Struct PrintTreeLayer

pub struct PrintTreeLayer { /* private fields */ }

GraphLayer (internally called layer::graph) This Layer prints a call graph to stdout. Please note that this layer both prints data about spans and events. Spans from the threads other than the main thread are not printed. Events from the main thread are attached to the latest main thread span. Depending on the Config::accumulate_events setting, the layer will either print the events of each span or accumulate the events of the children into the parent.

example output:

cargo test all_layers -- --nocapture

running 1 test
root span [ 178.94µs | 100.00% ]
Events:
  event in span2: 1
  event in span3 { field5: value5 }: 2

├── child span1 [ 4.63µs | 2.59% ] { field1 = value1 }
└── child span2 [ 93.40µs | 52.20% ] { field2 = value2 }
    Events:
      event in span2: 1
      event in span3 { field5: value5 }: 2
     
   ├── child span3 [ 15.47µs | 8.64% ] { field3 = value3 }
   │   Events:
   │     event in span3 { field5: value5 }: 2
   │   
   └── child span4 [ 2.87µs | 1.60% ] { field4 = value4 }

test tests::all_layers ... ok

Implementations

impl Layer

pub fn new(config: Config) -> (Self, Guard)

Trait Implementations

impl<S> Layer<S> for Layer

where S: Subscriber + for<'lookup> LookupSpan<'lookup>,

fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, _ctx: Context<'_, S>)

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

fn on_record(&self, id: &Id, values: &Record<'_>, _ctx: Context<'_, S>)

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

fn on_enter(&self, id: &Id, _ctx: Context<'_, S>)

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

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

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

fn on_event(&self, event: &Event<'_>, 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_close(&self, _id: Id, _ctx: Context<'_, S>)

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

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>,

Combines self with a Filter, returning a Filtered layer.

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

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

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