Win32FileTimeConverter (#3967)

sdk/storage/azure-storage-files-datalake/src/private/datalake_utilities.hpp

@@ -5,6 +5,7 @@
 
 #include <string>
 
+#include <azure/core/datetime.hpp>
 #include <azure/storage/blobs/blob_options.hpp>
 #include <azure/storage/common/storage_common.hpp>
 
@@ -28,4 +29,48 @@ namespace Azure { namespace Storage { namespace Files { namespace DataLake { nam
 
   Blobs::BlobClientOptions GetBlobClientOptions(const DataLakeClientOptions& options);
 
+  /**
+   * @brief Provides conversion methods for Win32 FILETIME to an #Azure::DateTime.
+   *
+   */
+  class Win32FileTimeConverter final {
+  public:
+    /**
+     * @brief Converts Win32 FILETIME to an #Azure::DateTime.
+     *
+     * @param win32Filetime The number of 100-nanoseconds since 1601-01-01.
+     * @return Calculated #Azure::DateTime.
+     */
+    static DateTime Win32FileTimeToDateTime(int64_t win32Filetime)
+    {
+      auto t = DateTime(1601) + Azure::_detail::Clock::duration(win32Filetime);
+      return DateTime(t);
+    }
+
+    /**
+     * @brief Converts a DateTime to Win32 FILETIME.
+     *
+     * @param dateTime The `%DateTime` to convert.
+     * @return The number of 100-nanoseconds since 1601-01-01.
+     */
+    static int64_t DateTimeToWin32FileTime(DateTime const& dateTime)
+    {
+      return std::chrono::duration_cast<Azure::_detail::Clock::duration>(dateTime - DateTime(1601))
+          .count();
+    }
+
+    /**
+     * @brief An instance of `%Win32FileTimeConverter` class cannot be created.
+     *
+     */
+    Win32FileTimeConverter() = delete;
+
+    /**
+     * @brief An instance of `%Win32FileTimeConverter` class cannot be destructed, because no
+     * instance can be created.
+     *
+     */
+    ~Win32FileTimeConverter() = delete;
+  };
+
 }}}}} // namespace Azure::Storage::Files::DataLake::_detail