Rework some things to be more fault tolerant

Author: Marlamin

TACTSharp/Build.cs

@@ -75,7 +75,7 @@ public void Load()
                     if (!File.Exists(groupIndexPath))
                     {
                         var groupIndex = new GroupIndex();
-                        groupIndex.Generate(cdn, Settings, groupArchiveIndex[0], CDNConfig.Values["archives"]);
+                        groupIndex.Generate(cdn, Settings, groupArchiveIndex[0], CDNConfig.Values["archives"], true);
                     }
                     GroupIndex = new IndexInstance(groupIndexPath);
                 }
@@ -93,8 +93,15 @@ public void Load()
             }
             else
             {
-                var fileIndexPath = cdn.GetFilePath("data", fileIndex[0] + ".index");
-                FileIndex = new IndexInstance(fileIndexPath);
+                try
+                {
+                    var fileIndexPath = cdn.GetFilePath("data", fileIndex[0] + ".index");
+                    FileIndex = new IndexInstance(fileIndexPath);
+
+                }catch(Exception e)
+                {
+                    Console.WriteLine("Failed to load file index: " + e.Message);
+                }
             }
 
             timer.Stop();
@@ -161,31 +168,28 @@ public byte[] OpenFileByCKey(ReadOnlySpan<byte> cKey)
 
         public byte[] OpenFileByEKey(ReadOnlySpan<byte> eKey, ulong decodedSize = 0)
         {
-            if (GroupIndex == null || FileIndex == null)
+            if (GroupIndex == null)
                 throw new Exception("Indexes not loaded");
 
             var (offset, size, archiveIndex) = GroupIndex.GetIndexInfo(eKey);
             byte[] fileBytes;
 
             if (offset == -1)
             {
-                var fileIndexEntry = FileIndex.GetIndexInfo(eKey);
-                if (fileIndexEntry.size == -1)
+                if(FileIndex != null)
                 {
-                    Console.WriteLine("Warning: EKey " + Convert.ToHexStringLower(eKey) + " not found in group or file index and might not be available on CDN.");
-                    fileBytes = cdn.GetFile("data", Convert.ToHexStringLower(eKey), 0, decodedSize, true);
-                }
-                else
-                {
-                    fileBytes = cdn.GetFile("data", Convert.ToHexStringLower(eKey), (ulong)fileIndexEntry.size, decodedSize, true);
+                    var fileIndexEntry = FileIndex.GetIndexInfo(eKey);
+                    if (fileIndexEntry.size != -1)
+                        return cdn.GetFile("data", Convert.ToHexStringLower(eKey), (ulong)fileIndexEntry.size, decodedSize, true);
                 }
+
+                Console.WriteLine("Warning: EKey " + Convert.ToHexStringLower(eKey) + " not found in group or file index and might not be available on CDN.");
+                return cdn.GetFile("data", Convert.ToHexStringLower(eKey), 0, decodedSize, true);
             }
             else
             {
-                fileBytes = cdn.GetFileFromArchive(Convert.ToHexStringLower(eKey), CDNConfig.Values["archives"][archiveIndex], offset, size, decodedSize, true);
+                return cdn.GetFileFromArchive(Convert.ToHexStringLower(eKey), CDNConfig.Values["archives"][archiveIndex], offset, size, decodedSize, true);
             }
-
-            return fileBytes;
         }
     }
 }

TACTSharp/CDN.cs

@@ -199,6 +199,8 @@ public async Task<string> GetPatchServiceFile(string product, string file = "ver
                 }
             }
 
+            throw new FileNotFoundException();
+
             for (var i = 0; i < CDNServers.Count; i++)
             {
                 var url = $"http://{CDNServers[i]}/{ProductDirectory}/{type}/{hash[0]}{hash[1]}/{hash[2]}{hash[3]}/{hash}";

TACTSharp/GroupIndex.cs

@@ -18,7 +18,7 @@ private struct IndexEntry
         private readonly List<IndexEntry> Entries = [];
         private readonly Lock entryLock = new();
 
-        public string Generate(CDN CDN, Settings Settings, string? hash, string[] archives)
+        public string Generate(CDN CDN, Settings Settings, string? hash, string[] archives, bool allowPartial = false)
         {
             if (string.IsNullOrEmpty(hash))
                 Console.WriteLine("Generating group index for unknown group-index");
@@ -41,7 +41,18 @@ public string Generate(CDN CDN, Settings Settings, string? hash, string[] archiv
                 }
                 else
                 {
-                    _ = CDN.GetFile("data", archives[archiveIndex] + ".index");
+                    try
+                    {
+                        _ = CDN.GetFile("data", archives[archiveIndex] + ".index");
+                    }
+                    catch(Exception e)
+                    {
+                        Console.WriteLine("Failed to load index file " + archives[archiveIndex] + ".index: " + e.Message);
+                        if (allowPartial)
+                            return;
+                        else
+                            throw;
+                    }
                     indexPath = Path.Combine(Settings.CacheDir, CDN.ProductDirectory, "data", archives[archiveIndex] + ".index");
                 }
 
@@ -168,7 +179,7 @@ public string Generate(CDN CDN, Settings Settings, string? hash, string[] archiv
 
                 if (!string.IsNullOrEmpty(hash))
                 {
-                    if (fullFooterMD5Hash != hash)
+                    if (fullFooterMD5Hash != hash && !allowPartial)
                         throw new Exception("Footer MD5 of group index does not match group index filename");
 
                     if (!Directory.Exists(Path.Combine(Settings.CacheDir, CDN.ProductDirectory, "data")))