diff Core/Cache/MemoryCache.h @ 284:06aa7b7b6723

implementation of a single-threaded cache mechanism
author Sebastien Jodogne <s.jodogne@gmail.com>
date Wed, 12 Dec 2012 15:40:18 +0100
parents
children 4031f73fe0e4
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Core/Cache/MemoryCache.h	Wed Dec 12 15:40:18 2012 +0100
@@ -0,0 +1,96 @@
+/**
+ * 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/>.
+ **/
+
+
+#pragma once
+
+#include <memory>
+#include "CacheIndex.h"
+#include "ICachePageProvider.h"
+
+namespace Orthanc
+{
+  /**
+   * WARNING: This class is NOT thread-safe.
+   **/
+  class MemoryCache
+  {
+  private:
+    struct Page
+    {
+      std::string id_;
+      std::auto_ptr<IDynamicObject> content_;
+    };
+
+    ICachePageProvider& provider_;
+    size_t cacheSize_;
+    CacheIndex<std::string, Page*>  index_;
+
+    Page& Load(const std::string& id);
+
+  public:
+    class Accessor
+    {
+      friend class MemoryCache;
+
+    private:
+      Page& element_;
+
+      Accessor(Page& element) : 
+        element_(element)
+      {
+      }
+
+    public:
+      const std::string GetId() const
+      {
+        return element_.id_;
+      }
+
+      IDynamicObject& GetContent()
+      {
+        return *element_.content_;
+      }
+
+      const IDynamicObject& GetContent() const
+      {
+        return *element_.content_;
+      }
+    };
+
+    MemoryCache(ICachePageProvider& provider,
+                size_t cacheSize);
+
+    ~MemoryCache();
+
+    Accessor* Access(const std::string& id);
+  };
+}