Filtered manifests from obsolete file list in VersionHandler.

VersionHandler no longer prompts to delete obsolete manifests in order
to smooth the experience of upgrading packages.

In addition, removed reimport of assets and flush of metadata modified
by the VersionHandler as both operations are *really* slow.  Asset
renaming (AssetDatabase.ImportAsset()) is now the slowest operation
in the plugin.

Bug: 35141238, 35587604
Change-Id: I6b5923500b834d27253f00a22fcf482234208f3d

Author: Stewart Miles

source/VersionHandler/src/VersionHandler.cs

@@ -402,6 +402,7 @@ public bool RenameAsset(string newFilename) {
                 }
             }
             try {
+              // b/35587604 this is *really* slow.
               string error = AssetDatabase.RenameAsset(
                   filename, filenameComponents.basenameNoExtension);
               if (!String.IsNullOrEmpty(error)) {
@@ -410,7 +411,6 @@ public bool RenameAsset(string newFilename) {
                       newFilename + " (" + error + ")");
                   return false;
               }
-              AssetDatabase.ImportAsset(newFilename);
             } catch (Exception) {
                 // Unity 5.3 and below can end up throw all sorts of
                 // exceptions here when attempting to reload renamed
@@ -523,6 +523,20 @@ public FileMetadata this[long version] {
             }
         }
 
+        /// <summary>
+        /// Get the most referenced FileMetadata from this object.
+        /// </summary>
+        /// <returns>FileMetadata instance if this object contains at least one version, null
+        /// otherwise.</returns>
+        public FileMetadata MostRecentVersion {
+            get {
+                var numberOfVersions = metadataByVersion.Count;
+                return numberOfVersions > 0 ?
+                    (FileMetadata)(
+                        (new ArrayList(metadataByVersion.Values))[numberOfVersions - 1]) : null;
+            }
+        }
+
         /// <summary>
         /// Determine whether the PluginImporter class is available in
         /// UnityEditor. Unity 4 does not have the PluginImporter class so
@@ -569,9 +583,7 @@ public bool EnableMostRecentPlugins() {
 
             // If the canonical file is out of date, update it.
             if (numberOfVersions > 0) {
-                FileMetadata mostRecentVersion =
-                    (FileMetadata)((new ArrayList(metadataByVersion.Values))
-                                   [numberOfVersions - 1]);
+                FileMetadata mostRecentVersion = MostRecentVersion;
                 if (mostRecentVersion.filename != filenameCanonical) {
                     FileMetadata canonicalMetadata = null;
                     foreach (var metadata in metadataByVersion.Values) {
@@ -643,9 +655,6 @@ public bool EnableMostRecentPlugins() {
                         "Unexpected error enumerating targets: " + e.Message);
                     }
                 }
-                if (modifiedThisVersion) {
-                    pluginImporter.SaveAndReimport();
-                }
                 // If the version was modified and it's obsolete keep track of
                 // it to log it later.
                 if (obsoleteVersion && modifiedThisVersion) {
@@ -832,6 +841,11 @@ public class ManifestReferences {
         /// </summary>
         public FileMetadata currentMetadata = null;
 
+        /// <summary>
+        /// Metadata for each version of this manifest.
+        /// </summary>
+        public FileMetadataByVersion metadataByVersion = null;
+
         /// <summary>
         /// Set of current files in this package.
         /// </summary>
@@ -870,6 +884,7 @@ public bool ParseManifests(FileMetadataByVersion metadataByVersion,
             foreach (FileMetadata metadata in metadataByVersion.Values) {
                 versionIndex++;
                 if (!metadata.isManifest) return false;
+                this.metadataByVersion = metadataByVersion;
                 bool manifestNeedsUpdate = false;
                 HashSet<string> filesInManifest =
                     versionIndex < numberOfVersions ?
@@ -949,12 +964,22 @@ public class ObsoleteFiles {
         /// </summary>
         public HashSet<string> unreferenced;
 
+        /// <summary>
+        /// Same as the "unreferenced" member exluding manifest files.
+        /// </summary>
+        public HashSet<string> unreferencedExcludingManifests;
+
         /// <summary>
         /// Obsolete files that are referenced by manifests.  Each item in
         /// the dictionary contains a list of manifests referencing the file.
         /// </summary>
         public Dictionary<string, List<string>> referenced;
 
