Add stable marshaller helper for bool

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

util/proto/marshal.go

@@ -16,10 +16,10 @@ func BytesMarshal(field int, buf, v []byte) (int, error) {
 		return 0, nil
 	}
 
+	prefix := field<<3 | 0x2
+
 	// buf length check can prevent panic at PutUvarint, but it will make
 	// marshaller a bit slower.
-
-	prefix := field<<3 | 0x2
 	i := binary.PutUvarint(buf, uint64(prefix))
 	i += binary.PutUvarint(buf[i:], uint64(len(v)))
 	i += copy(buf[i:], v)
@@ -46,6 +46,30 @@ func StringSize(field int, v string) int {
 	return BytesSize(field, []byte(v))
 }
 
+func BoolMarshal(field int, buf []byte, v bool) (int, error) {
+	if !v {
+		return 0, nil
+	}
+
+	prefix := field << 3
+
+	// buf length check can prevent panic at PutUvarint, but it will make
+	// marshaller a bit slower.
+	i := binary.PutUvarint(buf, uint64(prefix))
+	buf[i] = 0x1
+
+	return i + 1, nil
+}
+
+func BoolSize(field int, v bool) int {
+	if !v {
+		return 0
+	}
+
+	prefix := field << 3
+	return VarUIntSize(uint64(prefix)) + 1 // bool is always 1 byte long
+}
+
 // varUIntSize returns length of varint byte sequence for uint64 value 'x'.
 func VarUIntSize(x uint64) int {
 	return (bits.Len64(x|1) + 6) / 7