Adding nsync for NLSR
diff --git a/nsync/src/sync-diff-leaf.h b/nsync/src/sync-diff-leaf.h
new file mode 100644
index 0000000..6e09efe
--- /dev/null
+++ b/nsync/src/sync-diff-leaf.h
@@ -0,0 +1,91 @@
+/* -*- 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_LEAF_H
+#define SYNC_DIFF_LEAF_H
+
+#include "sync-leaf.h"
+#include <boost/exception/all.hpp>
+
+namespace Sync {
+
+/**
+ * @ingroup sync
+ * @brief Annotation for SYNC leaf
+ */
+enum Operation
+ {
+ UPDATE, ///< @brief Leaf was added or updated
+ REMOVE ///< @brief Leaf was removed
+ };
+
+/**
+ * @ingroup sync
+ * @brief Annotated SYNC leaf
+ */
+class DiffLeaf : public Leaf
+{
+public:
+ /**
+ * @brief Constructor to create an UPDATE diff leaf
+ * @param info Smart pointer to leaf's name
+ * @param seq Initial sequence number of the pointer
+ */
+ DiffLeaf (NameInfoConstPtr info, const SeqNo &seq);
+
+ /**
+ * @brief Constructor to create an REMOVE diff leaf
+ * @param info Smart pointer to leaf's name
+ *
+ * This constructor creates a leaf with phony sequence number
+ * with 0 session ID and 0 sequence number
+ */
+ DiffLeaf (NameInfoConstPtr info);
+
+ virtual ~DiffLeaf () { }
+
+ /**
+ * @brief Get diff leaf type
+ */
+ Operation
+ getOperation () const { return m_op; }
+
+private:
+ Operation m_op;
+};
+
+typedef boost::shared_ptr<DiffLeaf> DiffLeafPtr;
+typedef boost::shared_ptr<const DiffLeaf> DiffLeafConstPtr;
+
+std::ostream &
+operator << (std::ostream &os, Operation op);
+
+std::istream &
+operator >> (std::istream &is, Operation &op);
+
+namespace Error {
+struct SyncDiffLeafOperationParseError : virtual boost::exception, virtual std::exception { };
+} // Error
+
+} // Sync
+
+#endif // SYNC_DIFF_LEAF_H