Initial commit - WPinternals 2.6

DiscUtils/IClusterBasedFileSystem.cs

@@ -0,0 +1,85 @@
+//
+// Copyright (c) 2008-2011, Kenneth Bell
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+
+namespace DiscUtils
+{
+    /// <summary>
+    /// Base class for all file systems based on a cluster model.
+    /// </summary>
+    public interface IClusterBasedFileSystem : IFileSystem
+    {
+        /// <summary>
+        /// Gets the size (in bytes) of each cluster.
+        /// </summary>
+        long ClusterSize
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Gets the total number of clusters managed by the file system.
+        /// </summary>
+        long TotalClusters
+        {
+            get;
+        }
+
+        /// <summary>
+        /// Converts a cluster (index) into an absolute byte position in the underlying stream.
+        /// </summary>
+        /// <param name="cluster">The cluster to convert.</param>
+        /// <returns>The corresponding absolute byte position.</returns>
+        long ClusterToOffset(long cluster);
+
+        /// <summary>
+        /// Converts an absolute byte position in the underlying stream to a cluster (index).
+        /// </summary>
+        /// <param name="offset">The byte position to convert.</param>
+        /// <returns>The cluster containing the specified byte.</returns>
+        long OffsetToCluster(long offset);
+
+        /// <summary>
+        /// Converts a file name to the list of clusters occupied by the file's data.
+        /// </summary>
+        /// <param name="path">The path to inspect.</param>
+        /// <returns>The clusters.</returns>
+        /// <remarks>Note that in some file systems, small files may not have dedicated
+        /// clusters.  Only dedicated clusters will be returned.</remarks>
+        Range<long, long>[] PathToClusters(string path);
+
+        /// <summary>
+        /// Converts a file name to the extents containing its data.
+        /// </summary>
+        /// <param name="path">The path to inspect.</param>
+        /// <returns>The file extents, as absolute byte positions in the underlying stream.</returns>
+        /// <remarks>Use this method with caution - not all file systems will store all bytes
+        /// directly in extents.  Files may be compressed, sparse or encrypted.  This method
+        /// merely indicates where file data is stored, not what's stored.</remarks>
+        StreamExtent[] PathToExtents(string path);
+
+        /// <summary>
+        /// Gets an object that can convert between clusters and files.
+        /// </summary>
+        /// <returns>The cluster map.</returns>
+        ClusterMap BuildClusterMap();
+    }
+}