perf: small perf improvements in OTel API (#2842)

Co-authored-by: Cijo Thomas <cijo.thomas@gmail.com>

Author: gruebel

opentelemetry/src/common.rs

@@ -482,9 +482,10 @@ impl PartialEq for InstrumentationScope {
         self.name == other.name
             && self.version == other.version
             && self.schema_url == other.schema_url
+            && self.attributes.len() == other.attributes.len()
             && {
-                let mut self_attrs = self.attributes.clone();
-                let mut other_attrs = other.attributes.clone();
+                let mut self_attrs = Vec::from_iter(&self.attributes);
+                let mut other_attrs = Vec::from_iter(&other.attributes);
                 self_attrs.sort_unstable_by(|a, b| a.key.cmp(&b.key));
                 other_attrs.sort_unstable_by(|a, b| a.key.cmp(&b.key));
                 self_attrs == other_attrs
@@ -499,7 +500,7 @@ impl hash::Hash for InstrumentationScope {
         self.name.hash(state);
         self.version.hash(state);
         self.schema_url.hash(state);
-        let mut sorted_attrs = self.attributes.clone();
+        let mut sorted_attrs = Vec::from_iter(&self.attributes);
         sorted_attrs.sort_unstable_by(|a, b| a.key.cmp(&b.key));
         for attribute in sorted_attrs {
             attribute.hash(state);

opentelemetry/src/propagation/composite.rs

@@ -77,9 +77,7 @@ impl TextMapCompositePropagator {
     pub fn new(propagators: Vec<Box<dyn TextMapPropagator + Send + Sync>>) -> Self {
         let mut fields = HashSet::new();
         for propagator in &propagators {
-            for field in propagator.fields() {
-                fields.insert(field.to_string());
-            }
+            fields.extend(propagator.fields().map(ToString::to_string));
         }
 
         TextMapCompositePropagator {

opentelemetry/src/trace/span_context.rs

@@ -134,7 +134,7 @@ impl TraceState {
             return Err(TraceStateError::Value(value));
         }
 
-        let mut trace_state = self.delete_from_deque(key.clone());
+        let mut trace_state = self.delete_from_deque(&key);
         let kvs = trace_state.0.get_or_insert(VecDeque::with_capacity(1));
 
         kvs.push_front((key, value));
@@ -155,14 +155,14 @@ impl TraceState {
             return Err(TraceStateError::Key(key));
         }
 
-        Ok(self.delete_from_deque(key))
+        Ok(self.delete_from_deque(&key))
     }
 
     /// Delete key from trace state's deque. The key MUST be valid
-    fn delete_from_deque(&self, key: String) -> TraceState {
+    fn delete_from_deque(&self, key: &str) -> TraceState {
         let mut owned = self.clone();
         if let Some(kvs) = owned.0.as_mut() {
-            if let Some(index) = kvs.iter().position(|x| *x.0 == *key) {
+            if let Some(index) = kvs.iter().position(|x| x.0 == key) {
                 kvs.remove(index);
             }
         }