QmlJS: Change from QMap to QHash for QString keys.

Tests indicate that lookup in QHash<QString, ...> is more performant
even for short strings.

Change-Id: I8e5a73d0f1a72e202522f397b16901887f9c3591
Reviewed-on: http://codereview.qt-project.org/5070
Reviewed-by: Leandro T. C. Melo <leandro.melo@nokia.com>

src/libs/qmljs/qmljscheck.cpp

@@ -264,7 +264,7 @@ protected:
         ReturnOrThrow = 3
     };
     State _state;
-    QMap<QString, Node *> _labels;
+    QHash<QString, Node *> _labels;
     QSet<Node *> _labelledBreaks;
 
     virtual void onUnreachable(Node *)

src/libs/qmljs/qmljsdocument.h

@@ -33,7 +33,6 @@
 #define QMLDOCUMENT_H
 
 #include <QtCore/QList>
-#include <QtCore/QMap>
 #include <QtCore/QPair>
 #include <QtCore/QSharedPointer>
 #include <QtCore/QString>

src/libs/qmljs/qmljsinterpreter.cpp

@@ -1280,7 +1280,7 @@ template QList<QmlObjectValue *> CppQmlTypes::load< QHash<QString, FakeMetaObjec
 
 QList<QmlObjectValue *> CppQmlTypes::typesForImport(const QString &packageName, ComponentVersion version) const
 {
-    QMap<QString, QmlObjectValue *> objectValuesByName;
+    QHash<QString, QmlObjectValue *> objectValuesByName;
 
     foreach (QmlObjectValue *qmlObjectValue, _typesByPackage.value(packageName)) {
         if (qmlObjectValue->version() <= version) {

src/libs/qmljs/qmljslink.cpp

@@ -159,7 +159,7 @@ Link::Link(const Snapshot &snapshot, const QStringList &importPaths, const Libra
         // populate global object with context properties from C++
         ObjectValue *global = d->valueOwner->globalObject();
         foreach (const ModelManagerInterface::CppData &cppData, cppDataHash) {
-            QMapIterator<QString, QString> it(cppData.contextProperties);
+            QHashIterator<QString, QString> it(cppData.contextProperties);
             while (it.hasNext()) {
                 it.next();
                 const Value *value = 0;

src/libs/qmljs/qmljsmodelmanagerinterface.h

@@ -114,7 +114,7 @@ public:
     {
     public:
         QList<LanguageUtils::FakeMetaObject::ConstPtr> exportedTypes;
-        QMap<QString, QString> contextProperties;
+        QHash<QString, QString> contextProperties;
     };
 
     typedef QHash<QString, CppData> CppDataHash;