79 lines
2.3 KiB
C++
79 lines
2.3 KiB
C++
/* This file is part of Clementine.
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Copyright 2010, David Sansome <me@davidsansome.com>
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Clementine is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Clementine is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Clementine. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef SHAREDPOINTERMANAGER_H
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#define SHAREDPOINTERMANAGER_H
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#include <boost/shared_ptr.hpp>
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#include <map>
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#include <utility>
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template<typename T>
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struct SharedPointerManager {
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typedef T cpp_type;
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typedef boost::shared_ptr<cpp_type> smart_pointer_type;
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typedef std::pair<smart_pointer_type, int> smart_pointer_count;
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typedef std::map<cpp_type*, smart_pointer_count> pointer_map_type;
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static pointer_map_type* _pointer_map;
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static void init() {
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if(!_pointer_map)
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_pointer_map = new pointer_map_type();
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}
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// Add a new reference or increment a previous reference
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static int AddRef(smart_pointer_type& ref) {
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init();
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typename pointer_map_type::iterator it = _pointer_map->find(ref.get());
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if (it != _pointer_map->end())
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return ++(*it).second.second;
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_pointer_map->insert(std::make_pair(ref.get(), std::make_pair(ref, 1)));
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return 1;
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}
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// Release a reference
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static int SubRef(cpp_type* ptr) {
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init();
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typename pointer_map_type::iterator it = _pointer_map->find(ptr);
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if (it == _pointer_map->end())
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return -1;
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int count = --(*it).second.second;
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if (0 == count)
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_pointer_map->erase(it);
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return count;
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}
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// Create a new smart pointer instance (from copy in map if available)
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static smart_pointer_type* CreatePointer(cpp_type* ptr) {
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init();
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typename pointer_map_type::iterator it = _pointer_map->find(ptr);
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if (it == _pointer_map->end())
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return new smart_pointer_type(ptr);
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else
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return new smart_pointer_type((*it).second.first);
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}
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};
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#endif // SHAREDPOINTERMANAGER_H
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