JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / runtime / JSString.h

diff --git a/runtime/JSString.h b/runtime/JSString.h
index af03025170e0e743bd4e1f671736eab4119362bf..10ec799e583d4760222d0afeaab5f0af8618805d 100644 (file)
--- a/runtime/JSString.h
+++ b/runtime/JSString.h
@@ -22,17 +22,18 @@
 
 #ifndef JSString_h
 #define JSString_h
 
 #ifndef JSString_h
 #define JSString_h

-

 #include "CallFrame.h"
 #include "CommonIdentifiers.h"
 #include "Identifier.h"
 #include "CallFrame.h"
 #include "CommonIdentifiers.h"
 #include "Identifier.h"

-#include "JSNumberCell.h"

 #include "PropertyDescriptor.h"
 #include "PropertySlot.h"
 #include "PropertyDescriptor.h"
 #include "PropertySlot.h"

+#include "Structure.h"

 
 namespace JSC {
 
     class JSString;
 
 namespace JSC {
 
     class JSString;

+    class JSRopeString;
+    class LLIntOffsetsExtractor;

 
     JSString* jsEmptyString(JSGlobalData*);
     JSString* jsEmptyString(ExecState*);
 
     JSString* jsEmptyString(JSGlobalData*);
     JSString* jsEmptyString(ExecState*);


@@ -41,7 +42,6 @@ namespace JSC {
 
     JSString* jsSingleCharacterString(JSGlobalData*, UChar);
     JSString* jsSingleCharacterString(ExecState*, UChar);
 
     JSString* jsSingleCharacterString(JSGlobalData*, UChar);
     JSString* jsSingleCharacterString(ExecState*, UChar);

-    JSString* jsSingleCharacterSubstring(JSGlobalData*, const UString&, unsigned offset);

     JSString* jsSingleCharacterSubstring(ExecState*, const UString&, unsigned offset);
     JSString* jsSubstring(JSGlobalData*, const UString&, unsigned offset, unsigned length);
     JSString* jsSubstring(ExecState*, const UString&, unsigned offset, unsigned length);
     JSString* jsSingleCharacterSubstring(ExecState*, const UString&, unsigned offset);
     JSString* jsSubstring(JSGlobalData*, const UString&, unsigned offset, unsigned length);
     JSString* jsSubstring(ExecState*, const UString&, unsigned offset, unsigned length);


@@ -59,336 +59,244 @@ namespace JSC {
     JSString* jsOwnedString(JSGlobalData*, const UString&); 
     JSString* jsOwnedString(ExecState*, const UString&); 
 
     JSString* jsOwnedString(JSGlobalData*, const UString&); 
     JSString* jsOwnedString(ExecState*, const UString&); 
 

-    typedef void (*JSStringFinalizerCallback)(JSString*, void* context);
-    JSString* jsStringWithFinalizer(ExecState*, const UString&, JSStringFinalizerCallback callback, void* context);
+    JSRopeString* jsStringBuilder(JSGlobalData*);

 
 

-    class JS_EXPORTCLASS JSString : public JSCell {
+    class JSString : public JSCell {

     public:
         friend class JIT;
         friend class JSGlobalData;
     public:
         friend class JIT;
         friend class JSGlobalData;

+        friend class SpecializedThunkJIT;
+        friend class JSRopeString;
+        friend struct ThunkHelpers;

 
 

