Changeset 36325 in webkit for trunk/JavaScriptCore/kjs/JSObject.h

Timestamp:

Sep 10, 2008, 7:42:18 PM (17 years ago)

Author:

[email protected]

Message:

2008-09-10 Sam Weinig <​[email protected]>

Reviewed by Geoff Garen.

Add inline property storage for JSObject.

1.2% progression on Sunspider. .5% progression on the v8 test suite.

• JavaScriptCore.exp:
• VM/CTI.cpp: (JSC::CTI::privateCompileGetByIdProto): (JSC::CTI::privateCompileGetByIdChain):
• kjs/JSObject.cpp: (JSC::JSObject::mark): There is no reason to check storageSize now that we start from 0. (JSC::JSObject::allocatePropertyStorage): Allocates/reallocates heap storage.
• kjs/JSObject.h: (JSC::JSObject::offsetForLocation): m_propertyStorage is not an OwnArrayPtr now so there is no reason to .get() (JSC::JSObject::usingInlineStorage): (JSC::JSObject::JSObject): Start with m_propertyStorage pointing to the inline storage. (JSC::JSObject::~JSObject): Free the heap storage if not using the inline storage. (JSC::JSObject::putDirect): Switch to the heap storage only when we know we know that we are about to add a property that will overflow the inline storage.
• kjs/PropertyMap.cpp: (JSC::PropertyMap::createTable): Don't allocate the propertyStorage, that is now handled by JSObject. (JSC::PropertyMap::rehash): PropertyStorage is not a OwnArrayPtr anymore.
• kjs/PropertyMap.h: (JSC::PropertyMap::storageSize): Rename from markingCount.
• kjs/StructureID.cpp: (JSC::StructureID::addPropertyTransition): Don't resize the property storage if we are using inline storage.
• kjs/StructureID.h:

File:

• trunk/JavaScriptCore/kjs/JSObject.h (modified) (8 diffs)

trunk/JavaScriptCore/kjs/JSObject.h

@@ -143 +143 @@
         size_t offsetForLocation(JSValue** location)
         {
-            return location - m_propertyStorage.get();
+            return location - m_propertyStorage;
         }
 
@@ -176 +176 @@
         virtual bool isNotAnObjectErrorStub() const { return false; }
 
+        void allocatePropertyStorage(size_t oldSize, size_t newSize);
+        bool usingInlineStorage() const { return m_propertyStorage == m_inlineStorage; }
+
     protected:
         bool getOwnPropertySlotForWrite(ExecState*, const Identifier&, PropertySlot&, bool& slotIsWriteable);
@@ -185 +188 @@
         StructureID* createInheritorID();
 
-        PropertyStorage m_propertyStorage;
+        static const size_t inlineStorageCapacity = 2;
+
         RefPtr<StructureID> m_inheritorID;
+
+        PropertyStorage m_propertyStorage;        
+        JSValue* m_inlineStorage[inlineStorageCapacity];
     };
 
@@ -193 +200 @@
 inline JSObject::JSObject(JSObject* prototype)
     : JSCell(prototype->inheritorID())
+    , m_propertyStorage(m_inlineStorage)
 {
     ASSERT(m_structureID);
@@ -202 +210 @@
 inline JSObject::JSObject(PassRefPtr<StructureID> structureID)
     : JSCell(structureID.releaseRef()) // ~JSObject balances this ref()
+    , m_propertyStorage(m_inlineStorage)
 {
     ASSERT(m_structureID);
@@ -209 +218 @@
 {
     ASSERT(m_structureID);
+    if (m_propertyStorage != m_inlineStorage)
+        delete [] m_propertyStorage;
     m_structureID->deref();
 }
@@ -365 +376 @@
 
      if (m_structureID->isDictionary()) {
+         unsigned currentAttributes;
+         size_t offset = m_structureID->propertyMap().getOffset(propertyName, currentAttributes);
+         if (offset != WTF::notFound) {
+             if (checkReadOnly && currentAttributes & ReadOnly)
+                 return;
+             m_propertyStorage[offset] = value;
+             slot.setExistingProperty(this, offset);
+             return;
+         }
+
+         if (m_structureID->propertyMap().storageSize() == inlineStorageCapacity)
+             allocatePropertyStorage(m_structureID->propertyMap().storageSize(), m_structureID->propertyMap().size());
          m_structureID->propertyMap().put(propertyName, value, attributes, checkReadOnly, this, slot, m_propertyStorage);
          return;
@@ -379 +402 @@
      }
 
-     RefPtr<StructureID> structureID = StructureID::addPropertyTransition(m_structureID, propertyName, value, attributes, checkReadOnly, this, slot, m_propertyStorage);
+     if (m_structureID->propertyMap().storageSize() == inlineStorageCapacity)
+         allocatePropertyStorage(m_structureID->propertyMap().storageSize(), m_structureID->propertyMap().size());
+
+     RefPtr<StructureID> structureID = StructureID::addPropertyTransition(m_structureID, propertyName, value, attributes, this, slot, m_propertyStorage);
      setStructureID(structureID.release());
 }