TUN-3403: Unit test for origin/proxy to test serving HTTP and Websocket

vendor/github.com/gobwas/ws/write.go

@@ -0,0 +1,104 @@
+package ws
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+// Header size length bounds in bytes.
+const (
+	MaxHeaderSize = 14
+	MinHeaderSize = 2
+)
+
+const (
+	bit0 = 0x80
+	bit1 = 0x40
+	bit2 = 0x20
+	bit3 = 0x10
+	bit4 = 0x08
+	bit5 = 0x04
+	bit6 = 0x02
+	bit7 = 0x01
+
+	len7  = int64(125)
+	len16 = int64(^(uint16(0)))
+	len64 = int64(^(uint64(0)) >> 1)
+)
+
+// HeaderSize returns number of bytes that are needed to encode given header.
+// It returns -1 if header is malformed.
+func HeaderSize(h Header) (n int) {
+	switch {
+	case h.Length < 126:
+		n = 2
+	case h.Length <= len16:
+		n = 4
+	case h.Length <= len64:
+		n = 10
+	default:
+		return -1
+	}
+	if h.Masked {
+		n += len(h.Mask)
+	}
+	return n
+}
+
+// WriteHeader writes header binary representation into w.
+func WriteHeader(w io.Writer, h Header) error {
+	// Make slice of bytes with capacity 14 that could hold any header.
+	bts := make([]byte, MaxHeaderSize)
+
+	if h.Fin {
+		bts[0] |= bit0
+	}
+	bts[0] |= h.Rsv << 4
+	bts[0] |= byte(h.OpCode)
+
+	var n int
+	switch {
+	case h.Length <= len7:
+		bts[1] = byte(h.Length)
+		n = 2
+
+	case h.Length <= len16:
+		bts[1] = 126
+		binary.BigEndian.PutUint16(bts[2:4], uint16(h.Length))
+		n = 4
+
+	case h.Length <= len64:
+		bts[1] = 127
+		binary.BigEndian.PutUint64(bts[2:10], uint64(h.Length))
+		n = 10
+
+	default:
+		return ErrHeaderLengthUnexpected
+	}
+
+	if h.Masked {
+		bts[1] |= bit0
+		n += copy(bts[n:], h.Mask[:])
+	}
+
+	_, err := w.Write(bts[:n])
+
+	return err
+}
+
+// WriteFrame writes frame binary representation into w.
+func WriteFrame(w io.Writer, f Frame) error {
+	err := WriteHeader(w, f.Header)
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(f.Payload)
+	return err
+}
+
+// MustWriteFrame is like WriteFrame but panics if frame can not be read.
+func MustWriteFrame(w io.Writer, f Frame) {
+	if err := WriteFrame(w, f); err != nil {
+		panic(err)
+	}
+}