X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/ba379fdc102753d6be2c4d937058fe40257329fe..1981f5dfe8d77d97469d20652f712a09400c48ed:/runtime/JSString.h

diff --git a/runtime/JSString.h b/runtime/JSString.h
index ade3c3b..10ec799 100644
--- a/runtime/JSString.h
+++ b/runtime/JSString.h
@@ -22,16 +22,18 @@
 
 #ifndef JSString_h
 #define JSString_h
-
 #include "CallFrame.h"
 #include "CommonIdentifiers.h"
 #include "Identifier.h"
-#include "JSNumberCell.h"
+#include "PropertyDescriptor.h"
 #include "PropertySlot.h"
+#include "Structure.h"
 
 namespace JSC {
 
     class JSString;
+    class JSRopeString;
+    class LLIntOffsetsExtractor;
 
     JSString* jsEmptyString(JSGlobalData*);
     JSString* jsEmptyString(ExecState*);
@@ -40,7 +42,6 @@ namespace JSC {
 
     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);
@@ -58,71 +59,244 @@ namespace JSC {
     JSString* jsOwnedString(JSGlobalData*, const UString&); 
     JSString* jsOwnedString(ExecState*, const UString&); 
 
+    JSRopeString* jsStringBuilder(JSGlobalData*);
+
     class JSString : public JSCell {
+    public:
         friend class JIT;
-        friend class VPtrSet;
+        friend class JSGlobalData;
+        friend class SpecializedThunkJIT;
+        friend class JSRopeString;
+        friend struct ThunkHelpers;
 
-    public:
-        JSString(JSGlobalData* globalData, const UString& value)
-            : JSCell(globalData->stringStructure.get())
+        typedef JSCell Base;
+
+        static void destroy(JSCell*);
+
+    private:
+        JSString(JSGlobalData& globalData, PassRefPtr<StringImpl> value)
+            : JSCell(globalData, globalData.stringStructure.get())
             , m_value(value)
         {
-            Heap::heap(this)->reportExtraMemoryCost(value.cost());
         }
 
-        enum HasOtherOwnerType { HasOtherOwner };
-        JSString(JSGlobalData* globalData, const UString& value, HasOtherOwnerType)
-            : JSCell(globalData->stringStructure.get())
-            , m_value(value)
+        JSString(JSGlobalData& globalData)
+            : JSCell(globalData, globalData.stringStructure.get())
         {
         }
-        JSString(JSGlobalData* globalData, PassRefPtr<UString::Rep> value, HasOtherOwnerType)
-            : JSCell(globalData->stringStructure.get())
-            , m_value(value)
+
+        void finishCreation(JSGlobalData& globalData, size_t length)
+        {
+            ASSERT(!m_value.isNull());
+            Base::finishCreation(globalData);
+            m_length = length;
+            m_is8Bit = m_value.impl()->is8Bit();
+        }
+
+        void finishCreation(JSGlobalData& globalData, size_t length, size_t cost)
         {
+            ASSERT(!m_value.isNull());
+            Base::finishCreation(globalData);
+            m_length = length;
+            m_is8Bit = m_value.impl()->is8Bit();
+            Heap::heap(this)->reportExtraMemoryCost(cost);
+        }
+
+    protected:
+        void finishCreation(JSGlobalData& globalData)
+        {
+            Base::finishCreation(globalData);
+            m_length = 0;
+            m_is8Bit = true;
         }
         
-        const UString& value() const { return m_value; }
+    public:
+        static JSString* create(JSGlobalData& globalData, PassRefPtr<StringImpl> 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;
+        }
+        static JSString* createHasOtherOwner(JSGlobalData& globalData, PassRefPtr<StringImpl> 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;
+        }
+
+        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 canGetIndex(unsigned i) { return i < m_length; }
+        JSString* getIndex(ExecState*, unsigned);
+
+        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&);
 
-        bool canGetIndex(unsigned i) { return i < static_cast<unsigned>(m_value.size()); }
-        JSString* getIndex(JSGlobalData*, unsigned);
+    protected:
+        bool isRope() const { return m_value.isNull(); }
+        bool is8Bit() const { return m_is8Bit; }
 
-        static PassRefPtr<Structure> createStructure(JSValue proto) { return Structure::create(proto, TypeInfo(StringType, NeedsThisConversion)); }
+        // 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:
-        enum VPtrStealingHackType { VPtrStealingHack };
-        JSString(VPtrStealingHackType) 
-            : JSCell(0)
+        JSRopeString(JSGlobalData& globalData)
+            : JSString(globalData)
         {
         }
 
