messages: Use pb_get_encoded_size

firmware/messages.c

@@ -169,10 +169,8 @@ bool msg_write_common(char type, uint16_t msg_id, const void *msg_ptr)
 		return false;
 	}
 
-	pb_ostream_t sizestream = {0, 0, SIZE_MAX, 0, 0};
-	bool status = pb_encode(&sizestream, fields, msg_ptr);
-
-	if (!status) {
+	size_t len;
+	if (!pb_get_encoded_size(&len, fields, msg_ptr)) {
 		return false;
 	}
 
@@ -193,7 +191,6 @@ bool msg_write_common(char type, uint16_t msg_id, const void *msg_ptr)
 		return false;
 	}
 
-	uint32_t len = sizestream.bytes_written;
 	append('#');
 	append('#');
 	append((msg_id >> 8) & 0xFF);
@@ -203,7 +200,7 @@ bool msg_write_common(char type, uint16_t msg_id, const void *msg_ptr)
 	append((len >> 8) & 0xFF);
 	append(len & 0xFF);
 	pb_ostream_t stream = {pb_callback, 0, SIZE_MAX, 0, 0};
-	status = pb_encode(&stream, fields, msg_ptr);
+	bool status = pb_encode(&stream, fields, msg_ptr);
 	if (type == 'n') {
 		msg_out_pad();
 	}