ArrayBuffer.cpp revision 2fc2651226baac27029e38c9d6ef883fa32084db 
1/*
2 * Copyright (C) 2009 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 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#include "config.h"
27#include "ArrayBuffer.h"
28
29#include <wtf/RefPtr.h>
30
31namespace WebCore {
32
33PassRefPtr<ArrayBuffer> ArrayBuffer::create(unsigned numElements, unsigned elementByteSize)
34{
35    void* data = tryAllocate(numElements, elementByteSize);
36    if (!data)
37        return 0;
38    return adoptRef(new ArrayBuffer(data, numElements * elementByteSize));
39}
40
41PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBuffer* other)
42{
43    return ArrayBuffer::create(other->data(), other->byteLength());
44}
45
46PassRefPtr<ArrayBuffer> ArrayBuffer::create(void* source, unsigned byteLength)
47{
48    void* data = tryAllocate(byteLength, 1);
49    if (!data)
50        return 0;
51    RefPtr<ArrayBuffer> buffer = adoptRef(new ArrayBuffer(data, byteLength));
52    memcpy(buffer->data(), source, byteLength);
53    return buffer.release();
54}
55
56ArrayBuffer::ArrayBuffer(void* data, unsigned sizeInBytes)
57    : m_sizeInBytes(sizeInBytes)
58    , m_data(data)
59{
60}
61
62void* ArrayBuffer::data()
63{
64    return m_data;
65}
66
67const void* ArrayBuffer::data() const
68{
69    return m_data;
70}
71
72unsigned ArrayBuffer::byteLength() const
73{
74    return m_sizeInBytes;
75}
76
77ArrayBuffer::~ArrayBuffer()
78{
79    WTF::fastFree(m_data);
80}
81
82void* ArrayBuffer::tryAllocate(unsigned numElements, unsigned elementByteSize)
83{
84    void* result;
85    // Do not allow 32-bit overflow of the total size.
86    // FIXME: Why not? The tryFastCalloc function already checks its arguments,
87    // and will fail if there is any overflow, so why should we include a
88    // redudant unnecessarily restrictive check here?
89    if (numElements) {
90        unsigned totalSize = numElements * elementByteSize;
91        if (totalSize / numElements != elementByteSize)
92            return 0;
93    }
94    if (WTF::tryFastCalloc(numElements, elementByteSize).getValue(result))
95        return result;
96    return 0;
97}
98
99}
100