Struct SiftingLayer 

pub struct SiftingLayer<S, L, FnLB>
where
    S: Subscriber + for<'lookup> LookupSpan<'lookup>,
    L: TsLayer<S> + Send + Sync + 'static,
    FnLB: FnMut(&Selector, &Values) -> L,
{ /* private fields */ }

A tracing-subscriber Layer that sifts trough spans and forwards events to dynamically created Layers.

Just like all the layers it’s generic over S which is a Subscriber. It is also generic over L which is the dynamically created layer and FnLB (LB stand for Layer Builder) which is the closure responsible to create a new Layer at runtime.

The FnLB will receive a Selector and a SelectorValues and is responsible to create a unique layer for the specific set of SelectorValues. FnLB will be called once for every distinct set of SelectorValues.

Implementations

impl<S, L, FnLB> Layer<S, L, FnLB>

where S: Subscriber + for<'lookup> LookupSpan<'lookup>, L: TsLayer<S> + Send + Sync + 'static, FnLB: FnMut(&Selector, &Values) -> L,

pub fn new(sift_selector: Selector, layer_builder: FnLB) -> Self

To create a SiftingLayer a selector must be provided as well as a closure that creates layers based on the selectors values.

Trait Implementations

impl<S, L, FnLB> Layer<S> for Layer<S, L, FnLB>

where S: Subscriber + for<'lookup> LookupSpan<'lookup>, L: TsLayer<S> + Send + Sync + 'static, FnLB: FnMut(&Selector, &Values) -> L + 'static,

fn on_new_span( &self, attrs: &TSpanAttributes<'_>, id: &SpanId, ctx: Context<'_, S>, )

Notifies this layer that a new span was constructed with the given Attributes and Id.

fn on_record(&self, id: &SpanId, values: &TSpanRecord<'_>, ctx: Context<'_, S>)

Notifies this layer that a span with the given Id recorded the given values.

fn on_enter(&self, id: &SpanId, ctx: Context<'_, S>)

Notifies this layer that a span with the given ID was entered.

fn on_exit(&self, id: &SpanId, ctx: Context<'_, S>)

Notifies this layer that the span with the given ID was exited.

fn on_close(&self, id: SpanId, ctx: Context<'_, S>)

Notifies this layer that the span with the given ID has been closed.

fn on_event(&self, event: &TEvent<'_>, ctx: Context<'_, S>)

Notifies this layer that an event has occurred.

fn on_register_dispatch(&self, subscriber: &Dispatch)

Performs late initialization when installing this layer as a Subscriber.

fn on_layer(&mut self, subscriber: &mut S)

Performs late initialization when attaching a Layer to a Subscriber.

fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest

Registers a new callsite with this layer, returning whether or not the layer is interested in being notified about the callsite, similarly to Subscriber::register_callsite.

fn enabled(&self, metadata: &Metadata<'_>, ctx: Context<'_, S>) -> bool

Returns true if this layer is interested in a span or event with the given metadata in the current Context, similarly to Subscriber::enabled.

fn on_follows_from(&self, _span: &Id, _follows: &Id, _ctx: Context<'_, S>)

Notifies this layer that a span with the ID span recorded that it follows from the span with the ID follows.

fn event_enabled(&self, _event: &Event<'_>, _ctx: Context<'_, S>) -> bool

Called before on_event, to determine if on_event should be called.

fn on_id_change(&self, _old: &Id, _new: &Id, _ctx: Context<'_, S>)

Notifies this layer that a span ID has been cloned, and that the subscriber returned a different ID.

fn and_then<L>(self, layer: L) -> Layered<L, Self, S>

where L: Layer<S>, Self: Sized,

Composes this layer around the given Layer, returning a Layered struct implementing Layer.

fn with_subscriber(self, inner: S) -> Layered<Self, S>

where Self: Sized,

Composes this Layer with the given Subscriber, returning a Layered struct that implements Subscriber.

fn with_filter<F>(self, filter: F) -> Filtered<Self, F, S>

where Self: Sized, F: Filter<S>,

Available on crate features registry and std only.

Combines self with a Filter, returning a Filtered layer.

fn boxed(self) -> Box<dyn Layer<S> + Sync + Send>

where Self: Sized + Layer<S> + Send + Sync + 'static, S: Subscriber,

Available on crate features alloc or std only.

Erases the type of this Layer, returning a Boxed dyn Layer trait object.