Mercurial > hg > orthanc
diff Core/MultiThreading/CacheIndex.cpp @ 282:915ed24547ea
cache lru policy
author | Sebastien Jodogne <s.jodogne@gmail.com> |
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date | Wed, 12 Dec 2012 13:17:42 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Core/MultiThreading/CacheIndex.cpp Wed Dec 12 13:17:42 2012 +0100 @@ -0,0 +1,140 @@ +/** + * Orthanc - A Lightweight, RESTful DICOM Store + * Copyright (C) 2012 Medical Physics Department, CHU of Liege, + * Belgium + * + * This program is free software: you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, either version 3 of the + * License, or (at your option) any later version. + * + * In addition, as a special exception, the copyright holders of this + * program give permission to link the code of its release with the + * OpenSSL project's "OpenSSL" library (or with modified versions of it + * that use the same license as the "OpenSSL" library), and distribute + * the linked executables. You must obey the GNU General Public License + * in all respects for all of the code used other than "OpenSSL". If you + * modify file(s) with this exception, you may extend this exception to + * your version of the file(s), but you are not obligated to do so. If + * you do not wish to do so, delete this exception statement from your + * version. If you delete this exception statement from all source files + * in the program, then also delete it here. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + **/ + + +#include "CacheIndex.h" + +#include <cassert> +#include <string> +#include "../OrthancException.h" +#include "../IDynamicObject.h" + +namespace Orthanc +{ + template <typename T, typename Payload> + void CacheIndex<T, Payload>::CheckInvariants() const + { +#ifndef NDEBUG + assert(index_.size() == queue_.size()); + + for (typename Index::const_iterator + it = index_.begin(); it != index_.end(); it++) + { + assert(it->second != queue_.end()); + assert(it->second->first == it->first); + } +#endif + } + + + template <typename T, typename Payload> + void CacheIndex<T, Payload>::Add(T id, Payload payload) + { + if (Contains(id)) + { + throw OrthancException(ErrorCode_BadSequenceOfCalls); + } + + queue_.push_front(std::make_pair(id, payload)); + index_[id] = queue_.begin(); + + CheckInvariants(); + } + + + template <typename T, typename Payload> + void CacheIndex<T, Payload>::TagAsMostRecent(T id) + { + if (!Contains(id)) + { + throw OrthancException(ErrorCode_InexistentItem); + } + + typename Index::iterator it = index_.find(id); + assert(it != index_.end()); + + std::pair<T, Payload> item = *(it->second); + + queue_.erase(it->second); + queue_.push_front(item); + index_[id] = queue_.begin(); + + CheckInvariants(); + } + + + template <typename T, typename Payload> + Payload CacheIndex<T, Payload>::Invalidate(T id) + { + if (!Contains(id)) + { + throw OrthancException(ErrorCode_InexistentItem); + } + + typename Index::iterator it = index_.find(id); + assert(it != index_.end()); + + Payload payload = it->second->second; + queue_.erase(it->second); + index_.erase(it); + + CheckInvariants(); + return payload; + } + + + template <typename T, typename Payload> + T CacheIndex<T, Payload>::RemoveOldest(Payload& payload) + { + if (IsEmpty()) + { + throw OrthancException(ErrorCode_BadSequenceOfCalls); + } + + std::pair<T, Payload> item = queue_.back(); + T oldest = item.first; + payload = item.second; + + queue_.pop_back(); + assert(index_.find(oldest) != index_.end()); + index_.erase(oldest); + + CheckInvariants(); + + return oldest; + } + + + // Explicit template instanciation for some data types + template class CacheIndex<std::string, NullType>; + template class CacheIndex<std::string, int>; + template class CacheIndex<const char*, IDynamicObject*>; +}