Module holochain_tracing::span

Span.

How to inject/extract a span

You can inject/extract the context of a span by using SpanContext::inject_to_xxx and SpanContext::extract_from_xxx methods respectively.

The simplest way is to use HashMap as the carrier as follows:

use std::collections::HashMap;
use rustracing_jaeger::span::SpanContext;

// Extraction
let mut carrier = HashMap::new();
carrier.insert(
    "uber-trace-id".to_string(),  // NOTE: The key must be lower-case
    "6309ab92c95468edea0dc1a9772ae2dc:409423a204bc17a8:0:1".to_string(),
);
let context = SpanContext::extract_from_text_map(&carrier)?.unwrap();
let trace_id = context.state().trace_id();
assert_eq!(trace_id.to_string(), "6309ab92c95468edea0dc1a9772ae2dc");

// Injection
let mut injected_carrier = HashMap::new();
context.inject_to_text_map(&mut injected_carrier)?;
assert_eq!(injected_carrier, carrier);

References

• constants.go
• context.go
• propagation.go

Structs

SpanContextState	Jaeger specific span context state.
SpanContextStateBuilder	SpanContextState builder.
TraceId	Unique 128bit identifier of a trace.

Type Definitions

CandidateSpan	Candidate span for tracing.
FinishedSpan	Finished span.
Span	Span.
SpanContext	Span context.
SpanHandle	Span handle.
SpanReceiver	Span receiver.
SpanReference	Span reference.
SpanSender	Sender of finished spans to the destination channel.
StartSpanOptions	Options for starting a span.