-        // A Rope is a string composed of a set of substrings.
-        class Rope : public RefCounted<Rope> {
-        public:
-            // A Rope is composed from a set of smaller strings called Fibers.
-            // Each Fiber in a rope is either UString::Rep or another Rope.
-            class Fiber {
-            public:
-                Fiber() : m_value(0) {}
-                Fiber(UString::Rep* string) : m_value(reinterpret_cast<intptr_t>(string)) {}
-                Fiber(Rope* rope) : m_value(reinterpret_cast<intptr_t>(rope) | 1) {}
-
-                Fiber(void* nonFiber) : m_value(reinterpret_cast<intptr_t>(nonFiber)) {}
-
-                void deref()
-                {
-                    if (isRope())
-                        rope()->deref();
-                    else
-                        string()->deref();
-                }
-
-                Fiber& ref()
-                {
-                    if (isString())
-                        string()->ref();
-                    else
-                        rope()->ref();
-                    return *this;
-                }
-
-                unsigned refAndGetLength()
-                {
-                    if (isString()) {
-                        UString::Rep* rep = string();
-                        return rep->ref()->size();
-                    } else {
-                        Rope* r = rope();
-                        r->ref();
-                        return r->stringLength();
-                    }
-                }
-
-                bool isRope() { return m_value & 1; }
-                Rope* rope() { return reinterpret_cast<Rope*>(m_value & ~1); }
-                bool isString() { return !isRope(); }
-                UString::Rep* string() { return reinterpret_cast<UString::Rep*>(m_value); }
-
-                void* nonFiber() { return reinterpret_cast<void*>(m_value); }
-            private:
-                intptr_t m_value;
-            };
-
-            // Creates a Rope comprising of 'ropeLength' Fibers.
-            // The Rope is constructed in an uninitialized state - initialize must be called for each Fiber in the Rope.
-            static PassRefPtr<Rope> createOrNull(unsigned ropeLength)
-            {
-                void* allocation;
-                if (tryFastMalloc(sizeof(Rope) + (ropeLength - 1) * sizeof(Fiber)).getValue(allocation))
-                    return adoptRef(new (allocation) Rope(ropeLength));
-                return 0;
-            }
-
-            ~Rope();
-            void destructNonRecursive();
-
-            void append(unsigned &index, Fiber& fiber)
-            {
-                m_fibers[index++] = fiber;
-                m_stringLength += fiber.refAndGetLength();
-            }
-            void append(unsigned &index, const UString& string)
-            {
-                UString::Rep* rep = string.rep();
-                m_fibers[index++] = Fiber(rep);
-                m_stringLength += rep->ref()->size();
-            }
-            void append(unsigned& index, JSString* jsString)
-            {
-                if (jsString->isRope()) {
-                    for (unsigned i = 0; i < jsString->m_ropeLength; ++i)
-                        append(index, jsString->m_fibers[i]);
-                } else
-                    append(index, jsString->string());
-            }
-
-            unsigned ropeLength() { return m_ropeLength; }
-            unsigned stringLength() { return m_stringLength; }
-            Fiber& fibers(unsigned index) { return m_fibers[index]; }
+        typedef JSCell Base;

 
 

-        private:
-            Rope(unsigned ropeLength) : m_ropeLength(ropeLength), m_stringLength(0) {}
-            void* operator new(size_t, void* inPlace) { return inPlace; }
-            
-            unsigned m_ropeLength;
-            unsigned m_stringLength;
-            Fiber m_fibers[1];
-        };
+        static void destroy(JSCell*);

 
 

-        ALWAYS_INLINE JSString(JSGlobalData* globalData, const UString& value)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(value.size())
+    private:
+        JSString(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
+            : JSCell(globalData, globalData.stringStructure.get())

             , m_value(value)
             , m_value(value)

-            , m_ropeLength(0)

         {
         {

-            Heap::heap(this)->reportExtraMemoryCost(value.cost());

         }
 
         }
 

-        enum HasOtherOwnerType { HasOtherOwner };
-        JSString(JSGlobalData* globalData, const UString& value, HasOtherOwnerType)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(value.size())
-            , m_value(value)
-            , m_ropeLength(0)
-        {
-        }
-        JSString(JSGlobalData* globalData, PassRefPtr<UString::Rep> value, HasOtherOwnerType)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(value->size())
-            , m_value(value)
-            , m_ropeLength(0)
-        {
-        }
-        JSString(JSGlobalData* globalData, PassRefPtr<JSString::Rope> rope)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(rope->stringLength())
-            , m_ropeLength(1)
-        {
-            m_fibers[0] = rope.releaseRef();
-        }
-        // This constructor constructs a new string by concatenating s1 & s2.
-        // This should only be called with ropeLength <= 3.
-        JSString(JSGlobalData* globalData, unsigned ropeLength, JSString* s1, JSString* s2)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(s1->length() + s2->length())
-            , m_ropeLength(ropeLength)
-        {
-            ASSERT(ropeLength <= s_maxInternalRopeLength);
-            unsigned index = 0;
-            appendStringInConstruct(index, s1);
-            appendStringInConstruct(index, s2);
-            ASSERT(ropeLength == index);
-        }
-        // This constructor constructs a new string by concatenating s1 & s2.
-        // This should only be called with ropeLength <= 3.
-        JSString(JSGlobalData* globalData, unsigned ropeLength, JSString* s1, const UString& u2)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(s1->length() + u2.size())
-            , m_ropeLength(ropeLength)
-        {
-            ASSERT(ropeLength <= s_maxInternalRopeLength);
-            unsigned index = 0;
-            appendStringInConstruct(index, s1);
-            appendStringInConstruct(index, u2);
-            ASSERT(ropeLength == index);
-        }
-        // This constructor constructs a new string by concatenating s1 & s2.
-        // This should only be called with ropeLength <= 3.
-        JSString(JSGlobalData* globalData, unsigned ropeLength, const UString& u1, JSString* s2)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(u1.size() + s2->length())
-            , m_ropeLength(ropeLength)
+        JSString(JSGlobalData& globalData)
+            : JSCell(globalData, globalData.stringStructure.get())

         {
         {

-            ASSERT(ropeLength <= s_maxInternalRopeLength);
-            unsigned index = 0;
-            appendStringInConstruct(index, u1);
-            appendStringInConstruct(index, s2);
-            ASSERT(ropeLength == index);

