Struct TracingField 

pub struct TracingField { /* private fields */ }

Unified tracing metadata for a context key.

Controls three behaviors:

• Extract: populate a context variable from a tracing span field
• Enrich log: include the context value in log output
• Record span: record the context value into span fields

Created via TracingFieldBuilder:

use dcontext_tracing::TracingField;

builder.register_with::<String>("request_id", |opts| {
    opts.cached().with_metadata(
        TracingField::builder("rid")
            .extract_from_str(|s| Some(s.to_string()))
            .enrich_display::<String>()  // enables both log + span
            .build()
    )
});

Implementations

impl TracingField

pub fn builder(log_name: &'static str) -> TracingFieldBuilder

Start building a TracingField with the given log field name.

The log_name is the field name used in log output and (by default) span recording. It can differ from the context key.

pub fn log_name(&self) -> &'static str

The field name used in log output.

pub fn span_field(&self) -> Option<&'static str>

The span field name to extract from, if extraction is enabled.

pub fn record_field(&self) -> &'static str

The span field name to record into. Returns record_field if set, otherwise log_name.

pub fn has_extract(&self) -> bool

Whether this field has extraction enabled.

pub fn has_enrich(&self) -> bool

Whether this field has any enrichment enabled (log or span).

pub fn has_log_enrich(&self) -> bool

Whether this field has log enrichment enabled.

pub fn has_span_record(&self) -> bool

Whether this field has span recording enabled.

pub fn format(&self, any_val: &dyn Any) -> Option<String>

Format a type-erased value for log enrichment. Returns None if log enrichment is not enabled or the type doesn’t match.

pub fn format_for_span(&self, any_val: &dyn Any) -> Option<String>

Format a type-erased value for span recording. Returns None if span recording is not enabled or the type doesn’t match.