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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library 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, or (at your option) any later

// version.

// This 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

// General Public License for more details.

// You should have received a copy of the GNU General Public License

// along with this library; see the file COPYING3.  If not see

// <http://www.gnu.org/licenses/>.

// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.

// Permission to use, copy, modify, sell, and distribute this software

// is hereby granted without fee, provided that the above copyright

// notice appears in all copies, and that both that copyright notice

// and this permission notice appear in supporting documentation. None

// of the above authors, nor IBM Haifa Research Laboratories, make any

// representation about the suitability of this software for any

// purpose. It is provided "as is" without express or implied

// warranty.

/**

 * @file string_ranged_hash_fn.hpp

 * Contains a ranged string hash function.

 */

#ifndef PB_DS_STRING_RANGED_HASH_FN_HPP

#define PB_DS_STRING_RANGED_HASH_FN_HPP

#include <string>

#include <hash_fn/dna_str_limit.hpp>

namespace __gnu_pbds

{

  namespace test

  {

    template<typename Comb_Fn>

    class string_ranged_hash_fn : public Comb_Fn

    {

    private:

      size_t _M_limit;

    public:

      typedef Comb_Fn comb_fn;

      typedef detail::comb_hash_fn_string_form<comb_fn> string_form;

      inline size_t

      operator()(const std::string& r_str) const

      {

        size_t ret = 0;

        std::string::const_iterator b = r_str.begin();

        std::string::const_iterator e = r_str.end();

        size_t i = 0;

        while (i < _M_limit&&  b != e)

          {

            ret *= 5;

            ret += static_cast<size_t>(*(b++));

            ++i;

          }

        return (comb_fn::operator()(ret));

      }

      void

      swap(string_ranged_hash_fn<Comb_Fn>& other)

      {

        std::swap(_M_limit, other._M_limit);

        comb_fn::swap(other);

      }

      void

      notify_resized(size_t new_size)

      {

        comb_fn::notify_resized(new_size);

        _M_limit = dna_str_limit(new_size);

      }

      static std::string

      name()

      { return ("string_ranged_hash_fn_" + string_form<comb_fn>::name()); }

      static std::string

      desc()

      { return ("string ranged-hash using" + string_form<comb_fn>::desc()); }

    };

  } // namespace test

} // namespace __gnu_pbds

#endif