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 <runtime/JSObject.h>
  32 #include <runtime/Protect.h>
  33 #include <runtime/UString.h>
  34 #include <wtf/HashMap.h>
  35 #include <wtf/RefCounted.h>
  36
  37 struct StaticValueEntry {
  38     StaticValueEntry(JSObjectGetPropertyCallback _getProperty, JSObjectSetPropertyCallback _setProperty, JSPropertyAttributes _attributes)
  39         : getProperty(_getProperty), setProperty(_setProperty), attributes(_attributes)
  40     {
  41     }
  42
  43     JSObjectGetPropertyCallback getProperty;
  44     JSObjectSetPropertyCallback setProperty;
  45     JSPropertyAttributes attributes;
  46 };
  47
  48 struct StaticFunctionEntry {
  49     StaticFunctionEntry(JSObjectCallAsFunctionCallback _callAsFunction, JSPropertyAttributes _attributes)
  50         : callAsFunction(_callAsFunction), attributes(_attributes)
  51     {
  52     }
  53
  54     JSObjectCallAsFunctionCallback callAsFunction;
  55     JSPropertyAttributes attributes;
  56 };
  57
  58 typedef HashMap<RefPtr<JSC::UString::Rep>, StaticValueEntry*> OpaqueJSClassStaticValuesTable;
  59 typedef HashMap<RefPtr<JSC::UString::Rep>, StaticFunctionEntry*> OpaqueJSClassStaticFunctionsTable;
  60
  61 class OpaqueJSClass;
  62
  63 // An OpaqueJSClass (JSClass) is created without a context, so it can be used with any context, even across context groups.
  64 // This structure holds data members that vary across context groups.
  65 struct OpaqueJSClassContextData : Noncopyable {
  66     OpaqueJSClassContextData(OpaqueJSClass*);
  67     ~OpaqueJSClassContextData();
  68
  69     // It is necessary to keep OpaqueJSClass alive because of the following rare scenario:
  70     // 1. A class is created and used, so its context data is stored in JSGlobalData hash map.
  71     // 2. The class is released, and when all JS objects that use it are collected, OpaqueJSClass
  72     // is deleted (that's the part prevented by this RefPtr).
  73     // 3. Another class is created at the same address.
  74     // 4. When it is used, the old context data is found in JSGlobalData and used.
  75     RefPtr<OpaqueJSClass> m_class;
  76
  77     OpaqueJSClassStaticValuesTable* staticValues;
  78     OpaqueJSClassStaticFunctionsTable* staticFunctions;
  79     JSC::JSObject* cachedPrototype;
  80 };
  81
  82 struct OpaqueJSClass : public ThreadSafeShared<OpaqueJSClass> {
  83     static PassRefPtr<OpaqueJSClass> create(const JSClassDefinition*);
  84     static PassRefPtr<OpaqueJSClass> createNoAutomaticPrototype(const JSClassDefinition*);
  85     ~OpaqueJSClass();
  86
  87     JSC::UString className();
  88     OpaqueJSClassStaticValuesTable* staticValues(JSC::ExecState*);
  89     OpaqueJSClassStaticFunctionsTable* staticFunctions(JSC::ExecState*);
  90     JSC::JSObject* prototype(JSC::ExecState*);
  91
  92     OpaqueJSClass* parentClass;
  93     OpaqueJSClass* prototypeClass;
  94
  95     JSObjectInitializeCallback initialize;
  96     JSObjectFinalizeCallback finalize;
  97     JSObjectHasPropertyCallback hasProperty;
  98     JSObjectGetPropertyCallback getProperty;
  99     JSObjectSetPropertyCallback setProperty;
 100     JSObjectDeletePropertyCallback deleteProperty;
 101     JSObjectGetPropertyNamesCallback getPropertyNames;
 102     JSObjectCallAsFunctionCallback callAsFunction;
 103     JSObjectCallAsConstructorCallback callAsConstructor;
 104     JSObjectHasInstanceCallback hasInstance;
 105     JSObjectConvertToTypeCallback convertToType;
 106
 107 private:
 108     friend struct OpaqueJSClassContextData;
 109
 110     OpaqueJSClass();
 111     OpaqueJSClass(const OpaqueJSClass&);
 112     OpaqueJSClass(const JSClassDefinition*, OpaqueJSClass* protoClass);
 113
 114     OpaqueJSClassContextData& contextData(JSC::ExecState*);
 115
 116     // UStrings in these data members should not be put into any IdentifierTable.
 117     JSC::UString m_className;
 118     OpaqueJSClassStaticValuesTable* m_staticValues;
 119     OpaqueJSClassStaticFunctionsTable* m_staticFunctions;
 120 };
 121
 122 #endif // JSClassRef_h