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
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 GOOGLE 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 GOOGLE 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 "core/html/parser/BackgroundHTMLInputStream.h"
28
29namespace blink {
30
31BackgroundHTMLInputStream::BackgroundHTMLInputStream()
32    : m_firstValidCheckpointIndex(0)
33    , m_firstValidSegmentIndex(0)
34    , m_totalCheckpointTokenCount(0)
35{
36}
37
38void BackgroundHTMLInputStream::append(const String& input)
39{
40    m_current.append(SegmentedString(input));
41    m_segments.append(input);
42}
43
44void BackgroundHTMLInputStream::close()
45{
46    m_current.close();
47}
48
49HTMLInputCheckpoint BackgroundHTMLInputStream::createCheckpoint(size_t tokensExtractedSincePreviousCheckpoint)
50{
51    HTMLInputCheckpoint checkpoint = m_checkpoints.size();
52    m_checkpoints.append(Checkpoint(m_current, m_segments.size(), tokensExtractedSincePreviousCheckpoint));
53    m_totalCheckpointTokenCount += tokensExtractedSincePreviousCheckpoint;
54    return checkpoint;
55}
56
57void BackgroundHTMLInputStream::invalidateCheckpointsBefore(HTMLInputCheckpoint newFirstValidCheckpointIndex)
58{
59    ASSERT(newFirstValidCheckpointIndex < m_checkpoints.size());
60    // There is nothing to do for the first valid checkpoint.
61    if (m_firstValidCheckpointIndex == newFirstValidCheckpointIndex)
62        return;
63
64    ASSERT(newFirstValidCheckpointIndex > m_firstValidCheckpointIndex);
65    const Checkpoint& lastInvalidCheckpoint = m_checkpoints[newFirstValidCheckpointIndex - 1];
66
67    ASSERT(m_firstValidSegmentIndex <= lastInvalidCheckpoint.numberOfSegmentsAlreadyAppended);
68    for (size_t i = m_firstValidSegmentIndex; i < lastInvalidCheckpoint.numberOfSegmentsAlreadyAppended; ++i)
69        m_segments[i] = String();
70    m_firstValidSegmentIndex = lastInvalidCheckpoint.numberOfSegmentsAlreadyAppended;
71
72    for (size_t i = m_firstValidCheckpointIndex; i < newFirstValidCheckpointIndex; ++i)
73        m_checkpoints[i].clear();
74    m_firstValidCheckpointIndex = newFirstValidCheckpointIndex;
75
76    updateTotalCheckpointTokenCount();
77}
78
79void BackgroundHTMLInputStream::rewindTo(HTMLInputCheckpoint checkpointIndex, const String& unparsedInput)
80{
81    ASSERT(checkpointIndex < m_checkpoints.size()); // If this ASSERT fires, checkpointIndex is invalid.
82    const Checkpoint& checkpoint = m_checkpoints[checkpointIndex];
83    ASSERT(!checkpoint.isNull());
84
85    bool isClosed = m_current.isClosed();
86
87    m_current = checkpoint.input;
88
89    for (size_t i = checkpoint.numberOfSegmentsAlreadyAppended; i < m_segments.size(); ++i) {
90        ASSERT(!m_segments[i].isNull());
91        m_current.append(SegmentedString(m_segments[i]));
92    }
93
94    if (!unparsedInput.isEmpty())
95        m_current.prepend(SegmentedString(unparsedInput));
96
97    if (isClosed && !m_current.isClosed())
98        m_current.close();
99
100    ASSERT(m_current.isClosed() == isClosed);
101
102    m_segments.clear();
103    m_checkpoints.clear();
104    m_firstValidCheckpointIndex = 0;
105    m_firstValidSegmentIndex = 0;
106
107    updateTotalCheckpointTokenCount();
108}
109
110void BackgroundHTMLInputStream::updateTotalCheckpointTokenCount()
111{
112    m_totalCheckpointTokenCount = 0;
113    size_t lastCheckpointIndex = m_checkpoints.size();
114    for (size_t i = 0; i < lastCheckpointIndex; ++i)
115        m_totalCheckpointTokenCount += m_checkpoints[i].tokensExtractedSincePreviousCheckpoint;
116}
117
118}
119