Improve compatibility with older builds

Author: Marlamin

TACTSharp/Build.cs

@@ -83,35 +83,48 @@ public void Load()
             timer.Stop();
             Console.WriteLine("Group index loaded in " + Math.Ceiling(timer.Elapsed.TotalMilliseconds) + "ms");
 
-            timer.Restart();
-            if (!CDNConfig.Values.TryGetValue("file-index", out var fileIndex))
-                throw new Exception("No file index found in CDN config");
-
-            if (!string.IsNullOrEmpty(Settings.BaseDir) && File.Exists(Path.Combine(Settings.BaseDir, "Data", "indices", fileIndex[0] + ".index")))
+            ulong decodedEncodingSize = 0;
+            ulong encodedEncodingSize = 0;
+            if (BuildConfig.Values.TryGetValue("encoding-size", out var bcEncodingSize))
             {
-                FileIndex = new IndexInstance(Path.Combine(Settings.BaseDir, "Data", "indices", fileIndex[0] + ".index"));
+                decodedEncodingSize = ulong.Parse(bcEncodingSize[0]);
+                encodedEncodingSize = ulong.Parse(bcEncodingSize[1]);
             }
-            else
-            {
-                try
-                {
-                    var fileIndexPath = cdn.GetFilePath("data", fileIndex[0] + ".index");
-                    FileIndex = new IndexInstance(fileIndexPath);
 
-                }catch(Exception e)
+            timer.Restart();
+            Encoding = new EncodingInstance(cdn.GetDecodedFilePath("data", BuildConfig.Values["encoding"][1], encodedEncodingSize, decodedEncodingSize), (int)decodedEncodingSize);
+            timer.Stop();
+            Console.WriteLine("Encoding loaded in " + Math.Ceiling(timer.Elapsed.TotalMilliseconds) + "ms");
+
+            timer.Restart();
+            if (CDNConfig.Values.TryGetValue("file-index", out var fileIndex))
+            {
+                if (!string.IsNullOrEmpty(Settings.BaseDir) && File.Exists(Path.Combine(Settings.BaseDir, "Data", "indices", fileIndex[0] + ".index")))
                 {
-                    Console.WriteLine("Failed to load file index: " + e.Message);
+                    FileIndex = new IndexInstance(Path.Combine(Settings.BaseDir, "Data", "indices", fileIndex[0] + ".index"));
                 }
-            }
+                else
+                {
+                    try
+                    {
+                        var fileIndexPath = cdn.GetFilePath("data", fileIndex[0] + ".index");
+                        FileIndex = new IndexInstance(fileIndexPath);
 
-            timer.Stop();
-            Console.WriteLine("File index loaded in " + Math.Ceiling(timer.Elapsed.TotalMilliseconds) + "ms");
+                    }
+                    catch (Exception e)
+                    {
+                        Console.WriteLine("Failed to load file index: " + e.Message);
+                    }
+                }
 
-            var encodingSize = ulong.Parse(BuildConfig.Values["encoding-size"][0]);
-            timer.Restart();
-            Encoding = new EncodingInstance(cdn.GetDecodedFilePath("data", BuildConfig.Values["encoding"][1], ulong.Parse(BuildConfig.Values["encoding-size"][1]), encodingSize), (int)encodingSize);
-            timer.Stop();
-            Console.WriteLine("Encoding loaded in " + Math.Ceiling(timer.Elapsed.TotalMilliseconds) + "ms");
+                timer.Stop();
+                Console.WriteLine("File index loaded in " + Math.Ceiling(timer.Elapsed.TotalMilliseconds) + "ms");
+            }
+            else
+            {
+                // TODO: We might want to manually build up file-index based on encoding entries not present in indexes.
+                Console.WriteLine("No file index found in CDN config, skipping file index loading.");
+            }
 
             timer.Restart();
             if (!BuildConfig.Values.TryGetValue("root", out var rootKey))
@@ -144,7 +157,7 @@ public byte[] OpenFileByFDID(uint fileDataID)
                 throw new Exception("Root not loaded");
 
             var fileData = Root.GetEntriesByFDID(fileDataID);
-            if(fileData.Count == 0)
+            if (fileData.Count == 0)
                 throw new Exception("File not found in root");
 
             return OpenFileByCKey(fileData[0].md5.AsSpan());
@@ -176,7 +189,7 @@ public byte[] OpenFileByEKey(ReadOnlySpan<byte> eKey, ulong decodedSize = 0)
 
             if (offset == -1)
             {
-                if(FileIndex != null)
+                if (FileIndex != null)
                 {
                     var fileIndexEntry = FileIndex.GetIndexInfo(eKey);
                     if (fileIndexEntry.size != -1)

TACTSharp/EncodingInstance.cs

@@ -22,10 +22,14 @@ public class EncodingInstance
 
         public static readonly EncodingResult Zero = new(0, [], 0);
 
-        public EncodingInstance(string filePath, int fileSize)
+        public EncodingInstance(string filePath, int fileSize = 0)
         {
             _filePath = filePath;
-            _fileSize = fileSize;
+
+            if (fileSize != 0)
+                _fileSize = fileSize;
+            else
+                _fileSize = (int)new FileInfo(filePath).Length;
 
             this.encodingFile = MemoryMappedFile.CreateFromFile(filePath, FileMode.Open, null, 0, MemoryMappedFileAccess.Read);
             this.accessor = encodingFile.CreateViewAccessor(0, 0, MemoryMappedFileAccess.Read);