the massive refactoring effort

[chaz/yoink] / src / moof / manager.hh

diff --git a/src/moof/manager.hh b/src/moof/manager.hh
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+
+/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
+**]  All rights reserved.
+*
+* vi:ts=4 sw=4 tw=75
+*
+* Distributable under the terms and conditions of the 2-clause BSD license;
+* see the file COPYING for a complete text of the license.
+*
+**************************************************************************/
+
+#ifndef _MOOF_MANAGER_HH_
+#define _MOOF_MANAGER_HH_
+
+/**
+ * \file manager.hh
+ * A manager is a collection of named objects of the same type.  Libraries
+ * use reference counting to automagically delete objects which no longer
+ * have any interested code.
+ */
+
+#include <string>
+
+#include <boost/shared_ptr.hpp>
+
+#include <moof/hash.hh>
+
+
+namespace moof {
+
+
+template <class T>
+class manager
+{
+public:
+
+       manager() :
+               retain_count_(1) {}
+
+       const std::string& name() const
+       {
+               return name_;
+       }
+
+       static boost::shared_ptr<T> instance(const std::string& name)
+       {
+               return boost::shared_ptr<T>(retain(name), &release);
+       }
+
+
+private:
+
+       typedef stlplus::hash<std::string,T*,hash_function> ptr_lookup;
+
+       static T* retain(const std::string& name)
+       {
+               typename ptr_lookup::iterator it = ptr_lookup_.find(name);
+
+               if (it != ptr_lookup_.end())
+               {
+                       ++((*it).second->retain_count_);
+                       return (*it).second;
+               }
+               else
+               {
+                       T* new_object(new T);
+                       if (new_object)
+                       {
+                               new_object->name_ = name;
+                               new_object->init(name);
+                               ptr_lookup_.insert(std::make_pair(name, new_object));
+                       }
+                       return new_object; 
+               }
+       }
+
+       static void release(T* obj)
+       {
+               if (--(obj->retain_count_) == 0)
+               {
+                       ptr_lookup_.erase(obj->name_);
+                       delete obj;
+               }
+       }
+
+
+       static ptr_lookup       ptr_lookup_;
+       std::string                     name_;
+       unsigned                        retain_count_;
+};
+
+template <class T>
+hash<std::string,T*,hash_function> manager<T>::ptr_lookup_;
+
+
+} // namespace moof
+
+#endif // _MOOF_MANAGER_HH_
+