libcore/MovieLibrary.h

   1 //
   2 //   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
   3 //   Free Software Foundation, Inc
   4 //
   5 // This program is free software; you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation; either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software
  17 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19 #ifndef GNASH_MOVIELIBRARY_H
  20 #define GNASH_MOVIELIBRARY_H
  21
  22 #include "rc.h"
  23 #include "movie_definition.h"
  24
  25 #include <boost/intrusive_ptr.hpp>
  26 #include <string>
  27 #include <map>
  28 #include <algorithm>
  29
  30 namespace gnash {
  31
  32 /// Library of SWF movies indexed by URL strings
  33 //
  34 /// Elements are actually movie_definitions, the ones
  35 /// associated with URLS. They may be BitmapMovieDefinitions or
  36 /// SWFMovieDefinitions.
  37 class MovieLibrary
  38 {
  39 public:
  40
  41     struct LibraryItem
  42     {
  43         boost::intrusive_ptr<movie_definition> def;
  44         unsigned hitCount;
  45     };
  46
  47     typedef std::map<std::string, LibraryItem> LibraryContainer;
  48
  49     MovieLibrary()
  50         :
  51         _limit(8)
  52     {
  53         RcInitFile& rcfile = RcInitFile::getDefaultInstance();
  54             setLimit(rcfile.getMovieLibraryLimit());
  55     }
  56
  57     /// Sets the maximum number of items to hold in the library. When adding new
  58     /// items, the one with the least hit count is being removed in that case.
  59     /// Zero is a valid limit (disables library).
  60     void setLimit(LibraryContainer::size_type limit)
  61     {
  62         _limit = limit;
  63         limitSize(_limit);
  64     }
  65
  66     bool get(const std::string& key,
  67             boost::intrusive_ptr<movie_definition>* ret)
  68     {
  69         std::lock_guard<std::mutex> lock(_mapMutex);
  70         LibraryContainer::iterator it = _map.find(key);
  71         if (it == _map.end()) return false;
  72
  73         *ret = it->second.def;
  74         it->second.hitCount++;
  75         return true;
  76     }
  77
  78     void add(const std::string& key, movie_definition* mov)
  79     {
  80
  81         if (!_limit) return;
  82
  83         if (_limit) limitSize(_limit - 1);
  84
  85         LibraryItem temp;
  86
  87         temp.def = mov;
  88         temp.hitCount = 0;
  89
  90         std::lock_guard<std::mutex> lock(_mapMutex);
  91         _map[key] = temp;
  92     }
  93
  94
  95     void clear()
  96     {
  97         std::lock_guard<std::mutex> lock(_mapMutex);
  98         _map.clear();
  99     }
 100
 101 private:
 102
 103     static bool findWorstHitCount(const LibraryContainer::value_type& a,
 104                                 const LibraryContainer::value_type& b)
 105     {
 106         return (a.second.hitCount < b.second.hitCount);
 107     }
 108
 109     LibraryContainer _map;
 110     unsigned _limit;
 111
 112     void limitSize(LibraryContainer::size_type max) {
 113
 114         if (max < 1) {
 115             clear();
 116             return;
 117         }
 118
 119         while (_map.size() > max) {
 120             std::lock_guard<std::mutex> lock(_mapMutex);
 121             _map.erase(std::min_element(_map.begin(), _map.end(),
 122                         &findWorstHitCount));
 123         }
 124
 125     }
 126
 127     mutable std::mutex _mapMutex;
 128
 129 };
 130
 131 }
 132 #endif
 133
 134
 135 // Local Variables:
 136 // mode: C++
 137 // c-basic-offset: 8
 138 // tab-width: 8
 139 // indent-tabs-mode: t
 140 // End: