Struct Sse 

pub struct Sse<H> { /* private fields */ }

A Handler that responds to requests with a server-sent event stream.

Build one from any SseHandler with Sse::new or sse. Unlike SseConnExt::with_sse_stream, this can send heartbeat comments, because it obtains a runtime from the server at startup.

The conn is passed through untouched — continuing on to subsequent handlers — if the request’s Accept header excludes text/event-stream, or if SseHandler::connect returns None. A request with no Accept header accepts anything, per RFC 9110 §12.5.1.

Implementations

impl<H: SseHandler> Sse<H>

pub fn new(handler: H) -> Self

Builds a new Sse handler from any SseHandler.

pub fn with_heartbeat(self, heartbeat: Duration) -> Self

Sends an empty comment whenever heartbeat elapses without the stream yielding an event.

The interval is measured from the most recent event, not from the start of the response, so a busy stream sends no heartbeats at all. Clients discard the comment.

This is a contract about what the server sends, not a guarantee about the connection. Regular traffic makes an idle stream less likely to be dropped by an intermediary, and makes the server notice a departed client sooner — it only learns of one when it next writes — but neither is assured.

Trait Implementations

impl<H> Debug for Sse<H>

where H: Debug,

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

Formats the value using the given formatter.

impl<H: SseHandler> Handler for Sse<H>

async fn run(&self, conn: Conn) -> Conn

Executes this handler, performing any modifications to the Conn that are desired.

async fn init(&mut self, info: &mut Info)

Performs one-time async set up on a mutable borrow of the Handler before the server starts accepting requests. This allows a Handler to be defined in synchronous code but perform async setup such as establishing a database connection or fetching some state from an external source. This is optional, and chances are high that you do not need this.

fn before_send(&self, conn: Conn) -> impl Future<Output = Conn> + Send

Performs any final modifications to this conn after all handlers have been run. Although this is a slight deviation from the simple conn->conn->conn chain represented by most Handlers, it provides an easy way for libraries to effectively inject a second handler into a response chain. This is useful for loggers that need to record information both before and after other handlers have run, as well as database transaction handlers and similar library code.

fn has_upgrade(&self, upgrade: &Upgrade) -> bool

predicate function answering the question of whether this Handler would like to take ownership of the negotiated Upgrade. If this returns true, you must implement Handler::upgrade. The first handler that responds true to this will receive ownership of the trillium::Upgrade in a subsequent call to Handler::upgrade

fn upgrade(&self, upgrade: Upgrade) -> impl Future<Output = ()> + Send

This will only be called if the handler reponds true to Handler::has_upgrade and will only be called once for this upgrade. There is no return value, and this function takes exclusive ownership of the underlying transport once this is called. You can downcast the transport to whatever the source transport type is and perform any non-http protocol communication that has been negotiated. You probably don’t want this unless you’re implementing something like websockets. Please note that for many transports such as TcpStreams, dropping the transport (and therefore the Upgrade) will hang up / disconnect.

fn name(&self) -> Cow<'static, str>

Customize the name of your handler. This is used in Debug implementations. The default is the type name of this handler.