Improve lookup speed of QMetaType::type() for normalized types

Two improvements are made:
1) Store the length of the built-in types to avoid calling
strcmp() when there's no way the types will match; and
2) Speculate on the input already being normalized.

When the type name is already in normalized form (which we
believe to be the common case), normalizing is wasteful
(allocating a bytearray that's going to contain exactly the
same string as the original input).

Use the same pattern as used in QObject::connect(), which
speculates on the signature already being normalized; only
if the lookup fails, the signature is normalized and looked
up again.

For the QMetaType::builtinTypes benchmark, this improves
performance by roughly 4x.

For the QMetaType::builtinTypesNotNormalized benchmark, the
performance is half of that before, because the lookup is
done twice. But we choose to optimize for the already-normalized
case. This makes a big difference in the QtScript QObject
bindings, for example.

Reviewed-by: Harald Fernengel

1 files changed, 103 insertions, 94 deletions

diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index 870baab..bfc3e28 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -223,100 +223,103 @@ QT_BEGIN_NAMESPACE
     \sa Q_DECLARE_METATYPE(), QVariant::setValue(), QVariant::value(), QVariant::fromValue()
 */
 
+#define QT_ADD_STATIC_METATYPE(STR, TP) \
+    { STR, sizeof(STR) - 1, TP }
+
 /* Note: these MUST be in the order of the enums */
-static const struct { const char * typeName; int type; } types[] = {
+static const struct { const char * typeName; int typeNameLength; int type; } types[] = {
 
     /* All Core types */
-    {"void", QMetaType::Void},
-    {"bool", QMetaType::Bool},
-    {"int", QMetaType::Int},
-    {"uint", QMetaType::UInt},
-    {"qlonglong", QMetaType::LongLong},
-    {"qulonglong", QMetaType::ULongLong},
-    {"double", QMetaType::Double},
-    {"QChar", QMetaType::QChar},
-    {"QVariantMap", QMetaType::QVariantMap},
-    {"QVariantList", QMetaType::QVariantList},
-    {"QString", QMetaType::QString},
-    {"QStringList", QMetaType::QStringList},
-    {"QByteArray", QMetaType::QByteArray},
-    {"QBitArray", QMetaType::QBitArray},
-    {"QDate", QMetaType::QDate},
-    {"QTime", QMetaType::QTime},
-    {"QDateTime", QMetaType::QDateTime},
-    {"QUrl", QMetaType::QUrl},
-    {"QLocale", QMetaType::QLocale},
-    {"QRect", QMetaType::QRect},
-    {"QRectF", QMetaType::QRectF},
-    {"QSize", QMetaType::QSize},
-    {"QSizeF", QMetaType::QSizeF},
-    {"QLine", QMetaType::QLine},
-    {"QLineF", QMetaType::QLineF},
-    {"QPoint", QMetaType::QPoint},
-    {"QPointF", QMetaType::QPointF},
-    {"QRegExp", QMetaType::QRegExp},
-    {"QVariantHash", QMetaType::QVariantHash},
+    QT_ADD_STATIC_METATYPE("void", QMetaType::Void),
+    QT_ADD_STATIC_METATYPE("bool", QMetaType::Bool),
+    QT_ADD_STATIC_METATYPE("int", QMetaType::Int),
+    QT_ADD_STATIC_METATYPE("uint", QMetaType::UInt),
+    QT_ADD_STATIC_METATYPE("qlonglong", QMetaType::LongLong),
+    QT_ADD_STATIC_METATYPE("qulonglong", QMetaType::ULongLong),
+    QT_ADD_STATIC_METATYPE("double", QMetaType::Double),
+    QT_ADD_STATIC_METATYPE("QChar", QMetaType::QChar),
+    QT_ADD_STATIC_METATYPE("QVariantMap", QMetaType::QVariantMap),
+    QT_ADD_STATIC_METATYPE("QVariantList", QMetaType::QVariantList),
+    QT_ADD_STATIC_METATYPE("QString", QMetaType::QString),
+    QT_ADD_STATIC_METATYPE("QStringList", QMetaType::QStringList),
+    QT_ADD_STATIC_METATYPE("QByteArray", QMetaType::QByteArray),
+    QT_ADD_STATIC_METATYPE("QBitArray", QMetaType::QBitArray),
+    QT_ADD_STATIC_METATYPE("QDate", QMetaType::QDate),
+    QT_ADD_STATIC_METATYPE("QTime", QMetaType::QTime),
+    QT_ADD_STATIC_METATYPE("QDateTime", QMetaType::QDateTime),
+    QT_ADD_STATIC_METATYPE("QUrl", QMetaType::QUrl),
+    QT_ADD_STATIC_METATYPE("QLocale", QMetaType::QLocale),
+    QT_ADD_STATIC_METATYPE("QRect", QMetaType::QRect),
+    QT_ADD_STATIC_METATYPE("QRectF", QMetaType::QRectF),
+    QT_ADD_STATIC_METATYPE("QSize", QMetaType::QSize),
+    QT_ADD_STATIC_METATYPE("QSizeF", QMetaType::QSizeF),
+    QT_ADD_STATIC_METATYPE("QLine", QMetaType::QLine),
+    QT_ADD_STATIC_METATYPE("QLineF", QMetaType::QLineF),
+    QT_ADD_STATIC_METATYPE("QPoint", QMetaType::QPoint),
+    QT_ADD_STATIC_METATYPE("QPointF", QMetaType::QPointF),
+    QT_ADD_STATIC_METATYPE("QRegExp", QMetaType::QRegExp),
+    QT_ADD_STATIC_METATYPE("QVariantHash", QMetaType::QVariantHash),
 
