Changeset 260 for branches/eraser6/Manager/DirectExecutor.cs

Timestamp:

3/12/2008 5:34:32 AM (5 years ago)

Author:

lowjoel

Message:

-Change the RemoveFile? and RemoveFolder? functions to be static since they don't need the this reference
-Factor the random filename generator code out to a separate function
-Guard all MoveTo? files with an exception handler since antivirus programs may lock the file temporally

File:

• branches/eraser6/Manager/DirectExecutor.cs (modified) (6 diffs)

branches/eraser6/Manager/DirectExecutor.cs

@@ -361 +361 @@
                 {
                     //Set the end of the stream after the wrap-round the cluster size
-                    uint clusterSize = Drives.GetDriveClusterSize(info.Directory.Root.FullName);
+                    uint clusterSize = Drive.GetClusterSize(info.Directory.Root.FullName);
                     long roundUpFileLength = strm.Length % clusterSize;
                     if (roundUpFileLength != 0)
@@ -419 +419 @@
         /// </summary>
         /// <param name="info">The FileInfo object representing the file.</param>
-        private void RemoveFile(FileInfo info)
+        private static void RemoveFile(FileInfo info)
         {
             //Set the date of the file to be invalid to prevent forensic
@@ -431 +431 @@
             for (int i = 0; i < FilenameErasePasses; ++i)
             {
-                //Get a random file name
-                PRNG prng = PRNGManager.GetInstance(Globals.Settings.ActivePRNG);
-                byte[] newFileNameAry = new byte[info.Name.Length];
-                prng.NextBytes(newFileNameAry);
-
-                //Validate the name
-                const string validFileNameChars = "0123456789abcdefghijklmnopqrs" +
-                    "tuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
-                for (int j = 0, k = newFileNameAry.Length; j < k; ++j)
-                    newFileNameAry[j] = (byte)validFileNameChars[
-                        (int)newFileNameAry[j] % validFileNameChars.Length];
-
                 //Rename the file.
                 string newPath = info.DirectoryName + Path.DirectorySeparatorChar +
-                    (new System.Text.UTF8Encoding()).GetString(newFileNameAry);
-                info.MoveTo(newPath);
+                    GetRandomFileName(info.Name.Length);
+
+                //Try to rename the file. If it fails, it is probably due to another
+                //process locking the file. Defer, then rename again.
+                try
+                {
+                    info.MoveTo(newPath);
+                }
+                catch (IOException)
+                {
+                    Thread.Sleep(100);
+                    --i;
+                }
             }
 
@@ -453 +452 @@
         }
 
-        private void RemoveFolder(DirectoryInfo info)
+        private static void RemoveFolder(DirectoryInfo info)
         {
             foreach (FileInfo file in info.GetFiles())
@@ -463 +462 @@
             for (int i = 0; i < FilenameErasePasses; ++i)
             {
-                //Get a random file name
-                PRNG prng = PRNGManager.GetInstance(Globals.Settings.ActivePRNG);
-                byte[] newFileNameAry = new byte[info.Name.Length];
-                prng.NextBytes(newFileNameAry);
-
-                //Validate the name
-                const string validFileNameChars = "0123456789abcdefghijklmnopqrs" +
-                    "tuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
-                for (int j = 0, k = newFileNameAry.Length; j < k; ++j)
-                    newFileNameAry[j] = (byte)validFileNameChars[
-                        (int)newFileNameAry[j] % validFileNameChars.Length];
-
                 //Rename the folder.
                 string newPath = info.Parent.FullName + Path.DirectorySeparatorChar +
-                    (new System.Text.UTF8Encoding()).GetString(newFileNameAry);
+                    GetRandomFileName(info.Name.Length);
 
                 //Try to rename the file. If it fails, it is probably due to another
@@ -497 +484 @@
 
         /// <summary>
+        /// Generates a random file name with the given length.
+        /// </summary>
+        /// <param name="length">The length of the file name to generate.</param>
+        /// <returns>A random file name.</returns>
+        private static string GetRandomFileName(int length)
+        {
+            //Get a random file name
+            PRNG prng = PRNGManager.GetInstance(Globals.Settings.ActivePRNG);
+            byte[] newFileNameAry = new byte[length];
+            prng.NextBytes(newFileNameAry);
+
+            //Validate the name
+            string validFileNameChars = "0123456789abcdefghijklmnopqrstuvwxyz" +
+                "ABCDEFGHIJKLMNOPQRSTUVWXYZ _+=-()[]{}',`~!";
+            for (int j = 0, k = newFileNameAry.Length; j < k; ++j)
+                newFileNameAry[j] = (byte)validFileNameChars[
+                    (int)newFileNameAry[j] % validFileNameChars.Length];
+
+            return new System.Text.UTF8Encoding().GetString(newFileNameAry);
+        }
+
+        /// <summary>
         /// The thread object.
         /// </summary>