chore: remove unnecessary utils (#267)

Author: RTann

client/proxy.go

@@ -21,6 +21,7 @@ import (
 	"net"
 	"net/http"
 	"net/http/httputil"
+	"strings"
 
 	"github.com/golang/glog"
 	"github.com/pkg/errors"
@@ -30,7 +31,6 @@ import (
 	"golang.stackrox.io/grpc-http1/internal/grpcweb"
 	"golang.stackrox.io/grpc-http1/internal/httputils"
 	"golang.stackrox.io/grpc-http1/internal/pipeconn"
-	"golang.stackrox.io/grpc-http1/internal/stringutils"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/connectivity"
@@ -49,7 +49,7 @@ func modifyResponse(resp *http.Response) error {
 		// Make sure headers do not get flushed, as otherwise the gRPC client will complain about missing trailers.
 		resp.Header.Set(dontFlushHeadersHeaderKey, "true")
 	}
-	contentType, contentSubType := stringutils.Split2(resp.Header.Get("Content-Type"), "+")
+	contentType, contentSubType, _ := strings.Cut(resp.Header.Get("Content-Type"), "+")
 	if contentType != "application/grpc-web" {
 		// No modification necessary if we aren't handling a gRPC web response.
 		return nil

internal/grpcweb/response_writer.go

@@ -18,10 +18,8 @@ import (
 	"bytes"
 	"encoding/binary"
 	"net/http"
+	"slices"
 	"strings"
-
-	"golang.stackrox.io/grpc-http1/internal/sliceutils"
-	"golang.stackrox.io/grpc-http1/internal/stringutils"
 )
 
 type responseWriter struct {
@@ -69,12 +67,12 @@ func (w *responseWriter) prepareHeadersIfNecessary() {
 	}
 
 	hdr := w.w.Header()
-	w.announcedTrailers = sliceutils.ShallowClone(hdr["Trailer"])
+	w.announcedTrailers = slices.Clone(hdr["Trailer"])
 	// Trailers are sent in a data frame, so don't announce trailers as otherwise downstream proxies might get confused.
 	hdr.Del("Trailer")
 
 	// "Downgrade" response content type to grpc-web.
-	contentType, contentSubtype := stringutils.Split2(hdr.Get("Content-Type"), "+")
+	contentType, contentSubtype, _ := strings.Cut(hdr.Get("Content-Type"), "+")
 
 	respContentType := "application/grpc-web"
 	if contentType == "application/grpc" && contentSubtype != "" {

internal/sliceutils/utils.go

@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"slices"
 	"strings"
 	"sync"
 	"unicode"
@@ -27,8 +28,6 @@ import (
 	"golang.stackrox.io/grpc-http1/internal/grpcweb"
 	"golang.stackrox.io/grpc-http1/internal/grpcwebsocket"
 	"golang.stackrox.io/grpc-http1/internal/size"
-	"golang.stackrox.io/grpc-http1/internal/sliceutils"
-	"golang.stackrox.io/grpc-http1/internal/stringutils"
 	"google.golang.org/grpc"
 )
 
@@ -108,11 +107,11 @@ func handleGRPCWeb(w http.ResponseWriter, req *http.Request, validPaths map[stri
 	}
 
 	acceptedContentTypes := strings.FieldsFunc(strings.Join(req.Header["Accept"], ","), spaceOrComma)
-	acceptGRPCWeb := sliceutils.Find(acceptedContentTypes, "application/grpc-web") != -1
+	acceptGRPCWeb := slices.Index(acceptedContentTypes, "application/grpc-web") != -1
 	// The standard gRPC client doesn't actually send an `Accept: application/grpc` header, so always assume
 	// the client accepts gRPC _unless_ it explicitly specifies an `application/grpc-web` accept header
 	// WITHOUT an `application/grpc` accept header.
-	acceptGRPC := !acceptGRPCWeb || sliceutils.Find(acceptedContentTypes, "application/grpc") != -1
+	acceptGRPC := !acceptGRPCWeb || slices.Index(acceptedContentTypes, "application/grpc") != -1
 
 	// Only consider sending a gRPC response if we are not told to prefer gRPC-Web or the client doesn't support
 	// gRPC-Web.
@@ -197,7 +196,7 @@ func CreateDowngradingHandler(grpcSrv *grpc.Server, httpHandler http.Handler, op
 }
 
 func isContentTypeValid(contentType string) bool {
-	ct, _ := stringutils.Split2(contentType, "+")
+	ct, _, _ := strings.Cut(contentType, "+")
 	return ct == "application/grpc" || ct == "application/grpc-web"
 }
 

internal/sliceutils/utils_test.go

@@ -18,11 +18,11 @@ import (
 	"bytes"
 	"io"
 	"net/http"
+	"slices"
 	"strings"
 
 	"github.com/golang/glog"
 	"golang.stackrox.io/grpc-http1/internal/grpcproto"
-	"golang.stackrox.io/grpc-http1/internal/sliceutils"
 )
 
 // wsResponseWriter is a http.ResponseWriter to be used for WebSocket connections.
@@ -67,7 +67,7 @@ func (w *wsResponseWriter) WriteHeader(statusCode int) {
 	}
 
 	hdr := w.header
-	w.announcedTrailers = sliceutils.ShallowClone(hdr["Trailer"])
+	w.announcedTrailers = slices.Clone(hdr["Trailer"])
 	// Trailers will be sent un-announced in non-Trailers-only responses.
 	hdr.Del("Trailer")