     /* All GUI types */
-    {"QColorGroup", 63},
-    {"QFont", QMetaType::QFont},
-    {"QPixmap", QMetaType::QPixmap},
-    {"QBrush", QMetaType::QBrush},
-    {"QColor", QMetaType::QColor},
-    {"QPalette", QMetaType::QPalette},
-    {"QIcon", QMetaType::QIcon},
-    {"QImage", QMetaType::QImage},
-    {"QPolygon", QMetaType::QPolygon},
-    {"QRegion", QMetaType::QRegion},
-    {"QBitmap", QMetaType::QBitmap},
-    {"QCursor", QMetaType::QCursor},
-    {"QSizePolicy", QMetaType::QSizePolicy},
-    {"QKeySequence", QMetaType::QKeySequence},
-    {"QPen", QMetaType::QPen},
-    {"QTextLength", QMetaType::QTextLength},
-    {"QTextFormat", QMetaType::QTextFormat},
-    {"QMatrix", QMetaType::QMatrix},
-    {"QTransform", QMetaType::QTransform},
-    {"QMatrix4x4", QMetaType::QMatrix4x4},
-    {"QVector2D", QMetaType::QVector2D},
-    {"QVector3D", QMetaType::QVector3D},
-    {"QVector4D", QMetaType::QVector4D},
-    {"QQuaternion", QMetaType::QQuaternion},
+    QT_ADD_STATIC_METATYPE("QColorGroup", 63),
+    QT_ADD_STATIC_METATYPE("QFont", QMetaType::QFont),
+    QT_ADD_STATIC_METATYPE("QPixmap", QMetaType::QPixmap),
+    QT_ADD_STATIC_METATYPE("QBrush", QMetaType::QBrush),
+    QT_ADD_STATIC_METATYPE("QColor", QMetaType::QColor),
+    QT_ADD_STATIC_METATYPE("QPalette", QMetaType::QPalette),
+    QT_ADD_STATIC_METATYPE("QIcon", QMetaType::QIcon),
+    QT_ADD_STATIC_METATYPE("QImage", QMetaType::QImage),
+    QT_ADD_STATIC_METATYPE("QPolygon", QMetaType::QPolygon),
+    QT_ADD_STATIC_METATYPE("QRegion", QMetaType::QRegion),
+    QT_ADD_STATIC_METATYPE("QBitmap", QMetaType::QBitmap),
+    QT_ADD_STATIC_METATYPE("QCursor", QMetaType::QCursor),
+    QT_ADD_STATIC_METATYPE("QSizePolicy", QMetaType::QSizePolicy),
+    QT_ADD_STATIC_METATYPE("QKeySequence", QMetaType::QKeySequence),
+    QT_ADD_STATIC_METATYPE("QPen", QMetaType::QPen),
+    QT_ADD_STATIC_METATYPE("QTextLength", QMetaType::QTextLength),
+    QT_ADD_STATIC_METATYPE("QTextFormat", QMetaType::QTextFormat),
+    QT_ADD_STATIC_METATYPE("QMatrix", QMetaType::QMatrix),
+    QT_ADD_STATIC_METATYPE("QTransform", QMetaType::QTransform),
+    QT_ADD_STATIC_METATYPE("QMatrix4x4", QMetaType::QMatrix4x4),
+    QT_ADD_STATIC_METATYPE("QVector2D", QMetaType::QVector2D),
+    QT_ADD_STATIC_METATYPE("QVector3D", QMetaType::QVector3D),
+    QT_ADD_STATIC_METATYPE("QVector4D", QMetaType::QVector4D),
+    QT_ADD_STATIC_METATYPE("QQuaternion", QMetaType::QQuaternion),
 
