improve netProtocol performance for well-known protocols (open-telemetry#6845)

Co-authored-by: Robert Pająk <pellared@hotmail.com>

Author: boekkooi-impossiblecloud

CHANGELOG.md

@@ -48,6 +48,13 @@ migration](https://github.com/open-telemetry/semantic-conventions/blob/main/docs
  The `code.namespace` attribute is no longer added. (#6870)
 - The `code.function` attribute emitted by `go.opentelemetry.io/contrib/bridges/otelzap` now stores the package path-qualified function name instead of just the function name.
  The `code.namespace` attribute is no longer added. (#6870)
+- Improve performance by reducing allocations for common request protocols in the modules below. (#6845)
+ - `go.opentelemetry.io/contrib/instrumentation/github.com/emicklei/go-restful/otelrestful`
+ - `go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin`
+ - `go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux`
+ - `go.opentelemetry.io/contrib/instrumentation/github.com/labstack/echo/otelecho`
+ - `go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace`
+ - `go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp`
 
 ### Deprecated
 

instrumentation/github.com/emicklei/go-restful/otelrestful/internal/semconv/util.go

@@ -78,7 +78,16 @@ func serverClientIP(xForwardedFor string) string {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }
 

instrumentation/github.com/emicklei/go-restful/otelrestful/internal/semconvutil/netconv.go

@@ -200,6 +200,15 @@ func splitHostPort(hostport string) (host string, port int) {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }

instrumentation/github.com/gin-gonic/gin/otelgin/internal/semconv/util.go

@@ -78,7 +78,16 @@ func serverClientIP(xForwardedFor string) string {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }
 

instrumentation/github.com/gin-gonic/gin/otelgin/internal/semconvutil/netconv.go

@@ -200,6 +200,15 @@ func splitHostPort(hostport string) (host string, port int) {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }

instrumentation/github.com/gorilla/mux/otelmux/internal/semconv/util.go

@@ -78,7 +78,16 @@ func serverClientIP(xForwardedFor string) string {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }
 

instrumentation/github.com/gorilla/mux/otelmux/internal/semconvutil/netconv.go

@@ -200,6 +200,15 @@ func splitHostPort(hostport string) (host string, port int) {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }

instrumentation/github.com/labstack/echo/otelecho/internal/semconvutil/netconv.go

@@ -200,6 +200,15 @@ func splitHostPort(hostport string) (host string, port int) {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }

instrumentation/net/http/httptrace/otelhttptrace/internal/semconv/util.go

@@ -78,7 +78,16 @@ func serverClientIP(xForwardedFor string) string {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }
 

instrumentation/net/http/httptrace/otelhttptrace/internal/semconvutil/netconv.go

@@ -200,6 +200,15 @@ func splitHostPort(hostport string) (host string, port int) {
 
 func netProtocol(proto string) (name string, version string) {
 name, version, _ = strings.Cut(proto, "/")
-name = strings.ToLower(name)
+switch name {
+case "HTTP":
+name = "http"
+case "QUIC":
+name = "quic"
+case "SPDY":
+name = "spdy"
+default:
+name = strings.ToLower(name)
+}
 return name, version
 }