optimize local library scanning (#112)

ErsatzTV.Application/MediaSources/Commands/ScanLocalLibraryHandler.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
@@ -61,21 +62,30 @@ namespace ErsatzTV.Application.MediaSources.Commands
             var lastScan = new DateTimeOffset(localLibrary.LastScan ?? DateTime.MinValue, TimeSpan.Zero);
             if (forceScan || lastScan < DateTimeOffset.Now - TimeSpan.FromHours(6))
             {
+                var sw = new Stopwatch();
+                sw.Start();
+
                 foreach (LibraryPath libraryPath in localLibrary.Paths)
                 {
                     switch (localLibrary.MediaKind)
                     {
                         case LibraryMediaKind.Movies:
-                            await _movieFolderScanner.ScanFolder(libraryPath, ffprobePath);
+                            await _movieFolderScanner.ScanFolder(libraryPath, ffprobePath, lastScan);
                             break;
                         case LibraryMediaKind.Shows:
-                            await _televisionFolderScanner.ScanFolder(libraryPath, ffprobePath);
+                            await _televisionFolderScanner.ScanFolder(libraryPath, ffprobePath, lastScan);
                             break;
                     }
                 }
 
                 localLibrary.LastScan = DateTime.UtcNow;
                 await _libraryRepository.UpdateLastScan(localLibrary);
+
+                sw.Stop();
+                _logger.LogDebug(
+                    "Scan of library {Name} completed in {Duration}",
+                    localLibrary.Name,
+                    TimeSpan.FromMilliseconds(sw.ElapsedMilliseconds));
             }
             else
             {

ErsatzTV.Core.Tests/Metadata/MovieFolderScannerTests.cs

@@ -81,7 +81,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Path = BadFakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsLeft.Should().BeTrue();
                 result.IfLeft(error => error.Should().BeOfType<MediaSourceInaccessible>());
@@ -101,7 +104,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -137,7 +143,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -174,7 +183,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -215,7 +227,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -259,7 +274,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -303,7 +321,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -346,7 +367,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -385,7 +409,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -418,7 +445,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -453,7 +483,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 
@@ -477,7 +510,10 @@ namespace ErsatzTV.Core.Tests.Metadata
                 );
                 var libraryPath = new LibraryPath { Id = 1, Path = FakeRoot };
 
-                Either<BaseError, Unit> result = await service.ScanFolder(libraryPath, FFprobePath);
+                Either<BaseError, Unit> result = await service.ScanFolder(
+                    libraryPath,
+                    FFprobePath,
+                    DateTimeOffset.MinValue);
 
                 result.IsRight.Should().BeTrue();
 

ErsatzTV.Core/Interfaces/Metadata/IMovieFolderScanner.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using LanguageExt;
 
@@ -6,6 +7,6 @@ namespace ErsatzTV.Core.Interfaces.Metadata
 {
     public interface IMovieFolderScanner
     {
-        Task<Either<BaseError, Unit>> ScanFolder(LibraryPath libraryPath, string ffprobePath);
+        Task<Either<BaseError, Unit>> ScanFolder(LibraryPath libraryPath, string ffprobePath, DateTimeOffset lastScan);
     }
 }

ErsatzTV.Core/Interfaces/Metadata/ITelevisionFolderScanner.cs

@@ -1,4 +1,5 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using LanguageExt;
 
@@ -6,6 +7,6 @@ namespace ErsatzTV.Core.Interfaces.Metadata
 {
     public interface ITelevisionFolderScanner
     {
-        Task<Either<BaseError, Unit>> ScanFolder(LibraryPath libraryPath, string ffprobePath);
+        Task<Either<BaseError, Unit>> ScanFolder(LibraryPath libraryPath, string ffprobePath, DateTimeOffset lastScan);
     }
 }

ErsatzTV.Core/Metadata/MovieFolderScanner.cs

@@ -42,7 +42,10 @@ namespace ErsatzTV.Core.Metadata
             _logger = logger;
         }
 
-        public async Task<Either<BaseError, Unit>> ScanFolder(LibraryPath libraryPath, string ffprobePath)
+        public async Task<Either<BaseError, Unit>> ScanFolder(
+            LibraryPath libraryPath,
+            string ffprobePath,
+            DateTimeOffset lastScan)
         {
             if (!_localFileSystem.IsLibraryPathAccessible(libraryPath))
             {
@@ -76,6 +79,11 @@ namespace ErsatzTV.Core.Metadata
                     continue;
                 }
 
+                if (_localFileSystem.GetLastWriteTime(movieFolder) < lastScan)
+                {
+                    continue;
+                }
+
                 foreach (string file in allFiles.OrderBy(identity))
                 {
                     // TODO: figure out how to rebuild playlists

ErsatzTV.Core/Metadata/TelevisionFolderScanner.cs

@@ -45,7 +45,10 @@ namespace ErsatzTV.Core.Metadata
             _logger = logger;
         }
 
-        public async Task<Either<BaseError, Unit>> ScanFolder(LibraryPath libraryPath, string ffprobePath)
+        public async Task<Either<BaseError, Unit>> ScanFolder(
+            LibraryPath libraryPath,
+            string ffprobePath,
+            DateTimeOffset lastScan)
         {
             if (!_localFileSystem.IsLibraryPathAccessible(libraryPath))
             {
@@ -77,7 +80,7 @@ namespace ErsatzTV.Core.Metadata
                             await _searchIndex.UpdateItems(new List<MediaItem> { result.Item });
                         }
 
-                        await ScanSeasons(libraryPath, ffprobePath, result.Item, showFolder);
+                        await ScanSeasons(libraryPath, ffprobePath, result.Item, showFolder, lastScan);
                     },
                     _ => Task.FromResult(Unit.Default));
             }
@@ -113,7 +116,8 @@ namespace ErsatzTV.Core.Metadata
             LibraryPath libraryPath,
             string ffprobePath,
             Show show,
-            string showFolder)
+            string showFolder,
+            DateTimeOffset lastScan)
         {
             foreach (string seasonFolder in _localFileSystem.ListSubdirectories(showFolder).Filter(ShouldIncludeFolder)
                 .OrderBy(identity))
@@ -127,7 +131,7 @@ namespace ErsatzTV.Core.Metadata
                             .BindT(season => UpdatePoster(season, seasonFolder));
 
                         await maybeSeason.Match(
-                            season => ScanEpisodes(libraryPath, ffprobePath, season, seasonFolder),
+                            season => ScanEpisodes(libraryPath, ffprobePath, season, seasonFolder, lastScan),
                             _ => Task.FromResult(Unit.Default));
                     });
             }
@@ -139,8 +143,14 @@ namespace ErsatzTV.Core.Metadata
             LibraryPath libraryPath,
             string ffprobePath,
             Season season,
-            string seasonPath)
+            string seasonPath,
+            DateTimeOffset lastScan)
         {
+            if (_localFileSystem.GetLastWriteTime(seasonPath) < lastScan)
+            {
+                return Unit.Default;
+            }
+
             foreach (string file in _localFileSystem.ListFiles(seasonPath)
                 .Filter(f => VideoFileExtensions.Contains(Path.GetExtension(f))).OrderBy(identity))
             {