Merge pull request #400 from swurzinger/song-loading-speedup

improve song enumeration performance

Vocaluxe/Base/CBackgroundMusic.cs

@@ -157,7 +157,7 @@ namespace Vocaluxe.Base
             if (_Initialized)
                 return;
 
-            List<string> soundFiles = CHelper.ListSoundFiles(CSettings.FolderNameBackgroundMusic, true, true);
+            IEnumerable<string> soundFiles = CHelper.ListSoundFiles(CSettings.FolderNameBackgroundMusic, true, true);
 
             foreach (string path in soundFiles)
                 _BGMusicFiles.Add(new CPlaylistElement(path));

Vocaluxe/Base/CCover.cs

@@ -174,7 +174,7 @@ namespace Vocaluxe.Base
             _CoverThemes.Clear();
 
             string folderPath = Path.Combine(CSettings.ProgramFolder, CSettings.FolderNameCover);
-            List<string> files = CHelper.ListFiles(folderPath, "*.xml");
+            IEnumerable<string> files = CHelper.ListFiles(folderPath, "*.xml");
 
             var xml = new CXmlDeserializer();
             foreach (string file in files)
@@ -207,7 +207,7 @@ namespace Vocaluxe.Base
 
             Debug.Assert(!String.IsNullOrEmpty(coverTheme.Info.Name));
 
-            List<string> files = CHelper.ListImageFiles(coverTheme.FolderPath, true, true);
+            IEnumerable<string> files = CHelper.ListImageFiles(coverTheme.FolderPath, true, true);
 
             lock (_Covers)
             {

Vocaluxe/Base/CSongs.cs

@@ -339,18 +339,17 @@ namespace Vocaluxe.Base
                 SongsLoaded = false;
                 _Songs.Clear();
 
-                var files = new List<string>();
+                var files = Enumerable.Empty<string>();
                
                 using (CBenchmark.Time("List Songs"))
                 {
                     
-                    foreach (string p in CConfig.SongFolders)
+                    foreach (string path in CConfig.SongFolders)
                     {
-                        if (Directory.Exists(p))
+                        if (Directory.Exists(path))
                         {
-                            string path = p;
-                            files.AddRange(CHelper.ListFiles(path, "*.txt", true, true));
-                            files.AddRange(CHelper.ListFiles(path, "*.txd", true, true));
+                            files = files.Union(CHelper.ListFiles(path, "*.txt", true, true));
+                            files = files.Union(CHelper.ListFiles(path, "*.txd", true, true));
                         }
                     }
                 }

Vocaluxe/Base/ThemeSystem/CTheme.cs

@@ -86,7 +86,7 @@ namespace Vocaluxe.Base.ThemeSystem
             }
 
             string path = Path.Combine(_Folder, Name);
-            List<string> files = CHelper.ListFiles(path, "*.xml");
+            IEnumerable<string> files = CHelper.ListFiles(path, "*.xml");
 
             // Load skins, succeed if at least 1 skin was loaded
             bool ok = false;

Vocaluxe/Base/ThemeSystem/CThemes.cs

@@ -135,7 +135,7 @@ namespace Vocaluxe.Base.ThemeSystem
 
         public static bool ReadThemesFromFolder(string path, int partyModeID)
         {
-            List<string> files = CHelper.ListFiles(path, "*.xml", false, true);
+            IEnumerable<string> files = CHelper.ListFiles(path, "*.xml", false, true);
 
             List<CTheme> newThemes = new List<CTheme>();
             foreach (string file in files)

VocaluxeLib/CHelper.cs

@@ -20,6 +20,7 @@ using System.Collections.Generic;
 using System.Drawing;
 using System.Globalization;
 using System.IO;
+using System.Linq;
 using VocaluxeLib.Log;
 
 namespace VocaluxeLib
@@ -165,25 +166,20 @@ namespace VocaluxeLib
         /// <param name="recursive">Search directories recursively</param>
         /// <param name="fullpath">False for just file names, True for full path</param>
         /// <returns>List of file names</returns>
-        public static List<string> ListFiles(string path, string searchPattern, bool recursive = false, bool fullpath = false)
+        public static IEnumerable<string> ListFiles(string path, string searchPattern, bool recursive = false, bool fullpath = false)
         {
-            var files = new List<string>();
+            IEnumerable<string> files = Enumerable.Empty<string>();
             var dir = new DirectoryInfo(path);
             if (!dir.Exists)
                 return files;
 
