Implemented preemptive caching (#2944)

Files/DataModels/SidebarPinnedModel.cs

@@ -190,7 +190,7 @@ public async Task AddItemToSidebarAsync(string path)
         {
             var item = await FilesystemTasks.Wrap(() => DrivesManager.GetRootFromPathAsync(path));
             var res = await FilesystemTasks.Wrap(() => StorageFileExtensions.DangerousGetFolderFromPathAsync(path, item));
-            if (res || (FilesystemResult)ItemViewModel.CheckFolderAccessWithWin32(path))
+            if (res || (FilesystemResult)FolderHelpers.CheckFolderAccessWithWin32(path))
             {
                 int insertIndex = MainPage.SideBarItems.IndexOf(MainPage.SideBarItems.Last(x => x.ItemType == NavigationControlItemType.Location
                 && !x.Path.Equals(App.AppSettings.RecycleBinPath))) + 1;

Files/Extensions/EnumerableExtensions.cs

@@ -1,4 +1,7 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using System.Threading.Tasks.Dataflow;
 
 namespace Files.Extensions
 {
@@ -12,5 +15,29 @@ internal static class EnumerableExtensions
         /// <returns><see cref="IEnumerable{T}"/> with <paramref name="item"/></returns>
         internal static IEnumerable<T> CreateEnumerable<T>(this T item) =>
             new List<T>() { item };
+
+        /// <summary>
+        /// Executes given lambda parallely on given data set with max degree of parallelism set up
+        /// </summary>
+        /// <typeparam name="T">The item type</typeparam>
+        /// <param name="source">Data to process</param>
+        /// <param name="body">Lambda to execute on all items</param>
+        /// <param name="maxDegreeOfParallelism">Max degree of parallelism (-1 for unbounded execution)</param>
+        /// <returns></returns>
+        internal static Task AsyncParallelForEach<T>(this IEnumerable<T> source, Func<T, Task> body, int maxDegreeOfParallelism)
+        {
+            var options = new ExecutionDataflowBlockOptions
+            {
+                MaxDegreeOfParallelism = maxDegreeOfParallelism
+            };
+
+            var block = new ActionBlock<T>(body, options);
+
+            foreach (var item in source)
+                block.Post(item);
+
+            block.Complete();
+            return block.Completion;
+        }
     }
 }

Files/Extensions/TaskExtensions.cs

@@ -0,0 +1,21 @@
+using System.Threading.Tasks;
+
+namespace Files.Extensions
+{
+    internal static class TaskExtensions
+    {
+#pragma warning disable RCS1175 // Unused this parameter.
+#pragma warning disable IDE0060 // Remove unused parameter
+        /// <summary>
+        /// This function is to explicitly state that we know that we're runnign task without awaiting.
+        /// This makes visual studio to drop warning, but the programmer intent is still clearly stated.
+        /// </summary>
+        /// <param name="task"></param>
+        internal static void Forget(this Task task)
+        {
+            // do nothing, just forget about the task
+        }
+#pragma warning restore IDE0060 // Remove unused parameter
+#pragma warning restore RCS1175 // Unused this parameter.
+    }
+}

Files/Files.csproj

@@ -178,6 +178,10 @@
     <Compile Include="Enums\DynamicDialogButtons.cs" />
     <Compile Include="Enums\DynamicDialogResult.cs" />
     <Compile Include="Enums\FolderLayoutModes.cs" />
+    <Compile Include="Extensions\TaskExtensions.cs" />
+    <Compile Include="Filesystem\FolderHelpers.cs" />
+    <Compile Include="Filesystem\StorageEnumerators\UniversalStorageEnumerator.cs" />
+    <Compile Include="Filesystem\StorageEnumerators\Win32StorageEnumerator.cs" />
     <Compile Include="Enums\FileSystemStatusCode.cs" />
     <Compile Include="Filesystem\CloudDrivesManager.cs" />
     <Compile Include="Filesystem\Cloud\Providers\OneDriveSharePointCloudProvider.cs" />

