Struct ProtocolListener 

pub struct ProtocolListener { /* private fields */ }

Accept inbound WebSocket peers and drive each one through the protocol-client state machine. Construct via ProtocolClientBuilder::listen.

Sendspin’s protocol-client/server roles are independent of who initiates the TCP connection — the protocol-client always sends client/hello first. This listener handles the server-initiated case; the ProtocolClient returned by Self::accept is indistinguishable in shape from one returned by ProtocolClientBuilder::connect.

Self::accept drives the full protocol handshake before returning, so it serves one inbound connection at a time — a slow handshake blocks the next accept(). If you need concurrent handshakes, or want to own the transport (custom TLS, HTTP routing, …), accept your own streams and drive ProtocolClientBuilder::accept on each, tokio::spawn-ing per peer.

The Sendspin spec allows multiple servers to initiate connections to the same client. The keep-or-switch policy belongs to the application: read ProtocolClient::server_hello for server_id and connection_reason, compare against your persisted last-played server, and send GoodbyeReason::AnotherServer to the loser. This listener does not enforce a policy.

Practical notes:

• Disconnect consumes the handle. Call ProtocolClient::disconnect pre-split, or connection.guard.disconnect(...) post-split.
• Self::accept is serial. If the loser’s goodbye is on the critical path, run it on a spawned task so the next inbound peer can handshake while the previous one is tearing down.

Implementations

impl ProtocolListener

pub fn path(self, path: impl Into<String>) -> Self

Restrict accepted connections to a specific HTTP path. Mismatches are rejected with HTTP 404 during the WebSocket handshake; the listener stays bound. Defaults to accepting any path.

Matching is exact: /sendspin does not match /sendspin/. A missing leading slash is added, so "sendspin" and "/sendspin" are equivalent — request paths always start with /, and the raw form would otherwise reject every connection.

pub async fn accept(&self) -> Result<(ProtocolClient, SocketAddr), Error>

Accept the next inbound connection, returning the driven ProtocolClient and the peer’s address. Performs the WebSocket handshake and protocol-client hello/state exchange.

Per-peer failures surface as Error without affecting the listener; callers typically call accept() in a loop.

Not cancel-safe: dropping the returned future mid-handshake tears down that connection. A peer that connects but stalls the handshake will block this future indefinitely, so wrap it in a timeout if untrusted peers can reach the socket.

pub fn local_addr(&self) -> Result<SocketAddr, Error>

Local bound address.

Trait Implementations

impl Debug for ProtocolListener

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.