Restructuring. Added services.

Aurora/Backend/Utils/FileSystemUtils.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Aurora.Backend.Utils
+{
+    public class FileSystemUtils
+    {
+
+        public FileSystemUtils()
+        {
+        }
+
+
+        /// <summary>
+        /// Asynchronousely recursively traverse a directory path.
+        /// </summary>
+        /// <param name="path">The path to the directory to traverse</param>
+        /// <param name="extensions">Comma separated list of file extensions to accept</param>
+        public static List<FileInfo> TraverseFoldersAsync(string path, string extensions)
+        {
+            string[] extensionList = extensions.Split(',');
+
+            ConcurrentBag<Task> tasks = new ConcurrentBag<Task>();
+            List<FileInfo> outFiles = new List<FileInfo>();
+            DirectoryInfo directoryInfo = new DirectoryInfo(path);
+
+            tasks.Add(Task.Run(() => Traverse(directoryInfo, tasks, outFiles, extensionList)));
+
+            Task waitingTask;
+            while (tasks.TryTake(out waitingTask))
+            {
+                waitingTask.Wait();
+            }
+
+            return outFiles;
+        }
+
+
+
+        /// <summary>
+        /// Recursive method to capture children of a directory.
+        /// </summary>
+        /// <param name="dir">The directory to traverse</param>
+        /// <param name="tasks">The list of currently running tasks</param>
+        private static void Traverse(DirectoryInfo dir, ConcurrentBag<Task> tasks, List<FileInfo> outFiles, string[] extensions)
+        {
+            try
+            {
+                DirectoryInfo[] directoryInfos = dir.GetDirectories();
+                //Enque children
+                foreach (DirectoryInfo childInfo in directoryInfos)
+                {
+                    tasks.Add(Task.Run(() => Traverse(childInfo, tasks, outFiles, extensions)));
+                }
+
+                //Collect files
+                foreach (FileInfo fileInfo in dir.GetFiles())
+                {
+                    if (extensions.Any(e => e == fileInfo.Extension))
+                    {
+                        //Don't know if this lock is necessary
+                        lock (outFiles)
+                        {
+                            outFiles.Add(fileInfo);
+                        }
+                    }
+
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"{ex.GetType()} {ex.Message}\n{ex.StackTrace}");
+                ex = ex.InnerException;
+            }
+        }
+
+    }
+}