     /* All Metatype builtins */
-    {"void*", QMetaType::VoidStar},
-    {"long", QMetaType::Long},
-    {"short", QMetaType::Short},
-    {"char", QMetaType::Char},
-    {"ulong", QMetaType::ULong},
-    {"ushort", QMetaType::UShort},
-    {"uchar", QMetaType::UChar},
-    {"float", QMetaType::Float},
-    {"QObject*", QMetaType::QObjectStar},
-    {"QWidget*", QMetaType::QWidgetStar},
+    QT_ADD_STATIC_METATYPE("void*", QMetaType::VoidStar),
+    QT_ADD_STATIC_METATYPE("long", QMetaType::Long),
+    QT_ADD_STATIC_METATYPE("short", QMetaType::Short),
+    QT_ADD_STATIC_METATYPE("char", QMetaType::Char),
+    QT_ADD_STATIC_METATYPE("ulong", QMetaType::ULong),
+    QT_ADD_STATIC_METATYPE("ushort", QMetaType::UShort),
+    QT_ADD_STATIC_METATYPE("uchar", QMetaType::UChar),
+    QT_ADD_STATIC_METATYPE("float", QMetaType::Float),
+    QT_ADD_STATIC_METATYPE("QObject*", QMetaType::QObjectStar),
+    QT_ADD_STATIC_METATYPE("QWidget*", QMetaType::QWidgetStar),
 
