Dogcows Code - chaz/yoink/blob - src/Moof/Manager.hh

   1
   2 /*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
   3 **]  All rights reserved.
   4 *
   5 * vi:ts=4 sw=4 tw=75
   6 *
   7 * Distributable under the terms and conditions of the 2-clause BSD license;
   8 * see the file COPYING for a complete text of the license.
   9 *
  10 **************************************************************************/
  11
  12 #ifndef _MOOF_MANAGER_HH_
  13 #define _MOOF_MANAGER_HH_
  14
  15 /**
  16  * @file Manager.hh
  17  * A library is a collection of named objects of the same type.  Libraries
  18  * use reference counting to automagically delete objects which no longer
  19  * have any interested code.
  20  */
  21
  22 #include <string>
  23
  24 #include <boost/shared_ptr.hpp>
  25
  26 #include <Moof/Hash.hh>
  27
  28
  29 namespace Mf {
  30
  31
  32 template <class T>
  33 class Manager
  34 {
  35 public:
  36
  37         Manager() :
  38                 mRetainCount(1) {}
  39
  40         const std::string& getName() const
  41         {
  42                 return mName;
  43         }
  44
  45         static boost::shared_ptr<T> getInstance(const std::string& name)
  46         {
  47                 return boost::shared_ptr<T>(retain(name), &release);
  48         }
  49
  50 private:
  51
  52         typedef stlplus::hash<std::string,T*,getHash> PtrMap;
  53
  54         static PtrMap   mPtrMap;
  55         std::string             mName;
  56         unsigned                mRetainCount;
  57
  58         static T* retain(const std::string& name)
  59         {
  60                 typename PtrMap::iterator it = mPtrMap.find(name);
  61
  62                 if (it != mPtrMap.end())
  63                 {
  64                         ++((*it).second->mRetainCount);
  65                         return (*it).second;
  66                 }
  67                 else
  68                 {
  69                         T* newObj(new T);
  70                         if (newObj)
  71                         {
  72                                 newObj->mName = name;
  73                                 newObj->init(name);
  74                                 mPtrMap.insert(std::make_pair(name, newObj));
  75                         }
  76                         return newObj;
  77                 }
  78         }
  79
  80         static void release(T* obj)
  81         {
  82                 if (--(obj->mRetainCount) == 0)
  83                 {
  84                         mPtrMap.erase(obj->mName);
  85                         delete obj;
  86                 }
  87         }
  88 };
  89
  90 template <class T>
  91 stlplus::hash<std::string,T*,getHash> Manager<T>::mPtrMap;
  92
  93
  94 } // namespace Mf
  95
  96 #endif // _MOOF_MANAGER_HH_
  97