         }
         }

-        // This constructor constructs a new string by concatenating v1, v2 & v3.
-        // This should only be called with ropeLength <= 3 ... which since every
-        // value must require a ropeLength of at least one implies that the length
-        // for each value must be exactly 1!
-        JSString(ExecState* exec, JSValue v1, JSValue v2, JSValue v3)
-            : JSCell(exec->globalData().stringStructure.get())
-            , m_stringLength(0)
-            , m_ropeLength(s_maxInternalRopeLength)
+
+        void finishCreation(JSGlobalData& globalData, size_t length)

         {
         {

-            unsigned index = 0;
-            appendValueInConstructAndIncrementLength(exec, index, v1);
-            appendValueInConstructAndIncrementLength(exec, index, v2);
-            appendValueInConstructAndIncrementLength(exec, index, v3);
-            ASSERT(index == s_maxInternalRopeLength);
+            ASSERT(!m_value.isNull());
+            Base::finishCreation(globalData);
+            m_length = length;
+            m_is8Bit = m_value.impl()->is8Bit();

         }
 
         }
 

-        JSString(JSGlobalData* globalData, const UString& value, JSStringFinalizerCallback finalizer, void* context)
-            : JSCell(globalData->stringStructure.get())
-            , m_stringLength(value.size())
-            , m_value(value)
-            , m_ropeLength(0)
+        void finishCreation(JSGlobalData& globalData, size_t length, size_t cost)

         {
         {

-            // nasty hack because we can't union non-POD types
-            m_fibers[0] = reinterpret_cast<void*>(reinterpret_cast<ptrdiff_t>(finalizer));
-            m_fibers[1] = context;
-            Heap::heap(this)->reportExtraMemoryCost(value.cost());
+            ASSERT(!m_value.isNull());
+            Base::finishCreation(globalData);
+            m_length = length;
+            m_is8Bit = m_value.impl()->is8Bit();
+            Heap::heap(this)->reportExtraMemoryCost(cost);

         }
 
         }
 

-        ~JSString()
+    protected:
+        void finishCreation(JSGlobalData& globalData)

         {
         {

-            ASSERT(vptr() == JSGlobalData::jsStringVPtr);
-            for (unsigned i = 0; i < m_ropeLength; ++i)
-                m_fibers[i].deref();
-
-            if (!m_ropeLength && m_fibers[0].nonFiber()) {
-                JSStringFinalizerCallback finalizer = reinterpret_cast<JSStringFinalizerCallback>(m_fibers[0].nonFiber());
-                finalizer(this, m_fibers[1].nonFiber());
-            }
+            Base::finishCreation(globalData);
+            m_length = 0;
+            m_is8Bit = true;

         }
         }

-
-        const UString& value(ExecState* exec) const
+        
+    public:
+        static JSString* create(JSGlobalData& globalData, PassRefPtr<StringImpl> value)

         {
         {

-            if (isRope())
-                resolveRope(exec);
-            return m_value;
+            ASSERT(value);
+            size_t length = value->length();
+            size_t cost = value->cost();
+            JSString* newString = new (NotNull, allocateCell<JSString>(globalData.heap)) JSString(globalData, value);
+            newString->finishCreation(globalData, length, cost);
+            return newString;

         }
         }

-        const UString tryGetValue() const
+        static JSString* createHasOtherOwner(JSGlobalData& globalData, PassRefPtr<StringImpl> value)

         {
         {

-            if (isRope())
-                UString();
-            return m_value;
+            ASSERT(value);
+            size_t length = value->length();
+            JSString* newString = new (NotNull, allocateCell<JSString>(globalData.heap)) JSString(globalData, value);
+            newString->finishCreation(globalData, length);
+            return newString;

         }
         }

-        unsigned length() { return m_stringLength; }

 
 

+        const UString& value(ExecState*) const;
+        const UString& tryGetValue() const;
+        unsigned length() { return m_length; }
+
+        JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
+        JS_EXPORT_PRIVATE bool toBoolean(ExecState*) const;
+        bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
+        JSObject* toObject(ExecState*, JSGlobalObject*) const;
+        double toNumber(ExecState*) const;
+        

         bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
         bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
         bool getStringPropertyDescriptor(ExecState*, const Identifier& propertyName, PropertyDescriptor&);
 
         bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
         bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
         bool getStringPropertyDescriptor(ExecState*, const Identifier& propertyName, PropertyDescriptor&);
 

-        bool canGetIndex(unsigned i) { return i < m_stringLength; }
+        bool canGetIndex(unsigned i) { return i < m_length; }

         JSString* getIndex(ExecState*, unsigned);
 
         JSString* getIndex(ExecState*, unsigned);
 