+            if (recursive && !fullpath)
+                throw new NotSupportedException("recursive file listing with relative path names is not supported");
+
             try
             {
-                // ReSharper disable LoopCanBeConvertedToQuery
-                foreach (FileInfo file in dir.GetFiles(searchPattern))
-                    // ReSharper restore LoopCanBeConvertedToQuery
-                    files.Add(!fullpath ? file.Name : file.FullName);
-
-                if (recursive)
-                {
-                    foreach (DirectoryInfo di in dir.GetDirectories())
-                        files.AddRange(ListFiles(di.FullName, searchPattern, true, fullpath));
-                }
+                files = Directory.EnumerateFiles(dir.FullName, searchPattern, recursive ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly);
+                files = files.Select(fullpath ? (Func<string, string>)Path.GetFullPath : Path.GetFileName);
             }
             catch (Exception) {}
 
@@ -198,13 +194,9 @@ namespace VocaluxeLib
         /// <param name="recursive">Search directories recursively</param>
         /// <param name="fullpath">False for just file names, True for full path</param>
         /// <returns>List of file names</returns>
-        public static List<string> ListFiles(string path, IEnumerable<string> searchPatterns, bool recursive = false, bool fullpath = false)
+        public static IEnumerable<string> ListFiles(string path, IEnumerable<string> searchPatterns, bool recursive = false, bool fullpath = false)
         {
-            var files = new List<string>();
-            foreach (string pattern in searchPatterns)
-                files.AddRange(ListFiles(path, pattern, recursive, fullpath));
-
-            return files;
+            return searchPatterns.SelectMany(pattern => ListFiles(path, pattern, recursive, fullpath));
         }
 
         /// <summary>
@@ -214,7 +206,7 @@ namespace VocaluxeLib
         /// <param name="recursive">Search directories recursively</param>
         /// <param name="fullpath">False for just file names, True for full path</param>
         /// <returns>List of image file names</returns>
-        public static List<string> ListImageFiles(string path, bool recursive = false, bool fullpath = false)
+        public static IEnumerable<string> ListImageFiles(string path, bool recursive = false, bool fullpath = false)
         {
             return ListFiles(path, _ImageFileTypes, recursive, fullpath);
         }
@@ -226,7 +218,7 @@ namespace VocaluxeLib
         /// <param name="recursive">Search directories recursively</param>
         /// <param name="fullpath">False for just file names, True for full path</param>
         /// <returns>List of image file names</returns>
-        public static List<string> ListSoundFiles(string path, bool recursive = false, bool fullpath = false)
+        public static IEnumerable<string> ListSoundFiles(string path, bool recursive = false, bool fullpath = false)
         {
             return ListFiles(path, _SoundFileTypes, recursive, fullpath);
         }

VocaluxeLib/Log/CLog.cs

@@ -196,10 +196,10 @@ namespace VocaluxeLib.Log
             int i = 0;
             return theRegex.Replace(template, delegate(Match match)
             {
-                if (propertyValues.Length >= i)
+                if (i >= propertyValues.Length)
                     return match.Value;
                 return propertyValues[i++].ToString();
-            }); 
+            });
         }
 
     }

VocaluxeLib/Songs/CSong.cs

@@ -325,7 +325,7 @@ namespace VocaluxeLib.Songs
         {
             if (CoverFileName == "")
             {
-                List<string> files = CHelper.ListImageFiles(Folder);
+                IEnumerable<string> files = CHelper.ListImageFiles(Folder);
                 foreach (String file in files)
                 {
                     if (file.ContainsIgnoreCase("[CO]") &&
@@ -336,7 +336,7 @@ namespace VocaluxeLib.Songs
 
             if (BackgroundFileNames.Count == 0)
             {
-                List<string> files = CHelper.ListImageFiles(Folder);
+                IEnumerable<string> files = CHelper.ListImageFiles(Folder);
                 foreach (String file in files)
                 {
                     if (file.ContainsIgnoreCase("[BG]") &&