Reduce memory consumption in QV4Bindings::Binding

As with QV8Bindings::Binding, access details from the QML IR
instruction object rather than storing a copy of the values.

Change-Id: I2b629ee1b06ed74c7b38e6d047ef6a98acd45086
Reviewed-by: Martin Jones <martin.jones@nokia.com>

4 files changed, 54 insertions, 64 deletions

diff --git a/src/qml/qml/qqmlcompiler.cpp b/src/qml/qml/qqmlcompiler.cpp
index 808e63388f..3805e98802 100644
--- a/src/qml/qml/qqmlcompiler.cpp
+++ b/src/qml/qml/qqmlcompiler.cpp
@@ -3664,9 +3664,6 @@ bool QQmlCompiler::completeComponentBuild()
         bool needsFallback = false;
         int index = bindingCompiler.compile(expr, enginePrivate, &needsFallback);
         if (index != -1) {
-            // Ensure the index value fits within the available space
-            Q_ASSERT(index < (1 << 15));
-
             binding.dataType = BindingReference::V4;
             binding.compiledIndex = index;
             binding.sharedIndex = -1;
@@ -3736,8 +3733,6 @@ bool QQmlCompiler::completeComponentBuild()
             functionArray += expression.toUtf8();
             lineNumber += expression.count(QLatin1Char('\n'));
 
-            // Ensure the index value fits within the available space
-            Q_ASSERT(ii < (1 << 15));
             reference->sharedIndex = ii;
         }
         functionArray.append("]", 1);
diff --git a/src/qml/qml/qqmlvme.cpp b/src/qml/qml/qqmlvme.cpp
index d6b60f724c..e565321eb9 100644
--- a/src/qml/qml/qqmlvme.cpp
+++ b/src/qml/qml/qqmlvme.cpp
@@ -846,9 +846,7 @@ QObject *QQmlVME::run(QList<QQmlError> *errors,
             if (instr.isRoot && BINDINGSKIPLIST.testBit(propertyIdx))
                 QML_NEXT_INSTR(StoreV4Binding);
 
-            QQmlAbstractBinding *binding = 
-                CTXT->v4bindings->configBinding(instr.value, instr.fallbackValue, target, scope, instr.property,
-                                                instr.propType, instr.line, instr.column);
+            QQmlAbstractBinding *binding = CTXT->v4bindings->configBinding(target, scope, &instr);
             bindValues.push(binding);
             binding->m_mePtr = &bindValues.top();
 
diff --git a/src/qml/qml/v4/qv4bindings.cpp b/src/qml/qml/v4/qv4bindings.cpp
index 643a6197fb..fb484546a2 100644
--- a/src/qml/qml/v4/qv4bindings.cpp
+++ b/src/qml/qml/v4/qv4bindings.cpp
@@ -298,21 +298,14 @@ QV4Bindings::~QV4Bindings()
     delete [] subscriptions; subscriptions = 0;
 }
 
-QQmlAbstractBinding *QV4Bindings::configBinding(int index, int fallbackIndex, QObject *target, QObject *scope,
-                                                int property, int propType, quint16 line, quint16 column)
+QQmlAbstractBinding *QV4Bindings::configBinding(QObject *target, QObject *scope,
+                                                const QQmlInstruction::instr_assignV4Binding *i)
 {
-    Q_ASSERT(propType <= std::numeric_limits<quint16>::max());
+    Binding *rv = bindings + i->value;
 
-    Binding *rv = bindings + index;
-
-    rv->index = index;
-    rv->fallbackIndex = fallbackIndex;
-    rv->property = property;
-    rv->propType = propType;
+    rv->instruction = i;
     rv->target = target;
     rv->scope = scope;
-    rv->line = line;
-    rv->column = column;
     rv->parent = this;
 
     addref(); // This is decremented in Binding::destroy()
@@ -325,8 +318,8 @@ void QV4Bindings::Binding::setEnabled(QQmlAbstractBinding *_This,
 {
     QV4Bindings::Binding *This = static_cast<QV4Bindings::Binding *>(_This);
 
-    if (This->enabled != e) {
-        This->enabled = e;
+    if (This->enabledFlag() != e) {
+        This->setEnabledFlag(e);
 
         if (e) update(_This, flags);
     }
@@ -342,7 +335,7 @@ void QV4Bindings::Binding::destroy(QQmlAbstractBinding *_This)
 {
     QV4Bindings::Binding *This = static_cast<QV4Bindings::Binding *>(_This);
 
