Struct LlmStreamWrapper 

pub struct LlmStreamWrapper { /* private fields */ }

Wraps an inner Stream<Item = Result<Json>> of raw chunks and:

1. Passes each chunk to the user-supplied collector closure. If the collector returns Err, the stream terminates with that error.
2. On stream exhaustion, calls the finalizer to produce an aggregated Json response, runs sanitize response guardrails on it, then emits the LLM END event.

This type is returned by crate::api::llm::llm_stream_call_execute and is usually consumed as an ordinary async stream. The wrapper preserves the originating scope stack so end-of-stream bookkeeping still uses the correct scope-local middleware and subscribers even when polling happens elsewhere.

Implementations

impl LlmStreamWrapper

pub fn new( inner: Pin<Box<dyn Stream<Item = Result<Json>> + Send>>, handle: LlmHandle, collector: Box<dyn FnMut(Json) -> Result<()> + Send>, finalizer: Box<dyn FnOnce() -> Json + Send>, _data: Option<Json>, metadata: Option<Json>, response_codec: Option<Arc<dyn LlmResponseCodec>>, ) -> Self

Create a new LlmStreamWrapper around the given raw stream.

Captures the current ScopeStackHandle at creation time so the correct scope stack is used when the stream is later polled, even if polling happens on a different task or thread.

Parameters

• inner: Raw stream of JSON chunks from the provider callback.
• handle: LlmHandle identifying the managed LLM span.
• collector: Per-chunk callback used to accumulate stream state or forward chunks elsewhere. Returning Err terminates the stream.
• finalizer: One-shot callback invoked when the stream finishes to synthesize the aggregated response payload.
• data: Retained compatibility payload; Agent Trajectory Observability Format (ATOF) end data is the finalized response.
• metadata: Optional event metadata merged into the emitted LLM-end event.
• response_codec: Optional codec used to derive annotated response metadata from the aggregated final payload.

Returns

A new LlmStreamWrapper ready to be polled.

pub fn scope_stack(&self) -> &ScopeStackHandle

Return the captured scope stack handle for this stream.

Callers can use this to bind the correct scope stack when spawning the stream on a different task via TASK_SCOPE_STACK.scope(...).

Returns

A shared reference to the ScopeStackHandle captured when the stream wrapper was created.

Trait Implementations

impl Drop for LlmStreamWrapper

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.

impl Stream for LlmStreamWrapper

type Item = Result<Value, FlowError>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.