-        static PassRefPtr<Structure> createStructure(JSValue proto) { return Structure::create(proto, TypeInfo(StringType, OverridesGetOwnPropertySlot | NeedsThisConversion), AnonymousSlotCount); }
+        static Structure* createStructure(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue proto)
+        {
+            return Structure::create(globalData, globalObject, proto, TypeInfo(StringType, OverridesGetOwnPropertySlot), &s_info);
+        }
+
+        static size_t offsetOfLength() { return OBJECT_OFFSETOF(JSString, m_length); }
+        static size_t offsetOfValue() { return OBJECT_OFFSETOF(JSString, m_value); }
+
+        static JS_EXPORTDATA const ClassInfo s_info;
+
+        static void visitChildren(JSCell*, SlotVisitor&);
+
+    protected:
+        bool isRope() const { return m_value.isNull(); }
+        bool is8Bit() const { return m_is8Bit; }
+
+        // A string is represented either by a UString or a rope of fibers.
+        bool m_is8Bit : 1;
+        unsigned m_length;
+        mutable UString m_value;
+
+    private:
+        friend class LLIntOffsetsExtractor;
+        
+        static JSObject* toThisObject(JSCell*, ExecState*);
+
+        // Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
+        static bool getOwnPropertySlot(JSCell*, ExecState*, const Identifier& propertyName, PropertySlot&);
+        static bool getOwnPropertySlotByIndex(JSCell*, ExecState*, unsigned propertyName, PropertySlot&);
+
+        UString& string() { ASSERT(!isRope()); return m_value; }
+
+        friend JSValue jsString(ExecState*, JSString*, JSString*);
+        friend JSString* jsSubstring(ExecState*, JSString*, unsigned offset, unsigned length);
+    };
+
+    class JSRopeString : public JSString {
+        friend class JSString;
+
+        friend JSRopeString* jsStringBuilder(JSGlobalData*);
+
+        class RopeBuilder {
+        public:
+            RopeBuilder(JSGlobalData& globalData)
+            : m_globalData(globalData)
+            , m_jsString(jsStringBuilder(&globalData))
+            , m_index(0)
+            {
+            }
+
+            void append(JSString* jsString)
+            {
+                if (m_index == JSRopeString::s_maxInternalRopeLength)
+                    expand();
+                m_jsString->m_fibers[m_index++].set(m_globalData, m_jsString, jsString);
+                m_jsString->m_length += jsString->m_length;
+                m_jsString->m_is8Bit = m_jsString->m_is8Bit && jsString->m_is8Bit;
+            }
+
+            JSRopeString* release()
+            {
+                JSRopeString* tmp = m_jsString;
+                m_jsString = 0;
+                return tmp;
+            }
+
+            unsigned length() { return m_jsString->m_length; }

 
 

+        private:
+            void expand();
+            
+            JSGlobalData& m_globalData;
+            JSRopeString* m_jsString;
+            size_t m_index;
+        };
+        

     private:
     private:

-        enum VPtrStealingHackType { VPtrStealingHack };
-        JSString(VPtrStealingHackType) 
-            : JSCell(0)
-            , m_ropeLength(0)
+        JSRopeString(JSGlobalData& globalData)
+            : JSString(globalData)

         {
         }
 
         {
         }
 

-        void resolveRope(ExecState*) const;
+        void finishCreation(JSGlobalData& globalData, JSString* s1, JSString* s2)
+        {
+            Base::finishCreation(globalData);
+            m_length = s1->length() + s2->length();
+            m_is8Bit = (s1->is8Bit() && s2->is8Bit());
+            m_fibers[0].set(globalData, this, s1);
+            m_fibers[1].set(globalData, this, s2);
+        }
+        
+        void finishCreation(JSGlobalData& globalData, JSString* s1, JSString* s2, JSString* s3)
+        {
+            Base::finishCreation(globalData);
+            m_length = s1->length() + s2->length() + s3->length();
+            m_is8Bit = (s1->is8Bit() && s2->is8Bit() &&  s3->is8Bit());
+            m_fibers[0].set(globalData, this, s1);
+            m_fibers[1].set(globalData, this, s2);
+            m_fibers[2].set(globalData, this, s3);
+        }

 
 

-        void appendStringInConstruct(unsigned& index, const UString& string)
+        void finishCreation(JSGlobalData& globalData)

         {
         {

-            m_fibers[index++] = Rope::Fiber(string.rep()->ref());
+            JSString::finishCreation(globalData);

         }
 
         }
 

-        void appendStringInConstruct(unsigned& index, JSString* jsString)
+        static JSRopeString* createNull(JSGlobalData& globalData)

         {
         {

-            if (jsString->isRope()) {
-                for (unsigned i = 0; i < jsString->m_ropeLength; ++i)
-                    m_fibers[index++] = jsString->m_fibers[i].ref();
-            } else
-                appendStringInConstruct(index, jsString->string());
+            JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(globalData.heap)) JSRopeString(globalData);
+            newString->finishCreation(globalData);
+            return newString;

