Icon cache and Task.Run tweaks (#9885)

* icon cache and task tweaks

* CR Feedback

* Use ValueTask for displayName cache

* CR feedback

* CR feedback

Author: hez2010

src/Files.App/Filesystem/StorageEnumerators/Win32StorageEnumerator.cs

@@ -44,7 +44,6 @@ public static async Task<List<ListedItem>> ListEntries(
         {
             var sampler = new IntervalSampler(500);
             var tempList = new List<ListedItem>();
-            var hasNextFile = false;
             var count = 0;
 
             IUserSettingsService userSettingsService = Ioc.Default.GetService<IUserSettingsService>();
@@ -123,14 +122,13 @@ public static async Task<List<ListedItem>> ListEntries(
                     break;
                 }
 
-                hasNextFile = FindNextFile(hFile, out findData);
                 if (intermediateAction != null && (count == 32 || sampler.CheckNow()))
                 {
                     await intermediateAction(tempList);
                     // clear the temporary list every time we do an intermediate action
                     tempList.Clear();
                 }
-            } while (hasNextFile);
+            } while (FindNextFile(hFile, out findData));
 
             FindClose(hFile);
             return tempList;

src/Files.App/Helpers/FileListCache/FileListCacheController.cs

@@ -19,25 +19,25 @@ private FileListCacheController()
 
         private readonly ConcurrentDictionary<string, string> fileNamesCache = new ConcurrentDictionary<string, string>();
 
-        public Task<string> ReadFileDisplayNameFromCache(string path, CancellationToken cancellationToken)
+        public ValueTask<string> ReadFileDisplayNameFromCache(string path, CancellationToken cancellationToken)
         {
             if (fileNamesCache.TryGetValue(path, out var displayName))
             {
-                return Task.FromResult(displayName);
+                return ValueTask.FromResult(displayName);
             }
 
-            return Task.FromResult<string>(null);
+            return ValueTask.FromResult<string>(null);
         }
 
-        public Task SaveFileDisplayNameToCache(string path, string displayName)
+        public ValueTask SaveFileDisplayNameToCache(string path, string displayName)
         {
             if (displayName == null)
             {
                 fileNamesCache.TryRemove(path, out _);
             }
 
             fileNamesCache[path] = displayName;
-            return Task.CompletedTask;
+            return ValueTask.CompletedTask;
         }
     }
 }

src/Files.App/Helpers/FileListCache/IFileListCache.cs

@@ -5,8 +5,8 @@ namespace Files.App.Helpers.FileListCache
 {
     internal interface IFileListCache
     {
-        public Task<string> ReadFileDisplayNameFromCache(string path, CancellationToken cancellationToken);
+        public ValueTask<string> ReadFileDisplayNameFromCache(string path, CancellationToken cancellationToken);
 
-        public Task SaveFileDisplayNameToCache(string path, string displayName);
+        public ValueTask SaveFileDisplayNameToCache(string path, string displayName);
     }
 }