Struct TracingFieldBuilder 

pub struct TracingFieldBuilder { /* private fields */ }

Builder for TracingField metadata.

Implementations

impl TracingFieldBuilder

pub fn span_field(self, name: &'static str) -> Self

Set the span field name to extract from.

If not set, the context key (from registration) is used as the span field name for extraction.

pub fn record_as(self, name: &'static str) -> Self

Set the span field name to record into.

If not set, log_name is used as the span field name for recording. Use this when the span field you want to record into differs from the log output field name.

pub fn extract_from_str<T>( self, f: impl Fn(&str) -> Option<T> + Send + Sync + 'static, ) -> Self

where T: Clone + Send + Sync + Serialize + DeserializeOwned + 'static,

Extract from string span field values.

The closure receives the string value and returns Some(T) if conversion succeeds. set_context is called automatically.

pub fn extract_from_u64<T>( self, f: impl Fn(u64) -> Option<T> + Send + Sync + 'static, ) -> Self

where T: Clone + Send + Sync + Serialize + DeserializeOwned + 'static,

Extract from u64 span field values.

pub fn extract_from_i64<T>( self, f: impl Fn(i64) -> Option<T> + Send + Sync + 'static, ) -> Self

where T: Clone + Send + Sync + Serialize + DeserializeOwned + 'static,

Extract from i64 span field values.

pub fn extract_from_bool<T>( self, f: impl Fn(bool) -> Option<T> + Send + Sync + 'static, ) -> Self

where T: Clone + Send + Sync + Serialize + DeserializeOwned + 'static,

Extract from bool span field values.

pub fn enrich_display<T: Display + 'static>(self) -> Self

Enrich both log output and span fields using Display.

This is shorthand for calling both .enrich_log_display::<T>() and .enrich_span_display::<T>().

pub fn enrich_debug<T: Debug + 'static>(self) -> Self

Enrich both log output and span fields using Debug.

This is shorthand for calling both .enrich_log_debug::<T>() and .enrich_span_debug::<T>().

pub fn enrich_custom<T: 'static>( self, f: impl Fn(&T) -> String + Send + Sync + 'static, ) -> Self

Enrich both log output and span fields with a custom formatting function.

This is shorthand for calling both .enrich_log_custom::<T>(f) and .enrich_span_custom::<T>(f) with the same function.

pub fn enrich_log_display<T: Display + 'static>(self) -> Self

Enrich log output only using Display.

The value will appear in log events via WithContextFields but will NOT be automatically recorded into span fields.

pub fn enrich_log_debug<T: Debug + 'static>(self) -> Self

Enrich log output only using Debug.

pub fn enrich_log_custom<T: 'static>( self, f: impl Fn(&T) -> String + Send + Sync + 'static, ) -> Self

Enrich log output only with a custom formatting function.

pub fn enrich_span_display<T: Display + 'static>(self) -> Self

Record into span fields using Display.

On span enter, the current context value is formatted and recorded into the span field (must be pre-declared with tracing::field::Empty). Spans without the field are silently skipped.

pub fn enrich_span_debug<T: Debug + 'static>(self) -> Self

Record into span fields using Debug.

pub fn enrich_span_custom<T: 'static>( self, f: impl Fn(&T) -> String + Send + Sync + 'static, ) -> Self

Record into span fields with a custom formatting function.

On span enter, the current context value is passed to f and the result is recorded into the span field.

pub fn build(self) -> TracingField

Build the TracingField metadata.