perf: additional performance improvements

CHANGELOG.md

@@ -8,20 +8,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
-- [#472] [#474] Added the `DependsOnContext` attribute, for declaring dependencies between extension contexts.
-- [#473] Added `BuildContext.SetEnableUVDistributionRecalculation` to allow opting out from the automatic call to
-  `Mesh.RecalculateUVDistributionMetrics` on generated meshes.
-- [#478] Added `ProfilerScope` API
-- [#481] Added `NDMFPreview.GetOriginalObjectForProxy`
-- [#480] Added `IExtensionContext.Owner` API. Setting this property will allow errors to be correctly attributed to the
-  plugin that contains an extension context.
-- [#479] Added `IAssetSaver` and `SerializationScope` APIs.
-  - NDMF plugins are encouraged to use `IAssetSaver.SaveAsset` instead of directly accessing `AssetContainer`. This will
-    split saved assets across multiple files, to avoid performance degradation as the number of assets in a container
-    grows.
 
 ### Fixed
-- [#479] Unpacking generated asset containers can break inter-asset references
+- [#482] Additional performance improvements
 
 ### Changed
 

Editor/API/BuildContext.cs

@@ -129,9 +129,6 @@ public BuildContext(GameObject obj, string assetRootPath, bool isClone = true)
 
             if (assetRootPath != null)
             {
-                // Ensure the target directory exists
-                Directory.CreateDirectory(assetRootPath);
-
                 AssetSaver = new AssetSaver(assetRootPath, avatarName);
             }
             else

Editor/API/Serialization/AssetSaver.cs

@@ -38,22 +38,55 @@ internal AssetSaver(string generatedAssetsRoot, string avatarName, int assetsPer
 
             if (AssetDatabase.IsValidFolder(subAssetPath))
             {
+                using var _2 = new ProfilerScope("DeleteFolder");
                 AssetDatabase.DeleteAsset(rootPath);
             }
+
+            using var _ = new ProfilerScope("Asset editing");
+            try
+            {
+                AssetDatabase.StartAssetEditing();
+
+                // Ensure directory exists recursively
+                var pathParts = subAssetPath.Split('/');
+                var currentDir = pathParts[0];
+
+                for (int i = 1; i < pathParts.Length; i++)
+                {
+                    var nextDir = currentDir + "/" + pathParts[i];
+                    if (!AssetDatabase.IsValidFolder(nextDir))
+                    {
+                        if (Directory.Exists(nextDir))
+                        {
+                            // Sometimes the asset database can be unaware of a folder on disk, so refresh it.
+                            // This is quite expensive, so only do it if necessary.
+                            Debug.Log("Force refresh due to " + nextDir);
+                            using var _2 = new ProfilerScope("AssetDatabase.Refresh");
+                            AssetDatabase.Refresh();
+                        }
+                        else
+                        {
+                            using var _2 = new ProfilerScope("CreateFolder");
+                            AssetDatabase.CreateFolder(currentDir, pathParts[i]);
+                        }
+                    }
+
+                    currentDir = nextDir;
+                }
+
+                var rootAssetPath = AssetDatabase.GenerateUniqueAssetPath(rootPath + "/" + avatarName + ".asset");
+                _rootAsset = ScriptableObject.CreateInstance<GeneratedAssets>();
+                AssetDatabase.CreateAsset(_rootAsset, rootAssetPath);
+                _currentSubContainer = CreateAssetContainer();
 
-            // Ensure directory exists recursively
-            if (!AssetDatabase.IsValidFolder(subAssetPath))
+                _assetCount = 0;
+            }
+            finally
             {
-                Directory.CreateDirectory(subAssetPath);
-                AssetDatabase.Refresh();
+                using var _2 = new ProfilerScope("StopAssetEditing");
+
+                AssetDatabase.StopAssetEditing();
             }
-
-            var rootAssetPath = AssetDatabase.GenerateUniqueAssetPath(rootPath + "/" + avatarName + ".asset");
-            _rootAsset = ScriptableObject.CreateInstance<GeneratedAssets>();
-            AssetDatabase.CreateAsset(_rootAsset, rootAssetPath);
-            _currentSubContainer = CreateAssetContainer();
-
-            _assetCount = 0;
         }
 
         public void SaveAsset(UnityEngine.Object? obj)