[frameworks/kio] src/core: UDSEntry: do not look for a shared value where values cannot repeat

Git commit 6015c53d52f77081fda1e43e44c8d1fe3061d324 by Méven Car.
Committed on 29/07/2026 at 18:04.
Pushed by meven into branch 'master'.

UDSEntry: do not look for a shared value where values cannot repeat

Loading an entry compares each string it reads with the one at the same position in the entry before,
to share that one when they are equal. No two entries of a listing carry the same name, url or local
path, so for those fields the comparison never finds anything to share.

A listing of a local folder, which is made of such entries, loads in 488 nanoseconds an entry rather
than 530. The fields whose values repeat, such as the user or the mime type, keep the sharing.

M  +25   -5    src/core/udsentry.cpp

https://invent.kde.org/frameworks/kio/-/commit/6015c53d52f77081fda1e43e44c8d1fe3061d324

diff --git a/src/core/udsentry.cpp b/src/core/udsentry.cpp
index 68cb2e214e..5f0435fda1 100644
--- a/src/core/udsentry.cpp
+++ b/src/core/udsentry.cpp
@@ -267,6 +267,20 @@ void UDSEntryPrivate::save(QDataStream &s) const
     }
 }
 
+// The value of these fields names the item, so no two entries of a listing carry the same one. The
+// target of a link and the name an item is displayed under can be the same for several items.
+static bool namesTheItem(uint udsField)
+{
+    switch (udsField) {
+    case UDSEntry::UDS_NAME:
+    case UDSEntry::UDS_URL:
+    case UDSEntry::UDS_LOCAL_PATH:
+        return true;
+    default:
+        return false;
+    }
+}
+
 void UDSEntryPrivate::load(QDataStream &s)
 {
     clear();
@@ -302,12 +316,18 @@ void UDSEntryPrivate::load(QDataStream &s)
         if (uds & KIO::UDSEntry::UDS_STRING) {
             s >> buffer;
 
-            QString &cachedString = cachedStrings[i];
-            if (buffer != cachedString) {
-                cachedString = buffer;
+            if (namesTheItem(uds)) {
+                stagedStrings.emplace_back(uds, buffer);
+            } else {
+                // Values repeat from one entry to the next often enough that sharing one is worth
+                // a comparison.
+                QString &cachedString = cachedStrings[i];
+                if (buffer != cachedString) {
+                    cachedString = buffer;
+                }
+
+                stagedStrings.emplace_back(uds, cachedString);
             }
-
-            stagedStrings.emplace_back(uds, cachedString);
         } else if (uds & KIO::UDSEntry::UDS_NUMBER) {
             long long value;
             s >> value;