base: Interest and Data packets can now be tagged with arbitrary information
This functionality is similar to StrategyInfoHost and StrategyInfo in
NFD. Current usage will include ndnSIM, where Interest and Data ndn-cxx
packets need to be associated with ns3::Packet data structures.
Change-Id: I313e4be0f4b6eac80f3824e3fd725968e265fdce
Refs: #2336
diff --git a/src/tag-host.hpp b/src/tag-host.hpp
new file mode 100644
index 0000000..0d1d39d
--- /dev/null
+++ b/src/tag-host.hpp
@@ -0,0 +1,101 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2015 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library 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 Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#ifndef NDN_TAG_HOST_HPP
+#define NDN_TAG_HOST_HPP
+
+#include "common.hpp"
+#include "tag.hpp"
+
+#include <map>
+
+namespace ndn {
+
+/** \brief Base class to store tag information (e.g., inside Interest and Data packets)
+ */
+class TagHost
+{
+public:
+ /** \brief get a tag item
+ * \tparam T type of the tag, which must be a subclass of ndn::Tag
+ * \retval nullptr if no Tag of type T is stored
+ */
+ template<typename T>
+ shared_ptr<T>
+ getTag() const;
+
+ /** \brief set a tag item
+ * \tparam T type of the tag, which must be a subclass of ndn::Tag
+ * \note Tag can be set even on a const tag host instance
+ */
+ template<typename T>
+ void
+ setTag(shared_ptr<T> tag) const;
+
+ /** \brief remove tag item
+ * \note Tag can be removed even on a const tag host instance
+ */
+ template<typename T>
+ void
+ removeTag() const;
+
+private:
+ mutable std::map<size_t, shared_ptr<Tag>> m_tags;
+};
+
+
+template<typename T>
+inline shared_ptr<T>
+TagHost::getTag() const
+{
+ static_assert(std::is_base_of<Tag, T>::value, "T must inherit from Tag");
+
+ auto it = m_tags.find(T::getTypeId());
+ if (it == m_tags.end()) {
+ return nullptr;
+ }
+ return static_pointer_cast<T>(it->second);
+}
+
+template<typename T>
+inline void
+TagHost::setTag(shared_ptr<T> tag) const
+{
+ static_assert(std::is_base_of<Tag, T>::value, "T must inherit from Tag");
+
+ if (tag == nullptr) {
+ m_tags.erase(T::getTypeId());
+ return;
+ }
+
+ m_tags[T::getTypeId()] = tag;
+}
+
+template<typename T>
+inline void
+TagHost::removeTag() const
+{
+ setTag<T>(nullptr);
+}
+
+} // namespace ndn
+
+#endif // NDN_TAG_HOST_HPP