Installation optimizations and fixes

Wabbajack.Lib/AInstaller.cs

@@ -334,7 +334,6 @@ namespace Wabbajack.Lib
                 .PMap(Queue, UpdateTracker, async f =>
                 {
                     var relativeTo = f.RelativeTo(OutputFolder);
-                    Utils.Status($"Checking if ModList file {relativeTo}");
                     if (indexed.ContainsKey(relativeTo) || f.InFolder(DownloadFolder))
                         return;
 
@@ -378,17 +377,19 @@ namespace Wabbajack.Lib
                 Utils.Log("Error when trying to clean empty folders. This doesn't really matter.");
             }
 
+            var existingfiles = OutputFolder.EnumerateFiles().ToHashSet();
+            
             UpdateTracker.NextStep("Looking for unmodified files");
             (await indexed.Values.PMap(Queue, UpdateTracker, async d =>
             {
                 // Bit backwards, but we want to return null for 
                 // all files we *want* installed. We return the files
                 // to remove from the install list.
-                Status($"Optimizing {d.To}");
                 var path = OutputFolder.Combine(d.To);
-                if (!path.Exists) return null;
+                if (!existingfiles.Contains(path)) return null;
 
                 if (path.Size != d.Size) return null;
+                Status($"Optimizing {d.To}");
                 
                 return await path.FileHashCachedAsync() == d.Hash ? d : null;
             }))

Wabbajack.Lib/MO2Installer.cs

@@ -248,23 +248,19 @@ namespace Wabbajack.Lib
 
         private async Task InstallIncludedDownloadMetas()
         {
-            await ModList.Directives
+            await ModList.Archives
-                   .OfType<ArchiveMeta>()
+                   .PMap(Queue, async archive =>
-                   .PMap(Queue, async directive =>
                    {
-                       Status($"Writing .meta file {directive.To}");
+                       if (HashedArchives.TryGetValue(archive.Hash, out var paths))
-                       foreach (var archive in ModList.Archives)
                        {
-                           if (HashedArchives.TryGetValue(archive.Hash, out var paths))
+                           var metaPath = paths.WithExtension(Consts.MetaFileExtension);
+                           if (!metaPath.Exists)
                            {
-                               var metaPath = paths.WithExtension(Consts.MetaFileExtension);
+                               Status($"Writing {metaPath.FileName}");
-                               if (!metaPath.Exists)
+                               var meta = AddInstalled(archive.State.GetMetaIni()).ToArray();
-                               {
+                               await metaPath.WriteAllLinesAsync(meta);
-                                   var meta = AddInstalled(archive.State.GetMetaIni()).ToArray();
-                                   await metaPath.WriteAllLinesAsync(meta);
-                               }
                            }
-                       } 
+                       }
                    });
         }
 

Wabbajack.VirtualFileSystem.Test/FileExtractorTests.cs

@@ -55,10 +55,10 @@ namespace Wabbajack.VirtualFileSystem.Test
             var results = await FileExtractor2.GatheringExtract(new NativeFileStreamFactory(archive.Path), 
                 _ => true,
                 async (path, sfn) =>
-            {
+                {
-                await using var s = await sfn.GetStream();
+                    await using var s = await sfn.GetStream();
-                return await s.xxHashAsync();
+                    return await s.xxHashAsync();
-            });
+                });
             
             Assert.Equal(10, results.Count);
             foreach (var (path, hash) in results)
@@ -67,6 +67,35 @@ namespace Wabbajack.VirtualFileSystem.Test
             }
         }
         
+        [Fact]
+        public async Task CanExtractEmptyFiles()
+        {
+            await using var temp = await TempFolder.Create();
+            await using var archive = new TempFile();
+            
+            for (int i = 0; i < 1; i ++)
+            {
+                await WriteRandomData(temp.Dir.Combine($"{i}.bin"), _rng.Next(10, 1024));
+            }
+            await (await temp.Dir.Combine("empty.txt").Create()).DisposeAsync();
+
+            await ZipUpFolder(temp.Dir, archive.Path, false);
+            
+            var results = await FileExtractor2.GatheringExtract(new NativeFileStreamFactory(archive.Path), 
+                _ => true,
+                async (path, sfn) =>
+                {
+                    await using var s = await sfn.GetStream();
+                    return await s.xxHashAsync();
+                });
+            
+            Assert.Equal(2, results.Count);
+            foreach (var (path, hash) in results)
+            {
+                Assert.Equal(await temp.Dir.Combine(path).FileHashAsync(), hash);
+            }
+        }
+        
         private static Extension OMODExtension = new Extension(".omod");
         private static Extension CRCExtension = new Extension(".crc");
 

Wabbajack.VirtualFileSystem/FileExtractor2/GatheringExtractor.cs

@@ -25,7 +25,6 @@ namespace Wabbajack.VirtualFileSystem
 
         public GatheringExtractor(Stream stream, Definitions.FileType sig, Predicate<RelativePath> shouldExtract, Func<RelativePath,IStreamFactory, ValueTask<T>> mapfn)
         {
-            
             _shouldExtract = shouldExtract;
             _mapFn = mapfn;
             _results = new Dictionary<RelativePath, T>();
@@ -89,6 +88,14 @@ namespace Wabbajack.VirtualFileSystem
         {
             if (_indexes.ContainsKey(index))
             {
+                var path = _indexes[index].Item1;
+                Utils.Status($"Extracting {path}", Percent.FactoryPutInRange(_results.Count, _indexes.Count));
+                // Empty files are never extracted via a write call, so we have to fake that now
+                if (_indexes[index].Item2 == 0)
+                {
+                    var result = _mapFn(path, new MemoryStreamFactory(new MemoryStream(), path)).Result;
+                    _results.Add(path, result);
+                }
                 outStream =  new GatheringExtractorStream<T>(this, index);
                 return 0;
             }