dumbpipe`](https://github.com/n0-computer/dumbpipe)
    - [ ] [`sendme`](https://github.com/n0-computer/sendme)

---------

Co-authored-by: Friedel Ziegelmayer <me@dignifiedquire.com>

Author: Frando

iroh/examples/echo.rs

@@ -8,7 +8,7 @@
 
 use iroh::{
     endpoint::Connection,
-    protocol::{ProtocolError, ProtocolHandler, Router},
+    protocol::{AcceptError, ProtocolHandler, Router},
     watcher::Watcher as _,
     Endpoint, NodeAddr,
 };
@@ -83,7 +83,7 @@ impl ProtocolHandler for Echo {
     ///
     /// The returned future runs on a newly spawned tokio task, so it can run as long as
     /// the connection lasts.
-    async fn accept(&self, connection: Connection) -> Result<(), ProtocolError> {
+    async fn accept(&self, connection: Connection) -> Result<(), AcceptError> {
         // We can get the remote's node id from the connection.
         let node_id = connection.remote_node_id()?;
         println!("accepted connection from {node_id}");

iroh/examples/search.rs

@@ -34,7 +34,7 @@ use std::{collections::BTreeSet, sync::Arc};
 use clap::Parser;
 use iroh::{
     endpoint::Connection,
-    protocol::{ProtocolError, ProtocolHandler, Router},
+    protocol::{AcceptError, ProtocolHandler, Router},
     Endpoint, NodeId,
 };
 use n0_snafu::{Result, ResultExt};
@@ -126,7 +126,7 @@ impl ProtocolHandler for BlobSearch {
     ///
     /// The returned future runs on a newly spawned tokio task, so it can run as long as
     /// the connection lasts.
-    async fn accept(&self, connection: Connection) -> Result<(), ProtocolError> {
+    async fn accept(&self, connection: Connection) -> Result<(), AcceptError> {
         // We can get the remote's node id from the connection.
         let node_id = connection.remote_node_id()?;
         println!("accepted connection from {node_id}");
@@ -136,21 +136,18 @@ impl ProtocolHandler for BlobSearch {
         let (mut send, mut recv) = connection.accept_bi().await?;
 
         // We read the query from the receive stream, while enforcing a max query length.
-        let query_bytes = recv
-            .read_to_end(64)
-            .await
-            .map_err(ProtocolError::from_err)?;
+        let query_bytes = recv.read_to_end(64).await.map_err(AcceptError::from_err)?;
 
         // Now, we can perform the actual query on our local database.
-        let query = String::from_utf8(query_bytes).map_err(ProtocolError::from_err)?;
+        let query = String::from_utf8(query_bytes).map_err(AcceptError::from_err)?;
         let num_matches = self.query_local(&query).await;
 
         // We want to return a list of hashes. We do the simplest thing possible, and just send
         // one hash after the other. Because the hashes have a fixed size of 32 bytes, this is
         // very easy to parse on the other end.
         send.write_all(&num_matches.to_le_bytes())
             .await
-            .map_err(ProtocolError::from_err)?;
+            .map_err(AcceptError::from_err)?;
 
         // By calling `finish` on the send stream we signal that we will not send anything
         // further, which makes the receive stream on the other end terminate.

iroh/src/protocol.rs

@@ -3,7 +3,7 @@
 //! ## Example
 //!
 //! ```no_run
-//! # use iroh::{endpoint::{Connection, BindError}, protocol::{ProtocolHandler, Router, ProtocolError}, Endpoint, NodeAddr};
+//! # use iroh::{endpoint::{Connection, BindError}, protocol::{AcceptError, ProtocolHandler, Router}, Endpoint, NodeAddr};
 //! #
 //! # async fn test_compile() -> Result<(), BindError> {
 //! let endpoint = Endpoint::builder().discovery_n0().bind().await?;
@@ -19,7 +19,7 @@
 //! struct Echo;
 //!
 //! impl ProtocolHandler for Echo {
-//!     async fn accept(&self, connection: Connection) -> Result<(), ProtocolError> {
+//!     async fn accept(&self, connection: Connection) -> Result<(), AcceptError> {
 //!         let (mut send, mut recv) = connection.accept_bi().await?;
 //!
 //!         // Echo any bytes received back directly.
@@ -98,16 +98,16 @@ pub struct RouterBuilder {
 #[allow(missing_docs)]
 #[derive(Debug, Snafu)]
 #[non_exhaustive]
-pub enum ProtocolError {
+pub enum AcceptError {
     #[snafu(transparent)]
-    Connect {
+    Connection {
         source: crate::endpoint::ConnectionError,
         backtrace: Option<Backtrace>,
         #[snafu(implicit)]
         span_trace: n0_snafu::SpanTrace,
     },
     #[snafu(transparent)]
-    RemoteNodeId { source: RemoteNodeIdError },
+    MissingRemoteNodeId { source: RemoteNodeIdError },
     #[snafu(display("Not allowed."))]
     NotAllowed {},
 
@@ -117,7 +117,7 @@ pub enum ProtocolError {
     },
 }
 
-impl ProtocolError {
+impl AcceptError {
     /// Creates a new user error from an arbitrary error type.
     pub fn from_err<T: std::error::Error + Send + Sync + 'static>(value: T) -> Self {
         Self::User {
@@ -126,13 +126,13 @@ impl ProtocolError {
     }
 }
 
-impl From<std::io::Error> for ProtocolError {
+impl From<std::io::Error> for AcceptError {
     fn from(err: std::io::Error) -> Self {
         Self::from_err(err)
     }
 }
 
