Do not try to optimize when there are too few files, it seems to bring more drawbacks than benefits

src/libs/database/impl/Session.cpp

@@ -346,26 +346,6 @@ namespace lms::db
         LMS_LOG(DB, INFO, "Vacuum complete!");
     }
 
-    void Session::refreshTracingLoggerStats()
-    {
-        auto* traceLogger{ core::Service<core::tracing::ITraceLogger>::get() };
-        if (!traceLogger)
-            return;
-
-        auto transaction{ createReadTransaction() };
-
-        traceLogger->setMetadata("db_artist_count", std::to_string(db::Artist::getCount(*this)));
-        traceLogger->setMetadata("db_cluster_count", std::to_string(db::Cluster::getCount(*this)));
-        traceLogger->setMetadata("db_cluster_type_count", std::to_string(db::ClusterType::getCount(*this)));
-        traceLogger->setMetadata("db_starred_artist_count", std::to_string(db::StarredArtist::getCount(*this)));
-        traceLogger->setMetadata("db_starred_release_count", std::to_string(db::StarredRelease::getCount(*this)));
-        traceLogger->setMetadata("db_starred_track_count", std::to_string(db::StarredTrack::getCount(*this)));
-        traceLogger->setMetadata("db_track_bookmark_count", std::to_string(db::TrackBookmark::getCount(*this)));
-        traceLogger->setMetadata("db_listen_count", std::to_string(db::Listen::getCount(*this)));
-        traceLogger->setMetadata("db_release_count", std::to_string(db::Release::getCount(*this)));
-        traceLogger->setMetadata("db_track_count", std::to_string(db::Track::getCount(*this)));
-    }
-
     void Session::fullAnalyze()
     {
         LMS_SCOPED_TRACE_OVERVIEW("Database", "Analyze");
@@ -393,6 +373,19 @@ namespace lms::db
         });
     }
 
+    std::size_t Session::getTotalFilesCount()
+    {
+        std::size_t res{};
+
+        res += db::Track::getCount(*this);
+        res += db::Image::getCount(*this);
+        res += db::TrackLyrics::getExternalLyricsCount(*this);
+        res += db::PlayListFile::getCount(*this);
+        res += db::ArtistInfo::getCount(*this);
+
+        return res;
+    }
+
     void Session::retrieveEntriesToAnalyze(std::vector<std::string>& entryList)
     {
         auto transaction{ createReadTransaction() };

src/libs/database/include/database/Session.hpp

@@ -52,14 +52,14 @@ namespace lms::db
         void retrieveEntriesToAnalyze(std::vector<std::string>& entryList);
         void analyzeEntry(const std::string& entry);
 
-        bool areAllTablesEmpty(); // need to acquire a read transaction
+        bool areAllTablesEmpty();         // need to acquire a read transaction
+        std::size_t getTotalFilesCount(); // need to acquire a read transaction
 
         void prepareTablesIfNeeded(); // need to run only once at startup
         bool migrateSchemaIfNeeded(); // returns true if migration was performed
         void createIndexesIfNeeded();
         void vacuumIfNeeded();
         void vacuum();
-        void refreshTracingLoggerStats();
 
         // returning a ptr here to ease further wrapping using operator->
         Wt::Dbo::Session* getDboSession() { return &_session; }

src/libs/services/scanner/CMakeLists.txt

@@ -27,6 +27,7 @@ add_library(lmsscanner STATIC
 	impl/steps/ScanStepUpdateLibraryFields.cpp
 	impl/FileScanners.cpp
 	impl/ScannerService.cpp
+	impl/ScannerServiceTraceLogger.cpp
 	impl/ScannerStats.cpp
 	)
 

src/libs/services/scanner/impl/ScannerService.cpp

@@ -166,6 +166,20 @@ namespace lms::scanner
         LMS_LOG(DBUPDATER, INFO, "Using " << _jobScheduler->getThreadCount() << " thread(s) for jobs");
         _jobScheduler->setShouldAbortCallback([this]() { return _abortScan; });
 
