Avoid repeatedly capturing the same callsite binding frame for each registered
handler. While the perf benefit of this change is minimal, the approach is also
conceptually cleaner.
When this feature is enabled (see `otel-tracing?`), Telemere's tracing
signal creators (`trace!`, `spy!`, etc.) will now manipulate OpenTelemetry's
span context when relevant.
Before this commit:
Telemere would detect and use OpenTelemetry span context, but
the inverse wasn't true: OpenTelemetry instrumentation wouldn't
recognize Telemere spans.
After this commit:
Telemere detects OpenTelemetry span context, and the inverse is
also true: OpenTelemetry instrumentation will recognize Telemere
spans.
The net effect:
When you use Telemere to trace forms that may themselves do
auto/manual OpenTelemetry instrumentation - the resulting spans
will now properly identify Telemere's spans as parents.
Note that this is interop is implemented in a unique way that retains
Telemere's usual benefits re: low costs at signal callsite, and ability
to skip costs when filtering / sampling / rate-limiting / etc.
On reflection the choice to drop ":" (and so type info) from ALL attribute
keywords seems excessive. We can instead restrict the change only to
the :level value.
Feedback welcome.
1. Added `*uid-fn*` to globally control uid style
2. Now distinguish between root and child uids
Root uids generally need to be longer.
3. Added to utils: `nano-uid-fn` and `hex-uid-fn`
These use new highly optimized implementations
when on JVM Clojure, and are highly flexible.
Tracing signals now include:
:parent {:keys [id uid instant]}
:root {:keys [id uid instant]}
The :instant info is undocumented, and useful for advanced cases like
the upcoming Span support for the OpenTelemetry handler.
