Struct Scanner 

pub struct Scanner { /* private fields */ }

Incrementally extracts RealUsage from a response stream (or a full body).

feed is called with raw response chunks and keeps only the trailing partial line buffered (O(1) memory beyond one line); finalize returns the merged usage once the stream ends.

Implementations

impl Scanner

pub fn new(provider: Provider, url_model: Option<String>) -> Self

pub fn with_cohort(self, cohort: Option<Arm>) -> Self

Tags the usage this scanner produces with an output-savings arm (#895).

pub fn with_wire_context(self, wire: Option<Box<WireContext>>) -> Self

Attaches the request-side gateway context (identity tags, wire savings, baseline inputs — enterprise#11/#17/#18) stamped onto the usage record.

pub fn with_header_cost(self, cost: Option<f64>) -> Self

Attaches a billed USD figure reported by the upstream via a response header (LiteLLM x-litellm-response-cost, or the operator-configured [proxy] cost_response_header, #1189). Applied at finalize only when the body did not already carry a measured cost — a body figure (OpenRouter usage.cost) is the bill itself and always wins.

pub fn feed(&mut self, chunk: &[u8])

Feeds a raw streaming chunk, scanning every complete line it completes.

pub fn feed_body(&mut self, body: &[u8])

Feeds a complete non-streaming JSON response body.

pub fn finalize(self) -> Option<RealUsage>

Consumes the scanner, flushing any trailing partial line (a final event may arrive without a newline) and returning the merged usage if any.