third_party/WebKit/Source/core/html/parser/BackgroundHTMLInputStream.cpp

   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
  29 namespace blink {
  30
  31 BackgroundHTMLInputStream::BackgroundHTMLInputStream()
  32     : m_firstValidCheckpointIndex(0)
  33     , m_firstValidSegmentIndex(0)
  34     , m_totalCheckpointTokenCount(0)
  35 {
  36 }
  37
  38 void BackgroundHTMLInputStream::append(const String& input)
  39 {
  40     m_current.append(SegmentedString(input));
  41     m_segments.append(input);
  42 }
  43
  44 void BackgroundHTMLInputStream::close()
  45 {
  46     m_current.close();
  47 }
  48
  49 HTMLInputCheckpoint 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
  57 void 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
  79 void 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
 110 void 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 }