core: rename Subscriber to Collect (#1015)

This PR renames the following:

- `tracing_core::Subscriber` to `tracing_core::Collect`
- `tracing_subscriber::layer::Layer` to `tracing_subscriber::layer::Subscribe`

Authored-by: David Barsksy <[email protected]>
Co-authored-by: Eliza Weisman <[email protected]>

Author: davidbarsky

tracing-opentelemetry/src/layer.rs

@@ -5,12 +5,12 @@ use std::fmt;
 use std::marker;
 use std::time::SystemTime;
 use tracing_core::span::{self, Attributes, Id, Record};
-use tracing_core::{field, Event, Subscriber};
+use tracing_core::{field, Collect, Event};
 #[cfg(feature = "tracing-log")]
 use tracing_log::NormalizeEvent;
-use tracing_subscriber::layer::Context;
 use tracing_subscriber::registry::LookupSpan;
-use tracing_subscriber::Layer;
+use tracing_subscriber::subscribe::Context;
+use tracing_subscriber::Subscribe;
 
 static SPAN_NAME_FIELD: &str = "otel.name";
 static SPAN_KIND_FIELD: &str = "otel.kind";
@@ -29,7 +29,7 @@ pub struct OpenTelemetryLayer<S, T> {
 
 impl<S> Default for OpenTelemetryLayer<S, api::NoopTracer>
 where
-    S: Subscriber + for<'span> LookupSpan<'span>,
+    S: Collect + for<'span> LookupSpan<'span>,
 {
     fn default() -> Self {
         OpenTelemetryLayer::new(api::NoopTracer {})
@@ -43,7 +43,7 @@ where
 /// # Examples
 ///
 /// ```rust,no_run
-/// use tracing_subscriber::layer::SubscriberExt;
+/// use tracing_subscriber::subscribe::CollectorExt;
 /// use tracing_subscriber::Registry;
 ///
 /// // Use the tracing subscriber `Registry`, or any other subscriber
@@ -53,7 +53,7 @@ where
 /// ```
 pub fn layer<S>() -> OpenTelemetryLayer<S, api::NoopTracer>
 where
-    S: Subscriber + for<'span> LookupSpan<'span>,
+    S: Collect + for<'span> LookupSpan<'span>,
 {
     OpenTelemetryLayer::default()
 }
@@ -261,7 +261,7 @@ impl<'a> field::Visit for SpanAttributeVisitor<'a> {
 
 impl<S, T> OpenTelemetryLayer<S, T>
 where
-    S: Subscriber + for<'span> LookupSpan<'span>,
+    S: Collect + for<'span> LookupSpan<'span>,
     T: api::Tracer + PreSampledTracer + 'static,
 {
     /// Set the [`Tracer`] that this layer will use to produce and track
@@ -275,7 +275,7 @@ where
     /// ```rust,no_run
     /// use opentelemetry::{api::Provider, sdk};
     /// use tracing_opentelemetry::OpenTelemetryLayer;
-    /// use tracing_subscriber::layer::SubscriberExt;
+    /// use tracing_subscriber::subscribe::CollectorExt;
     /// use tracing_subscriber::Registry;
     ///
     /// // Create a jaeger exporter for a `trace-demo` service.
@@ -325,7 +325,7 @@ where
     ///
     /// ```rust,no_run
     /// use opentelemetry::{api::Provider, sdk};
-    /// use tracing_subscriber::layer::SubscriberExt;
+    /// use tracing_subscriber::subscribe::CollectorExt;
     /// use tracing_subscriber::Registry;
     ///
     /// // Create a jaeger exporter for a `trace-demo` service.
@@ -424,9 +424,9 @@ where
     }
 }
 
