Implementing new cache replacement strategies: Random and FIFO
diff --git a/utils/trie-with-policy.h b/utils/trie-with-policy.h
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+/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 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: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef TRIE_WITH_POLICY_H_
+#define TRIE_WITH_POLICY_H_
+
+#include "trie.h"
+#include "lru-policy.h"
+
+template<typename FullKey,
+ typename Payload,
+ typename PayloadTraits,
+ typename PolicyTraits
+ >
+class trie_with_policy
+{
+public:
+ typedef trie< FullKey, Payload, PayloadTraits, typename PolicyTraits::policy_hook_type > parent_trie;
+ typedef typename parent_trie::iterator iterator;
+
+ inline
+ trie_with_policy (size_t bucketSize = 10, size_t bucketIncrement = 10)
+ : trie_ ("", bucketSize, bucketIncrement)
+ {
+ }
+
+ inline std::pair< iterator, bool >
+ insert (const FullKey &key, typename PayloadTraits::const_pointer_type payload)
+ {
+ std::pair<iterator, bool> item =
+ trie_.insert (key, payload);
+
+ if (item.second) // real insert
+ {
+ policy_.insert (s_iterator_to (item.first));
+ }
+ else
+ {
+ item.first->set_payload (payload);
+ policy_.update (s_iterator_to (item.first));
+ }
+
+ return item;
+ }
+
+ inline void
+ erase (iterator node)
+ {
+ if (node == end ()) return;
+
+ policy_.erase (s_iterator_to (node));
+ node->erase (); // will do cleanup here
+ }
+
+ /**
+ * @brief Find a node that has the longest common prefix with key (FIB/PIT lookup)
+ */
+ inline iterator
+ longest_prefix_match (const FullKey &key)
+ {
+ boost::tuple< iterator, bool, iterator > item = trie_.find (key);
+ if (item.template get<0> () != trie_.end ())
+ {
+ policy_.lookup (s_iterator_to (item.template get<0> ()));
+ }
+ return item.template get<0> ();
+ }
+
+ /**
+ * @brief Find a node that has prefix at least as the key (cache lookup)
+ */
+ inline iterator
+ deepest_prefix_match (const FullKey &key)
+ {
+ iterator foundItem, lastItem;
+ bool reachLast;
+ boost::tie (foundItem, reachLast, lastItem) = trie_.find (key);
+
+ // guard in case we don't have anything in the trie
+ if (lastItem == trie_.end ())
+ return trie_.end ();
+
+ if (reachLast)
+ {
+ if (foundItem == trie_.end ())
+ {
+ foundItem = lastItem->find (); // should be something
+ }
+ policy_.lookup (s_iterator_to (foundItem));
+ return foundItem;
+ }
+ else
+ { // couldn't find a node that has prefix at least as key
+ return trie_.end ();
+ }
+ }
+
+ /**
+ * @brief Find a node that has prefix at least as the key
+ */
+ template<class Predicate>
+ inline iterator
+ deepest_prefix_match (const FullKey &key, Predicate pred)
+ {
+ iterator foundItem, lastItem;
+ bool reachLast;
+ boost::tie (foundItem, reachLast, lastItem) = trie_.find (key);
+
+ // guard in case we don't have anything in the trie
+ if (lastItem == trie_.end ())
+ return trie_.end ();
+
+ if (reachLast)
+ {
+ foundItem = lastItem->find_if (pred); // may or may not find something
+ if (foundItem == trie_.end ())
+ {
+ return trie_.end ();
+ }
+ policy_.lookup (s_iterator_to (foundItem));
+ return foundItem;
+ }
+ else
+ { // couldn't find a node that has prefix at least as key
+ return trie_.end ();
+ }
+ }
+
+ // /**
+ // * @brief Perform the longest prefix match
+ // * @param key the key for which to perform the longest prefix match
+ // *
+ // * @return ->second is true if prefix in ->first is longer than key
+ // * ->third is always last node searched
+ // */
+ // inline boost::tuple< iterator, bool, iterator >
+ // find (const FullKey &key)
+ // {
+ // boost::tuple< iterator, bool, iterator > item = trie_.find (key);
+ // if (item.template get<0> () != trie_.end ())
+ // {
+ // policy_.lookup (s_iterator_to (item.template get<0> ()));
+ // }
+ // return boost::make_tuple (s_iterator_to (item.template get<0> ()),
+ // item.template get<1> (),
+ // s_iterator_to (item.template get<2> ()));
+ // }
+
+ // /**
+ // * @brief Find next payload of the sub-trie
+ // * @param start Start for the search (root for the sub-trie)
+ // * @returns end() or a valid iterator pointing to the trie leaf (order is not defined, enumeration )
+ // */
+ // inline iterator
+ // find (iterator start)
+ // {
+ // iterator item = start->find ();
+ // if (item != trie_.end ())
+ // {
+ // policy_.lookup (s_iterator_to (item));
+ // }
+ // return item;
+ // }
+
+ // /**
+ // * @brief Find next payload of the sub-trie satisfying the predicate
+ // * @param start Start for the search (root for the sub-trie)
+ // * @param pred predicate
+ // * @returns end() or a valid iterator pointing to the trie leaf (order is not defined, enumeration )
+ // */
+ // template<class Predicate>
+ // inline iterator
+ // find_if (iterator start, Predicate pred)
+ // {
+ // iterator item = start->find (pred);
+ // if (item != trie_.end ())
+ // {
+ // policy_.lookup (s_iterator_to (item));
+ // }
+ // return item;
+ // }
+
+ iterator end ()
+ {
+ return 0;
+ }
+
+ const parent_trie &
+ getTrie () const { return trie_; }
+
+ const typename PolicyTraits::policy &
+ getPolicy () const { return policy_; }
+
+ typename PolicyTraits::policy &
+ getPolicy () { return policy_; }
+
+ static inline iterator
+ s_iterator_to (typename parent_trie::iterator item)
+ {
+ if (item == 0)
+ return 0;
+ else
+ return &(*item);
+ }
+
+private:
+ parent_trie trie_;
+ typename PolicyTraits::policy policy_;
+};
+
+
+#endif // TRIE_WITH_POLICY_H_
+