-    This->enabled = false;
+    This->setEnabledFlag(false);
     This->removeFromObject();
     This->clear();
     This->removeError();
@@ -354,7 +347,7 @@ int QV4Bindings::Binding::propertyIndex(const QQmlAbstractBinding *_This)
     const QV4Bindings::Binding *This = static_cast<const QV4Bindings::Binding *>(_This);
 
     if (This->target.hasValue()) return This->target.constValue()->targetProperty;
-    else return This->property;
+    else return This->instruction->property;
 }
 
 QObject *QV4Bindings::Binding::object(const QQmlAbstractBinding *_This)
@@ -402,7 +395,7 @@ void QV4Bindings::subscriptionNotify(int id)
 
 void QV4Bindings::run(Binding *binding, QQmlPropertyPrivate::WriteFlags flags)
 {
-    if (!binding->enabled)
+    if (!binding->enabledFlag())
         return;
 
     QQmlContextData *context = QQmlAbstractExpression::context();
@@ -415,62 +408,68 @@ void QV4Bindings::run(Binding *binding, QQmlPropertyPrivate::WriteFlags flags)
 
     QQmlTrace trace("V4 Binding Update");
     trace.addDetail("URL", context->url);
-    trace.addDetail("Line", binding->line);
-    trace.addDetail("Column", binding->column);
+    trace.addDetail("Line", binding->instruction->line);
+    trace.addDetail("Column", binding->instruction->column);
+
+    QQmlBindingProfiler prof(context->urlString, binding->instruction->line, binding->instruction->column, QQmlProfilerService::V4Binding);
 
-    QQmlBindingProfiler prof(context->urlString, binding->line, binding->column, QQmlProfilerService::V4Binding);
+    const int propType = binding->instruction->propType;
+    const int property = binding->instruction->property;
 
-    if (binding->updating) {
+    if (binding->updatingFlag()) {
         QString name;
-        if (binding->propType) {
-            QQmlValueType *vt = QQmlValueTypeFactory::valueType(binding->propType);
+        if (propType) {
+            QQmlValueType *vt = QQmlValueTypeFactory::valueType(propType);
             Q_ASSERT(vt);
 
-            name = QLatin1String(binding->target->metaObject()->property(binding->property & 0x0000FFFF).name());
+            name = QLatin1String(binding->target->metaObject()->property(property & 0x0000FFFF).name());
             name.append(QLatin1Char('.'));
-            name.append(QLatin1String(vt->metaObject()->property(binding->property >> 16).name()));
+            name.append(QLatin1String(vt->metaObject()->property(property >> 16).name()));
         } else {
-            name = QLatin1String(binding->target->metaObject()->property(binding->property).name());
+            name = QLatin1String(binding->target->metaObject()->property(property).name());
         }
         qmlInfo(*binding->target) << tr("Binding loop detected for property \"%1\"").arg(name);
         return;
     }
 
+    int index = binding->instruction->value;
+    int fallbackIndex = binding->instruction->fallbackValue;
+
     bool invalidated = false;
-    bool *inv = (binding->fallbackIndex != -1) ? &invalidated : 0;
+    bool *inv = (fallbackIndex != -1) ? &invalidated : 0;
 
-    binding->updating = true;
-    if (binding->propType) {
-        QQmlValueType *vt = QQmlValueTypeFactory::valueType(binding->propType);
+    binding->setUpdatingFlag(true);
+    if (propType) {
+        QQmlValueType *vt = QQmlValueTypeFactory::valueType(propType);
         Q_ASSERT(vt);
-        vt->read(*binding->target, binding->property & 0x0000FFFF);
+        vt->read(*binding->target, property & 0x0000FFFF);
 
         QObject *target = vt;
-        run(binding->index, binding->executedBlocks, context, binding, binding->scope, target, flags, inv);
+        run(index, binding->executedBlocks, context, binding, binding->scope, target, flags, inv);
 
         if (!invalidated) {
-            vt->write(*binding->target, binding->property & 0x0000FFFF, flags);
+            vt->write(*binding->target, property & 0x0000FFFF, flags);
         }
     } else {
         QQmlData *data = QQmlData::get(*binding->target);
-        QQmlPropertyData *propertyData = (data && data->propertyCache ? data->propertyCache->property(binding->property) : 0);
+        QQmlPropertyData *propertyData = (data && data->propertyCache ? data->propertyCache->property(property) : 0);
 
         if (propertyData && propertyData->isVarProperty()) {
             // We will allocate a V8 handle in this conversion/store
             v8::HandleScope handle_scope;
             v8::Context::Scope context_scope(QQmlEnginePrivate::get(context->engine)->v8engine()->context());
 
