Struct EventStreamWriter 

pub struct EventStreamWriter { /* private fields */ }

Producer helper for a streaming HTTP response — thin sugar over plain event sends to the caller’s reply route (Java EventStreamWriter).

Implementations

impl EventStreamWriter

pub fn new( platform: &Platform, reply_to: &str, correlation_id: Option<&str>, ) -> Result<Self, AppError>

Create a writer for a reply route and correlation id.

Returns HTTP-400 when the reply route is empty — a streaming producer without a reply address has nowhere to stream.

pub fn from_request( platform: &Platform, request: &EventEnvelope, ) -> Result<Self, AppError>

Create a writer from the incoming request envelope (the usual form for an interceptor function).

pub fn first(&mut self, status: i32, content_type: &str) -> &mut Self

Optional head control carried by the first outgoing event: response status and content type. Later events cannot change the head.

pub fn first_with_ttl( &mut self, status: i32, content_type: &str, ttl_seconds: u64, ) -> &mut Self

Head control plus an idle-allowance override in seconds between segments (rides the first event as the x-ttl envelope header).

pub async fn write<T: Serialize>(&mut self, segment: T) -> Result<(), AppError>

Send one data segment (String, bytes or map — any serializable body).

pub async fn write_named<T: Serialize>( &mut self, event_name: &str, segment: T, ) -> Result<(), AppError>

Send one named segment — the name maps to the SSE event: field.

pub async fn close(&mut self) -> Result<(), AppError>

Declare end of transmission.

pub async fn close_with<T: Serialize>( &mut self, metadata: T, ) -> Result<(), AppError>

Declare end of transmission with trailing metadata (rendered as the terminal SSE event’s data; ignored in chunked mode).

pub async fn fail(&mut self, error: &AppError) -> Result<(), AppError>

Declare an in-band failure and end the stream.

pub fn is_closed(&self) -> bool

True when the stream has been closed or failed.