API/JSClassRef.h

   1 /*
   2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef JSClassRef_h
  27 #define JSClassRef_h
  28
  29 #include "JSObjectRef.h"
  30
  31 #include "Weak.h"
  32 #include "JSObject.h"
  33 #include "Protect.h"
  34 #include "UString.h"
  35 #include <wtf/HashMap.h>
  36
  37 struct StaticValueEntry {
  38     WTF_MAKE_FAST_ALLOCATED;
  39 public:
  40     StaticValueEntry(JSObjectGetPropertyCallback _getProperty, JSObjectSetPropertyCallback _setProperty, JSPropertyAttributes _attributes)
  41         : getProperty(_getProperty), setProperty(_setProperty), attributes(_attributes)
  42     {
  43     }
  44
  45     JSObjectGetPropertyCallback getProperty;
  46     JSObjectSetPropertyCallback setProperty;
  47     JSPropertyAttributes attributes;
  48 };
  49
  50 struct StaticFunctionEntry {
  51     WTF_MAKE_FAST_ALLOCATED;
  52 public:
  53     StaticFunctionEntry(JSObjectCallAsFunctionCallback _callAsFunction, JSPropertyAttributes _attributes)
  54         : callAsFunction(_callAsFunction), attributes(_attributes)
  55     {
  56     }
  57
  58     JSObjectCallAsFunctionCallback callAsFunction;
  59     JSPropertyAttributes attributes;
  60 };
  61
  62 typedef HashMap<RefPtr<StringImpl>, StaticValueEntry*> OpaqueJSClassStaticValuesTable;
  63 typedef HashMap<RefPtr<StringImpl>, StaticFunctionEntry*> OpaqueJSClassStaticFunctionsTable;
  64
  65 struct OpaqueJSClass;
  66
  67 // An OpaqueJSClass (JSClass) is created without a context, so it can be used with any context, even across context groups.
  68 // This structure holds data members that vary across context groups.
  69 struct OpaqueJSClassContextData {
  70     WTF_MAKE_NONCOPYABLE(OpaqueJSClassContextData); WTF_MAKE_FAST_ALLOCATED;
  71 public:
  72     OpaqueJSClassContextData(JSC::JSGlobalData&, OpaqueJSClass*);
  73     ~OpaqueJSClassContextData();
  74
  75     // It is necessary to keep OpaqueJSClass alive because of the following rare scenario:
  76     // 1. A class is created and used, so its context data is stored in JSGlobalData hash map.
  77     // 2. The class is released, and when all JS objects that use it are collected, OpaqueJSClass
  78     // is deleted (that's the part prevented by this RefPtr).
  79     // 3. Another class is created at the same address.
  80     // 4. When it is used, the old context data is found in JSGlobalData and used.
  81     RefPtr<OpaqueJSClass> m_class;
  82
  83     OpaqueJSClassStaticValuesTable* staticValues;
  84     OpaqueJSClassStaticFunctionsTable* staticFunctions;
  85     JSC::Weak<JSC::JSObject> cachedPrototype;
  86 };
  87
  88 struct OpaqueJSClass : public ThreadSafeRefCounted<OpaqueJSClass> {
  89     static PassRefPtr<OpaqueJSClass> create(const JSClassDefinition*);
  90     static PassRefPtr<OpaqueJSClass> createNoAutomaticPrototype(const JSClassDefinition*);
  91     ~OpaqueJSClass();
  92
  93     JSC::UString className();
  94     OpaqueJSClassStaticValuesTable* staticValues(JSC::ExecState*);
  95     OpaqueJSClassStaticFunctionsTable* staticFunctions(JSC::ExecState*);
  96     JSC::JSObject* prototype(JSC::ExecState*);
  97
  98     OpaqueJSClass* parentClass;
  99     OpaqueJSClass* prototypeClass;
 100
 101     JSObjectInitializeCallback initialize;
 102     JSObjectFinalizeCallback finalize;
 103     JSObjectHasPropertyCallback hasProperty;
 104     JSObjectGetPropertyCallback getProperty;
 105     JSObjectSetPropertyCallback setProperty;
 106     JSObjectDeletePropertyCallback deleteProperty;
 107     JSObjectGetPropertyNamesCallback getPropertyNames;
 108     JSObjectCallAsFunctionCallback callAsFunction;
 109     JSObjectCallAsConstructorCallback callAsConstructor;
 110     JSObjectHasInstanceCallback hasInstance;
 111     JSObjectConvertToTypeCallback convertToType;
 112
 113 private:
 114     friend struct OpaqueJSClassContextData;
 115
 116     OpaqueJSClass();
 117     OpaqueJSClass(const OpaqueJSClass&);
 118     OpaqueJSClass(const JSClassDefinition*, OpaqueJSClass* protoClass);
 119
 120     OpaqueJSClassContextData& contextData(JSC::ExecState*);
 121
 122     // UStrings in these data members should not be put into any IdentifierTable.
 123     JSC::UString m_className;
 124     OpaqueJSClassStaticValuesTable* m_staticValues;
 125     OpaqueJSClassStaticFunctionsTable* m_staticFunctions;
 126 };
 127
 128 #endif // JSClassRef_h