daemon/table/name-tree.hpp - NFD - Gitiles

 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
  * Copyright (c) 2014-2018,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
  *                           Washington University in St. Louis,
  *                           Beijing Institute of Technology,
  *                           The University of Memphis.
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
  *
  * NFD 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.
  *
  * NFD 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
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  */

 #ifndef NFD_DAEMON_TABLE_NAME_TREE_HPP
 #define NFD_DAEMON_TABLE_NAME_TREE_HPP

 #include "name-tree-iterator.hpp"

 #include "core/fib-max-depth.hpp"

 namespace nfd {
 namespace name_tree {

 /** \brief a common index structure for FIB, PIT, StrategyChoice, and Measurements
  */
 class NameTree : noncopyable
 {
 public:
   explicit
   NameTree(size_t nBuckets = 1024);

 public: // information
   /** \brief maximum depth of the name tree
    *
    *  Calling \c NameTree::lookup with a name with many components would cause the creation of many
    *  NameTree entries, which could take very long time. This constant limits the maximum number of
    *  name components in the name of a NameTree entry. Thus, it limits the number of NameTree
    *  entries created from a long name, bounding the processing complexity.
    */
   static constexpr size_t
   getMaxDepth()
   {
     return FIB_MAX_DEPTH;
   }

   /** \return number of name tree entries
    */
   size_t
   size() const
   {
     return m_ht.size();
   }

   /** \return number of hashtable buckets
    */
   size_t
   getNBuckets() const
   {
     return m_ht.getNBuckets();
   }

   /** \return name tree entry on which a table entry is attached,
    *          or nullptr if the table entry is detached
    */
   template<typename EntryT>
   Entry*
   getEntry(const EntryT& tableEntry) const
   {
     return Entry::get(tableEntry);
   }

 public: // mutation
   /** \brief find or insert an entry by name
    *
    *  This method seeks a name tree entry of name \c name.getPrefix(prefixLen).
    *  If the entry does not exist, it is created along with all ancestors.
    *  Existing iterators are unaffected during this operation.
    *
    *  \warning \p prefixLen must not exceed \c name.size().
    *  \warning \p prefixLen must not exceed \c getMaxDepth().
    */
   Entry&
   lookup(const Name& name, size_t prefixLen);

   /** \brief equivalent to `lookup(name, name.size())`
    */
   Entry&
   lookup(const Name& name)
   {
     return this->lookup(name, name.size());
   }

   /** \brief equivalent to `lookup(fibEntry.getPrefix())`
    *  \param fibEntry a FIB entry attached to this name tree, or \c Fib::s_emptyEntry
    *  \note This overload is more efficient than `lookup(const Name&)` in common cases.
    */
   Entry&
   lookup(const fib::Entry& fibEntry);

   /** \brief equivalent to
    *         `lookup(pitEntry.getName(), std::min(pitEntry.getName().size(), getMaxDepth()))`
    *  \param pitEntry a PIT entry attached to this name tree
    *  \note This overload is more efficient than `lookup(const Name&)` in common cases.
    */
   Entry&
   lookup(const pit::Entry& pitEntry);

   /** \brief equivalent to `lookup(measurementsEntry.getName())`
    *  \param measurementsEntry a Measurements entry attached to this name tree
    *  \note This overload is more efficient than `lookup(const Name&)` in common cases.
    */
   Entry&
   lookup(const measurements::Entry& measurementsEntry);

   /** \brief equivalent to `lookup(strategyChoiceEntry.getPrefix())`
    *  \param strategyChoiceEntry a StrategyChoice entry attached to this name tree
    *  \note This overload is more efficient than `lookup(const Name&)` in common cases.
    */
   Entry&
   lookup(const strategy_choice::Entry& strategyChoiceEntry);

   /** \brief delete the entry if it is empty
    *  \param entry a valid entry
    *  \param canEraseAncestors whether ancestors should be deleted if they become empty
    *  \return number of deleted entries
    *  \sa Entry::isEmpty()
    *  \post If the entry is empty, it's deleted. If \p canEraseAncestors is true,
    *        ancestors of the entry are also deleted if they become empty.
    *  \note This function must be called after detaching a table entry from a name tree entry,
    *  \note Existing iterators, except those pointing to deleted entries, are unaffected.
    */
   size_t
   eraseIfEmpty(Entry* entry, bool canEraseAncestors = true);

 public: // matching
   /** \brief exact match lookup
    *  \return entry with \c name.getPrefix(prefixLen), or nullptr if it does not exist
    */
   Entry*
   findExactMatch(const Name& name, size_t prefixLen = std::numeric_limits<size_t>::max()) const;

   /** \brief longest prefix matching
    *  \return entry whose name is a prefix of \p name and passes \p entrySelector,
    *          where no other entry with a longer name satisfies those requirements;
    *          or nullptr if no entry satisfying those requirements exists
    */
   Entry*
   findLongestPrefixMatch(const Name& name,
                          const EntrySelector& entrySelector = AnyEntry()) const;

