Function grpcPercentEncode

protocol_grpc.go:895–919

grpcPercentEncode follows RFC 3986 Section 2.1 and the gRPC HTTP/2 spec. It's a variant of URL-encoding with fewer reserved characters. It's intended to take UTF-8 encoded text and escape non-ASCII bytes so that they're valid HTTP/1 headers, while still maximizing readability of the data on the wire

(msg string)

//	https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#responses
//	https://datatracker.ietf.org/doc/html/rfc3986#section-2.1
func grpcPercentEncode(msg string) string {
	var hexCount int
	for i := range len(msg) {
		if grpcShouldEscape(msg[i]) {
			hexCount++
		}
	}
	if hexCount == 0 {
		return msg
	}
	// We need to escape some characters, so we'll need to allocate a new string.
	var out strings.Builder
	out.Grow(len(msg) + 2*hexCount)
	for i := range len(msg) {
		switch char := msg[i]; {
		case grpcShouldEscape(char):
			out.WriteByte('%')
			out.WriteByte(upperhex[char>>4])
			out.WriteByte(upperhex[char&15])
		default:
			out.WriteByte(char)
		}
	}
	return out.String()
}

func grpcPercentDecode(input string) (string, error) {
	percentCount := 0