Struct tracing_subscriber::registry::SpanRef

pub struct SpanRef<'a, R: LookupSpan<'a>> { /* fields omitted */ }

A reference to span data and the associated registry.

This type implements all the same methods as SpanData, and provides additional methods for querying the registry based on values from the span.

Methods

impl<'a, R> SpanRef<'a, R> where
    R: LookupSpan<'a>, 

pub fn id(&self) -> Id

Returns this span's ID.

pub fn metadata(&self) -> &'static Metadata<'static>

Returns a static reference to the span's metadata.

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

Returns the span's name,

pub fn fields(&self) -> &FieldSet

Returns a list of fields defined by the span.

pub fn parent_id(&self) -> Option<&Id>

Returns the ID of this span's parent, or None if this span is the root of its trace tree.

pub fn parent(&self) -> Option<Self>

Returns a SpanRef describing this span's parent, or None if this span is the root of its trace tree.

Important traits for Parents<'a, R>

impl<'a, R> Iterator for Parents<'a, R> where
    R: LookupSpan<'a>,  type Item = SpanRef<'a, R>;

pub fn parents(&self) -> Parents<'a, R>

Returns an iterator over all parents of this span, starting with the immediate parent.

The iterator will first return the span's immediate parent, followed by that span's parent, followed by that span's parent, and so on, until a it reaches a root span.

Important traits for FromRoot<'span, R>

impl<'span, R> Iterator for FromRoot<'span, R> where
    R: LookupSpan<'span>,  type Item = SpanRef<'span, R>;

pub fn from_root(&self) -> FromRoot<'a, R>

Returns an iterator over all parents of this span, starting with the root of the trace tree.

The iterator will return the root of the trace tree, followed by the next span, and then the next, until this span's immediate parent is returned.

Note: if the "smallvec" feature flag is not enabled, this may allocate.

pub fn extensions(&self) -> Extensions

Returns a reference to this span's Extensions.

The extensions may be used by Layers to store additional data describing the span.

pub fn extensions_mut(&self) -> ExtensionsMut

Returns a mutable reference to this span's Extensions.

The extensions may be used by Layers to store additional data describing the span.

Trait Implementations

impl<'a, R: Debug + LookupSpan<'a>> Debug for SpanRef<'a, R> where
    R::Data: Debug, 

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.