Builder for tracer

Author: izquierdo

opentelemetry/src/trace/tracer_provider.rs

@@ -1,4 +1,4 @@
-use crate::{trace::Tracer, InstrumentationLibrary, KeyValue};
+use crate::{trace::Tracer, InstrumentationLibrary, InstrumentationLibraryBuilder, KeyValue};
 use std::{borrow::Cow, sync::Arc};
 
 /// Types that can create instances of [`Tracer`].
@@ -45,48 +45,11 @@ pub trait TracerProvider {
         )
     }
 
-    /// Returns a new versioned tracer with a given name.
-    ///
-    /// The `name` should be the application name or the name of the library
-    /// providing instrumentation. If the name is empty, then an
-    /// implementation-defined default name may be used instead.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use opentelemetry::{global, trace::TracerProvider};
-    ///
-    /// let provider = global::tracer_provider();
-    ///
-    /// // tracer used in applications/binaries
-    /// let tracer = provider.tracer("my_app");
-    ///
-    /// // tracer used in libraries/crates that optionally includes version and schema url
-    /// let tracer = provider.versioned_tracer(
-    ///     "my_library",
-    ///     Some(env!("CARGO_PKG_VERSION")),
-    ///     Some("https://opentelemetry.io/schema/1.0.0"),
-    ///     None,
-    /// );
-    /// ```
-    fn versioned_tracer(
-        &self,
-        name: impl Into<Cow<'static, str>>,
-        version: Option<impl Into<Cow<'static, str>>>,
-        schema_url: Option<impl Into<Cow<'static, str>>>,
-        attributes: Option<Vec<KeyValue>>,
-    ) -> Self::Tracer {
-        let mut builder = InstrumentationLibrary::builder(name);
-        if let Some(v) = version {
-            builder = builder.with_version(v);
-        }
-        if let Some(s) = schema_url {
-            builder = builder.with_schema_url(s);
-        }
-        if let Some(a) = attributes {
-            builder = builder.with_attributes(a);
-        }
-        self.library_tracer(Arc::new(builder.build()))
+    fn tracer_builder(self, name: impl Into<Cow<'static, str>>) -> TracerBuilder<Self>
+    where
+        Self: Sized,
+    {
+        TracerBuilder::new(self, name)
     }
 
     /// Returns a new versioned tracer with the given instrumentation library.
@@ -112,3 +75,36 @@ pub trait TracerProvider {
     /// ```
     fn library_tracer(&self, library: Arc<InstrumentationLibrary>) -> Self::Tracer;
 }
+
+struct TracerBuilder<T: TracerProvider> {
+    provider: T,
+    library_builder: InstrumentationLibraryBuilder,
+}
+
+impl<T: TracerProvider> TracerBuilder<T> {
+    fn new(provider: T, name: impl Into<Cow<'static, str>>) -> Self {
+        TracerBuilder {
+            provider: provider,
+            library_builder: InstrumentationLibraryBuilder::new(name),
+        }
+    }
+
+    pub fn with_version(mut self, version: impl Into<Cow<'static, str>>) -> Self {
+        self.library_builder = self.library_builder.with_version(version);
+        self
+    }
+
+    pub fn with_schema_url(mut self, schema_url: impl Into<Cow<'static, str>>) -> Self {
+        self.library_builder = self.library_builder.with_schema_url(schema_url);
+        self
+    }
+
+    pub fn with_attributes(mut self, attributes: impl Into<Vec<KeyValue>>) -> Self {
+        self.library_builder = self.library_builder.with_attributes(attributes);
+        self
+    }
+
+    pub fn build(self) -> T::Tracer {
+        self.provider.library_tracer(self.library_builder.build())
+    }
+}