Initial commit - WPinternals 2.6

DiscUtils/ClusterMap.cs

@@ -0,0 +1,128 @@
+//
+// 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
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Text;
+
+    /// <summary>
+    /// Enumeration of possible cluster roles.
+    /// </summary>
+    /// <remarks>A cluster may be in more than one role.</remarks>
+    [Flags]
+    public enum ClusterRoles
+    {
+        /// <summary>
+        /// Unknown, or unspecified role.
+        /// </summary>
+        None     = 0x00,
+
+        /// <summary>
+        /// Cluster is free.
+        /// </summary>
+        Free     = 0x01,
+
+        /// <summary>
+        /// Cluster is in use by a normal file.
+        /// </summary>
+        DataFile = 0x02,
+
+        /// <summary>
+        /// Cluster is in use by a system file.
+        /// </summary>
+        /// <remarks>This isn't a file marked with the 'system' attribute,
+        /// rather files that form part of the file system namespace but also
+        /// form part of the file system meta-data.</remarks>
+        SystemFile = 0x04,
+
+        /// <summary>
+        /// Cluster is in use for meta-data.
+        /// </summary>
+        Metadata = 0x08,
+
+        /// <summary>
+        /// Cluster contains the boot region.
+        /// </summary>
+        BootArea = 0x10,
+
+        /// <summary>
+        /// Cluster is marked bad.
+        /// </summary>
+        Bad      = 0x20,
+    }
+
+    /// <summary>
+    /// Class that identifies the role of each cluster in a file system.
+    /// </summary>
+    public sealed class ClusterMap
+    {
+        private ClusterRoles[] _clusterToRole;
+        private object[] _clusterToFileId;
+        private Dictionary<object, string[]> _fileIdToPaths;
+
+        internal ClusterMap(ClusterRoles[] clusterToRole, object[] clusterToFileId, Dictionary<object, string[]> fileIdToPaths)
+        {
+            _clusterToRole = clusterToRole;
+            _clusterToFileId = clusterToFileId;
+            _fileIdToPaths = fileIdToPaths;
+        }
+
+        /// <summary>
+        /// Gets the role of a cluster within the file system.
+        /// </summary>
+        /// <param name="cluster">The cluster to inspect.</param>
+        /// <returns>The clusters role (or roles).</returns>
+        public ClusterRoles GetRole(long cluster)
+        {
+            if (_clusterToRole == null || _clusterToRole.Length < cluster)
+            {
+                return ClusterRoles.None;
+            }
+            else
+            {
+                return _clusterToRole[cluster];
+            }
+        }
+
+        /// <summary>
+        /// Converts a cluster to a list of file names.
+        /// </summary>
+        /// <param name="cluster">The cluster to inspect.</param>
+        /// <returns>A list of paths that map to the cluster.</returns>
+        /// <remarks>A list is returned because on file systems with the notion of
+        /// hard links, a cluster may correspond to multiple directory entries.</remarks>
+        public string[] ClusterToPaths(long cluster)
+        {
+            if ((GetRole(cluster) & (ClusterRoles.DataFile | ClusterRoles.SystemFile)) != 0)
+            {
+                object fileId = _clusterToFileId[cluster];
+                return _fileIdToPaths[fileId];
+            }
+            else
+            {
+                return new string[0];
+            }
+        }
+    }
+}