Module sse 

Decoding text/event-stream.

The encoder lives in ag-ui-core; this is the other half. It is a wire format parser fed by a network, so it assumes nothing about what it is handed: bytes arrive in arbitrary chunks that split lines, split UTF-8 sequences, and end without the terminating blank line the format calls for.

What it handles, because real servers and proxies do all of it:

• data: repeated over several lines, rejoined with \n — the format’s own way of carrying a payload that contains newlines.
• Comment lines (: keep-alive), which proxies inject to hold a connection open and which dispatch nothing.
• A body that ends without a blank line: SseDecoder::finish dispatches the last frame rather than dropping it.
• \n, \r\n and lone \r line endings, including a \r\n split across two chunks.
• A leading UTF-8 byte-order mark.
• A field with no colon, an empty field value, and unknown field names.
• A frame with no data field, which the format says not to dispatch.

What it refuses: invalid UTF-8, and a single frame larger than SseDecoder::max_frame_size — an unterminated line is otherwise an unbounded allocation driven by the other end. The cap is on the frame, not on the chunk: one read carrying a thousand complete frames is ordinary, and counting it against a per-frame limit would refuse a well-behaved server.

use ag_ui::client::transport::SseDecoder;

let mut decoder = SseDecoder::new();
decoder.push(b": keep-alive\n\ndata: {\"type\":\"RUN_ERROR\",\"mes")?;
assert!(decoder.next_frame()?.is_none());

decoder.push(b"sage\":\"boom\"}\n\n")?;
let frame = decoder.next_frame()?.expect("a complete frame");
assert_eq!(frame.into_event()?.event_type().as_str(), "RUN_ERROR");

Structs

SseDecoder

An incremental text/event-stream decoder.

SseFrame

One decoded text/event-stream frame.

Constants

DEFAULT_MAX_FRAME_SIZE

The default cap on one frame, before the decoder gives up: 8 MiB.

Functions

decode_events

Decodes a stream of byte chunks into a stream of events.