Optimized diff scan by not pulling the whole track columns

src/libs/database/impl/Track.cpp

@@ -258,6 +258,25 @@ namespace lms::db
         return utils::fetchQuerySingleResult(session.getDboSession()->query<Wt::Dbo::ptr<Track>>("SELECT t from track t").where("t.absolute_file_path = ?").bind(p));
     }
 
+    std::optional<FileInfo> Track::findFileInfo(Session& session, const std::filesystem::path& p)
+    {
+        session.checkReadTransaction();
+
+        auto query{ session.getDboSession()->query<std::tuple<int, Wt::WDateTime>>("SELECT t.scan_version, t.file_last_write FROM track t WHERE t.absolute_file_path = ?") };
+        query.bind(p);
+
+        std::optional<FileInfo> result;
+
+        utils::forEachQueryResult(query, [&](const auto& row) {
+            FileInfo info;
+            info.scanVersion = std::get<0>(row);
+            info.lastWrittenTime = std::get<1>(row);
+            result = info;
+        });
+
+        return result;
+    }
+
     Track::pointer Track::find(Session& session, TrackId id)
     {
         session.checkReadTransaction();

src/libs/database/include/database/Track.hpp

@@ -191,6 +191,7 @@ namespace lms::db
         // Find utility functions
         static std::size_t getCount(Session& session);
         static pointer findByPath(Session& session, const std::filesystem::path& p);
+        static std::optional<FileInfo> findFileInfo(Session& session, const std::filesystem::path& p);
         static pointer find(Session& session, TrackId id);
         static void find(Session& session, TrackId& lastRetrievedId, std::size_t count, const std::function<void(const Track::pointer&)>& func, MediaLibraryId library = {});
         static void find(Session& session, const IdRange<TrackId>& idRange, const std::function<void(const Track::pointer&)>& func);

src/libs/database/include/database/Types.hpp

@@ -114,6 +114,12 @@ namespace lms::db
         std::string name;
     };
 
+    struct FileInfo
+    {
+        Wt::WDateTime lastWrittenTime;
+        std::size_t scanVersion{};
+    };
+
     enum class ArtistSortMethod
     {
         None,

src/libs/services/scanner/impl/scanners/AudioFileScanner.cpp

@@ -63,6 +63,7 @@ namespace lms::scanner
         }
 
     } // namespace
+
     AudioFileScanner::AudioFileScanner(db::Db& db, const ScannerSettings& settings)
         : _db{ db }
         , _settings{ settings }
@@ -92,10 +93,10 @@ namespace lms::scanner
         db::Session& dbSession{ _db.getTLSSession() };
         auto transaction{ dbSession.createReadTransaction() };
 
-        const db::Track::pointer track{ db::Track::findByPath(dbSession, file.filePath) };
+        std::optional<db::FileInfo> fileInfo{ db::Track::findFileInfo(dbSession, file.filePath) };
-        return !track
+        return !fileInfo
-            || track->getLastWriteTime() != file.lastWriteTime
+            || fileInfo->lastWrittenTime != file.lastWriteTime
-            || track->getScanVersion() != _settings.audioScanVersion;
+            || fileInfo->scanVersion != _settings.audioScanVersion;
     }
 
     std::unique_ptr<IFileScanOperation> AudioFileScanner::createScanOperation(FileToScan&& fileToScan) const