use protobuf instead of tinyxml
diff --git a/include/sync-logic.h b/include/sync-logic.h
index 551cb06..5e32918 100644
--- a/include/sync-logic.h
+++ b/include/sync-logic.h
@@ -101,7 +101,7 @@
    * @param name the data name
    * @param dataBuffer the sync data
    */
-  void respondSyncData (const std::string &name, const std::string &dataBuffer);
+  void respondSyncData (const std::string &name, const char *wireData, size_t len);
 
   /**
    * @brief remove a participant's subtree from the sync tree
@@ -133,7 +133,7 @@
 
   void
   processSyncData (const std::string &name,
-                   DigestConstPtr digest, const std::string &dataBuffer);
+                   DigestConstPtr digest, const char *wireData, size_t len);
   
   void
   processSyncRecoveryInterest (const std::string &name,
diff --git a/include/sync-state.h b/include/sync-state.h
index c96160e..84c2400 100644
--- a/include/sync-state.h
+++ b/include/sync-state.h
@@ -93,7 +93,7 @@
  * @returns SyncStateMsg msg
  */
 SyncStateMsg &
-operator >> (SyncStateMsg &issm, const State &state);
+operator >> (SyncStateMsg &issm, State &state);
 
 namespace Error {
 /**