partial sync: segment hello and sync data

add segment publisher

refs: #4662

Change-Id: I62e7a2247bac58aeec364cd2a4e4d34259eae4af
diff --git a/src/partial-producer.hpp b/src/partial-producer.hpp
index a2db7ac..cb014fc 100644
--- a/src/partial-producer.hpp
+++ b/src/partial-producer.hpp
@@ -112,7 +112,8 @@
    * Either respond with sync data if consumer is behind or
    * store sync interest in m_pendingEntries
    *
-   * Sync data's name format is: /\<sync-prefix\>/sync/\<old-IBF\>/\<current-IBF\>
+   * Sync data's name format is: /\<syncPrefix\>/sync/\<BF\>/\<old-IBF\>/\<current-IBF\>
+   * (BF has 3 components).
    */
   void
   onSyncInterest(const ndn::Name& prefix, const ndn::Interest& interest);