Try to reuse the db track entry if the track file just moved, fixes #612

src/libs/database/impl/Session.cpp

@@ -256,6 +256,7 @@ namespace lms::db
             utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_media_library_release_idx ON track(media_library_id, release_id)");
             utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_mbid_idx ON track(mbid)");
             utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_name_idx ON track(name)");
+            utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_name_file_size_idx ON track(name, file_size)");
             utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_name_nocase_idx ON track(name COLLATE NOCASE)");
             utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_original_date_idx ON track(original_date)");
             utils::executeCommand(_session, "CREATE INDEX IF NOT EXISTS track_recording_mbid_idx ON track(recording_mbid)");

src/libs/database/impl/Track.cpp

@@ -180,6 +180,9 @@ namespace lms::db
             if (params.hasEmbeddedImage.has_value())
                 query.where("t.has_cover = ?").bind(params.hasEmbeddedImage.value());
 
+            if (params.fileSize.has_value())
+                query.where("t.file_size = ?").bind(static_cast<long long>(params.fileSize.value()));
+
             switch (params.sortMethod)
             {
             case TrackSortMethod::None:

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

@@ -86,6 +86,7 @@ namespace lms::db
             std::optional<int> discNumber;                           // matching this disc number
             DirectoryId directory;                                   // if set, tracks in this directory
             std::optional<bool> hasEmbeddedImage;                    // if set, tracks that have or not embedded images
+            std::optional<std::size_t> fileSize;                     // if set, tracks that match this file size
 
             FindParameters& setFilters(const Filters& _filters)
             {
@@ -186,6 +187,11 @@ namespace lms::db
                 hasEmbeddedImage = _hasEmbeddedImage;
                 return *this;
             }
+            FindParameters& setFileSize(std::optional<std::size_t> _fileSize)
+            {
+                fileSize = _fileSize;
+                return *this;
+            }
         };
 
         Track() = default;

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

@@ -345,6 +345,45 @@ namespace lms::scanner
             return db::Advisory::UnSet;
         }
 
+        db::Track::pointer findMovedTrackBySizeAndMetaData(db::Session& session, const metadata::Track& parsedTrack, const FileInfo& fileInfo)
+        {
+            db::Track::FindParameters params;
+            // Add as many fields as possible to limit errors
+            params.setName(parsedTrack.title);
+            if (parsedTrack.medium)
+            {
+                if (parsedTrack.medium->position)
+                    params.setDiscNumber(*parsedTrack.medium->position);
+                if (parsedTrack.medium->release)
+                    params.setReleaseName(parsedTrack.medium->release->name);
+            }
+            if (parsedTrack.position)
+                params.setTrackNumber(*parsedTrack.position);
+            params.setHasEmbeddedImage(parsedTrack.hasCover);
+            params.setFileSize(fileInfo.fileSize);
+
+            bool error{};
+            db::Track::pointer res;
+            db::Track::find(session, params, [&](const db::Track::pointer& track) {
+                // Check that the track is truly no longer where it was during the last scan
+                std::error_code ec;
+                if (std::filesystem::exists(track->getAbsoluteFilePath(), ec))
+                    return;
+
+                if (res)
+                {
+                    LMS_LOG(DBUPDATER, DEBUG, "Found too many candidates for file move. New file = " << fileInfo.relativePath << ", candidate = " << track->getAbsoluteFilePath() << ", previous candidate = " << res->getAbsoluteFilePath());
+                    error = true;
+                }
+                res = track;
+            });
+
+            if (error)
+                res = db::Track::pointer{};
+
+            return res;
+        }
+
         class AudioFileScanOperation : public IFileScanOperation
         {
         public:
@@ -463,6 +502,17 @@ namespace lms::scanner
                 }
             }
 
+            if (!track)
+            {
+                // maybe the file just moved?
+                track = findMovedTrackBySizeAndMetaData(dbSession, *_parsedTrack, *fileInfo);
+                if (track)
+                {
+                    LMS_LOG(DBUPDATER, DEBUG, "Considering track " << _file << " moved from " << track->getAbsoluteFilePath());
+                    track.modify()->setAbsoluteFilePath(_file);
+                }
+            }
+
             // We estimate this is an audio file if the duration is not null
             if (_parsedTrack->audioProperties.duration == std::chrono::milliseconds::zero())
             {