fix context leak causing tier1 responses to slow down progressively

docs/release-notes/change-log.md

@@ -9,6 +9,10 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## v1.5.2
+
+* Fix a context leak causing tier1 responses to slow down progressively
+
 ## v1.5.1
 
 * Fix a panic on tier2 when not using any wasm extension.

service/tier1.go

@@ -552,6 +552,7 @@ func tier1ResponseHandler(ctx context.Context, mut *sync.Mutex, logger *zap.Logg
 	userMeta := auth.Meta()
 	ip := auth.RealIP()
 	meter := dmetering.GetBytesMeter(ctx)
+	ctx = context.WithValue(ctx, "event_emitter", dmetering.GetDefaultEmitter())
 
 	return func(respAny substreams.ResponseFromAnyTier) error {
 		resp := respAny.(*pbsubstreamsrpc.Response)
@@ -567,7 +568,6 @@ func tier1ResponseHandler(ctx context.Context, mut *sync.Mutex, logger *zap.Logg
 			return connect.NewError(connect.CodeUnavailable, err)
 		}
 
-		ctx = context.WithValue(ctx, "event_emitter", dmetering.GetDefaultEmitter())
 		sendMetering(ctx, meter, userID, apiKeyID, ip, userMeta, "sf.substreams.rpc.v2/Blocks", resp, logger)
 		return nil
 	}