Keep tweaking extraction

Author: mnadareski

SabreTools.Serialization/Wrappers/MicrosoftCabinet.cs

@@ -118,7 +118,8 @@ public MicrosoftCabinet(Cabinet? model, Stream? data)
         /// <param name="outDir">Path to the output directory</param>
         /// <param name="includeDebug">True to include debug data, false otherwise</param>
         /// <returns>Indicates if all files were able to be extracted</returns>
-        public static bool ExtractAll(string filename, string outDir, bool includeDebug)
+        /// <remarks>Will extract all items found in the set with forward-only reading</remarks>
+        public static bool ExtractSet(string filename, string outDir, bool includeDebug)
         {
             // Get a wrapper for the set
             var current = OpenSet(filename);
@@ -144,13 +145,24 @@ public static bool ExtractAll(string filename, string outDir, bool includeDebug)
             return true;
         }
 
+        /// <summary>
+        /// Extract a cabinet to an output directory, if possible
+        /// </summary>
+        /// <param name="filename">Filename for one cabinet in the set</param>
+        /// <param name="outDir">Path to the output directory</param>
+        /// <param name="includeDebug">True to include debug data, false otherwise</param>
+        /// <returns>Indicates if all files were able to be extracted</returns>
+        /// <remarks>Will read spanned folders but won't attempt to extract unrelated folders</remarks>
+        public bool ExtractAll(string filename, string outDir, bool includeDebug)
+            => ExtractCabinet(filename, outDir, forwardOnly: false, includeDebug);
+
         /// <summary>
         /// Extract a cabinet file to an output directory, if possible
         /// </summary>
         /// <param name="filename">Filename for one cabinet in the set</param>
         /// <param name="outDir">Path to the output directory</param>
-        /// <param name="forwardOnly">Indicates if the cabinet set should only be read forward</param>
         /// <param name="includeDebug">True to include debug data, false otherwise</param>
+        /// <param name="forwardOnly">Indicates if decompression should be done forward-only</param>
         /// <returns>Indicates if all files were able to be extracted</returns>
         private bool ExtractCabinet(string filename, string outDir, bool forwardOnly, bool includeDebug)
         {
@@ -183,9 +195,14 @@ private bool ExtractCabinet(string filename, string outDir, bool forwardOnly, bo
         /// <param name="outDir">Path to the output directory</param>
         /// <param name="folder">Folder containing the blocks to decompress</param>
         /// <param name="folderIndex">Index of the folder in the cabinet</param>
-        /// <param name="forwardOnly">Indicates if the cabinet set should only be read forward</param>
+        /// <param name="forwardOnly">Indicates if decompression should be done forward-only</param>
         /// <param name="includeDebug">True to include debug data, false otherwise</param>
-        private void ExtractFolder(string filename, string outDir, CFFOLDER? folder, int folderIndex, bool forwardOnly, bool includeDebug)
+        private void ExtractFolder(string filename,
+            string outDir,
+            CFFOLDER? folder,
+            int folderIndex,
+            bool forwardOnly,
+            bool includeDebug)
         {
             // Decompress the blocks, if possible
             using var blockStream = DecompressBlocks(filename, folder, folderIndex, forwardOnly);
@@ -448,12 +465,14 @@ private int GetFolderIndex(CFFILE file)
         /// <param name="filename">Filename for one cabinet in the set</param>
         /// <param name="folder">Folder containing the blocks to decompress</param>
         /// <param name="folderIndex">Index of the folder in the cabinet</param>
-        /// <param name="forwardOnly">Indicates if the cabinet set should only be read forward</param>
+        /// <param name="forwardOnly">Indicates if decompression should be done forward-only</param>
         /// <returns>Stream representing the decompressed data on success, null otherwise</returns>
         public Stream? DecompressBlocks(string filename, CFFOLDER? folder, int folderIndex, bool forwardOnly)
         {
             // Ensure data blocks
-            var dataBlocks = GetDataBlocks(filename, folder, folderIndex, skipPrev: forwardOnly, skipNext: false);
+            var dataBlocks = forwardOnly
+                ? GetDataBlocksForward(filename, folder, folderIndex)
+                : GetDataBlocks(filename, folder, folderIndex);
             if (dataBlocks == null || dataBlocks.Length == 0)
                 return null;
 
@@ -481,15 +500,15 @@ private int GetFolderIndex(CFFILE file)
 
                     // MS-ZIP
                     case CompressionType.TYPE_MSZIP:
-                        long position = ms.Position;
+                        long preMsZipPosition = ms.Position;
                         mszip.CopyTo(db.CompressedData, ms);
-                        long decompressedSize = ms.Position - position;
+                        long msZipDecompressedSize = ms.Position - preMsZipPosition;
 
                         // Pad to the correct size but throw a warning about this
-                        if (decompressedSize < db.UncompressedSize)
+                        if (msZipDecompressedSize < db.UncompressedSize)
                         {
-                            Console.Error.WriteLine($"Data block {i} in folder {folderIndex} had mismatching sizes. Expected: {db.UncompressedSize}, Got: {decompressedSize}");
-                            byte[] padding = new byte[db.UncompressedSize - decompressedSize];
+                            Console.Error.WriteLine($"Data block {i} in folder {folderIndex} had mismatching sizes. Expected: {db.UncompressedSize}, Got: {msZipDecompressedSize}");
+                            byte[] padding = new byte[db.UncompressedSize - msZipDecompressedSize];
                             ms.Write(padding, 0, padding.Length);
                         }
 
@@ -580,6 +599,16 @@ private static CompressionType GetCompressionType(CFFOLDER folder)
             return [.. prevBlocks, .. folder.DataBlocks, .. nextBlocks];
         }
 
+        /// <summary>
+        /// Get the set of data blocks for a folder using forward reading only
+        /// </summary>
+        /// <param name="filename">Filename for one cabinet in the set</param>
+        /// <param name="folder">Folder containing the blocks to decompress</param>
+        /// <param name="folderIndex">Index of the folder in the cabinet</param>
+        /// <returns>Array of data blocks on success, null otherwise</returns>
+        private CFDATA[]? GetDataBlocksForward(string filename, CFFOLDER? folder, int folderIndex)
+            => GetDataBlocks(filename, folder, folderIndex, skipPrev: true, skipNext: false);
+
         /// <summary>
         /// Get all files for the current folder index
         /// </summary>