hash.h

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/*
 * Copyright (c) 2009-2015:  G-CSC, Goethe University Frankfurt
 * Author: Sebastian Reiter
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * 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 Lesser General Public License for more details.
 */
 
#ifndef __H__UG__hash__
#define __H__UG__hash__
 
#include <vector>
#include <utility>
#include "hash_iterator.h"
#include "hash_function.h"
 
namespace ug{
 
 
template <class TKey, class TValue>
class Hash
{
  private:
    struct Entry;
 
  public:
    typedef TKey  key_t;
    typedef TValue  value_t;
    typedef hash_iterator<key_t, value_t, Entry>    iterator;
//    typedef const_hash_iterator<key_t, value_t, Entry>  const_iterator;
 
    Hash();
    Hash(size_t hashSize);
 
    void resize_hash(size_t size);
    size_t hash_size() const;
 
//    void enable_auto_hash_resize(float maxElemToHashSizeRatio,
//                   float bestElemToHashSizeRatio);
//
//    void disable_auto_hash_resize();
 
 
 
    void reserve(size_t size);
 
 
    size_t capacity() const;
 
    size_t size() const;
 
    void clear();
 
    bool empty() const;
    bool has_entry(const key_t& key) const;
 
    value_t& get_entry(const key_t& key);
    const value_t& get_entry(const key_t& key) const;
    bool get_entry(value_t& valOut, const key_t& key) const;
 
    void insert(const key_t& key, const value_t& val);
    void erase(const key_t& key);
 
    iterator begin(const key_t& key);
    iterator end(const key_t& key);
 
//    const_iterator begin(const key_t& key) const;
//    const_iterator end(const key_t& key) const;
 
  private:
    size_t hash_index(const key_t& key) const;
    size_t find_entry(const key_t& key) const;
    inline size_t invalid_index() const {return -1;}
 
    struct Entry{
      key_t key;
      value_t value;
      size_t  next;
 
      Entry() {}
      Entry(const key_t& k, const value_t& v) :
        key(k), value(v), next(-1)
      {}
    };
 
    std::vector<Entry>  m_entries;
    size_t        m_numEntries;
    size_t        m_firstUnusedEntry;
 
    std::vector<std::pair<size_t, size_t> > m_hashList;
 
};
 
}// end of namespace
 
 
#include "hash_impl.hpp"
 
#endif