1/*
2 * Copyright (C) 2013 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 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
18 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef DataView_h
27#define DataView_h
28
29#include "ArrayBufferView.h"
30#include <wtf/FlipBytes.h>
31#include <wtf/PassRefPtr.h>
32
33namespace JSC {
34
35class DataView : public ArrayBufferView {
36protected:
37    DataView(PassRefPtr<ArrayBuffer>, unsigned byteOffset, unsigned byteLength);
38
39public:
40    JS_EXPORT_PRIVATE static PassRefPtr<DataView> create(PassRefPtr<ArrayBuffer>, unsigned byteOffset, unsigned length);
41    static PassRefPtr<DataView> create(PassRefPtr<ArrayBuffer>);
42
43    virtual unsigned byteLength() const override
44    {
45        return m_byteLength;
46    }
47
48    virtual TypedArrayType getType() const override
49    {
50        return TypeDataView;
51    }
52
53    virtual JSArrayBufferView* wrap(ExecState*, JSGlobalObject*) override;
54
55    template<typename T>
56    T get(unsigned offset, bool littleEndian, bool* status = 0)
57    {
58        if (status) {
59            if (offset + sizeof(T) > byteLength()) {
60                *status = false;
61                return T();
62            }
63            *status = true;
64        } else
65            ASSERT_WITH_SECURITY_IMPLICATION(offset + sizeof(T) <= byteLength());
66        return flipBytesIfLittleEndian(
67            *reinterpret_cast<T*>(static_cast<uint8_t*>(m_baseAddress) + offset),
68            littleEndian);
69    }
70
71    template<typename T>
72    T read(unsigned& offset, bool littleEndian, bool* status = 0)
73    {
74        T result = this->template get<T>(offset, littleEndian, status);
75        if (!status || *status)
76            offset += sizeof(T);
77        return result;
78    }
79
80    template<typename T>
81    void set(unsigned offset, T value, bool littleEndian, bool* status = 0)
82    {
83        if (status) {
84            if (offset + sizeof(T) > byteLength()) {
85                *status = false;
86                return;
87            }
88            *status = true;
89        } else
90            ASSERT_WITH_SECURITY_IMPLICATION(offset + sizeof(T) <= byteLength());
91        *reinterpret_cast<T*>(static_cast<uint8_t*>(m_baseAddress) + offset) =
92            flipBytesIfLittleEndian(value, littleEndian);
93    }
94
95private:
96    unsigned m_byteLength;
97};
98
99} // namespace JSC
100
101#endif // DataView_h
102
103