1/*
2 * Copyright (c) 2013, Google 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "config.h"
32#include "core/platform/graphics/skia/SkiaSharedBufferStream.h"
33
34#include "third_party/skia/include/core/SkStream.h"
35#include "core/platform/SharedBuffer.h"
36#include <algorithm>
37#include <cstring>
38
39namespace WebCore {
40
41size_t SkiaSharedBufferStream::read(void* buffer, size_t bytesRequested)
42{
43    const size_t bytesLeft = m_buffer->size() - m_offset;
44    const size_t bytesToConsume = std::min(bytesLeft, bytesRequested);
45
46    if (buffer) {
47        char* byteBuffer = reinterpret_cast<char*>(buffer);
48        unsigned byteOffset = m_offset;
49        unsigned bytesLeftToConsume = bytesToConsume;
50        while (bytesLeftToConsume > 0) {
51            const char* segment;
52            unsigned bytesInSegment = m_buffer->getSomeData(segment, byteOffset);
53            if (!bytesInSegment) {
54                unsigned bytesRead = bytesToConsume - bytesLeftToConsume;
55                m_offset += bytesRead;
56                return bytesRead;
57            }
58            unsigned bytesToCopy = std::min(bytesInSegment, bytesLeftToConsume);
59            std::memcpy(byteBuffer, segment, bytesToCopy);
60            bytesLeftToConsume -= bytesToCopy;
61            byteBuffer += bytesToCopy;
62            byteOffset += bytesToCopy;
63        }
64    }
65    m_offset += bytesToConsume;
66    return bytesToConsume;
67}
68
69bool SkiaSharedBufferStream::isAtEnd() const
70{
71    return this->getLength() == m_offset;
72}
73
74bool SkiaSharedBufferStream::rewind()
75{
76    m_offset = 0;
77    return true;
78}
79
80SkiaSharedBufferStream* SkiaSharedBufferStream::duplicate() const
81{
82    return new SkiaSharedBufferStream(m_buffer);
83}
84
85size_t SkiaSharedBufferStream::getPosition() const
86{
87    return m_offset;
88}
89
90bool SkiaSharedBufferStream::seek(size_t position)
91{
92    m_offset = std::min(position, static_cast<size_t>(m_buffer->size()));
93    return true;
94}
95
96bool SkiaSharedBufferStream::move(long offset)
97{
98    return this->seek(m_offset + offset);
99}
100
101SkiaSharedBufferStream* SkiaSharedBufferStream::fork() const
102{
103    SkiaSharedBufferStream* that = this->duplicate();
104    that->m_offset = this->m_offset;
105    return that;
106}
107
108size_t SkiaSharedBufferStream::getLength() const
109{
110    return m_buffer->size();
111}
112
113const void* SkiaSharedBufferStream::getMemoryBase()
114{
115    const char* segment;
116    unsigned bytesInSegment = m_buffer->getSomeData(segment);
117    return (bytesInSegment != m_buffer->size()) ? 0 : segment;
118}
119
120}
121