michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef vm_StringObject_h
michael@0: #define vm_StringObject_h
michael@0: 
michael@0: #include "jsobj.h"
michael@0: #include "jsstr.h"
michael@0: 
michael@0: #include "vm/Shape.h"
michael@0: 
michael@0: namespace js {
michael@0: 
michael@0: class StringObject : public JSObject
michael@0: {
michael@0:     static const unsigned PRIMITIVE_VALUE_SLOT = 0;
michael@0:     static const unsigned LENGTH_SLOT = 1;
michael@0: 
michael@0:   public:
michael@0:     static const unsigned RESERVED_SLOTS = 2;
michael@0: 
michael@0:     static const Class class_;
michael@0: 
michael@0:     /*
michael@0:      * Creates a new String object boxing the given string.  The object's
michael@0:      * [[Prototype]] is determined from context.
michael@0:      */
michael@0:     static inline StringObject *create(JSContext *cx, HandleString str,
michael@0:                                        NewObjectKind newKind = GenericObject);
michael@0: 
michael@0:     JSString *unbox() const {
michael@0:         return getFixedSlot(PRIMITIVE_VALUE_SLOT).toString();
michael@0:     }
michael@0: 
michael@0:     inline size_t length() const {
michael@0:         return size_t(getFixedSlot(LENGTH_SLOT).toInt32());
michael@0:     }
michael@0: 
michael@0:     static size_t offsetOfPrimitiveValue() {
michael@0:         return getFixedSlotOffset(PRIMITIVE_VALUE_SLOT);
michael@0:     }
michael@0:     static size_t offsetOfLength() {
michael@0:         return getFixedSlotOffset(LENGTH_SLOT);
michael@0:     }
michael@0: 
michael@0:   private:
michael@0:     inline bool init(JSContext *cx, HandleString str);
michael@0: 
michael@0:     void setStringThis(JSString *str) {
michael@0:         JS_ASSERT(getReservedSlot(PRIMITIVE_VALUE_SLOT).isUndefined());
michael@0:         setFixedSlot(PRIMITIVE_VALUE_SLOT, StringValue(str));
michael@0:         setFixedSlot(LENGTH_SLOT, Int32Value(int32_t(str->length())));
michael@0:     }
michael@0: 
michael@0:     /* For access to init, as String.prototype is special. */
michael@0:     friend JSObject *
michael@0:     ::js_InitStringClass(JSContext *cx, js::HandleObject global);
michael@0: 
michael@0:     /* For access to assignInitialShape. */
michael@0:     friend bool
michael@0:     EmptyShape::ensureInitialCustomShape<StringObject>(ExclusiveContext *cx,
michael@0:                                                        Handle<StringObject*> obj);
michael@0: 
michael@0:     /*
michael@0:      * Compute the initial shape to associate with fresh String objects, which
michael@0:      * encodes the initial length property. Return the shape after changing
michael@0:      * |obj|'s last property to it.
michael@0:      */
michael@0:     static Shape *
michael@0:     assignInitialShape(ExclusiveContext *cx, Handle<StringObject*> obj);
michael@0: };
michael@0: 
michael@0: } // namespace js
michael@0: 
michael@0: #endif /* vm_StringObject_h */