Add QQmlEngine::trimComponentCache()

Allow unused data in the engine's component cache to be safely discarded
so that the memory can be freed for other purposes.

Unloading of scripts that are no longer required after trimming unused
components is not yet supported.

Task-number: QTBUG-25653
Change-Id: I37bc9d5592eeb5edceeb34d010a555dcffd11cea
Reviewed-by: Michael Brasser <michael.brasser@nokia.com>

1 files changed, 10 insertions, 18 deletions

diff --git a/src/qml/qml/qqmlexpression.cpp b/src/qml/qml/qqmlexpression.cpp
index 89aa6b3906..d2842f7f4d 100644
--- a/src/qml/qml/qqmlexpression.cpp
+++ b/src/qml/qml/qqmlexpression.cpp
@@ -220,32 +220,24 @@ QQmlExpression::QQmlExpression(const QQmlScriptString &script, QObject *parent)
     if (!script.context()->isValid())
         return;
 
-    bool defaultConstruction = false;
+    bool defaultConstruction = true;
 
     int id = script.d.data()->bindingId;
-    if (id < 0) {
-        defaultConstruction = true;
-    } else {
+    if (id >= 0) {
         QQmlContextData *ctxtdata = QQmlContextData::get(script.context());
-
         QQmlEnginePrivate *engine = QQmlEnginePrivate::get(script.context()->engine());
-        QQmlCompiledData *cdata = 0;
-        QQmlTypeData *typeData = 0;
         if (engine && ctxtdata && !ctxtdata->url.isEmpty()) {
-            typeData = engine->typeLoader.get(ctxtdata->url);
-            cdata = typeData->compiledData();
-        }
+            QQmlTypeData *typeData = engine->typeLoader.getType(ctxtdata->url);
+            Q_ASSERT(typeData);
 
-        if (cdata)
-            d->init(ctxtdata, cdata->primitives.at(id), true, script.scopeObject(),
-                    cdata->name, script.d.data()->lineNumber, script.d.data()->columnNumber);
-        else
-           defaultConstruction = true;
+            if (QQmlCompiledData *cdata = typeData->compiledData()) {
+                defaultConstruction = false;
+                d->init(ctxtdata, cdata->primitives.at(id), true, script.scopeObject(),
+                        cdata->name, script.d.data()->lineNumber, script.d.data()->columnNumber);
+            }
 
-        if (cdata)
-            cdata->release();
-        if (typeData)
             typeData->release();
+        }
     }
 
     if (defaultConstruction)