     /* Type aliases - order doesn't matter */
-    {"unsigned long", QMetaType::ULong},
-    {"unsigned int", QMetaType::UInt},
-    {"unsigned short", QMetaType::UShort},
-    {"unsigned char", QMetaType::UChar},
-    {"long long", QMetaType::LongLong},
-    {"unsigned long long", QMetaType::ULongLong},
-    {"qint8", QMetaType::Char},
-    {"quint8", QMetaType::UChar},
-    {"qint16", QMetaType::Short},
-    {"quint16", QMetaType::UShort},
-    {"qint32", QMetaType::Int},
-    {"quint32", QMetaType::UInt},
-    {"qint64", QMetaType::LongLong},
-    {"quint64", QMetaType::ULongLong},
-    {"QList<QVariant>", QMetaType::QVariantList},
-    {"QMap<QString,QVariant>", QMetaType::QVariantMap},
-    {"QHash<QString,QVariant>", QMetaType::QVariantHash},
+    QT_ADD_STATIC_METATYPE("unsigned long", QMetaType::ULong),
+    QT_ADD_STATIC_METATYPE("unsigned int", QMetaType::UInt),
+    QT_ADD_STATIC_METATYPE("unsigned short", QMetaType::UShort),
+    QT_ADD_STATIC_METATYPE("unsigned char", QMetaType::UChar),
+    QT_ADD_STATIC_METATYPE("long long", QMetaType::LongLong),
+    QT_ADD_STATIC_METATYPE("unsigned long long", QMetaType::ULongLong),
+    QT_ADD_STATIC_METATYPE("qint8", QMetaType::Char),
+    QT_ADD_STATIC_METATYPE("quint8", QMetaType::UChar),
+    QT_ADD_STATIC_METATYPE("qint16", QMetaType::Short),
+    QT_ADD_STATIC_METATYPE("quint16", QMetaType::UShort),
+    QT_ADD_STATIC_METATYPE("qint32", QMetaType::Int),
+    QT_ADD_STATIC_METATYPE("quint32", QMetaType::UInt),
+    QT_ADD_STATIC_METATYPE("qint64", QMetaType::LongLong),
+    QT_ADD_STATIC_METATYPE("quint64", QMetaType::ULongLong),
+    QT_ADD_STATIC_METATYPE("QList<QVariant>", QMetaType::QVariantList),
+    QT_ADD_STATIC_METATYPE("QMap<QString,QVariant>", QMetaType::QVariantMap),
+    QT_ADD_STATIC_METATYPE("QHash<QString,QVariant>", QMetaType::QVariantHash),
     // let QMetaTypeId2 figure out the type at compile time
-    {"qreal", QMetaTypeId2<qreal>::MetaType},
+    QT_ADD_STATIC_METATYPE("qreal", QMetaTypeId2<qreal>::MetaType),
 
-    {0, QMetaType::Void}
+    {0, 0, QMetaType::Void}
 };
 
 struct QMetaTypeGuiHelper
@@ -409,19 +412,24 @@ const char *QMetaType::typeName(int type)
 /*! \internal
     Same as QMetaType::type(), but doesn't lock the mutex.
 */
-static int qMetaTypeType_unlocked(const QByteArray &typeName)
+static int qMetaTypeType_unlocked(const char *typeName)
 {
+    int length = qstrlen(typeName);
     int i = 0;
-    while (types[i].typeName && strcmp(typeName.constData(), types[i].typeName))
+    while (types[i].typeName && ((length != types[i].typeNameLength)
+                                 || strcmp(typeName, types[i].typeName))) {
         ++i;
+    }
     if (!types[i].type) {
         const QVector<QCustomTypeInfo> * const ct = customTypes();
         if (!ct)
             return 0;
 
         for (int v = 0; v < ct->count(); ++v) {
-            if (ct->at(v).typeName == typeName)
+            if ((length == ct->at(v).typeName.size())
+                 && !strcmp(typeName, ct->at(v).typeName.constData())) {
                 return v + QMetaType::User;
+            }
         }
     }
     return types[i].type;
@@ -447,7 +455,7 @@ int QMetaType::registerType(const char *typeName, Destructor destructor,
 #endif
 
     QWriteLocker locker(customTypesLock());
-    int idx = qMetaTypeType_unlocked(normalizedTypeName);
+    int idx = qMetaTypeType_unlocked(normalizedTypeName.constData());
 
     if (!idx) {
         QCustomTypeInfo inf;
@@ -514,14 +522,15 @@ bool QMetaType::isRegistered(int type)
 */
 int QMetaType::type(const char *typeName)
 {
-#ifdef QT_NO_QOBJECT
-    const NS(QByteArray) normalizedTypeName = typeName;
-#else
-    const NS(QByteArray) normalizedTypeName = QMetaObject::normalizedType(typeName);
-#endif
-
     QReadLocker locker(customTypesLock());
-    return qMetaTypeType_unlocked(normalizedTypeName);
+    int type = qMetaTypeType_unlocked(typeName);
+#ifndef QT_NO_QOBJECT
+    if (!type) {
+        const NS(QByteArray) normalizedTypeName = QMetaObject::normalizedType(typeName);
+        type = qMetaTypeType_unlocked(normalizedTypeName.constData());
+    }
+#endif
+    return type;
 }
 
 #ifndef QT_NO_DATASTREAM