-        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 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);
+        }
 
-        virtual JSObject* toThisObject(ExecState*) const;
-        virtual UString toThisString(ExecState*) const;
-        virtual JSString* toThisJSString(ExecState*);
+        void finishCreation(JSGlobalData& globalData)
+        {
+            JSString::finishCreation(globalData);
+        }
 
-        // Actually getPropertySlot, not getOwnPropertySlot (see JSCell).
-        virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
-        virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
+        static JSRopeString* createNull(JSGlobalData& globalData)
+        {
+            JSRopeString* newString = new (NotNull, allocateCell<JSRopeString>(globalData.heap)) JSRopeString(globalData);
+            newString->finishCreation(globalData);
+            return newString;
+        }
+
+    public:
+        static JSString* create(JSGlobalData& globalData, JSString* s1, JSString* s2)
+        {
+            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;
+        }
+
+        void visitFibers(SlotVisitor&);
 
-        UString m_value;
+    private:
+        friend JSValue jsString(ExecState*, Register*, unsigned);
+        friend JSValue jsStringFromArguments(ExecState*, JSValue);
+
+        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;
+        
+        mutable FixedArray<WriteBarrier<JSString>, s_maxInternalRopeLength> m_fibers;
     };
 
     JSString* asString(JSValue);
 
     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)
@@ -130,20 +304,21 @@ namespace JSC {
         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 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 new (globalData) JSString(globalData, 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)
@@ -151,25 +326,114 @@ namespace JSC {
         ASSERT(s);
         ASSERT(s[0]);
         ASSERT(s[1]);
-        return new (globalData) JSString(globalData, s);
+        return JSString::create(*globalData, UString(s).impl());
     }
 
     inline JSString* jsNontrivialString(JSGlobalData* globalData, const UString& s)
     {
-        ASSERT(s.size() > 1);
-        return 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(JSGlobalData* globalData, unsigned i)
+    inline JSString* JSString::getIndex(ExecState* exec, unsigned i)
     {
         ASSERT(canGetIndex(i));
-        return jsSingleCharacterSubstring(globalData, m_value, 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)
+    {
+        int size = s.length();
+        if (!size)
+            return globalData->smallStrings.emptyString(globalData);
+        if (size == 1) {
+            UChar c = s[0];
+            if (c <= maxSingleCharacterString)
+                return globalData->smallStrings.singleCharacterString(globalData, c);
+        }
+        return JSString::create(*globalData, s.impl());
+    }
+
+    inline JSString* jsSubstring(ExecState* exec, JSString* 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()));
+        JSGlobalData* globalData = &exec->globalData();
+        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)
+    {
+        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::create(s.impl(), offset, length));
+    }
+
+    inline JSString* jsOwnedString(JSGlobalData* globalData, const UString& s)
+    {
+        int size = s.length();
+        if (!size)
+            return globalData->smallStrings.emptyString(globalData);
+        if (size == 1) {
+            UChar c = s[0];
+            if (c <= maxSingleCharacterString)
+                return globalData->smallStrings.singleCharacterString(globalData, c);
+        }
+        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* 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); }
@@ -178,14 +442,14 @@ namespace JSC {
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
     {
         if (propertyName == exec->propertyNames().length) {
-            slot.setValue(jsNumber(exec, m_value.size()));
+            slot.setValue(jsNumber(m_length));
             return true;
         }
 
         bool isStrictUInt32;
-        unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
-        if (isStrictUInt32 && i < static_cast<unsigned>(m_value.size())) {
-            slot.setValue(jsSingleCharacterSubstring(exec, m_value, i));
+        unsigned i = propertyName.toUInt32(isStrictUInt32);
+        if (isStrictUInt32 && i < m_length) {
+            slot.setValue(getIndex(exec, i));
             return true;
         }
 
@@ -194,21 +458,74 @@ namespace JSC {
         
     ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
     {
-        if (propertyName < static_cast<unsigned>(m_value.size())) {
-            slot.setValue(jsSingleCharacterSubstring(exec, m_value, propertyName));
+        if (propertyName < m_length) {
+            slot.setValue(getIndex(exec, propertyName));
             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 ----------------------------
+    
+    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::toUString(ExecState* exec) const
+    {
+        if (isString())
+            return static_cast<JSString*>(asCell())->value(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);
+    }
+
+    ALWAYS_INLINE UString JSValue::toUStringInline(ExecState* exec) const
+    {
+        if (isString())
+            return static_cast<JSString*>(asCell())->value(exec);
+
+        return inlineJSValueNotStringtoUString(*this, exec);
     }
 
 } // namespace JSC