--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Loaders/IFetchingStrategy.h	Mon May 20 11:20:01 2019 +0200
@@ -0,0 +1,49 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2019 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero 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
+ * Affero General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include <boost/noncopyable.hpp>
+
+namespace OrthancStone
+{
+  class IFetchingStrategy : public boost::noncopyable
+  {
+  public:
+    virtual ~IFetchingStrategy()
+    {
+    }
+
+    virtual unsigned int GetItemsCount() const = 0;
+
+    virtual unsigned int GetMaxQuality() const = 0;
+
+    virtual bool GetNext(unsigned int& item,
+                         unsigned int& quality) = 0;
+
+    virtual void SetCurrent(unsigned int item) = 0;
+
+    // Ask the strategy to re-schedule the item with the lowest
+    // priority in the fetching order. This allows to know which item
+    // should be dropped from a cache.
+    virtual void RecycleFurthest(unsigned int& item) = 0;
+  };
+};