remove backoff from form parsing

http/httphi/bench_test.go

@@ -115,7 +115,7 @@ func BenchmarkRequestParseForm(b *testing.B) {
 	buf := make([]byte, 64)
 	var mux MuxSlice
 	mux.Handle("POST /f", func(ex *Exchange) {
-		err := ex.RequestParseForm(&benchForm, buf, nopBackoff)
+		err := ex.RequestParseForm(&benchForm, buf)
 		if err != nil || benchForm.Len() != 2 {
 			panic("invalid result")
 		}

http/httphi/exchange.go

@@ -423,8 +423,8 @@ func (exch *Exchange) RequestContentLength() (int64, error) {
 //
 // A request with no Content-Length has no body, RFC 9112 6.3, and yields an
 // empty form. Use [Exchange.RequestContentLength] to tell that apart from a body
-// that arrived empty. backoff paces reads that return no data, as in [Handle].
-func (exch *Exchange) RequestParseForm(dst *httpraw.Form, buf []byte, backoff lneto.BackoffStrategy) error {
+// that arrived empty.
+func (exch *Exchange) RequestParseForm(dst *httpraw.Form, buf []byte) error {
 	if !httpraw.MediaTypeIs(exch.RequestContentType(), "application/x-www-form-urlencoded") {
 		return errNotFormEncoded
 	} else if exch.RequestHeader("Transfer-Encoding") != nil {
@@ -440,18 +440,12 @@ func (exch *Exchange) RequestParseForm(dst *httpraw.Form, buf []byte, backoff ln
 		return lneto.ErrBufferFull // Refuse before reading, caller may answer 413.
 	}
 	buf = buf[:length]
-	var consecutiveBackoffs uint
 	for read := 0; read < len(buf); {
 		n, err := exch.ReadBody(buf[read:])
-		if err != nil {
-			return err
-		} else if n == 0 {
-			backoff.Do(consecutiveBackoffs)
-			consecutiveBackoffs++
-			continue
-		}
-		consecutiveBackoffs = 0
 		read += n
+		if n == 0 && err != nil {
+			return err
+		}
 	}
 	dst.Reset(buf)
 	return dst.Parse()

http/httphi/exchange_test.go

@@ -720,7 +720,7 @@ func TestExchangeRequestParseForm(t *testing.T) {
 			var sm MuxSlice
 			sm.Reset(1)
 			sm.Handle("/f", func(exch *Exchange) {
-				gotErr = exch.RequestParseForm(&form, make([]byte, bufSize), nopBackoff)
+				gotErr = exch.RequestParseForm(&form, make([]byte, bufSize))
 			})
 			serve(t, test.request, &sm)
 			if gotErr != test.wantErr {
@@ -743,7 +743,7 @@ func TestExchangeRequestParseFormSplit(t *testing.T) {
 	var sm MuxSlice
 	sm.Reset(1)
 	sm.Handle("/f", func(exch *Exchange) {
-		gotErr = exch.RequestParseForm(&form, make([]byte, 64), nopBackoff)
+		gotErr = exch.RequestParseForm(&form, make([]byte, 64))
 	})
 	exch := newExchange(t, conn, ExchangeConfig{RawBuf: make([]byte, 2*1024), RequestBufferLim: 1024})
 	if err := Handle(exch, &sm, nopBackoff); err != nil {
@@ -763,7 +763,7 @@ func TestExchangeRequestParseFormDecode(t *testing.T) {
 	var sm MuxSlice
 	sm.Reset(1)
 	sm.Handle("/f", func(exch *Exchange) {
-		if err := exch.RequestParseForm(&form, make([]byte, 64), nopBackoff); err != nil {
+		if err := exch.RequestParseForm(&form, make([]byte, 64)); err != nil {
 			t.Error(err)
 		} else if err = form.Decode(); err != nil {
 			t.Error(err)
@@ -1015,7 +1015,9 @@ func TestHandleRequestTooLargeAnswers431(t *testing.T) {
 	var request strings.Builder
 	request.WriteString("GET /echo HTTP/1.1\r\nHost: lneto.test\r\n")
 	for i := range 512 {
-		request.WriteString("H" + strconv.Itoa(i) + ":v\r\n")
+		request.WriteByte('H')
+		request.WriteString(strconv.Itoa(i))
+		request.WriteString(":v\r\n")
 	}
 	request.WriteString("\r\n")