1/*
2 * Copyright (C) 2014 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/xml/parser/SharedBufferReader.h"
33
34#include "platform/SharedBuffer.h"
35#include "wtf/PassRefPtr.h"
36#include "wtf/RefPtr.h"
37
38#include <algorithm>
39#include <cstring>
40
41namespace blink {
42
43SharedBufferReader::SharedBufferReader(PassRefPtr<SharedBuffer> buffer)
44    : m_buffer(buffer)
45    , m_currentOffset(0)
46{
47}
48
49SharedBufferReader::~SharedBufferReader()
50{
51}
52
53int SharedBufferReader::readData(char* outputBuffer, unsigned askedToRead)
54{
55    if (!m_buffer || m_currentOffset > m_buffer->size())
56        return 0;
57
58    unsigned bytesCopied = 0;
59    unsigned bytesLeft = m_buffer->size() - m_currentOffset;
60    unsigned lenToCopy = std::min(askedToRead, bytesLeft);
61
62    while (bytesCopied < lenToCopy) {
63        const char* data;
64        unsigned segmentSize = m_buffer->getSomeData(data, m_currentOffset);
65        if (!segmentSize)
66            break;
67
68        segmentSize = std::min(segmentSize, lenToCopy - bytesCopied);
69        memcpy(outputBuffer + bytesCopied, data, segmentSize);
70        bytesCopied += segmentSize;
71        m_currentOffset += segmentSize;
72    }
73
74    return bytesCopied;
75}
76
77} // namespace blink
78