chore: wrap headers in arc to save cloning per batch

Author: scottgerring

opentelemetry-otlp/src/exporter/http/logs.rs

@@ -77,7 +77,7 @@ impl LogExporter for OtlpHttpClient {
                         message: format!("Failed to build HTTP request: {e}"),
                     })?;
 
-                for (k, v) in &retry_data.headers {
+                for (k, v) in retry_data.headers.iter() {
                     request.headers_mut().insert(k.clone(), v.clone());
                 }
 
@@ -147,7 +147,7 @@ impl LogExporter for OtlpHttpClient {
             .body(body.into())
             .map_err(|e| OTelSdkError::InternalFailure(e.to_string()))?;
 
-        for (k, v) in &self.headers {
+        for (k, v) in self.headers.iter() {
             request.headers_mut().insert(k.clone(), v.clone());
         }
 

opentelemetry-otlp/src/exporter/http/metrics.rs

@@ -78,7 +78,7 @@ impl MetricsClient for OtlpHttpClient {
                         message: format!("Failed to build HTTP request: {e}"),
                     })?;
 
-                for (k, v) in &retry_data.headers {
+                for (k, v) in retry_data.headers.iter() {
                     request.headers_mut().insert(k.clone(), v.clone());
                 }
 
@@ -151,7 +151,7 @@ impl MetricsClient for OtlpHttpClient {
             .body(body.into())
             .map_err(|e| OTelSdkError::InternalFailure(format!("{e:?}")))?;
 
-        for (k, v) in &self.headers {
+        for (k, v) in self.headers.iter() {
             request.headers_mut().insert(k.clone(), v.clone());
         }
 

opentelemetry-otlp/src/exporter/http/mod.rs

@@ -49,7 +49,7 @@ pub(crate) fn classify_http_export_error(error: &HttpExportError) -> RetryErrorT
 #[derive(Debug)]
 pub(crate) struct HttpRetryData {
     pub body: Vec<u8>,
-    pub headers: HashMap<HeaderName, HeaderValue>,
+    pub headers: Arc<HashMap<HeaderName, HeaderValue>>,
     pub endpoint: String,
 }
 
@@ -329,7 +329,7 @@ impl HttpExporterBuilder {
 pub(crate) struct OtlpHttpClient {
     client: Mutex<Option<Arc<dyn HttpClient>>>,
     collector_endpoint: Uri,
-    headers: HashMap<HeaderName, HeaderValue>,
+    headers: Arc<HashMap<HeaderName, HeaderValue>>,
     protocol: Protocol,
     _timeout: Duration,
     compression: Option<crate::Compression>,
@@ -383,7 +383,7 @@ impl OtlpHttpClient {
         OtlpHttpClient {
             client: Mutex::new(Some(client)),
             collector_endpoint,
-            headers,
+            headers: Arc::new(headers),
             protocol,
             _timeout: timeout,
             compression,

opentelemetry-otlp/src/exporter/http/trace.rs

@@ -78,7 +78,7 @@ impl SpanExporter for OtlpHttpClient {
                         message: format!("Failed to build HTTP request: {e}"),
                     })?;
 
-                for (k, v) in &retry_data.headers {
+                for (k, v) in retry_data.headers.iter() {
                     request.headers_mut().insert(k.clone(), v.clone());
                 }
 
@@ -155,7 +155,7 @@ impl SpanExporter for OtlpHttpClient {
             Err(e) => return Err(OTelSdkError::InternalFailure(e.to_string())),
         };
 
-        for (k, v) in &self.headers {
+        for (k, v) in self.headers.iter() {
             request.headers_mut().insert(k.clone(), v.clone());
         }