Bug 520577

DESCRIPTION

Changing a single-picture selection within folder with grouped JPG and NEF files halts the main thread for 10-15 seconds

STEPS TO REPRODUCE

1. Select all files in a folder  (~1400 files, 21GB)
2. Right click -> Group -> Group Selected by Filename (resulting in ~700 groups since I shoot NEF+JPG)
3. Go to either preview or remain in thumbnails view, change selection with arrows 5-10 times

OBSERVED RESULT

DigiKam becomes unresponsive, the main thread goes to 100% CPU usage for 10-15 seconds

On any subsequent selection change the same happens -- rendering the experience unusable

EXPECTED RESULT

Works as if the files were not grouped

SOFTWARE/OS VERSIONS

Operating System (available in the Info Center app, or by running `kinfo` in a terminal window):
KDE Plasma Version: 6.6.5
KDE Frameworks Version: 6.26.0
Qt Version: 6.11.1
Kernel Version: 7.0.9-arch2-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 PRO 7840U w/ Radeon 780M Graphics
Memory: 64 GiB of RAM (58.6 GiB usable)
Graphics Processor: AMD Radeon 780M Graphics


ADDITIONAL INFORMATION

When the main thread shows 100% usage, below is the gbd backtrace for Thread#1, the Thread#1 is consistently stuck in that state during the unresponsive period. The rest of the threads are waiting with different calls (ppoll, epoll, etc)

Thread 1 (Thread 0x7f1520e36cc0 (LWP 57817) "digikam"):
#0  0x00007f154e49bb18 in ??? () at /usr/lib/libQt6Core.so.6
#1  0x00007f154e4aa2ee in QtPrivate::QStringList_contains(QList<QString> const*, QStringView, Qt::CaseSensitivity) () at /usr/lib/libQt6Core.so.6
#2  0x00007f15505095e6 in ??? () at /usr/lib/libdigikamcore.so.9.0.0
#3  0x00007f1550511dc0 in Digikam::LoadingCache::putThumbnail(QString const&, QPixmap const&, QString const&) () at /usr/lib/libdigikamcore.so.9.0.0
#4  0x00007f15504f158c in Digikam::ThumbnailLoadThread::slotThumbnailLoaded(Digikam::LoadingDescription const&, QImage const&) () at /usr/lib/libdigikamcore.so.9.0.0