Orthanc/OrthancFramework/Sources/Cache/MemoryObjectCache.h
2025-06-23 19:07:37 +05:30

112 lines
2.9 KiB
C++

/**
* Orthanc - A Lightweight, RESTful DICOM Store
* Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
* Department, University Hospital of Liege, Belgium
* Copyright (C) 2017-2023 Osimis S.A., Belgium
* Copyright (C) 2024-2025 Orthanc Team SRL, Belgium
* Copyright (C) 2021-2025 Sebastien Jodogne, ICTEAM UCLouvain, Belgium
*
* This program is free software: you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program. If not, see
* <http://www.gnu.org/licenses/>.
**/
#pragma once
#include "../OrthancFramework.h"
#include "ICacheable.h"
#include "LeastRecentlyUsedIndex.h"
#if !defined(__EMSCRIPTEN__)
// Multithreading is not supported in WebAssembly
# include <boost/thread/mutex.hpp>
# include <boost/thread/shared_mutex.hpp>
#endif
#include <boost/date_time/posix_time/posix_time.hpp>
namespace Orthanc
{
/**
* Note: this class is thread safe
**/
class ORTHANC_PUBLIC MemoryObjectCache : public boost::noncopyable
{
private:
class Item;
#if !defined(__EMSCRIPTEN__)
typedef boost::unique_lock<boost::shared_mutex> WriterLock;
typedef boost::shared_lock<boost::shared_mutex> ReaderLock;
// This mutex protects modifications to the structure of the cache (monitor)
boost::mutex cacheMutex_;
// This mutex protects modifications to the items that are stored in the cache
boost::shared_mutex contentMutex_;
#endif
size_t currentSize_;
size_t maxSize_;
LeastRecentlyUsedIndex<std::string, Item*> content_;
void Recycle(size_t targetSize);
public:
MemoryObjectCache();
~MemoryObjectCache();
size_t GetNumberOfItems(); // For unit tests only
size_t GetCurrentSize(); // For unit tests only
size_t GetMaximumSize();
void SetMaximumSize(size_t size);
void Acquire(const std::string& key,
ICacheable* value);
void Invalidate(const std::string& key);
class Accessor : public boost::noncopyable
{
private:
#if !defined(__EMSCRIPTEN__)
ReaderLock readerLock_;
WriterLock writerLock_;
boost::mutex::scoped_lock cacheLock_;
#endif
Item* item_;
public:
Accessor(MemoryObjectCache& cache,
const std::string& key,
bool unique);
bool IsValid() const
{
return item_ != NULL;
}
ICacheable& GetValue() const;
const boost::posix_time::ptime& GetTime() const;
};
};
}