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Improve performance in loading homework and file lists (#2)
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- Parallelize GetHomeworkList and GetFolderList.
- Change Get* to Enumerate* to improve performance.
- Bug fix: wrong file list shown when changing Student Work folder.
- Bug fix: program fail to work if Student Work folder end with path separator.
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@lwchkg
lwchkg committed Nov 29, 2020
1 parent 1b6793d commit ce97f90
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Showing 2 changed files with 98 additions and 47 deletions.
125 changes: 81 additions & 44 deletions TeamsAssignmentExplorer/DirAndFileScanner.cs
View file
@@ -1,7 +1,9 @@
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace TeamsAssignmentExplorer
{
Expand All @@ -23,11 +25,11 @@ public static List<string> GetFolderList()
{
var output = new List<string>();
string basePath = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
foreach (string orgDir in Directory.GetDirectories(basePath))
foreach (string orgDir in Directory.EnumerateDirectories(basePath))
{
try
{
foreach (string repoDir in Directory.GetDirectories(orgDir))
foreach (string repoDir in Directory.EnumerateDirectories(orgDir))
{
if (StringConstants.StudentWorkSuffixes.Any(s => repoDir.EndsWith(s)))
output.Add(repoDir);
Expand All @@ -41,85 +43,120 @@ public static List<string> GetFolderList()

public static List<HomeworkItem> GetHomeworkList(string basePath)
{
#if DEBUG
var stopwatch = new System.Diagnostics.Stopwatch();
stopwatch.Start();
#endif

// Glob [basePath]/Submitted files/[user]/[homework] and
// [basePath]/Working files/[user]/[homework]
var homeworkMap = new SortedDictionary<string, bool>();
var homeworkMap = new ConcurrentDictionary<string, bool>();

try
{
foreach (string submittedOrWorkingFilesDir in Directory.GetDirectories(basePath))
foreach (string submittedOrWorkingFilesDir in
Directory.EnumerateDirectories(basePath))
{
foreach (string userDir in Directory.GetDirectories(submittedOrWorkingFilesDir))
{
foreach (string homeworkDir in Directory.GetDirectories(userDir))
Parallel.ForEach(
Directory.EnumerateDirectories(submittedOrWorkingFilesDir),
userDir =>
{
string[] dirs = Directory.GetDirectories(homeworkDir);
bool isWorkingFiles = dirs.Length == 0;

if (!homeworkMap.ContainsKey(Path.GetFileName(homeworkDir)))
homeworkMap.Add(Path.GetFileName(homeworkDir), isWorkingFiles);
else if (!isWorkingFiles)
homeworkMap[Path.GetFileName(homeworkDir)] = false;
}
}
foreach (string homeworkDir in Directory.EnumerateDirectories(userDir))
{
bool isWorkingFiles = !Directory.EnumerateDirectories(homeworkDir)
.GetEnumerator()
.MoveNext();
homeworkMap.AddOrUpdate(Path.GetFileName(homeworkDir),
isWorkingFiles,
(_, value) => value || isWorkingFiles);
}
});
}
}
catch (Exception) { /* Do nothing. */ }

return homeworkMap.Select(r => new HomeworkItem() {
var list = homeworkMap.Select(r => new HomeworkItem() {
Homework = r.Key, WorkingFilesOnly = r.Value
}).ToList();
list.Sort((a, b) => a.Homework.CompareTo(b.Homework));

#if DEBUG
stopwatch.Stop();
System.Diagnostics.Debug.WriteLine("Traversing \"{0}\" takes {1} ms.", basePath,
stopwatch.ElapsedMilliseconds);
#endif

return list;
}

public static SubmittedAndWorkingFiles GetSubmittedAndWorkingFiles(string basePath,
string homework)
{
System.Diagnostics.Debug.Assert(homework.Trim() != "");

// Glob [basePath]/Submitted files/[user]/[homework]/Version */*.*
// and [basePath]/Working files/[user]/[homework]/Version */*.*
//
// Due to translations of folder names by Microsoft, we do not check for the phrases
// "Submitted files", "Working files" and "Version". Otherwise we need to add code for
// every translation.)
var submittedFiles = new List<string>();
var workingFiles = new List<string>();
#if DEBUG
var stopwatch = new System.Diagnostics.Stopwatch();
stopwatch.Start();
#endif

