QCollator: add public, static functions to do comparisons

Collation with the default QCollator object (no numeric, punctuation or
case sensitivity changes) is a common-place occurrence, so add two
functions to do this work.

It's also what QString::localeAwareCompare() calls.

The test ends up testing that default, static collator updates after the
default QLocale changes too.

Task-number: QTBUG-95050
Change-Id: I7e0b82c2d2fe464082d8fffd1696ac77f32840b2
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 51 insertions, 0 deletions

diff --git a/src/corelib/text/qcollator.cpp b/src/corelib/text/qcollator.cpp
index 425bfc82ff..8bffae83da 100644
--- a/src/corelib/text/qcollator.cpp
+++ b/src/corelib/text/qcollator.cpp
@@ -43,9 +43,33 @@
 #include "qstring.h"
 
 #include "qdebug.h"
+#include "qlocale_p.h"
+#include "qthreadstorage.h"
 
 QT_BEGIN_NAMESPACE
 
+namespace {
+struct GenerationalCollator
+{
+    QCollator theCollator;
+    int generation = QLocalePrivate::s_generation.loadRelaxed();
+public:
+    GenerationalCollator() = default;
+    GenerationalCollator(const QCollator &copy) : theCollator(copy) {}
+    QCollator &collator()
+    {
+        int currentGeneration = QLocalePrivate::s_generation.loadRelaxed();
+        if (Q_UNLIKELY(generation != currentGeneration)) {
+            // reinitialize the collator
+            generation = currentGeneration;
+            theCollator = QCollator();
+        }
+        return theCollator;
+    }
+};
+}
+Q_GLOBAL_STATIC(QThreadStorage<GenerationalCollator>, defaultCollator)
+
 /*!
     \class QCollator
     \inmodule QtCore
@@ -345,6 +369,33 @@ bool QCollator::ignorePunctuation() const
 #endif // QT_STRINGVIEW_LEVEL < 2
 
 /*!
+    \since 6.3
+
+    Compares the strings \a s1 and \a s2, returning their sorting order. This
+    function performs the same operation as compare() on a default-constructed
+    QCollator object.
+
+    \sa compare(), defaultSortKey()
+*/
+int QCollator::defaultCompare(QStringView s1, QStringView s2)
+{
+    return defaultCollator->localData().collator().compare(s1, s2);
+}
+
+/*!
+    \since 6.3
+
+    Returns the sort key for the string \a key. This function performs the same
+    operation as sortKey() on a default-constructed QCollator object.
+
+    \sa sortKey(), defaultCompare()
+*/
+QCollatorSortKey QCollator::defaultSortKey(QStringView key)
+{
+    return defaultCollator->localData().collator().sortKey(key.toString());
+}
+
+/*!
     \fn QCollatorSortKey QCollator::sortKey(const QString &string) const
 
     Returns a sortKey for \a string.