   /** \brief equivalent to `findLongestPrefixMatch(entry.getName(), entrySelector)`
    *  \note This overload is more efficient than
    *        `findLongestPrefixMatch(const Name&, const EntrySelector&)` in common cases.
    */
   Entry*
   findLongestPrefixMatch(const Entry& entry,
                          const EntrySelector& entrySelector = AnyEntry()) const;

   /** \brief equivalent to `findLongestPrefixMatch(getEntry(tableEntry)->getName(), entrySelector)`
    *  \tparam EntryT \c fib::Entry or \c measurements::Entry or \c strategy_choice::Entry
    *  \note This overload is more efficient than
    *        `findLongestPrefixMatch(const Name&, const EntrySelector&)` in common cases.
    *  \warning Undefined behavior may occur if \p tableEntry is not attached to this name tree.
    */
   template<typename EntryT>
   Entry*
   findLongestPrefixMatch(const EntryT& tableEntry,
                          const EntrySelector& entrySelector = AnyEntry()) const
   {
     const Entry* nte = this->getEntry(tableEntry);
     BOOST_ASSERT(nte != nullptr);
     return this->findLongestPrefixMatch(*nte, entrySelector);
   }

   /** \brief equivalent to `findLongestPrefixMatch(pitEntry.getName(), entrySelector)`
    *  \note This overload is more efficient than
    *        `findLongestPrefixMatch(const Name&, const EntrySelector&)` in common cases.
    *  \warning Undefined behavior may occur if \p pitEntry is not attached to this name tree.
    */
   Entry*
   findLongestPrefixMatch(const pit::Entry& pitEntry,
                          const EntrySelector& entrySelector = AnyEntry()) const;

   /** \brief all-prefixes match lookup
    *  \return a range where every entry has a name that is a prefix of \p name ,
    *          and matches \p entrySelector.
    *
    *  Example:
    *  \code
    *  Name name("/A/B/C");
    *  auto&& allMatches = nt.findAllMatches(name);
    *  for (const Entry& nte : allMatches) {
    *    BOOST_ASSERT(nte.getName().isPrefixOf(name));
    *    ...
    *  }
    *  \endcode
    *  \note Iteration order is implementation-defined.
    *  \warning If a name tree entry whose name is a prefix of \p name is inserted
    *           during the enumeration, it may or may not be visited.
    *           If a name tree entry whose name is a prefix of \p name is deleted
    *           during the enumeration, undefined behavior may occur.
    */
   Range
   findAllMatches(const Name& name,
                  const EntrySelector& entrySelector = AnyEntry()) const;

 public: // enumeration
   using const_iterator = Iterator;

   /** \brief enumerate all entries
    *  \return a range where every entry matches \p entrySelector
    *
    *  Example:
    *  \code
    *  auto&& enumerable = nt.fullEnumerate();
    *  for (const Entry& nte : enumerable) {
    *    ...
    *  }
    *  \endcode
    *  \note Iteration order is implementation-defined.
    *  \warning If a name tree entry is inserted or deleted during the enumeration,
    *           it may cause the enumeration to skip entries or visit some entries twice.
    */
   Range
   fullEnumerate(const EntrySelector& entrySelector = AnyEntry()) const;

   /** \brief enumerate all entries under a prefix
    *  \return a range where every entry has a name that starts with \p prefix,
    *          and matches \p entrySubTreeSelector.
    *
    *  Example:
    *  \code
    *  Name name("/A/B/C");
    *  auto&& enumerable = nt.partialEnumerate(name);
    *  for (const Entry& nte : enumerable) {
    *    BOOST_ASSERT(name.isPrefixOf(nte.getName()));
    *    ...
    *  }
    *  \endcode
    *  \note Iteration order is implementation-defined.
    *  \warning If a name tree entry under \p prefix is inserted or deleted during the enumeration,
    *           it may cause the enumeration to skip entries or visit some entries twice.
    */
   Range
   partialEnumerate(const Name& prefix,
                    const EntrySubTreeSelector& entrySubTreeSelector = AnyEntrySubTree()) const;

   /** \return an iterator to the beginning
    *  \sa fullEnumerate
    */
   const_iterator
   begin() const
   {
     return fullEnumerate().begin();
   }

   /** \return an iterator to the end
    *  \sa begin()
    */
   const_iterator
   end() const
   {
     return Iterator();
   }

 private:
   Hashtable m_ht;

   friend class EnumerationImpl;
 };

 } // namespace name_tree

 using name_tree::NameTree;

