Changeset 37645 in webkit for trunk/JavaScriptCore/kjs/JSObject.h

Timestamp:

Oct 16, 2008, 7:57:02 PM (17 years ago)

Author:

[email protected]

Message:

2008-10-16 Sam Weinig <​[email protected]>

Reviewed by Maciej Stachowiak.

Fix for ​https://bugs.webkit.org/show_bug.cgi?id=21683
Don't create intermediate StructureIDs for builtin objects

First step in reduce number of StructureIDs created when initializing the
JSGlobalObject.

• In order to avoid creating the intermediate StructureIDs use the new putDirectWithoutTransition and putDirectFunctionWithoutTransition to add properties to JSObjects without transitioning the StructureID. This patch just implements this strategy for ObjectPrototype but alone reduces the number of StructureIDs create for about:blank by 10, from 142 to 132.

• kjs/JSGlobalObject.cpp: (JSC::JSGlobalObject::reset):
• kjs/JSObject.cpp: (JSC::JSObject::putDirectFunctionWithoutTransition):
• kjs/JSObject.h: (JSC::JSObject::putDirectWithoutTransition):
• kjs/ObjectPrototype.cpp: (JSC::ObjectPrototype::ObjectPrototype):
• kjs/ObjectPrototype.h:
• kjs/StructureID.cpp: (JSC::StructureID::addPropertyWithoutTransition):
• kjs/StructureID.h:

File:

• trunk/JavaScriptCore/kjs/JSObject.h (modified) (2 diffs)

trunk/JavaScriptCore/kjs/JSObject.h

@@ -158 +158 @@
         void putDirect(const Identifier& propertyName, JSValue* value, unsigned attr, bool checkReadOnly, PutPropertySlot& slot);
         void putDirectFunction(ExecState* exec, InternalFunction* function, unsigned attr = 0);
+        void putDirectWithoutTransition(const Identifier& propertyName, JSValue* value, unsigned attr);
+        void putDirectFunctionWithoutTransition(ExecState* exec, InternalFunction* function, unsigned attr);
 
         // Fast access to known property offsets.
@@ -414 +416 @@
 }
 
+inline void JSObject::putDirectWithoutTransition(const Identifier& propertyName, JSValue* value, unsigned attributes)
+{
+    size_t currentCapacity = m_structureID->propertyStorageCapacity();
+    size_t offset = m_structureID->addPropertyWithoutTransition(propertyName, attributes);
+    if (currentCapacity != m_structureID->propertyStorageCapacity())
+        allocatePropertyStorage(currentCapacity, m_structureID->propertyStorageCapacity());
+    m_propertyStorage[offset] = value;
+}
+
 inline void JSObject::transitionTo(StructureID* newStructureID)
 {