+        std::size_t totalFilesCount{};
+        {
+            auto& session{ _db.getTLSSession() };
+            auto transaction{ session.createReadTransaction() };
+            totalFilesCount = session.getTotalFilesCount();
+        }
+
+        // Force optimize in case scanner aborted during a large import, but do this only if there are enough elements in the database
+        // Otherwise, indexes may be not used and queries may be slower and slower while adding more and more elements in the db
+        LMS_LOG(DBUPDATER, INFO, "Scanned file count = " << totalFilesCount);
+        if (totalFilesCount >= 1'000)
+            _db.getTLSSession().fullAnalyze();
+
+        refreshTracingLoggerStats();
         refreshScanSettings();
 
         start();
@@ -371,7 +385,8 @@ namespace lms::scanner
             _currentScanStepStats.reset(); // must be sync with _curState
         }
 
-        LMS_LOG(DBUPDATER, INFO, "Scan " << (_abortScan ? "aborted" : "complete") << ". Changes = " << stats.nbChanges() << " (added = " << stats.additions << ", removed = " << stats.deletions << ", updated = " << stats.updates << ", failures = " << stats.failures << "), Not changed = " << stats.skips << ", Scanned = " << stats.scans << " (errors = " << stats.errorsCount << "), features fetched = " << stats.featuresFetched << ",  duplicates = " << stats.duplicates.size());
+        refreshTracingLoggerStats();
+        LMS_LOG(DBUPDATER, INFO, "Scan " << (_abortScan ? "aborted" : "complete") << ". Changes = " << stats.getChangesCount() << " (added = " << stats.additions << ", removed = " << stats.deletions << ", updated = " << stats.updates << ", failures = " << stats.failures << "), Not changed = " << stats.skips << ", Scanned = " << stats.scans << " (errors = " << stats.errorsCount << "), features fetched = " << stats.featuresFetched << ",  duplicates = " << stats.duplicates.size());
 
         if (!_abortScan)
         {

src/libs/services/scanner/impl/ScannerService.hpp

@@ -82,6 +82,7 @@ namespace lms::scanner
 
         // Helpers
         void refreshScanSettings();
+        void refreshTracingLoggerStats();
 
         void notifyInProgressIfNeeded(const ScanStepStats& stats);
         void notifyInProgress(const ScanStepStats& stats);

src/libs/services/scanner/impl/ScannerServiceTraceLogger.cpp

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2013 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ScannerService.hpp"
+
+#include "database/objects/Artist.hpp"
+#include "database/objects/ArtistInfo.hpp"
+#include "database/objects/Cluster.hpp"
+#include "database/objects/Image.hpp"
+#include "database/objects/Listen.hpp"
+#include "database/objects/StarredArtist.hpp"
+#include "database/objects/StarredRelease.hpp"
+#include "database/objects/StarredTrack.hpp"
+#include "database/objects/Track.hpp"
+#include "database/objects/TrackArtistLink.hpp"
+#include "database/objects/TrackBookmark.hpp"
+#include "database/objects/TrackEmbeddedImage.hpp"
+#include "database/objects/TrackEmbeddedImageLink.hpp"
+
+namespace lms::scanner
+{
+    void ScannerService::refreshTracingLoggerStats()
+    {
+        auto* traceLogger{ core::Service<core::tracing::ITraceLogger>::get() };
+        if (!traceLogger)
+            return;
+
+        auto& session{ _db.getTLSSession() };
+        auto transaction{ session.createReadTransaction() };
+
+        traceLogger->setMetadata("db_artist_count", std::to_string(db::Artist::getCount(session)));
+        traceLogger->setMetadata("db_artist_info_count", std::to_string(db::ArtistInfo::getCount(session)));
+        traceLogger->setMetadata("db_cluster_count", std::to_string(db::Cluster::getCount(session)));
+        traceLogger->setMetadata("db_cluster_type_count", std::to_string(db::ClusterType::getCount(session)));
+        traceLogger->setMetadata("db_image_count", std::to_string(db::Image::getCount(session)));
+        traceLogger->setMetadata("db_listen_count", std::to_string(db::Listen::getCount(session)));
+        traceLogger->setMetadata("db_release_count", std::to_string(db::Release::getCount(session)));
+        traceLogger->setMetadata("db_starred_artist_count", std::to_string(db::StarredArtist::getCount(session)));
+        traceLogger->setMetadata("db_starred_release_count", std::to_string(db::StarredRelease::getCount(session)));
+        traceLogger->setMetadata("db_starred_track_count", std::to_string(db::StarredTrack::getCount(session)));
+        traceLogger->setMetadata("db_track_bookmark_count", std::to_string(db::TrackBookmark::getCount(session)));
+        traceLogger->setMetadata("db_track_count", std::to_string(db::Track::getCount(session)));
+        traceLogger->setMetadata("db_track_artist_link_count", std::to_string(db::TrackArtistLink::getCount(session)));
+        traceLogger->setMetadata("db_track_embedded_image_count", std::to_string(db::TrackEmbeddedImage::getCount(session)));
+        traceLogger->setMetadata("db_track_embedded_image_link_count", std::to_string(db::TrackEmbeddedImageLink::getCount(session)));
+    }
+} // namespace lms::scanner

src/libs/services/scanner/impl/ScannerStats.cpp

@@ -21,12 +21,12 @@
 
 namespace lms::scanner
 {
-    std::size_t ScanStats::nbFiles() const
+    std::size_t ScanStats::getTotalFileCount() const
     {
         return skips + additions + updates + failures;
     }
 
-    std::size_t ScanStats::nbChanges() const
+    std::size_t ScanStats::getChangesCount() const
     {
         return additions + deletions + updates;
     }

src/libs/services/scanner/impl/steps/ScanStepAssociateArtistImages.cpp

@@ -321,7 +321,7 @@ namespace lms::scanner
 
     bool ScanStepAssociateArtistImages::needProcess(const ScanContext& context) const
     {
-        if (context.stats.nbChanges() > 0)
+        if (context.stats.getChangesCount() > 0)
             return true;
 
         if (getLastScanSettings() && getLastScanSettings()->artistImageFallbackToRelease != _settings.artistImageFallbackToRelease)

src/libs/services/scanner/impl/steps/ScanStepAssociateExternalLyrics.cpp

@@ -145,7 +145,7 @@ namespace lms::scanner
 
     bool ScanStepAssociateExternalLyrics::needProcess(const ScanContext& context) const
     {
-        if (context.stats.nbChanges() > 0)
+        if (context.stats.getChangesCount() > 0)
             return true;
 
         return false;

src/libs/services/scanner/impl/steps/ScanStepAssociatePlayListTracks.cpp

@@ -251,7 +251,7 @@ namespace lms::scanner
 
     bool ScanStepAssociatePlayListTracks::needProcess(const ScanContext& context) const
     {
-        if (context.stats.nbChanges() > 0)
+        if (context.stats.getChangesCount() > 0)
             return true;
 
         if (getLastScanSettings() && getLastScanSettings()->skipSingleReleasePlayLists != _settings.skipSingleReleasePlayLists)

src/libs/services/scanner/impl/steps/ScanStepAssociateReleaseImages.cpp

@@ -266,7 +266,7 @@ namespace lms::scanner
 
     bool ScanStepAssociateReleaseImages::needProcess(const ScanContext& context) const
     {
-        return context.stats.nbChanges() > 0;
+        return context.stats.getChangesCount() > 0;
     }
 
     void ScanStepAssociateReleaseImages::process(ScanContext& context)

src/libs/services/scanner/impl/steps/ScanStepAssociateTrackImages.cpp

@@ -232,7 +232,7 @@ namespace lms::scanner
 
     bool ScanStepAssociateTrackImages::needProcess(const ScanContext& context) const
     {
-        return context.stats.nbChanges() > 0;
+        return context.stats.getChangesCount() > 0;
     }
 
     void ScanStepAssociateTrackImages::process(ScanContext& context)

src/libs/services/scanner/impl/steps/ScanStepCheckForRemovedFiles.cpp

@@ -194,12 +194,7 @@ namespace lms::scanner
 
         {
             auto transaction{ session.createReadTransaction() };
-            context.currentStepStats.totalElems = 0;
-            context.currentStepStats.totalElems += db::Track::getCount(session);
-            context.currentStepStats.totalElems += db::Image::getCount(session);
-            context.currentStepStats.totalElems += db::TrackLyrics::getExternalLyricsCount(session);
-            context.currentStepStats.totalElems += db::PlayListFile::getCount(session);
-            context.currentStepStats.totalElems += db::ArtistInfo::getCount(session);
+            context.currentStepStats.totalElems = session.getTotalFilesCount();
         }
         LMS_LOG(DBUPDATER, DEBUG, context.currentStepStats.totalElems << " files to be checked...");
 

src/libs/services/scanner/impl/steps/ScanStepComputeClusterStats.cpp

@@ -29,10 +29,7 @@ namespace lms::scanner
 {
     bool ScanStepComputeClusterStats::needProcess(const ScanContext& context) const
     {
-        if (context.stats.nbChanges() > 0)
-            return true;
-
-        return false;
+        return context.stats.getChangesCount() > 0;
     }
 
     void ScanStepComputeClusterStats::process(ScanContext& context)

src/libs/services/scanner/impl/steps/ScanStepOptimize.cpp

@@ -32,8 +32,13 @@ namespace lms::scanner
         if (context.scanOptions.forceOptimize)
             return true;
 
-        if (context.stats.nbChanges() > (context.stats.nbFiles() / 10))
+        // Don't optimize if there are too few files: it may lead to some indexes not being used
+        // and will drastically slow down the scan process when adding more files later
+        if (context.stats.getChangesCount() > (context.stats.getTotalFileCount() / 5)
+            && context.stats.getTotalFileCount() >= 1'000)
+        {
             return true;
+        }
 
         return false;
     }

src/libs/services/scanner/include/services/scanner/ScannerStats.hpp

@@ -100,7 +100,7 @@ namespace lms::scanner
         std::size_t errorsCount{}; // maybe bigger than errors.size() if too many errors
         std::vector<ScanDuplicate> duplicates;
 
-        std::size_t nbFiles() const;
-        std::size_t nbChanges() const;
+        std::size_t getTotalFileCount() const;
+        std::size_t getChangesCount() const;
     };
 } // namespace lms::scanner

src/lms/main.cpp

@@ -333,11 +333,6 @@ namespace lms
                     session.vacuum();
                 else
                     session.vacuumIfNeeded();
-
-                // force optimize in case scanner aborted during a large import:
-                // queries may be too slow to even be able to relaunch a scan using the web interface
-                session.fullAnalyze();
-                database->getTLSSession().refreshTracingLoggerStats();
             }
 
             ui::LmsApplicationManager appManager;
@@ -385,7 +380,6 @@ namespace lms
                 // Flush cover cache even if no changes:
                 // covers may be external files that changed and we don't keep track of them for now (but we should)
                 artworkService->flushCache();
-                database->getTLSSession().refreshTracingLoggerStats();
             });
 
             core::Service<feedback::IFeedbackService> feedbackService{ feedback::createFeedbackService(ioContext, *database) };

src/lms/ui/LmsApplication.cpp

@@ -542,7 +542,7 @@ namespace lms::ui
                 notifyMsg(Notification::Type::Info,
                     Wt::WString::tr("Lms.Admin.Database.database"),
                     Wt::WString::tr("Lms.Admin.Database.scan-complete")
-                        .arg(static_cast<unsigned>(stats.nbFiles()))
+                        .arg(static_cast<unsigned>(stats.getTotalFileCount()))
                         .arg(static_cast<unsigned>(stats.additions))
                         .arg(static_cast<unsigned>(stats.updates))
                         .arg(static_cast<unsigned>(stats.deletions))

src/lms/ui/admin/ScannerController.cpp

@@ -115,7 +115,7 @@ namespace lms::ui
         if (status.lastCompleteScanStats)
         {
             _lastScanStatus->setText(Wt::WString::tr("Lms.Admin.ScannerController.last-scan-status")
-                                         .arg(status.lastCompleteScanStats->nbFiles())
+                                         .arg(status.lastCompleteScanStats->getTotalFileCount())
                                          .arg(durationToString(status.lastCompleteScanStats->startTime, status.lastCompleteScanStats->stopTime))
                                          .arg(status.lastCompleteScanStats->stopTime.date().toString(Wt::WLocale::currentLocale().dateFormat()))
                                          .arg(status.lastCompleteScanStats->stopTime.time().toString(Wt::WLocale::currentLocale().timeFormat()))

src/lms/ui/resource/ArtworkResource.cpp

@@ -57,7 +57,7 @@ namespace lms::ui
     ArtworkResource::ArtworkResource()
     {
         LmsApp->getScannerEvents().scanComplete.connect(this, [this](const scanner::ScanStats& stats) {
-            if (stats.nbChanges())
+            if (stats.getChangesCount())
                 setChanged();
         });
     }