-impl<S, T> Layer<S> for OpenTelemetryLayer<S, T>
+impl<S, T> Subscribe<S> for OpenTelemetryLayer<S, T>
 where
-    S: Subscriber + for<'span> LookupSpan<'span>,
+    S: Collect + for<'span> LookupSpan<'span>,
     T: api::Tracer + PreSampledTracer + 'static,
 {
     /// Creates an [OpenTelemetry `Span`] for the corresponding [tracing `Span`].
@@ -627,7 +627,7 @@ mod tests {
         let tracer = TestTracer(Arc::new(Mutex::new(None)));
         let subscriber = tracing_subscriber::registry().with(layer().with_tracer(tracer.clone()));
 
-        tracing::subscriber::with_default(subscriber, || {
+        tracing::collect::with_default(subscriber, || {
             tracing::debug_span!("static_name", otel.name = dynamic_name.as_str());
         });
 
@@ -640,7 +640,7 @@ mod tests {
         let tracer = TestTracer(Arc::new(Mutex::new(None)));
         let subscriber = tracing_subscriber::registry().with(layer().with_tracer(tracer.clone()));
 
-        tracing::subscriber::with_default(subscriber, || {
+        tracing::collect::with_default(subscriber, || {
             tracing::debug_span!("request", otel.kind = "Server");
         });
 
@@ -661,7 +661,7 @@ mod tests {
         )));
         let _g = existing_cx.attach();
 
-        tracing::subscriber::with_default(subscriber, || {
+        tracing::collect::with_default(subscriber, || {
             tracing::debug_span!("request", otel.kind = "Server");
         });
 

tracing-opentelemetry/src/lib.rs

@@ -53,7 +53,7 @@
 //! ```
 //! use opentelemetry::{api::Provider, sdk};
 //! use tracing::{error, span};
-//! use tracing_subscriber::layer::SubscriberExt;
+//! use tracing_subscriber::subscribe::CollectorExt;
 //! use tracing_subscriber::Registry;
 //!
 //! // Create a new tracer
@@ -65,7 +65,7 @@
 //! let subscriber = Registry::default().with(telemetry);
 //!
 //! // Trace executed code
-//! tracing::subscriber::with_default(subscriber, || {
+//! tracing::collect::with_default(subscriber, || {
 //!     // Spans will be sent to the configured OpenTelemetry exporter
 //!     let root = span!(tracing::Level::TRACE, "app_start", work_units = 2);
 //!     let _enter = root.enter();
@@ -98,7 +98,7 @@
 )]
 #![cfg_attr(docsrs, deny(broken_intra_doc_links))]
 
-/// Implementation of the trace::Layer as a source of OpenTelemetry data.
+/// Implementation of the trace::Subscriber as a source of OpenTelemetry data.
 mod layer;
 /// Span extension which enables OpenTelemetry context management.
 mod span_ext;

tracing-opentelemetry/src/span_ext.rs

@@ -74,9 +74,9 @@ pub trait OpenTelemetrySpanExt {
 
 impl OpenTelemetrySpanExt for tracing::Span {
     fn set_parent(&self, parent_context: &api::Context) {
-        self.with_subscriber(move |(id, subscriber)| {
-            if let Some(get_context) = subscriber.downcast_ref::<WithContext>() {
-                get_context.with_context(subscriber, id, move |builder, _tracer| {
+        self.with_collector(move |(id, collector)| {
+            if let Some(get_context) = collector.downcast_ref::<WithContext>() {
+                get_context.with_context(collector, id, move |builder, _tracer| {
                     builder.parent_context = parent_context.remote_span_context().cloned()
                 });
             }
@@ -85,9 +85,9 @@ impl OpenTelemetrySpanExt for tracing::Span {
 
     fn context(&self) -> api::Context {
         let mut span_context = None;
-        self.with_subscriber(|(id, subscriber)| {
-            if let Some(get_context) = subscriber.downcast_ref::<WithContext>() {
-                get_context.with_context(subscriber, id, |builder, tracer| {
+        self.with_collector(|(id, collector)| {
+            if let Some(get_context) = collector.downcast_ref::<WithContext>() {
+                get_context.with_context(collector, id, |builder, tracer| {
                     span_context = Some(tracer.sampled_span_context(builder));
                 })
             }