-impl From<quinn::ClosedStream> for ProtocolError {
+impl From<quinn::ClosedStream> for AcceptError {
     fn from(err: quinn::ClosedStream) -> Self {
         Self::from_err(err)
     }
@@ -158,7 +158,7 @@ pub trait ProtocolHandler: Send + Sync + std::fmt::Debug + 'static {
     fn on_connecting(
         &self,
         connecting: Connecting,
-    ) -> impl Future<Output = Result<Connection, ProtocolError>> + Send {
+    ) -> impl Future<Output = Result<Connection, AcceptError>> + Send {
         async move {
             let conn = connecting.await?;
             Ok(conn)
@@ -177,7 +177,7 @@ pub trait ProtocolHandler: Send + Sync + std::fmt::Debug + 'static {
     fn accept(
         &self,
         connection: Connection,
-    ) -> impl Future<Output = Result<(), ProtocolError>> + Send;
+    ) -> impl Future<Output = Result<(), AcceptError>> + Send;
 
     /// Called when the router shuts down.
     ///
@@ -191,11 +191,11 @@ pub trait ProtocolHandler: Send + Sync + std::fmt::Debug + 'static {
 }
 
 impl<T: ProtocolHandler> ProtocolHandler for Arc<T> {
-    async fn on_connecting(&self, conn: Connecting) -> Result<Connection, ProtocolError> {
+    async fn on_connecting(&self, conn: Connecting) -> Result<Connection, AcceptError> {
         self.as_ref().on_connecting(conn).await
     }
 
-    async fn accept(&self, conn: Connection) -> Result<(), ProtocolError> {
+    async fn accept(&self, conn: Connection) -> Result<(), AcceptError> {
         self.as_ref().accept(conn).await
     }
 
@@ -205,11 +205,11 @@ impl<T: ProtocolHandler> ProtocolHandler for Arc<T> {
 }
 
 impl<T: ProtocolHandler> ProtocolHandler for Box<T> {
-    async fn on_connecting(&self, conn: Connecting) -> Result<Connection, ProtocolError> {
+    async fn on_connecting(&self, conn: Connecting) -> Result<Connection, AcceptError> {
         self.as_ref().on_connecting(conn).await
     }
 
-    async fn accept(&self, conn: Connection) -> Result<(), ProtocolError> {
+    async fn accept(&self, conn: Connection) -> Result<(), AcceptError> {
         self.as_ref().accept(conn).await
     }
 
@@ -227,7 +227,7 @@ pub(crate) trait DynProtocolHandler: Send + Sync + std::fmt::Debug + 'static {
     fn on_connecting(
         &self,
         connecting: Connecting,
-    ) -> Pin<Box<dyn Future<Output = Result<Connection, ProtocolError>> + Send + '_>> {
+    ) -> Pin<Box<dyn Future<Output = Result<Connection, AcceptError>> + Send + '_>> {
         Box::pin(async move {
             let conn = connecting.await?;
             Ok(conn)
@@ -238,7 +238,7 @@ pub(crate) trait DynProtocolHandler: Send + Sync + std::fmt::Debug + 'static {
     fn accept(
         &self,
         connection: Connection,
-    ) -> Pin<Box<dyn Future<Output = Result<(), ProtocolError>> + Send + '_>>;
+    ) -> Pin<Box<dyn Future<Output = Result<(), AcceptError>> + Send + '_>>;
 
     /// See [`ProtocolHandler::shutdown`].
     fn shutdown(&self) -> Pin<Box<dyn Future<Output = ()> + Send + '_>> {
@@ -250,14 +250,14 @@ impl<P: ProtocolHandler> DynProtocolHandler for P {
     fn accept(
         &self,
         connection: Connection,
-    ) -> Pin<Box<dyn Future<Output = Result<(), ProtocolError>> + Send + '_>> {
+    ) -> Pin<Box<dyn Future<Output = Result<(), AcceptError>> + Send + '_>> {
         Box::pin(<Self as ProtocolHandler>::accept(self, connection))
     }
 
     fn on_connecting(
         &self,
         connecting: Connecting,
-    ) -> Pin<Box<dyn Future<Output = Result<Connection, ProtocolError>> + Send + '_>> {
+    ) -> Pin<Box<dyn Future<Output = Result<Connection, AcceptError>> + Send + '_>> {
         Box::pin(<Self as ProtocolHandler>::on_connecting(self, connecting))
     }
 
@@ -519,11 +519,11 @@ impl<P: ProtocolHandler + Clone> ProtocolHandler for AccessLimit<P> {
     fn on_connecting(
         &self,
         conn: Connecting,
-    ) -> impl Future<Output = Result<Connection, ProtocolError>> + Send {
+    ) -> impl Future<Output = Result<Connection, AcceptError>> + Send {
         self.proto.on_connecting(conn)
     }
 
-    async fn accept(&self, conn: Connection) -> Result<(), ProtocolError> {
+    async fn accept(&self, conn: Connection) -> Result<(), AcceptError> {
         let remote = conn.remote_node_id()?;
         let is_allowed = (self.limiter)(remote);
         if !is_allowed {
@@ -572,7 +572,7 @@ mod tests {
     const ECHO_ALPN: &[u8] = b"/iroh/echo/1";
 
     impl ProtocolHandler for Echo {
-        async fn accept(&self, connection: Connection) -> Result<(), ProtocolError> {
+        async fn accept(&self, connection: Connection) -> Result<(), AcceptError> {
             println!("accepting echo");
             let (mut send, mut recv) = connection.accept_bi().await?;
 
@@ -619,7 +619,7 @@ mod tests {
         const TEST_ALPN: &[u8] = b"/iroh/test/1";
 
         impl ProtocolHandler for TestProtocol {
-            async fn accept(&self, connection: Connection) -> Result<(), ProtocolError> {
+            async fn accept(&self, connection: Connection) -> Result<(), AcceptError> {
                 self.connections.lock().expect("poisoned").push(connection);
                 Ok(())
             }