[graphics/digikam] /: Uses QSet instead QList to prepare build fingerprints and speed-up pre-processing with large collections.

Git commit b06de7a3eda2478500c73ca56aecbf010566b08a by Gilles Caulier.
Committed on 17/08/2026 at 22:22.
Pushed by cgilles into branch 'master'.

Uses QSet instead QList to prepare build fingerprints and speed-up pre-processing with large collections.
BUGS: 524383
FIXED-IN: 9.2.0

M  +1    -1    NEWS
M  +4    -10   core/utilities/maintenance/tools/fingerprints/fingerprintsgenerator.cpp

https://invent.kde.org/graphics/digikam/-/commit/b06de7a3eda2478500c73ca56aecbf010566b08a

diff --git a/NEWS b/NEWS
index d7ff969aa1..c8332e5489 100644
--- a/NEWS
+++ b/NEWS
@@ -69,7 +69,7 @@ BUGFIXES:
 043 --> 524196 - Solved for me after performing the mention steps.
 044 --> 524254 - Unable to add /usr/bin/tesseract binary to digiKam.
 045 --> 511758 - digiKam is almost unusable when mysql is not connected over lan.
-046 --> 
+046 --> 524383 - Fingerprint maintenance stuck at 0% for hours on large collections — calculateAffectedAlbums() is O(N²) due to QList::contains() per item.
 047 --> 
 048 --> 
 049 --> 
diff --git a/core/utilities/maintenance/tools/fingerprints/fingerprintsgenerator.cpp b/core/utilities/maintenance/tools/fingerprints/fingerprintsgenerator.cpp
index e81668a729..d16eb9aeb9 100644
--- a/core/utilities/maintenance/tools/fingerprints/fingerprintsgenerator.cpp
+++ b/core/utilities/maintenance/tools/fingerprints/fingerprintsgenerator.cpp
@@ -55,7 +55,7 @@ public:
 
     AlbumList            albumList;
 
-    QList<qlonglong>     allItemIds;
+    QSet<qlonglong>      allItemIds;
 
     QFuture<void>        affectedAlbumTask;
     QFutureWatcher<void> affectedAlbumWatcher;
@@ -137,7 +137,7 @@ void FingerPrintsGenerator::slotAffectedAlbumsFinished()
 
     setTotalItems(d->allItemIds.count());
 
-    d->thread->generateFingerprints(d->allItemIds, d->rebuildAll);
+    d->thread->generateFingerprints(d->allItemIds.values(), d->rebuildAll);
     d->thread->start();
 }
 
@@ -159,10 +159,7 @@ void FingerPrintsGenerator::calculateAffectedAlbums()
 
             for (const qlonglong& id : ids)
             {
-                if (!d->allItemIds.contains(id))
-                {
-                    d->allItemIds << id;
-                }
+                d->allItemIds.insert(id);
             }
         }
         else if ((*it)->type() == Album::TAG)
@@ -171,10 +168,7 @@ void FingerPrintsGenerator::calculateAffectedAlbums()
 
             for (const qlonglong& id : ids)
             {
-                if (!d->allItemIds.contains(id))
-                {
-                    d->allItemIds << id;
-                }
+                d->allItemIds.insert(id);
             }
         }
     }