         }
 
         }
 

-        void appendValueInConstructAndIncrementLength(ExecState* exec, unsigned& index, JSValue v)
+    public:
+        static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2)

         {
         {

-            if (v.isString()) {
-                ASSERT(asCell(v)->isString());
-                JSString* s = static_cast<JSString*>(asCell(v));
-                ASSERT(s->ropeLength() == 1);
-                appendStringInConstruct(index, s);
-                m_stringLength += s->length();
-            } else {
-                UString u(v.toString(exec));
-                m_fibers[index++] = Rope::Fiber(u.rep()->ref());
-                m_stringLength += u.size();
-            }
+            JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(globalData.heap)) JSRopeString(globalData);
+            newString->finishCreation(globalData, s1, s2);
+            return newString;
+        }
+        static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2, JSString* s3)
+        {
+            JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(globalData.heap)) JSRopeString(globalData);
+            newString->finishCreation(globalData, s1, s2, s3);
+            return newString;

         }
 
         }
 

-        virtual JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
-        virtual bool getPrimitiveNumber(ExecState*, double& number, JSValue& value);
-        virtual bool toBoolean(ExecState*) const;
-        virtual double toNumber(ExecState*) const;
-        virtual JSObject* toObject(ExecState*) const;
-        virtual UString toString(ExecState*) const;
+        void visitFibers(SlotVisitor&);

 
 

-        virtual JSObject* toThisObject(ExecState*) const;
-        virtual UString toThisString(ExecState*) const;
-        virtual JSString* toThisJSString(ExecState*);
+    private:
+        friend JSValue jsString(ExecState*, Register*, unsigned);
+        friend JSValue jsStringFromArguments(ExecState*, JSValue);

 
 

-        // Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
-        virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
-        virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
-        virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);
+        JS_EXPORT_PRIVATE void resolveRope(ExecState*) const;
+        void resolveRopeSlowCase8(LChar*) const;
+        void resolveRopeSlowCase(UChar*) const;
+        void outOfMemory(ExecState*) const;
+        
+        JSString* getIndexSlowCase(ExecState*, unsigned);

 
         static const unsigned s_maxInternalRopeLength = 3;
 
         static const unsigned s_maxInternalRopeLength = 3;

-
-        // A string is represented either by a UString or a Rope.
-        unsigned m_stringLength;
-        mutable UString m_value;
-        mutable unsigned m_ropeLength;
-        mutable Rope::Fiber m_fibers[s_maxInternalRopeLength];
-
-        bool isRope() const { return m_ropeLength; }
-        UString& string() { ASSERT(!isRope()); return m_value; }
-        unsigned ropeLength() { return m_ropeLength ? m_ropeLength : 1; }
-
-        friend JSValue jsString(ExecState* exec, JSString* s1, JSString* s2);
-        friend JSValue jsString(ExecState* exec, const UString& u1, JSString* s2);
-        friend JSValue jsString(ExecState* exec, JSString* s1, const UString& u2);
-        friend JSValue jsString(ExecState* exec, Register* strings, unsigned count);
-        friend JSValue jsString(ExecState* exec, JSValue thisValue, const ArgList& args);
-        friend JSString* jsStringWithFinalizer(ExecState*, const UString&, JSStringFinalizerCallback callback, void* context);
+        
+        mutable FixedArray<WriteBarrier<JSString>, s_maxInternalRopeLength> m_fibers;

     };
 
     JSString* asString(JSValue);
 
     };
 
     JSString* asString(JSValue);
 

-    // When an object is created from a different DLL, MSVC changes vptr to a "local" one right after invoking a constructor,
-    // see <http://groups.google.com/group/microsoft.public.vc.language/msg/55cdcefeaf770212>.
-    // This breaks isJSString(), and we don't need that hack anyway, so we change vptr back to primary one.
-    // The below function must be called by any inline function that invokes a JSString constructor.
-#if COMPILER(MSVC) && !defined(BUILDING_JavaScriptCore)
-    inline JSString* fixupVPtr(JSGlobalData* globalData, JSString* string) { string->setVPtr(globalData->jsStringVPtr); return string; }
-#else
-    inline JSString* fixupVPtr(JSGlobalData*, JSString* string) { return string; }
-#endif
-

     inline JSString* asString(JSValue value)
     {
     inline JSString* asString(JSValue value)
     {

-        ASSERT(asCell(value)->isString());
-        return static_cast<JSString*>(asCell(value));
+        ASSERT(value.asCell()->isString());
+        return jsCast<JSString*>(value.asCell());

     }
 
     inline JSString* jsEmptyString(JSGlobalData* globalData)
     }
 
     inline JSString* jsEmptyString(JSGlobalData* globalData)