var submittedFiles = new ConcurrentBag<string>();
var workingFiles = new ConcurrentBag<string>();
try
{
foreach (string submittedOrWorkingFilesDir in Directory.GetDirectories(basePath))
foreach (string submittedOrWorkingFilesDir in
Directory.EnumerateDirectories(basePath))
{
foreach (string userDir in Directory.GetDirectories(submittedOrWorkingFilesDir))
{
string hwPath = Path.Combine(userDir, homework);
if (!Directory.Exists(hwPath))
continue;
foreach (string versionDir in Directory.GetDirectories(hwPath))
Parallel.ForEach(Directory.EnumerateDirectories(submittedOrWorkingFilesDir),
userDir =>
{
var files = Directory.GetFiles(versionDir);
Array.Sort(files);
foreach (string file in files)
{
// Strip base path from the filename.
submittedFiles.Add(file.Substring(basePath.Length + 1));
}
}
string hwPath = Path.Combine(userDir, homework);
if (!Directory.Exists(hwPath)) return;
{ // Scope
var files = Directory.GetFiles(hwPath);
Array.Sort(files);
foreach (string file in files)
foreach (string versionDir in Directory.EnumerateDirectories(hwPath))
{
// Strip base path from the filename.
workingFiles.Add(file.Substring(basePath.Length + 1));
foreach (string file in Directory.EnumerateFiles(versionDir))
submittedFiles.Add(StripBasePath(file, basePath));
}
}
}
foreach (string file in Directory.EnumerateFiles(hwPath))
workingFiles.Add(StripBasePath(file, basePath));
});
}
}
catch (Exception) { /* Do nothing */ }

List<string> submittedFilesSorted = submittedFiles.ToList();
submittedFilesSorted.Sort();
List<string> workingFilesSorted = workingFiles.ToList();
workingFilesSorted.Sort();

#if DEBUG
stopwatch.Stop();
System.Diagnostics.Debug.WriteLine("Traversing homework \"{0}\" takes {1} ms.",
homework, stopwatch.ElapsedMilliseconds);
#endif

return new SubmittedAndWorkingFiles() {
SubmittedFiles = submittedFiles,
WorkingFiles = workingFiles
SubmittedFiles = submittedFilesSorted,
WorkingFiles = workingFilesSorted
};
}

private static string StripBasePath(string path, string basePath)
{
if (!path.StartsWith(basePath))
return path;

if (basePath.Last() == Path.DirectorySeparatorChar)
return path.Substring(basePath.Length);
return path.Substring(basePath.Length + 1);
}
}
}
20 changes: 17 additions & 3 deletions TeamsAssignmentExplorer/MainWindow.xaml.cs
View file
Expand Up @@ -4,6 +4,7 @@
using System.ComponentModel;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
Expand All @@ -18,6 +19,7 @@ namespace TeamsAssignmentExplorer
/// </summary>
public partial class MainWindow : Window
{
const string loadingHomeworkList = "(Loading homework list...)";
const string selectFromDropDown = "(Please select from the drop-down list.)";

public class FileListItem
Expand Down Expand Up @@ -144,9 +146,13 @@ protected void UpdateFolderList()
}


protected void UpdateHomeworkList()
protected async Task UpdateHomeworkList()
{
var list = DirAndFileScanner.GetHomeworkList(FormData.Folder);
FormData.Homework = loadingHomeworkList;
HomeworkComboBox.IsEnabled = false;

var list = await Task.Factory.StartNew(
() => DirAndFileScanner.GetHomeworkList(FormData.Folder));
HomeworkList.Clear();
foreach (var item in list)
{
Expand All @@ -160,6 +166,7 @@ protected void UpdateHomeworkList()
}

FormData.Homework = selectFromDropDown;
HomeworkComboBox.IsEnabled = true;
return;
}

Expand Down Expand Up @@ -189,6 +196,13 @@ protected bool IsPreviousOrSameVersion(string prev, string next)

protected void MaybeUpdateFileList()
{
// TODO: investigate FormData.Homework can be empty if Folder is changed. This should
// not happen.
// Do not execute update if Homework is nothing.
if (FormData.Homework.Trim() == "") return;
if (FormData.Homework == loadingHomeworkList) return;
if (FormData.Homework == selectFromDropDown) return;

var allFiles = DirAndFileScanner.GetSubmittedAndWorkingFiles(FormData.Folder,
FormData.Homework);
List<string> files = allFiles.SubmittedFiles;
Expand Down Expand Up @@ -221,7 +235,7 @@ protected void MaybeUpdateFileList()
protected void FormData_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == "Folder")
UpdateHomeworkList();
_ = UpdateHomeworkList();
else if (e.PropertyName == "Homework" || e.PropertyName == "ShowWorkingFiles")
MaybeUpdateFileList();
}
Expand Down

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