feat: Waku v2 bridge

Issue #12610

vendor/github.com/libp2p/go-msgio/num.go

@@ -0,0 +1,34 @@
+package msgio
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+// NBO is NetworkByteOrder
+var NBO = binary.BigEndian
+
+// WriteLen writes a length to the given writer.
+func WriteLen(w io.Writer, l int) error {
+	ul := uint32(l)
+	return binary.Write(w, NBO, &ul)
+}
+
+// ReadLen reads a length from the given reader.
+// if buf is non-nil, it reuses the buffer. Ex:
+//
+//	l, err := ReadLen(r, nil)
+//	_, err := ReadLen(r, buf)
+func ReadLen(r io.Reader, buf []byte) (int, error) {
+	if len(buf) < 4 {
+		buf = make([]byte, 4)
+	}
+	buf = buf[:4]
+
+	if _, err := io.ReadFull(r, buf); err != nil {
+		return 0, err
+	}
+
+	n := int(NBO.Uint32(buf))
+	return n, nil
+}