@@ -396,20 +304,21 @@ namespace JSC {
         return globalData->smallStrings.emptyString(globalData);
     }
 
         return globalData->smallStrings.emptyString(globalData);
     }
 

-    inline JSString* jsSingleCharacterString(JSGlobalData* globalData, UChar c)
+    ALWAYS_INLINE JSString* jsSingleCharacterString(JSGlobalData* globalData, UChar c)

     {
     {

-        if (c <= 0xFF)
+        if (c <= maxSingleCharacterString)

             return globalData->smallStrings.singleCharacterString(globalData, c);
             return globalData->smallStrings.singleCharacterString(globalData, c);

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(&c, 1)));
+        return JSString::create(*globalData, UString(&c, 1).impl());

     }
 
     }
 

-    inline JSString* jsSingleCharacterSubstring(JSGlobalData* globalData, const UString& s, unsigned offset)
+    ALWAYS_INLINE JSString* jsSingleCharacterSubstring(ExecState* exec, const UString& s, unsigned offset)

     {
     {

-        ASSERT(offset < static_cast<unsigned>(s.size()));
-        UChar c = s.data()[offset];
-        if (c <= 0xFF)
+        JSGlobalData* globalData = &exec->globalData();
+        ASSERT(offset < static_cast<unsigned>(s.length()));
+        UChar c = s[offset];
+        if (c <= maxSingleCharacterString)

             return globalData->smallStrings.singleCharacterString(globalData, c);
             return globalData->smallStrings.singleCharacterString(globalData, c);

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(UString::Rep::create(s.rep(), offset, 1))));
+        return JSString::create(*globalData, StringImpl::create(s.impl(), offset, 1));

     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)
     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const char* s)


@@ -417,73 +326,114 @@ namespace JSC {
         ASSERT(s);
         ASSERT(s[0]);
         ASSERT(s[1]);
         ASSERT(s);
         ASSERT(s[0]);
         ASSERT(s[1]);

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
+        return JSString::create(*globalData, UString(s).impl());

     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
     {
     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
     {

-        ASSERT(s.size() > 1);
-        return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
+        ASSERT(s.length() > 1);
+        return JSString::create(*globalData, s.impl());
+    }
+
+    inline const UString& JSString::value(ExecState* exec) const
+    {
+        if (isRope())
+            static_cast<const JSRopeString*>(this)->resolveRope(exec);
+        return m_value;
+    }
+
+    inline const UString& JSString::tryGetValue() const
+    {
+        if (isRope())
+            static_cast<const JSRopeString*>(this)->resolveRope(0);
+        return m_value;

     }
 
     inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
     {
         ASSERT(canGetIndex(i));
     }
 
     inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
     {
         ASSERT(canGetIndex(i));

-        return jsSingleCharacterSubstring(&exec->globalData(), value(exec), i);
+        if (isRope())
+            return static_cast<JSRopeString*>(this)->getIndexSlowCase(exec, i);
+        ASSERT(i < m_value.length());
+        return jsSingleCharacterSubstring(exec, m_value, i);

     }
 
     inline JSString* jsString(JSGlobalData* globalData, const UString& s)
     {
     }
 
     inline JSString* jsString(JSGlobalData* globalData, const UString& s)
     {

-        int size = s.size();
+        int size = s.length();

         if (!size)
             return globalData->smallStrings.emptyString(globalData);
         if (size == 1) {
         if (!size)
             return globalData->smallStrings.emptyString(globalData);
         if (size == 1) {

-            UChar c = s.data()[0];
-            if (c <= 0xFF)
+            UChar c = s[0];
+            if (c <= maxSingleCharacterString)

                 return globalData->smallStrings.singleCharacterString(globalData, c);
         }
                 return globalData->smallStrings.singleCharacterString(globalData, c);
         }

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, s));
+        return JSString::create(*globalData, s.impl());

     }
 
     }
 

-    inline JSString* jsStringWithFinalizer(ExecState* exec, const UString& s, JSStringFinalizerCallback callback, void* context)
+    inline JSString* jsSubstring(ExecState* exec, JSString* s, unsigned offset, unsigned length)

     {
     {

-        ASSERT(s.size() && (s.size() > 1 || s.data()[0] > 0xFF));
+        ASSERT(offset <= static_cast<unsigned>(s->length()));
+        ASSERT(length <= static_cast<unsigned>(s->length()));
+        ASSERT(offset + length <= static_cast<unsigned>(s->length()));

         JSGlobalData* globalData = &exec->globalData();
         JSGlobalData* globalData = &exec->globalData();