 } // namespace nfd

 #endif // NFD_DAEMON_TABLE_NAME_TREE_HPP
	/* -- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -- */
	/*
	* Copyright (c) 2014-2018, Regents of the University of California,
	* Arizona Board of Regents,
	* Colorado State University,
	* University Pierre & Marie Curie, Sorbonne University,
	* Washington University in St. Louis,
	* Beijing Institute of Technology,
	* The University of Memphis.
	*
	* This file is part of NFD (Named Data Networking Forwarding Daemon).
	* See AUTHORS.md for complete list of NFD authors and contributors.
	*
	* NFD 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.
	*
	* NFD 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
	* NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
	*/

	#ifndef NFD_DAEMON_TABLE_NAME_TREE_HPP
	#define NFD_DAEMON_TABLE_NAME_TREE_HPP

	#include "name-tree-iterator.hpp"

	#include "core/fib-max-depth.hpp"

	namespace nfd {
	namespace name_tree {

	/** \brief a common index structure for FIB, PIT, StrategyChoice, and Measurements
	*/
	class NameTree : noncopyable
	{
	public:
	explicit
	NameTree(size_t nBuckets = 1024);

	public: // information
	/** \brief maximum depth of the name tree
	*
	* Calling \c NameTree::lookup with a name with many components would cause the creation of many
	* NameTree entries, which could take very long time. This constant limits the maximum number of
	* name components in the name of a NameTree entry. Thus, it limits the number of NameTree
	* entries created from a long name, bounding the processing complexity.
	*/
	static constexpr size_t
	getMaxDepth()
	{
	return FIB_MAX_DEPTH;
	}

	/** \return number of name tree entries
	*/
	size_t
	size() const
	{
	return m_ht.size();
	}

	/** \return number of hashtable buckets
	*/
	size_t
	getNBuckets() const
	{
	return m_ht.getNBuckets();
	}

	/** \return name tree entry on which a table entry is attached,
	* or nullptr if the table entry is detached
	*/
	template<typename EntryT>
	Entry*
	getEntry(const EntryT& tableEntry) const
	{
	return Entry::get(tableEntry);
	}

	public: // mutation
	/** \brief find or insert an entry by name
	*
	* This method seeks a name tree entry of name \c name.getPrefix(prefixLen).
	* If the entry does not exist, it is created along with all ancestors.
	* Existing iterators are unaffected during this operation.
	*
	* \warning \p prefixLen must not exceed \c name.size().
	* \warning \p prefixLen must not exceed \c getMaxDepth().
	*/
	Entry&
	lookup(const Name& name, size_t prefixLen);

	/** \brief equivalent to `lookup(name, name.size())`
	*/
	Entry&
	lookup(const Name& name)
	{
	return this->lookup(name, name.size());
	}

	/** \brief equivalent to `lookup(fibEntry.getPrefix())`
	* \param fibEntry a FIB entry attached to this name tree, or \c Fib::s_emptyEntry
	* \note This overload is more efficient than `lookup(const Name&)` in common cases.
	*/
	Entry&
	lookup(const fib::Entry& fibEntry);

	/** \brief equivalent to
	* `lookup(pitEntry.getName(), std::min(pitEntry.getName().size(), getMaxDepth()))`
	* \param pitEntry a PIT entry attached to this name tree
	* \note This overload is more efficient than `lookup(const Name&)` in common cases.
	*/
	Entry&
	lookup(const pit::Entry& pitEntry);

	/** \brief equivalent to `lookup(measurementsEntry.getName())`
	* \param measurementsEntry a Measurements entry attached to this name tree
	* \note This overload is more efficient than `lookup(const Name&)` in common cases.
	*/
	Entry&
	lookup(const measurements::Entry& measurementsEntry);

	/** \brief equivalent to `lookup(strategyChoiceEntry.getPrefix())`
	* \param strategyChoiceEntry a StrategyChoice entry attached to this name tree
	* \note This overload is more efficient than `lookup(const Name&)` in common cases.
	*/
	Entry&
	lookup(const strategy_choice::Entry& strategyChoiceEntry);

	/** \brief delete the entry if it is empty
	* \param entry a valid entry
	* \param canEraseAncestors whether ancestors should be deleted if they become empty
	* \return number of deleted entries
	* \sa Entry::isEmpty()
	* \post If the entry is empty, it's deleted. If \p canEraseAncestors is true,
	* ancestors of the entry are also deleted if they become empty.
	* \note This function must be called after detaching a table entry from a name tree entry,
	* \note Existing iterators, except those pointing to deleted entries, are unaffected.
	*/
	size_t
	eraseIfEmpty(Entry* entry, bool canEraseAncestors = true);

	public: // matching
	/** \brief exact match lookup
	* \return entry with \c name.getPrefix(prefixLen), or nullptr if it does not exist
	*/
	Entry*
	findExactMatch(const Name& name, size_t prefixLen = std::numeric_limits<size_t>::max()) const;

