1/*
2 * Copyright (C) 2009 Apple Inc. All rights reserved.
3 * Copyright (C) 2013 Google Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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 COMPUTER, INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28#include "wtf/ArrayBufferContents.h"
29
30#include "wtf/Assertions.h"
31#include "wtf/PartitionAlloc.h"
32#include "wtf/WTF.h"
33#include <string.h>
34
35namespace WTF {
36
37ArrayBufferContents::ArrayBufferContents()
38    : m_data(0)
39    , m_sizeInBytes(0)
40    , m_deallocationObserver(0) { }
41
42ArrayBufferContents::ArrayBufferContents(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
43    : m_data(0)
44    , m_sizeInBytes(0)
45    , m_deallocationObserver(0)
46{
47    // Do not allow 32-bit overflow of the total size.
48    if (numElements) {
49        unsigned totalSize = numElements * elementByteSize;
50        if (totalSize / numElements != elementByteSize) {
51            m_data = 0;
52            return;
53        }
54    }
55    allocateMemory(numElements * elementByteSize, policy, m_data);
56    m_sizeInBytes = numElements * elementByteSize;
57}
58
59ArrayBufferContents::ArrayBufferContents(
60    void* data, unsigned sizeInBytes, ArrayBufferDeallocationObserver* observer)
61    : m_data(data)
62    , m_sizeInBytes(sizeInBytes)
63    , m_deallocationObserver(observer)
64{
65    if (!m_data) {
66        ASSERT(!m_sizeInBytes);
67        m_sizeInBytes = 0;
68        // Allow null data if size is 0 bytes, make sure m_data is valid pointer.
69        // (partitionAllocGeneric guarantees valid pointer for size 0)
70        allocateMemory(0, ZeroInitialize, m_data);
71    }
72}
73
74ArrayBufferContents::~ArrayBufferContents()
75{
76    freeMemory(m_data, m_sizeInBytes);
77    clear();
78}
79
80void ArrayBufferContents::clear()
81{
82    if (m_data && m_deallocationObserver)
83        m_deallocationObserver->arrayBufferDeallocated(m_sizeInBytes);
84    m_data = 0;
85    m_sizeInBytes = 0;
86    m_deallocationObserver = 0;
87}
88
89void ArrayBufferContents::transfer(ArrayBufferContents& other)
90{
91    ASSERT(!other.m_data);
92    other.m_data = m_data;
93    other.m_sizeInBytes = m_sizeInBytes;
94    clear();
95}
96
97void ArrayBufferContents::copyTo(ArrayBufferContents& other)
98{
99    ASSERT(!other.m_sizeInBytes);
100    other.freeMemory(other.m_data, other.m_sizeInBytes);
101    allocateMemory(m_sizeInBytes, DontInitialize, other.m_data);
102    if (!other.m_data)
103        return;
104    memcpy(other.m_data, m_data, m_sizeInBytes);
105    other.m_sizeInBytes = m_sizeInBytes;
106}
107
108void ArrayBufferContents::allocateMemory(size_t size, InitializationPolicy policy, void*& data)
109{
110    data = partitionAllocGenericFlags(WTF::Partitions::getBufferPartition(), PartitionAllocReturnNull, size);
111    if (policy == ZeroInitialize && data)
112        memset(data, '\0', size);
113}
114
115void ArrayBufferContents::freeMemory(void* data, size_t)
116{
117    partitionFreeGeneric(WTF::Partitions::getBufferPartition(), data);
118}
119
120} // namespace WTF
121