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, s, callback, context));
+        if (!length)
+            return globalData->smallStrings.emptyString(globalData);
+        return jsSubstring(globalData, s->value(exec), offset, length);
+    }
+
+    inline JSString* jsSubstring8(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
+    {
+        ASSERT(offset <= static_cast<unsigned>(s.length()));
+        ASSERT(length <= static_cast<unsigned>(s.length()));
+        ASSERT(offset + length <= static_cast<unsigned>(s.length()));
+        if (!length)
+            return globalData->smallStrings.emptyString(globalData);
+        if (length == 1) {
+            UChar c = s[offset];
+            if (c <= maxSingleCharacterString)
+                return globalData->smallStrings.singleCharacterString(globalData, c);
+        }
+        return JSString::createHasOtherOwner(*globalData, StringImpl::create8(s.impl(), offset, length));

     }
 
     inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
     {
     }
 
     inline JSString* jsSubstring(JSGlobalData* globalData, const UString& s, unsigned offset, unsigned length)
     {

-        ASSERT(offset <= static_cast<unsigned>(s.size()));
-        ASSERT(length <= static_cast<unsigned>(s.size()));
-        ASSERT(offset + length <= static_cast<unsigned>(s.size()));
+        ASSERT(offset <= static_cast<unsigned>(s.length()));
+        ASSERT(length <= static_cast<unsigned>(s.length()));
+        ASSERT(offset + length <= static_cast<unsigned>(s.length()));

         if (!length)
             return globalData->smallStrings.emptyString(globalData);
         if (length == 1) {
         if (!length)
             return globalData->smallStrings.emptyString(globalData);
         if (length == 1) {

-            UChar c = s.data()[offset];
-            if (c <= 0xFF)
+            UChar c = s[offset];
+            if (c <= maxSingleCharacterString)

                 return globalData->smallStrings.singleCharacterString(globalData, c);
         }
                 return globalData->smallStrings.singleCharacterString(globalData, c);
         }

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, UString(UString::Rep::create(s.rep(), offset, length)), JSString::HasOtherOwner));
+        return JSString::createHasOtherOwner(*globalData, StringImpl::create(s.impl(), offset, length));

     }
 
     inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
     {
     }
 
     inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
     {

-        int size = s.size();
+        int size = s.length();

         if (!size)
             return globalData->smallStrings.emptyString(globalData);
         if (size == 1) {
         if (!size)
             return globalData->smallStrings.emptyString(globalData);
         if (size == 1) {

-            UChar c = s.data()[0];
-            if (c <= 0xFF)
+            UChar c = s[0];
+            if (c <= maxSingleCharacterString)

                 return globalData->smallStrings.singleCharacterString(globalData, c);
         }
                 return globalData->smallStrings.singleCharacterString(globalData, c);
         }

-        return fixupVPtr(globalData, new (globalData) JSString(globalData, s, JSString::HasOtherOwner));
+        return JSString::createHasOtherOwner(*globalData, s.impl());
+    }
+
+    inline JSRopeString* jsStringBuilder(JSGlobalData* globalData)
+    {
+        return JSRopeString::createNull(*globalData);

     }
 
     inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }
     inline JSString* jsString(ExecState* exec, const UString& s) { return jsString(&exec->globalData(), s); }
     inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->globalData(), c); }
     }
 
     inline JSString* jsEmptyString(ExecState* exec) { return jsEmptyString(&exec->globalData()); }
     inline JSString* jsString(ExecState* exec, const UString& s) { return jsString(&exec->globalData(), s); }
     inline JSString* jsSingleCharacterString(ExecState* exec, UChar c) { return jsSingleCharacterString(&exec->globalData(), c); }

-    inline JSString* jsSingleCharacterSubstring(ExecState* exec, const UString& s, unsigned offset) { return jsSingleCharacterSubstring(&exec->globalData(), s, offset); }
+    inline JSString* jsSubstring8(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring8(&exec->globalData(), s, offset, length); }

     inline JSString* jsSubstring(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring(&exec->globalData(), s, offset, length); }
     inline JSString* jsNontrivialString(ExecState* exec, const UString& s) { return jsNontrivialString(&exec->globalData(), s); }
     inline JSString* jsNontrivialString(ExecState* exec, const char* s) { return jsNontrivialString(&exec->globalData(), s); }
     inline JSString* jsSubstring(ExecState* exec, const UString& s, unsigned offset, unsigned length) { return jsSubstring(&exec->globalData(), s, offset, length); }
     inline JSString* jsNontrivialString(ExecState* exec, const UString& s) { return jsNontrivialString(&exec->globalData(), s); }
     inline JSString* jsNontrivialString(ExecState* exec, const char* s) { return jsNontrivialString(&exec->globalData(), s); }


@@ -492,14 +442,14 @@ namespace JSC {
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
     {
         if (propertyName == exec->propertyNames().length) {
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
     {
         if (propertyName == exec->propertyNames().length) {

-            slot.setValue(jsNumber(exec, m_stringLength));
+            slot.setValue(jsNumber(m_length));

             return true;
         }
 
         bool isStrictUInt32;
             return true;
         }
 
         bool isStrictUInt32;

