QQmlPropertyCache: Allow property cache vector to be size-reset

This drops all the property caches and resizes the storage. We'll need
this when we retain property caches after unlinking.

Change-Id: Ieb88cea770f5771cab03d8f8d2feef7bc2fb7c52
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

1 files changed, 25 insertions, 11 deletions

diff --git a/src/qml/qml/qqmlpropertycachevector_p.h b/src/qml/qml/qqmlpropertycachevector_p.h
index a208b3fa6e..1cee914220 100644
--- a/src/qml/qml/qqmlpropertycachevector_p.h
+++ b/src/qml/qml/qqmlpropertycachevector_p.h
@@ -42,28 +42,30 @@ public:
     }
     void clear()
     {
+        for (int i = 0; i < data.size(); ++i)
+            releaseElement(i);
+        data.clear();
+    }
+
+    void resetAndResize(int size)
+    {
         for (int i = 0; i < data.size(); ++i) {
-            const auto &cache = data.at(i);
-            if (cache.isT2()) {
-                if (QQmlPropertyCache *data = cache.asT2())
-                    data->release();
-            } else if (const QQmlPropertyCache *data = cache.asT1()) {
-                data->release();
-            }
+            releaseElement(i);
+            data[i] = BiPointer();
         }
-        data.clear();
+        data.resize(size);
     }
 
     void append(const QQmlPropertyCache::ConstPtr &cache) {
         cache->addref();
-        data.append(QBiPointer<const QQmlPropertyCache, QQmlPropertyCache>(cache.data()));
+        data.append(BiPointer(cache.data()));
         Q_ASSERT(data.last().isT1());
         Q_ASSERT(data.size() <= std::numeric_limits<int>::max());
     }
 
     void appendOwn(const QQmlPropertyCache::Ptr &cache) {
         cache->addref();
-        data.append(QBiPointer<const QQmlPropertyCache, QQmlPropertyCache>(cache.data()));
+        data.append(BiPointer(cache.data()));
         Q_ASSERT(data.last().isT2());
         Q_ASSERT(data.size() <= std::numeric_limits<int>::max());
     }
@@ -122,8 +124,20 @@ public:
     }
 
 private:
+    void releaseElement(int i)
+    {
+        const auto &cache = data.at(i);
+        if (cache.isT2()) {
+            if (QQmlPropertyCache *data = cache.asT2())
+                data->release();
+        } else if (const QQmlPropertyCache *data = cache.asT1()) {
+            data->release();
+        }
+    }
+
     Q_DISABLE_COPY(QQmlPropertyCacheVector)
-    QVector<QBiPointer<const QQmlPropertyCache, QQmlPropertyCache>> data;
+    using BiPointer = QBiPointer<const QQmlPropertyCache, QQmlPropertyCache>;
+    QVector<BiPointer> data;
 };
 
 QT_END_NAMESPACE