--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Common/BaseStorage.cpp	Fri Oct 14 11:00:18 2022 +0200
@@ -0,0 +1,95 @@
+/**
+ * Cloud storage plugins for Orthanc
+ * Copyright (C) 2020-2021 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/>.
+ **/
+
+
+#include "BaseStorage.h"
+#include <boost/filesystem/fstream.hpp>
+
+boost::filesystem::path BaseStorage::GetOrthancFileSystemPath(const std::string& uuid, const std::string& fileSystemRootPath)
+{
+  boost::filesystem::path path = fileSystemRootPath;
+
+  path /= std::string(&uuid[0], &uuid[2]);
+  path /= std::string(&uuid[2], &uuid[4]);
+  path /= uuid;
+
+  path.make_preferred();
+
+  return path;
+}
+
+
+std::string BaseStorage::GetPath(const char* uuid, OrthancPluginContentType type, bool encryptionEnabled, bool useAlternateExtension)
+{
+  if (enableLegacyStorageStructure_)
+  {
+    return GetOrthancFileSystemPath(uuid, rootPath_).string();
+  }
+  else
+  {
+    boost::filesystem::path path = rootPath_;
+    std::string filename = std::string(uuid);
+
+    if (type == OrthancPluginContentType_Dicom)
+    {
+      filename += ".dcm";
+    }
+    else if (type == OrthancPluginContentType_DicomAsJson)
+    {
+      filename += ".json";
+    }
+    else if (type == OrthancPluginContentType_DicomUntilPixelData && !useAlternateExtension)  // for some time, header files were saved with .unk (happened with S3 storage plugin between version 1.2.0 and 1.3.0 - 21.5.1 and 21.6.2)
+    {
+      filename += ".dcm.head";
+    }
+    else
+    {
+      filename += ".unk";
+    }
+
+    if (encryptionEnabled)
+    {
+      filename += ".enc";
+    }
+    path /= filename;
+
+    return path.string();
+  }
+}
+
+bool BaseStorage::ReadCommonConfiguration(bool& enableLegacyStorageStructure, bool& storageContainsUnknownFiles, const OrthancPlugins::OrthancConfiguration& pluginSection)
+{
+  std::string storageStructure = pluginSection.GetStringValue("StorageStructure", "flat");
+  if (storageStructure == "flat")
+  {
+    enableLegacyStorageStructure = false;
+  }
+  else
+  {
+    enableLegacyStorageStructure = true;
+    if (storageStructure != "legacy")
+    {
+      OrthancPlugins::LogError("ObjectStorage/StorageStructure configuration invalid value: " + storageStructure + ", allowed values are 'flat' and 'legacy'");
+      return false;
+    }
+  }
+
+  storageContainsUnknownFiles = pluginSection.GetBooleanValue("EnableLegacyUnknownFiles", false);
+
+  return true;
+}