-            run(binding->index, binding->executedBlocks, context, binding, binding->scope, *binding->target, flags, inv);
+            run(index, binding->executedBlocks, context, binding, binding->scope, *binding->target, flags, inv);
         } else {
-            run(binding->index, binding->executedBlocks, context, binding, binding->scope, *binding->target, flags, inv);
+            run(index, binding->executedBlocks, context, binding, binding->scope, *binding->target, flags, inv);
         }
     }
-    binding->updating = false;
+    binding->setUpdatingFlag(false);
 
     if (invalidated) {
         // This binding is no longer valid - fallback to V8
-        Q_ASSERT(binding->fallbackIndex > -1);
-        QQmlAbstractBinding *b = QQmlPropertyPrivate::activateSharedBinding(context, binding->fallbackIndex, flags);
+        Q_ASSERT(fallbackIndex > -1);
+        QQmlAbstractBinding *b = QQmlPropertyPrivate::activateSharedBinding(context, fallbackIndex, flags);
         Q_ASSERT(b == binding);
         b->destroy();
     }
diff --git a/src/qml/qml/v4/qv4bindings_p.h b/src/qml/qml/v4/qv4bindings_p.h
index eae5703c50..0553e575a5 100644
--- a/src/qml/qml/v4/qv4bindings_p.h
+++ b/src/qml/qml/v4/qv4bindings_p.h
@@ -55,6 +55,7 @@
 
 #include "private/qqmlexpression_p.h"
 #include "private/qqmlbinding_p.h"
+#include "private/qqmlinstruction_p.h"
 #include "private/qv4instruction_p.h"
 #include "private/qpointervaluepair_p.h"
 
@@ -71,17 +72,16 @@ public:
     QV4Bindings(const char *program, QQmlContextData *context);
     virtual ~QV4Bindings();
 
-    QQmlAbstractBinding *configBinding(int index, int fallbackIndex, QObject *target,
-                                       QObject *scope, int property, int propType,
-                                       quint16 line, quint16 column);
+    QQmlAbstractBinding *configBinding(QObject *target, QObject *scope,
+                                       const QQmlInstruction::instr_assignV4Binding *);
 
 #ifdef QML_THREADED_INTERPRETER
     static void **getDecodeInstrTable();
 #endif
 
     struct Binding : public QQmlAbstractBinding, public QQmlDelayedError {
-        Binding() : QQmlAbstractBinding(V4), index(-1), fallbackIndex(-1), enabled(false),
-                    updating(0), property(0), propType(0), scope(0), target(0), executedBlocks(0), parent(0) {}
+        Binding()
+            : QQmlAbstractBinding(V4), target(0), scope(0), instruction(0), executedBlocks(0), parent(0) {}
 
         // Inherited from QQmlAbstractBinding
         static void destroy(QQmlAbstractBinding *);
@@ -96,23 +96,21 @@ public:
             int targetProperty;
         };
 
-        int index:15;
-        int fallbackIndex:15;
-        bool enabled:1;
-        bool updating:1;
+        QPointerValuePair<QObject, Retarget> target;
+        QObject *scope;
 
-        // Encoding of property is: coreIndex | (valueTypeIndex << 16)
-        // propType and valueTypeIndex are only set if the property is a value type property
-        int property;
-        quint16 propType;
+        // To save memory, we store flags inside the instruction pointer.
+        //    instruction.flag1: enabled
+        //    instruction.flag2: updating
+        QFlagPointer<const QQmlInstruction::instr_assignV4Binding> instruction;
 
-        QObject *scope;
-        quint16 line;
-        quint16 column;
-        QPointerValuePair<QObject, Retarget> target;
         quint32 executedBlocks;
-
         QV4Bindings *parent;
+
+        inline bool enabledFlag() const { return instruction.flag(); }
+        inline void setEnabledFlag(bool v) { instruction.setFlagValue(v); }
+        inline bool updatingFlag() const { return instruction.flag2(); }
+        inline void setUpdatingFlag(bool v) { instruction.setFlag2Value(v); }
     };
 
 private: