Simplify Leaf and its sub-classes.
Change-Id: I711db26bedee2bebdd39ffd8b637fa8918c16ff9
diff --git a/src/leaf.hpp b/src/leaf.hpp
new file mode 100644
index 0000000..635c087
--- /dev/null
+++ b/src/leaf.hpp
@@ -0,0 +1,93 @@
+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2012-2014 University of California, Los Angeles
+ *
+ * This file is part of ChronoSync, synchronization library for distributed realtime
+ * applications for NDN.
+ *
+ * ChronoSync is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * ChronoSync 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
+ * ChronoSync, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Zhenkai Zhu <http://irl.cs.ucla.edu/~zhenkai/>
+ * @author Chaoyi Bian <bcy@pku.edu.cn>
+ * @author Alexander Afanasyev <http://lasr.cs.ucla.edu/afanasyev/index.html>
+ * @author Yingdi Yu <yingdi@cs.ucla.edu>
+ */
+
+#ifndef CHRONOSYNC_LEAF_HPP
+#define CHRONOSYNC_LEAF_HPP
+
+#include "common.hpp"
+#include <ndn-cxx/util/digest.hpp>
+
+namespace chronosync {
+
+typedef uint64_t SeqNo;
+
+/**
+ * @brief Sync tree leaf
+ *
+ * The leaf node should be copyable when used to construct diff between two states.
+ */
+class Leaf
+{
+public:
+ Leaf(const Name& sessionName, const SeqNo& seq);
+
+ Leaf(const Name& userPrefix, uint64_t session, const SeqNo& seq);
+
+ virtual
+ ~Leaf();
+
+ const Name&
+ getSessionName() const
+ {
+ return m_sessionName;
+ }
+
+ const SeqNo&
+ getSeq() const
+ {
+ return m_seq;
+ }
+
+ ndn::ConstBufferPtr
+ getDigest() const;
+
+ /**
+ * @brief Update sequence number of the leaf
+ * @param seq Sequence number
+ *
+ * If seq is no greater than getSeq(), this operation has no effect.
+ */
+ virtual void
+ setSeq(const SeqNo& seq);
+
+private:
+ void
+ updateDigest();
+
+private:
+ Name m_sessionName;
+ SeqNo m_seq;
+
+ mutable ndn::util::Sha256 m_digest;
+};
+
+typedef boost::shared_ptr<Leaf> LeafPtr;
+typedef boost::shared_ptr<const Leaf> ConstLeafPtr;
+
+std::ostream&
+operator<<(std::ostream& os, const Leaf& leaf);
+
+} // namespace chronosync
+
+#endif // CHRONOSYNC_LEAF_HPP