Home | History | Annotate | Download | only in resize_policy
      1 // -*- C++ -*-
      2 
      3 // Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
      4 //
      5 // This file is part of the GNU ISO C++ Library.  This library is free
      6 // software; you can redistribute it and/or modify it under the terms
      7 // of the GNU General Public License as published by the Free Software
      8 // Foundation; either version 3, or (at your option) any later
      9 // version.
     10 
     11 // This library is distributed in the hope that it will be useful, but
     12 // WITHOUT ANY WARRANTY; without even the implied warranty of
     13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14 // General Public License for more details.
     15 
     16 // Under Section 7 of GPL version 3, you are granted additional
     17 // permissions described in the GCC Runtime Library Exception, version
     18 // 3.1, as published by the Free Software Foundation.
     19 
     20 // You should have received a copy of the GNU General Public License and
     21 // a copy of the GCC Runtime Library Exception along with this program;
     22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
     23 // <http://www.gnu.org/licenses/>.
     24 
     25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
     26 
     27 // Permission to use, copy, modify, sell, and distribute this software
     28 // is hereby granted without fee, provided that the above copyright
     29 // notice appears in all copies, and that both that copyright notice
     30 // and this permission notice appear in supporting documentation. None
     31 // of the above authors, nor IBM Haifa Research Laboratories, make any
     32 // representation about the suitability of this software for any
     33 // purpose. It is provided "as is" without express or implied
     34 // warranty.
     35 
     36 /**
     37  * @file sample_resize_policy.hpp
     38  * Contains a sample resize policy for hash tables.
     39  */
     40 
     41 #ifndef PB_DS_SAMPLE_RESIZE_POLICY_HPP
     42 #define PB_DS_SAMPLE_RESIZE_POLICY_HPP
     43 
     44 // A sample resize policy.
     45 class sample_resize_policy
     46 {
     47 public:
     48 
     49   // Size type.
     50   typedef size_t size_type;
     51 
     52   // Default constructor.
     53   sample_resize_policy();
     54 
     55   // Copy constructor.
     56   sample_range_hashing(const sample_resize_policy& other);
     57 
     58   // Swaps content.
     59   inline void
     60   swap(sample_resize_policy& other);
     61 
     62 protected:
     63 
     64   // Notifies a search started.
     65   inline void
     66   notify_insert_search_start();
     67 
     68   // Notifies a search encountered a collision.
     69   inline void
     70   notify_insert_search_collision();
     71 
     72   // Notifies a search ended.
     73   inline void
     74   notify_insert_search_end();
     75 
     76   // Notifies a search started.
     77   inline void
     78   notify_find_search_start();
     79 
     80   // Notifies a search encountered a collision.
     81   inline void
     82   notify_find_search_collision();
     83 
     84   // Notifies a search ended.
     85   inline void
     86   notify_find_search_end();
     87 
     88   // Notifies a search started.
     89   inline void
     90   notify_erase_search_start();
     91 
     92   // Notifies a search encountered a collision.
     93   inline void
     94   notify_erase_search_collision();
     95 
     96   // Notifies a search ended.
     97   inline void
     98   notify_erase_search_end();
     99 
    100   // Notifies an element was inserted.
    101   inline void
    102   notify_inserted(size_type num_e);
    103 
    104   // Notifies an element was erased.
    105   inline void
    106   notify_erased(size_type num_e);
    107 
    108   // Notifies the table was cleared.
    109   void
    110   notify_cleared();
    111 
    112   // Notifies the table was resized to new_size.
    113   void
    114   notify_resized(size_type new_size);
    115 
    116   // Queries whether a resize is needed.
    117   inline bool
    118   is_resize_needed() const;
    119 
    120   // Queries what the new size should be.
    121   size_type
    122   get_new_size(size_type size, size_type num_used_e) const;
    123 };
    124 
    125 #endif
    126