	/** \brief longest prefix matching
	* \return entry whose name is a prefix of \p name and passes \p entrySelector,
	* where no other entry with a longer name satisfies those requirements;
	* or nullptr if no entry satisfying those requirements exists
	*/
	Entry*
	findLongestPrefixMatch(const Name& name,
	const EntrySelector& entrySelector = AnyEntry()) const;

	/** \brief equivalent to `findLongestPrefixMatch(entry.getName(), entrySelector)`
	* \note This overload is more efficient than
	* `findLongestPrefixMatch(const Name&, const EntrySelector&)` in common cases.
	*/
	Entry*
	findLongestPrefixMatch(const Entry& entry,
	const EntrySelector& entrySelector = AnyEntry()) const;

	/** \brief equivalent to `findLongestPrefixMatch(getEntry(tableEntry)->getName(), entrySelector)`
	* \tparam EntryT \c fib::Entry or \c measurements::Entry or \c strategy_choice::Entry
	* \note This overload is more efficient than
	* `findLongestPrefixMatch(const Name&, const EntrySelector&)` in common cases.
	* \warning Undefined behavior may occur if \p tableEntry is not attached to this name tree.
	*/
	template<typename EntryT>
	Entry*
	findLongestPrefixMatch(const EntryT& tableEntry,
	const EntrySelector& entrySelector = AnyEntry()) const
	{
	const Entry* nte = this->getEntry(tableEntry);
	BOOST_ASSERT(nte != nullptr);
	return this->findLongestPrefixMatch(*nte, entrySelector);
	}

	/** \brief equivalent to `findLongestPrefixMatch(pitEntry.getName(), entrySelector)`
	* \note This overload is more efficient than
	* `findLongestPrefixMatch(const Name&, const EntrySelector&)` in common cases.
	* \warning Undefined behavior may occur if \p pitEntry is not attached to this name tree.
	*/
	Entry*
	findLongestPrefixMatch(const pit::Entry& pitEntry,
	const EntrySelector& entrySelector = AnyEntry()) const;

	/** \brief all-prefixes match lookup
	* \return a range where every entry has a name that is a prefix of \p name ,
	* and matches \p entrySelector.
	*
	* Example:
	* \code
	* Name name("/A/B/C");
	* auto&& allMatches = nt.findAllMatches(name);
	* for (const Entry& nte : allMatches) {
	* BOOST_ASSERT(nte.getName().isPrefixOf(name));
	* ...
	* }
	* \endcode
	* \note Iteration order is implementation-defined.
	* \warning If a name tree entry whose name is a prefix of \p name is inserted
	* during the enumeration, it may or may not be visited.
	* If a name tree entry whose name is a prefix of \p name is deleted
	* during the enumeration, undefined behavior may occur.
	*/
	Range
	findAllMatches(const Name& name,
	const EntrySelector& entrySelector = AnyEntry()) const;

	public: // enumeration
	using const_iterator = Iterator;

	/** \brief enumerate all entries
	* \return a range where every entry matches \p entrySelector
	*
	* Example:
	* \code
	* auto&& enumerable = nt.fullEnumerate();
	* for (const Entry& nte : enumerable) {
	* ...
	* }
	* \endcode
	* \note Iteration order is implementation-defined.
	* \warning If a name tree entry is inserted or deleted during the enumeration,
	* it may cause the enumeration to skip entries or visit some entries twice.
	*/
	Range
	fullEnumerate(const EntrySelector& entrySelector = AnyEntry()) const;

	/** \brief enumerate all entries under a prefix
	* \return a range where every entry has a name that starts with \p prefix,
	* and matches \p entrySubTreeSelector.
	*
	* Example:
	* \code
	* Name name("/A/B/C");
	* auto&& enumerable = nt.partialEnumerate(name);
	* for (const Entry& nte : enumerable) {
	* BOOST_ASSERT(name.isPrefixOf(nte.getName()));
	* ...
	* }
	* \endcode
	* \note Iteration order is implementation-defined.
	* \warning If a name tree entry under \p prefix is inserted or deleted during the enumeration,
	* it may cause the enumeration to skip entries or visit some entries twice.
	*/
	Range
	partialEnumerate(const Name& prefix,
	const EntrySubTreeSelector& entrySubTreeSelector = AnyEntrySubTree()) const;

	/** \return an iterator to the beginning
	* \sa fullEnumerate
	*/
	const_iterator
	begin() const
	{
	return fullEnumerate().begin();
	}

	/** \return an iterator to the end
	* \sa begin()
	*/
	const_iterator
	end() const
	{
	return Iterator();
	}

	private:
	Hashtable m_ht;

	friend class EnumerationImpl;
	};

	} // namespace name_tree

	using name_tree::NameTree;

	} // namespace nfd

	#endif // NFD_DAEMON_TABLE_NAME_TREE_HPP