+ /* XMSG_PART_DONE: a split part is finished; used by XferDestTaper and
+ * XferSourceTaper elements to indicate that the element is paused and
+ * awaiting instructions to start a new part. Not all of the attributes
+ * are applicable to both elements.
+ *
+ * Attributes:
+ * - successful (true if the whole part was written; always false for
+ * XferSourceTaper)
+ * - eom (true if the device is at EOM; always false for XferSourceTaper)
+ * - eof (recipient should not call start_part; always false for
+ * XferSourceTaper)
+ * - size (bytes written to or read from the volume)
+ * - duration (time spent writing, not counting changer ops, etc.)
+ * - partnum (the zero-based number of this part in the overall
+ * dumpfile; always 0 for XferSourceTaper)
+ * - fileno (the on-media file number used for this part, or 0 if no file
+ * was used)
+ */
+ XMSG_PART_DONE = 5,
+
+ /* XMSG_READY: some elements do some additional, potentially long-term
+ * startup operations after the xfer itself starts. This message is used
+ * to indicate that the startup was successful.
+ *
+ * Attributes:
+ * (none)
+ */
+ XMSG_READY = 6,