Function foundations::telemetry::tracing::start_trace

pub fn start_trace(
    root_span_name: impl Into<Cow<'static, str>>,
    options: StartTraceOptions
) -> SpanScope

Available on (crate features logging or metrics or telemetry or tracing) and crate feature tracing only.

Starts a new trace. Ends the current one if it is available and links the new one with it.

Can also be used to stitch traces with the context received from other services, and can force enable or disable tracing of certain code parts by overriding the sampling ratio.

Examples

use foundations::telemetry::TelemetryContext;
use foundations::telemetry::tracing::{self, test_trace, StartTraceOptions};

// Test context is used for demonstration purposes to show the resulting traces.
let ctx = TelemetryContext::test();
let _scope = ctx.scope();

{
    let _root = tracing::span("root");

    {
        let _span1 = tracing::span("span1");
    }

    let _new_root_span = tracing::start_trace(
        "new root",
        Default::default(),
    );

    let _span2 = tracing::span("span2");
}

assert_eq!(
    ctx.traces(Default::default()),
    vec![
        test_trace! {
            "root" => {
                "span1",
                "[new root ref]"
            }
        },
        test_trace! {
            "new root" => {
                "span2"
            }
        }
    ]
);