Adding nsync for NLSR
diff --git a/nsync/src/sync-diff-state.h b/nsync/src/sync-diff-state.h
new file mode 100644
index 0000000..d944c3e
--- /dev/null
+++ b/nsync/src/sync-diff-state.h
@@ -0,0 +1,102 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2012 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Zhenkai Zhu <zhenkai@cs.ucla.edu>
+ * Chaoyi Bian <bcy@pku.edu.cn>
+ * Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef SYNC_DIFF_STATE_H
+#define SYNC_DIFF_STATE_H
+
+#include "sync-state.h"
+#include <iostream>
+
+namespace Sync {
+
+class DiffState;
+typedef boost::shared_ptr<DiffState> DiffStatePtr;
+typedef boost::shared_ptr<DiffState> DiffStateConstPtr;
+
+/**
+ * @ingroup ccnx
+ * @brief Differential SYNC state
+ */
+class DiffState : public State
+{
+public:
+ /**
+ * @see Default constructor
+ */
+ DiffState ();
+ virtual ~DiffState ();
+
+ /**
+ * @brief Set successor for the diff state
+ * @param next successor state
+ */
+ void
+ setNext (DiffStatePtr next)
+ {
+ m_next = next;
+ }
+
+ /**
+ * @brief Set digest for the diff state (obtained from a corresponding full state)
+ * @param digest A read only smart pointer to a digest object (that should be unmodified anywhere else)
+ */
+ void
+ setDigest (DigestConstPtr digest) { m_digest = digest; }
+
+ /**
+ * @brief Get digest for the diff state
+ */
+ DigestConstPtr
+ getDigest () const { return m_digest; }
+
+ /**
+ * @brief Accumulate differences from `this' state to the most current state
+ * @returns Accumulated differences from `this' state to the most current state
+ */
+ DiffStatePtr
+ diff () const;
+
+ /**
+ * @brief Combine differences from `this' and `state'
+ * @param state Differential state to combine with
+ * @return Combined differences
+ *
+ * In case of collisions, `this' leaf will be replaced with the leaf of `state'
+ */
+ DiffState&
+ operator += (const DiffState &state);
+
+ // from State
+ virtual boost::tuple<bool/*inserted*/, bool/*updated*/, SeqNo/*oldSeqNo*/>
+ update (NameInfoConstPtr info, const SeqNo &seq);
+
+ virtual bool
+ remove (NameInfoConstPtr info);
+
+private:
+ DiffStatePtr m_next;
+ DigestConstPtr m_digest;
+};
+
+} // Sync
+
+#endif // SYNC_DIFF_STATE_H