-        unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
-        if (isStrictUInt32 && i < m_stringLength) {
-            slot.setValue(jsSingleCharacterSubstring(exec, value(exec), i));
+        unsigned i = propertyName.toUInt32(isStrictUInt32);
+        if (isStrictUInt32 && i < m_length) {
+            slot.setValue(getIndex(exec, i));

             return true;
         }
 
             return true;
         }
 


@@ -508,61 +458,74 @@ namespace JSC {
         
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
     {
         
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
     {

-        if (propertyName < m_stringLength) {
-            slot.setValue(jsSingleCharacterSubstring(exec, value(exec), propertyName));
+        if (propertyName < m_length) {
+            slot.setValue(getIndex(exec, propertyName));

             return true;
         }
 
         return false;
     }
 
             return true;
         }
 
         return false;
     }
 

-    inline bool isJSString(JSGlobalData* globalData, JSValue v) { return v.isCell() && v.asCell()->vptr() == globalData->jsStringVPtr; }
+    inline bool isJSString(JSValue v) { return v.isCell() && v.asCell()->classInfo() == &JSString::s_info; }
+
+    inline bool JSCell::toBoolean(ExecState* exec) const
+    {
+        if (isString()) 
+            return static_cast<const JSString*>(this)->toBoolean(exec);
+        return !structure()->typeInfo().masqueradesAsUndefined();
+    }

 
     // --- JSValue inlines ----------------------------
 
     // --- JSValue inlines ----------------------------

+    
+    inline bool JSValue::toBoolean(ExecState* exec) const
+    {
+        if (isInt32())
+            return asInt32();
+        if (isDouble())
+            return asDouble() > 0.0 || asDouble() < 0.0; // false for NaN
+        if (isCell())
+            return asCell()->toBoolean(exec);
+        return isTrue(); // false, null, and undefined all convert to false.
+    }

 
 

-    inline JSString* JSValue::toThisJSString(ExecState* exec)
+    inline JSString* JSValue::toString(ExecState* exec) const

     {
     {

-        return isCell() ? asCell()->toThisJSString(exec) : jsString(exec, toString(exec));
+        if (isString())
+            return jsCast<JSString*>(asCell());
+        return toStringSlowCase(exec);

     }
 
     }
 

-    inline UString JSValue::toString(ExecState* exec) const
+    inline UString JSValue::toUString(ExecState* exec) const

     {
         if (isString())
             return static_cast<JSString*>(asCell())->value(exec);
     {
         if (isString())
             return static_cast<JSString*>(asCell())->value(exec);

-        if (isInt32())
-            return exec->globalData().numericStrings.add(asInt32());
-        if (isDouble())
-            return exec->globalData().numericStrings.add(asDouble());
-        if (isTrue())
-            return "true";
-        if (isFalse())
-            return "false";
-        if (isNull())
-            return "null";
-        if (isUndefined())
-            return "undefined";
-        ASSERT(isCell());
-        return asCell()->toString(exec);
+        return toUStringSlowCase(exec);
+    }
+
+    ALWAYS_INLINE UString inlineJSValueNotStringtoUString(const JSValue& value, ExecState* exec)
+    {
+        JSGlobalData& globalData = exec->globalData();
+        if (value.isInt32())
+            return globalData.numericStrings.add(value.asInt32());
+        if (value.isDouble())
+            return globalData.numericStrings.add(value.asDouble());
+        if (value.isTrue())
+            return globalData.propertyNames->trueKeyword.ustring();
+        if (value.isFalse())
+            return globalData.propertyNames->falseKeyword.ustring();
+        if (value.isNull())
+            return globalData.propertyNames->nullKeyword.ustring();
+        if (value.isUndefined())
+            return globalData.propertyNames->undefinedKeyword.ustring();
+        return value.toString(exec)->value(exec);

     }
 
     }
 

-    inline UString JSValue::toPrimitiveString(ExecState* exec) const
+    ALWAYS_INLINE UString JSValue::toUStringInline(ExecState* exec) const

     {
         if (isString())
             return static_cast<JSString*>(asCell())->value(exec);
     {
         if (isString())
             return static_cast<JSString*>(asCell())->value(exec);

-        if (isInt32())
-            return exec->globalData().numericStrings.add(asInt32());
-        if (isDouble())
-            return exec->globalData().numericStrings.add(asDouble());
-        if (isTrue())
-            return "true";
-        if (isFalse())
-            return "false";
-        if (isNull())
-            return "null";
-        if (isUndefined())
-            return "undefined";
-        ASSERT(isCell());
-        return asCell()->toPrimitive(exec, NoPreference).toString(exec);
+
+        return inlineJSValueNotStringtoUString(*this, exec);

     }
 
 } // namespace JSC
     }
 
 } // namespace JSC