v0.34.0_7

src/proxy/upstream_helpers.rs

@@ -312,21 +312,29 @@ async fn observe(State(state): State<Arc<App>>, mut request: Request, next: Next
             response.headers_mut().remove("alt-svc");
         }
         let global_compression = &snapshot.envelope.config.compression;
-        let mut compression = global_compression.clone();
-        if let Some(frontend) = frontend_context.as_ref() {
-            compression = frontend
-                .compression
-                .resolve(global_compression, &compression);
-        }
-        if let Some(route) = effective_route_context {
-            if let crate::config::CompiledSource::WebServer(service) = &route.source {
-                compression = service
+        // All scoped policies have the global codec ceiling. With no accepted
+        // global encoding (e.g. Accept-Encoding: identity), encode is a no-op:
+        // avoid even constructing/resolving the per-request settings.
+        if method != Method::HEAD
+            && crate::compression::preferred_encoding(&original_headers, global_compression).is_some()
+        {
+            let mut compression = global_compression.clone();
+            if let Some(frontend) = frontend_context.as_ref() {
+                compression = frontend
                     .compression
                     .resolve(global_compression, &compression);
             }
+            if let Some(route) = effective_route_context {
+                if let crate::config::CompiledSource::WebServer(service) = &route.source {
+                    compression = service
+                        .compression
+                        .resolve(global_compression, &compression);
+                }
+            }
+            response = crate::compression::encode(
+                response, &original_headers, &method, &compression,
+            ).await;
         }
-        response =
-            crate::compression::encode(response, &original_headers, &method, &compression).await;
         if let Some(encoding) = response
             .extensions()
             .get::<crate::compression::AppliedEncoding>()