From ce6764cbf890a1b128436c9547ab17919c3c6ef2 Mon Sep 17 00:00:00 2001
From: Stanley Dimant <root.darkarchon@outlook.com>
Date: Sat, 3 Sep 2022 17:57:09 +0200
Subject: [PATCH] add some locking around modifiedfiles

---
 MareSynchronos/Managers/FileCacheManager.cs   | 21 ++++++++++++++-----
 .../WebAPI/ApIController.Functions.Files.cs   |  8 +++++--
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/MareSynchronos/Managers/FileCacheManager.cs b/MareSynchronos/Managers/FileCacheManager.cs
index d415e3c..1ce838e 100644
--- a/MareSynchronos/Managers/FileCacheManager.cs
+++ b/MareSynchronos/Managers/FileCacheManager.cs
@@ -23,6 +23,7 @@ namespace MareSynchronos.Managers
         private readonly CancellationTokenSource _rescanTaskCancellationTokenSource = new();
         private CancellationTokenSource _rescanTaskRunCancellationTokenSource = new();
         private CancellationTokenSource? _scanCancellationTokenSource;
+        private object modifiedFilesLock = new object();
         public FileCacheManager(IpcManager ipcManager, Configuration pluginConfiguration)
         {
             Logger.Verbose("Creating " + nameof(FileCacheManager));
@@ -142,7 +143,10 @@ namespace MareSynchronos.Managers
 
         private void OnModified(object sender, FileSystemEventArgs e)
         {
-            _modifiedFiles.Add(e.FullPath);
+            lock (modifiedFilesLock)
+            {
+                _modifiedFiles.Add(e.FullPath);
+            }
             _ = StartRescan();
         }
 
@@ -189,14 +193,21 @@ namespace MareSynchronos.Managers
 
             Logger.Debug("File changes detected");
 
-            if (!_modifiedFiles.Any()) return;
+            lock (modifiedFilesLock)
+            {
+                if (!_modifiedFiles.Any()) return;
+            }
 
             _rescanTask = Task.Run(async () =>
             {
-                var listCopy = _modifiedFiles.ToList();
-                _modifiedFiles.Clear();
+                List<string> modifiedFilesCopy = new List<string>();
+                lock (modifiedFilesLock)
+                {
+                    modifiedFilesCopy = _modifiedFiles.ToList();
+                    _modifiedFiles.Clear();
+                }
                 await using var db = new FileCacheContext();
-                foreach (var item in listCopy.Distinct())
+                foreach (var item in modifiedFilesCopy.Distinct())
                 {
                     var fi = new FileInfo(item);
                     if (!fi.Exists)
diff --git a/MareSynchronos/WebAPI/ApIController.Functions.Files.cs b/MareSynchronos/WebAPI/ApIController.Functions.Files.cs
index 2c224be..e927e3f 100644
--- a/MareSynchronos/WebAPI/ApIController.Functions.Files.cs
+++ b/MareSynchronos/WebAPI/ApIController.Functions.Files.cs
@@ -123,9 +123,13 @@ namespace MareSynchronos.WebAPI
             {
                 await using (var db = new FileCacheContext())
                 {
-                    allFilesInDb = CurrentDownloads[currentDownloadId]
+                    var fileCount = CurrentDownloads[currentDownloadId]
                         .Where(c => c.CanBeTransferred)
-                        .All(h => db.FileCaches.Any(f => f.Hash == h.Hash));
+                        .Count(h => db.FileCaches.Any(f => f.Hash == h.Hash));
+                    var totalFiles = CurrentDownloads[currentDownloadId].Count(c => c.CanBeTransferred);
+                    Logger.Debug("Waiting for files to be in the DB, added " + fileCount + " of " + totalFiles);
+
+                    allFilesInDb = fileCount == totalFiles;
                 }
 
                 await Task.Delay(250, ct);