libstdc++
sample_resize_policy.hpp
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00001 // -*- C++ -*-
00002 
00003 // Copyright (C) 2005, 2006, 2009, 2010 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the terms
00007 // of the GNU General Public License as published by the Free Software
00008 // Foundation; either version 3, or (at your option) any later
00009 // version.
00010 
00011 // This library is distributed in the hope that it will be useful, but
00012 // WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014 // General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
00026 
00027 // Permission to use, copy, modify, sell, and distribute this software
00028 // is hereby granted without fee, provided that the above copyright
00029 // notice appears in all copies, and that both that copyright notice
00030 // and this permission notice appear in supporting documentation. None
00031 // of the above authors, nor IBM Haifa Research Laboratories, make any
00032 // representation about the suitability of this software for any
00033 // purpose. It is provided "as is" without express or implied
00034 // warranty.
00035 
00036 /**
00037  * @file sample_resize_policy.hpp
00038  * Contains a sample resize policy for hash tables.
00039  */
00040 
00041 #ifndef PB_DS_SAMPLE_RESIZE_POLICY_HPP
00042 #define PB_DS_SAMPLE_RESIZE_POLICY_HPP
00043 
00044 namespace __gnu_pbds
00045 {
00046   /// A sample resize policy.
00047   class sample_resize_policy
00048   {
00049   public:
00050     /// Size type.
00051     typedef std::size_t size_type;
00052 
00053     /// Default constructor.
00054     sample_resize_policy();
00055 
00056     /// Copy constructor.
00057     sample_range_hashing(const sample_resize_policy& other);
00058 
00059     /// Swaps content.
00060     inline void
00061     swap(sample_resize_policy& other);
00062 
00063   protected:
00064     /// Notifies a search started.
00065     inline void
00066     notify_insert_search_start();
00067 
00068     /// Notifies a search encountered a collision.
00069     inline void
00070     notify_insert_search_collision();
00071 
00072     /// Notifies a search ended.
00073     inline void
00074     notify_insert_search_end();
00075 
00076     /// Notifies a search started.
00077     inline void
00078     notify_find_search_start();
00079 
00080     /// Notifies a search encountered a collision.
00081     inline void
00082     notify_find_search_collision();
00083 
00084     /// Notifies a search ended.
00085     inline void
00086     notify_find_search_end();
00087 
00088     /// Notifies a search started.
00089     inline void
00090     notify_erase_search_start();
00091 
00092     /// Notifies a search encountered a collision.
00093     inline void
00094     notify_erase_search_collision();
00095 
00096     /// Notifies a search ended.
00097     inline void
00098     notify_erase_search_end();
00099 
00100     /// Notifies an element was inserted.
00101     inline void
00102     notify_inserted(size_type num_e);
00103 
00104     /// Notifies an element was erased.
00105     inline void
00106     notify_erased(size_type num_e);
00107 
00108     /// Notifies the table was cleared.
00109     void
00110     notify_cleared();
00111 
00112     /// Notifies the table was resized to new_size.
00113     void
00114     notify_resized(size_type new_size);
00115 
00116     /// Queries whether a resize is needed.
00117     inline bool
00118     is_resize_needed() const;
00119 
00120     /// Queries what the new size should be.
00121     size_type
00122     get_new_size(size_type size, size_type num_used_e) const;
00123   };
00124 }
00125 #endif