Struct Span 

pub struct Span { /* private fields */ }

An active span that accumulates events and attributes.

Created via SpanCollector::start_span (root) or Span::child (nested). Submits a CompletedSpan to the collector when dropped or when end() is called explicitly.

Internally holds Option<CompletedSpan> with end_time_ns = 0 until the span finishes. On drop, end_time_ns is set and the span is submitted — no field-by-field move between separate structs.

Implementations

impl Span

pub fn child(&self, name: impl Into<Cow<'static, str>>, kind: SpanKind) -> Span

Create a child span inheriting the trace ID and collector from this span.

The child’s parent_span_id is set to this span’s span_id. If this span is a no-op (sampled out), the child is also a no-op.

pub fn enter(&mut self) -> &mut Self

Set this span as the thread-local “current span” for logging integration.

The thread-local context is cleared when this span drops. Nested calls properly restore the previous context.

pub fn add_event( &mut self, name: impl Into<Cow<'static, str>>, attributes: Vec<SpanAttribute>, )

Add a timestamped event to this span.

Takes ownership of the attributes vector to avoid cloning.

pub fn add_simple_event(&mut self, name: impl Into<Cow<'static, str>>)

Add a timestamped event with no attributes.

pub fn set_attribute( &mut self, key: impl Into<Cow<'static, str>>, value: impl Into<SpanValue>, )

Set a span attribute.

pub fn set_status(&mut self, status: SpanStatus)

Set the span status.

pub fn trace_id(&self) -> TraceId

Get the trace ID of this span.

pub fn span_id(&self) -> SpanId

Get the span ID of this span.

pub fn traceparent(&self) -> String

Encode this span’s context as a W3C traceparent header for outgoing requests.

Returns an empty string for no-op (sampled-out) spans.

pub fn end(self)

Explicitly end the span and submit it to the collector.

Equivalent to dropping the span. After calling this, the span is consumed.

Trait Implementations

impl Drop for Span

fn drop(&mut self)

Executes the destructor for this type.