+        /// <summary>
+        /// Same as the "referenced" member exluding manifest files.
+        /// </summary>
+        public Dictionary<string, List<string>> referencedExcludingManifests;
+
         /// <summary>
         /// Build an ObsoleteFiles instance searching a set of
         /// ManifestReferences and a FileMetadataSet for old files.
@@ -975,22 +1000,31 @@ public ObsoleteFiles(
             // global sets.
             var currentFiles = new HashSet<string>();
             var obsoleteFiles = new HashSet<string>();
+            var manifestFilenames = new HashSet<string>();
             foreach (var manifestReferences in manifestReferencesList) {
                 currentFiles.UnionWith(manifestReferences.currentFiles);
                 obsoleteFiles.UnionWith(manifestReferences.obsoleteFiles);
+                foreach (var manifestMetadata in manifestReferences.metadataByVersion.Values) {
+                    manifestFilenames.Add(manifestMetadata.filename);
+                }
             }
             // Fold in obsolete files that are not referenced by manifests.
             foreach (var metadataByVersion in metadataSet.Values) {
-                obsoleteFiles.UnionWith(
-                    metadataByVersion.FindObsoleteVersions());
+                var obsoleteVersions = metadataByVersion.FindObsoleteVersions();
+                obsoleteFiles.UnionWith(obsoleteVersions);
+                if (metadataByVersion.MostRecentVersion.isManifest) {
+                    manifestFilenames.UnionWith(obsoleteVersions);
+                }
             }
             // Filter the obsoleteFiles set for all obsolete files currently
             // in use and add to a dictionary indexed by filename
             // which contains a list of manifest filenames which reference
             // each file.
             var referencedObsoleteFiles =
                 new Dictionary<string, List<string>>();
+            var referencedObsoleteFilesExcludingManifests = new Dictionary<string, List<string>>();
             var obsoleteFilesToDelete = new HashSet<string>();
+            var obsoleteFilesToDeleteExcludingManifests = new HashSet<string>();
             foreach (var obsoleteFile in obsoleteFiles) {
                 var manifestsReferencingFile = new List<string>();
                 foreach (var manifestReferences in manifestReferencesList) {
@@ -1004,15 +1038,25 @@ public ObsoleteFiles(
                 if (!File.Exists(obsoleteFile)) {
                     continue;
                 }
+                bool isManifest = manifestFilenames.Contains(obsoleteFile);
                 if (manifestsReferencingFile.Count > 0) {
                     referencedObsoleteFiles[obsoleteFile] =
                         manifestsReferencingFile;
+                    if (!isManifest) {
+                        referencedObsoleteFilesExcludingManifests[obsoleteFile] =
+                            manifestsReferencingFile;
+                    }
                 } else {
                     obsoleteFilesToDelete.Add(obsoleteFile);
+                    if (!isManifest) {
+                        obsoleteFilesToDeleteExcludingManifests.Add(obsoleteFile);
+                    }
                 }
             }
             unreferenced = obsoleteFilesToDelete;
+            unreferencedExcludingManifests = obsoleteFilesToDeleteExcludingManifests;
             referenced = referencedObsoleteFiles;
+            referencedExcludingManifests = referencedObsoleteFilesExcludingManifests;
         }
     }
 
@@ -1153,7 +1197,6 @@ public static void UpdateVersionedAssets(bool forceUpdate = false) {
 
         var metadataSet = FileMetadataSet.FindWithPendingUpdates(
             FileMetadataSet.ParseFromFilenames(FindAllAssets()));
-
         if (metadataSet.EnableMostRecentPlugins()) {
             AssetDatabase.Refresh();
         }
@@ -1166,13 +1209,14 @@ public static void UpdateVersionedAssets(bool forceUpdate = false) {
         // enabled.
         bool deleteFiles = true;
         if (obsoleteFiles.unreferenced.Count > 0) {
-            if (CleanUpPromptEnabled && deleteFiles) {
+            if (CleanUpPromptEnabled && deleteFiles &&
+                obsoleteFiles.unreferencedExcludingManifests.Count > 0) {
                 deleteFiles = EditorUtility.DisplayDialog(
                     PLUGIN_NAME,
                     "Would you like to delete the following obsolete files " +
                     "in your project?\n\n" +
                     String.Join("\n", new List<string>(
-                                        obsoleteFiles.unreferenced).ToArray()),
+                                        obsoleteFiles.unreferencedExcludingManifests).ToArray()),
                     "Yes", cancel: "No");
             }
             foreach (var filename in obsoleteFiles.unreferenced) {
@@ -1189,21 +1233,20 @@ public static void UpdateVersionedAssets(bool forceUpdate = false) {
         // confirmation of deletion.
         if (obsoleteFiles.referenced.Count > 0) {
             List<string> referencesString = new List<string>();
-            foreach (var item in obsoleteFiles.referenced) {
+            foreach (var item in obsoleteFiles.referencedExcludingManifests) {
                 List<string> lines = new List<string>();
-                lines.Add(item.Key);
                 foreach (var reference in item.Value) {
-                    lines.Add("    " + reference);
+                    lines.Add(String.Format("{0}: {1}", reference, item.Key));
                 }
                 referencesString.Add(String.Join("\n", lines.ToArray()));
             }
-            deleteFiles = EditorUtility.DisplayDialog(
-               PLUGIN_NAME,
-               "The following obsolete files are referenced by packages in " +
-               "your project, would you like to delete them?\n\n" +
-               String.Join("\n", referencesString.ToArray()),
-               "Yes", cancel: "No");
-
+            deleteFiles = obsoleteFiles.referencedExcludingManifests.Values.Count == 0 ||
+                EditorUtility.DisplayDialog(
+                   PLUGIN_NAME,
+                   "The following obsolete files are referenced by packages in " +
+                   "your project, would you like to delete them?\n\n" +
+                   String.Join("\n", referencesString.ToArray()),
+                   "Yes", cancel: "No");
             foreach (var item in obsoleteFiles.referenced) {
                 if (deleteFiles) {
                     MoveAssetToTrash(item.Key);