1  /*
 2   * Copyright (C) 2013-2019 Apple 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 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 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  #pragma once
27  
28  #include "ArrayBuffer.h"
29  #include "JSObject.h"
30  
31  namespace JSC {
32  
33  class JSArrayBuffer final : public JSNonFinalObject {
34  public:
35      using Base = JSNonFinalObject;
36      static constexpr unsigned StructureFlags = Base::StructureFlags;
37  
38      template<typename CellType, SubspaceAccess mode>
39      static IsoSubspace* subspaceFor(VM& vm)
40      {
41          return vm.arrayBufferSpace<mode>();
42      }
43  
44      // This function will register the new wrapper with the vm's TypedArrayController.
45      JS_EXPORT_PRIVATE static JSArrayBuffer* create(VM&, Structure*, RefPtr<ArrayBuffer>&&);
46  
47      ArrayBuffer* impl() const { return m_impl; }
48      
49      static Structure* createStructure(VM&, JSGlobalObject*, JSValue prototype);
50  
51      JS_EXPORT_PRIVATE bool isShared() const;
52      ArrayBufferSharingMode sharingMode() const;
53      
54      DECLARE_EXPORT_INFO;
55      
56      // This is the default DOM unwrapping. It calls toUnsharedArrayBuffer().
57      static ArrayBuffer* toWrapped(VM&, JSValue);
58      static ArrayBuffer* toWrappedAllowShared(VM&, JSValue);
59      
60  private:
61      JSArrayBuffer(VM&, Structure*, RefPtr<ArrayBuffer>&&);
62      void finishCreation(VM&, JSGlobalObject*);
63  
64      static size_t estimatedSize(JSCell*, VM&);
65  
66      ArrayBuffer* m_impl;
67  };
68  
69  inline ArrayBuffer* toPossiblySharedArrayBuffer(VM& vm, JSValue value)
70  {
71      JSArrayBuffer* wrapper = jsDynamicCast<JSArrayBuffer*>(vm, value);
72      if (!wrapper)
73          return nullptr;
74      return wrapper->impl();
75  }
76  
77  inline ArrayBuffer* toUnsharedArrayBuffer(VM& vm, JSValue value)
78  {
79      ArrayBuffer* result = toPossiblySharedArrayBuffer(vm, value);
80      if (!result || result->isShared())
81          return nullptr;
82      return result;
83  }
84  
85  inline ArrayBuffer* JSArrayBuffer::toWrapped(VM& vm, JSValue value)
86  {
87      return toUnsharedArrayBuffer(vm, value);
88  }
89  
90  inline ArrayBuffer* JSArrayBuffer::toWrappedAllowShared(VM& vm, JSValue value)
91  {
92      return toPossiblySharedArrayBuffer(vm, value);
93  }
94  
95  } // namespace JSC