make Tracer::Clone cheaper #1092 (#1093)

Author: shaun-cox

opentelemetry-sdk/src/trace/provider.rs

@@ -135,8 +135,12 @@ impl opentelemetry_api::trace::TracerProvider for TracerProvider {
         } else {
             name
         };
-        let instrumentation_lib =
-            InstrumentationLibrary::new(component_name, version, schema_url, attributes);
+        let instrumentation_lib = Arc::new(InstrumentationLibrary::new(
+            component_name,
+            version,
+            schema_url,
+            attributes,
+        ));
 
         Tracer::new(instrumentation_lib, Arc::downgrade(&self.inner))
     }

opentelemetry-sdk/src/trace/tracer.rs

@@ -22,12 +22,12 @@ use opentelemetry_api::trace::{
 };
 use opentelemetry_api::{Context, Key, KeyValue, OrderMap, Value};
 use std::fmt;
-use std::sync::Weak;
+use std::sync::{Arc, Weak};
 
 /// `Tracer` implementation to create and manage spans
 #[derive(Clone)]
 pub struct Tracer {
-    instrumentation_lib: InstrumentationLibrary,
+    instrumentation_lib: Arc<InstrumentationLibrary>,
     provider: Weak<TracerProviderInner>,
 }
 
@@ -45,7 +45,7 @@ impl fmt::Debug for Tracer {
 impl Tracer {
     /// Create a new tracer (used internally by `TracerProvider`s).
     pub(crate) fn new(
-        instrumentation_lib: InstrumentationLibrary,
+        instrumentation_lib: Arc<InstrumentationLibrary>,
         provider: Weak<TracerProviderInner>,
     ) -> Self {
         Tracer {