Struct TraceContext 

#[non_exhaustive]
pub struct TraceContext {
    pub trace_id: TraceId,
    pub parent_id: Option<SpanId>,
    pub flags: u8,
    pub tracestate: Option<HeaderValue>,
}

The trace a request belongs to.

Put in the request’s extensions by the host before the request reaches the REST pipeline or GraphQL, so anything downstream can find it without parsing the headers again.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

trace_id: TraceId

The trace the request is part of.

parent_id: Option<SpanId>

The caller’s span, when the request said which it was. None when the trace started here.

flags: u8

trace-flags as the caller sent them; bit 0 is “sampled”. Zero when the trace started here.

tracestate: Option<HeaderValue>

tracestate, carried as it came, for whatever propagates the trace on. Only kept beside a traceparent that parsed: the specification has it mean nothing on its own.

Implementations

impl TraceContext

pub fn root(trace_id: TraceId) -> Self

A trace that starts with this request.

pub fn from_headers(headers: &HeaderMap) -> Option<Self>

The trace the request’s traceparent and tracestate name, or None when there is no traceparent or it cannot be used.

More than one traceparent is refused rather than one of them picked: the specification leaves no way to tell which is meant. Several tracestate headers are one list split across lines, and are joined.

pub fn sampled(&self) -> bool

Whether the caller said this trace is being recorded.

Trait Implementations

impl Clone for TraceContext

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TraceContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for TraceContext

impl PartialEq for TraceContext

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for TraceContext