Files/Filesystem/FilesystemOperations/FilesystemOperations.cs

@@ -206,7 +206,7 @@ await DialogDisplayHelper.ShowDialogAsync(
                         }
                         if (fsCopyResult)
                         {
-                            if (associatedInstance.FilesystemViewModel.CheckFolderForHiddenAttribute(source.Path))
+                            if (FolderHelpers.CheckFolderForHiddenAttribute(source.Path))
                             {
                                 // The source folder was hidden, apply hidden attribute to destination
                                 NativeFileOperationsHelper.SetFileAttribute(fsCopyResult.Result.Path, FileAttributes.Hidden);
@@ -434,7 +434,7 @@ await DialogDisplayHelper.ShowDialogAsync(
                             }
                             if (fsResultMove)
                             {
-                                if (associatedInstance.FilesystemViewModel.CheckFolderForHiddenAttribute(source.Path))
+                                if (FolderHelpers.CheckFolderForHiddenAttribute(source.Path))
                                 {
                                     // The source folder was hidden, apply hidden attribute to destination
                                     NativeFileOperationsHelper.SetFileAttribute(fsResultMove.Result.Path, FileAttributes.Hidden);

Files/Filesystem/FolderHelpers.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using Windows.Storage;
+using static Files.Helpers.NativeFindStorageItemHelper;
+using FileAttributes = System.IO.FileAttributes;
+
+namespace Files.Filesystem
+{
+    public static class FolderHelpers
+    {
+        public static bool CheckFolderAccessWithWin32(string path)
+        {
+            FINDEX_INFO_LEVELS findInfoLevel = FINDEX_INFO_LEVELS.FindExInfoBasic;
+            int additionalFlags = FIND_FIRST_EX_LARGE_FETCH;
+            IntPtr hFileTsk = FindFirstFileExFromApp(path + "\\*.*", findInfoLevel, out WIN32_FIND_DATA findDataTsk, FINDEX_SEARCH_OPS.FindExSearchNameMatch, IntPtr.Zero,
+                additionalFlags);
+            if (hFileTsk.ToInt64() != -1)
+            {
+                FindClose(hFileTsk);
+                return true;
+            }
+            return false;
+        }
+
+        public static bool CheckFolderForHiddenAttribute(string path)
+        {
+            if (string.IsNullOrEmpty(path))
+            {
+                return false;
+            }
+            FINDEX_INFO_LEVELS findInfoLevel = FINDEX_INFO_LEVELS.FindExInfoBasic;
+            int additionalFlags = FIND_FIRST_EX_LARGE_FETCH;
+            IntPtr hFileTsk = FindFirstFileExFromApp(path + "\\*.*", findInfoLevel, out WIN32_FIND_DATA findDataTsk, FINDEX_SEARCH_OPS.FindExSearchNameMatch, IntPtr.Zero,
+                additionalFlags);
+            if (hFileTsk.ToInt64() == -1)
+            {
+                return false;
+            }
+            var isHidden = ((FileAttributes)findDataTsk.dwFileAttributes & FileAttributes.Hidden) == FileAttributes.Hidden;
+            FindClose(hFileTsk);
+            return isHidden;
+        }
+
+        public static async Task<bool> CheckBitlockerStatusAsync(StorageFolder rootFolder, string path)
+        {
+            if (rootFolder == null || rootFolder.Properties == null)
+            {
+                return false;
+            }
+            if (Path.IsPathRooted(path) && Path.GetPathRoot(path) == path)
+            {
+                IDictionary<string, object> extraProperties = await rootFolder.Properties.RetrievePropertiesAsync(new string[] { "System.Volume.BitLockerProtection" });
+                return (int?)extraProperties["System.Volume.BitLockerProtection"] == 6; // Drive is bitlocker protected and locked
+            }
+            return false;
+        }
+
+        /// <summary>
+        /// This function is used to determine whether or not a folder has any contents.
+        /// </summary>
+        /// <param name="targetPath">The path to the target folder</param>
+        ///
+        public static bool CheckForFilesFolders(string targetPath)
+        {
+            FINDEX_INFO_LEVELS findInfoLevel = FINDEX_INFO_LEVELS.FindExInfoBasic;
+            int additionalFlags = FIND_FIRST_EX_LARGE_FETCH;
+
+            IntPtr hFile = FindFirstFileExFromApp(targetPath + "\\*.*", findInfoLevel, out WIN32_FIND_DATA _, FINDEX_SEARCH_OPS.FindExSearchNameMatch, IntPtr.Zero, additionalFlags);
+            FindNextFile(hFile, out _);
+            var result = FindNextFile(hFile, out _);
+            FindClose(hFile);
+            return result;
+        }
+    }
+}