rama::http::body::sse

Struct EventDecoder

pub struct EventDecoder<T = String>where
    T: EventDataRead,
{ /* private fields */ }

Available on crate features http and std only.

Expand description

Push-driven decoder turning raw SSE bytes into Events.

Push borrowed chunks to inspect an SSE body while forwarding it unchanged. Use EventStream to decode a stream of chunks instead.

Push a chunk, drain what it completed, repeat, and call finish once the body ends:

use rama_http_types::sse::EventDecoder;

let mut decoder = EventDecoder::<String>::new();

for chunk in [&b"data: hello\n"[..], b"\ndata: wor", b"ld\n\n"] {
    decoder.push(chunk)?;
    for event in decoder.events() {
        let event = event?;
        assert!(matches!(event.data(), Some(data) if data == "hello" || data == "world"));
    }
}
decoder.finish()?;

Chunks may split lines, UTF-8 sequences and CRLF pairs anywhere. Partial lines and undecoded chunk tails are buffered.

Events dispatch on blank lines. finish is optional; it checks trailing UTF-8 without dispatching an event. on_incomplete receives the buffered partial line on finish or drop.

Input is unlimited by default. For untrusted input, set max_line_len and max_event_len. These limits do not cap the undecoded backlog; drain events between pushes.

A decode error is fatal by default. lenient mode instead recovers to the next event boundary, losing only the events around the fault — useful when observing a stream that must not be blinded by one bad event.

Implementations§

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impl<T> EventDecoder<T>
where T: EventDataRead,

pub fn new() -> EventDecoder<T>

Create a new EventDecoder.

pub fn maybe_with_max_line_len(self, max: Option<usize>) -> EventDecoder<T>

Fail decoding once a single line grows past max bytes, terminator excluded.

pub fn maybe_set_max_line_len( &mut self, max: Option<usize>, ) -> &mut EventDecoder<T>

Fail decoding once a single line grows past max bytes, terminator excluded.

pub fn with_max_line_len(self, max: usize) -> EventDecoder<T>

Fail decoding once a single line grows past max bytes, terminator excluded.

pub fn set_max_line_len(&mut self, max: usize) -> &mut EventDecoder<T>

Fail decoding once a single line grows past max bytes, terminator excluded.

pub fn without_max_line_len(self) -> EventDecoder<T>

Fail decoding once a single line grows past max bytes, terminator excluded.

pub fn unset_max_line_len(&mut self) -> &mut EventDecoder<T>

Fail decoding once a single line grows past max bytes, terminator excluded.

pub fn maybe_with_max_event_len(self, max: Option<usize>) -> EventDecoder<T>

Fail decoding once an event exceeds max raw line bytes. Includes field names, separators, comments, unknown fields and partial lines; excludes line terminators. Resets per event.

pub fn maybe_set_max_event_len( &mut self, max: Option<usize>, ) -> &mut EventDecoder<T>

Fail decoding once an event exceeds max raw line bytes. Includes field names, separators, comments, unknown fields and partial lines; excludes line terminators. Resets per event.

pub fn with_max_event_len(self, max: usize) -> EventDecoder<T>

Fail decoding once an event exceeds max raw line bytes. Includes field names, separators, comments, unknown fields and partial lines; excludes line terminators. Resets per event.

pub fn set_max_event_len(&mut self, max: usize) -> &mut EventDecoder<T>

Fail decoding once an event exceeds max raw line bytes. Includes field names, separators, comments, unknown fields and partial lines; excludes line terminators. Resets per event.

pub fn without_max_event_len(self) -> EventDecoder<T>

Fail decoding once an event exceeds max raw line bytes. Includes field names, separators, comments, unknown fields and partial lines; excludes line terminators. Resets per event.

pub fn unset_max_event_len(&mut self) -> &mut EventDecoder<T>

Fail decoding once an event exceeds max raw line bytes. Includes field names, separators, comments, unknown fields and partial lines; excludes line terminators. Resets per event.

pub fn maybe_with_on_incomplete( self, cb: Option<Box<dyn FnOnce(Vec<u8>) + Sync + Send>>, ) -> EventDecoder<T>

Pass a nonempty buffered partial line to cb at most once, on finish or drop.

Bytes may contain invalid UTF-8. Completed lines from an unfinished event and undrained input are excluded.

pub fn maybe_set_on_incomplete( &mut self, cb: Option<Box<dyn FnOnce(Vec<u8>) + Sync + Send>>, ) -> &mut EventDecoder<T>

Pass a nonempty buffered partial line to cb at most once, on finish or drop.

Bytes may contain invalid UTF-8. Completed lines from an unfinished event and undrained input are excluded.

pub fn with_on_incomplete( self, cb: Box<dyn FnOnce(Vec<u8>) + Sync + Send>, ) -> EventDecoder<T>

Pass a nonempty buffered partial line to cb at most once, on finish or drop.

Bytes may contain invalid UTF-8. Completed lines from an unfinished event and undrained input are excluded.

pub fn set_on_incomplete( &mut self, cb: Box<dyn FnOnce(Vec<u8>) + Sync + Send>, ) -> &mut EventDecoder<T>

Pass a nonempty buffered partial line to cb at most once, on finish or drop.

Bytes may contain invalid UTF-8. Completed lines from an unfinished event and undrained input are excluded.

pub fn without_on_incomplete(self) -> EventDecoder<T>

Pass a nonempty buffered partial line to cb at most once, on finish or drop.

Bytes may contain invalid UTF-8. Completed lines from an unfinished event and undrained input are excluded.

pub fn unset_on_incomplete(&mut self) -> &mut EventDecoder<T>

Pass a nonempty buffered partial line to cb at most once, on finish or drop.

Bytes may contain invalid UTF-8. Completed lines from an unfinished event and undrained input are excluded.

pub fn with_lenient(self, lenient: bool) -> EventDecoder<T>

Recover from a decode fault instead of failing the whole stream.

When on, a fault drops the event being built and skips to the next blank line, then resumes — losing only the events around it, never the rest of the stream. Off by default. See resync_count and with_on_resync to observe recovery.

pub fn set_lenient(&mut self, lenient: bool) -> &mut EventDecoder<T>

Recover from a decode fault instead of failing the whole stream.

When on, a fault drops the event being built and skips to the next blank line, then resumes — losing only the events around it, never the rest of the stream. Off by default. See resync_count and with_on_resync to observe recovery.