1/*
2 * Copyright (C) 2010 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 APPLE 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 APPLE 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/HTMLParserScheduler.h"
28
29#include "core/dom/Document.h"
30#include "core/html/parser/HTMLDocumentParser.h"
31#include "core/frame/FrameView.h"
32
33namespace blink {
34
35// parserChunkSize is used to define how many tokens the parser will
36// process before checking against parserTimeLimit and possibly yielding.
37// This is a performance optimization to prevent checking after every token.
38const int HTMLParserScheduler::parserChunkSize = 4096;
39
40// parserTimeLimit is the seconds the parser will run in one write() call
41// before yielding. Inline <script> execution can cause it to exceed the limit.
42const double HTMLParserScheduler::parserTimeLimit = 0.2;
43
44ActiveParserSession::ActiveParserSession(Document* document)
45    : m_document(document)
46{
47    if (!m_document)
48        return;
49    m_document->incrementActiveParserCount();
50}
51
52ActiveParserSession::~ActiveParserSession()
53{
54    if (!m_document)
55        return;
56    m_document->decrementActiveParserCount();
57}
58
59PumpSession::PumpSession(unsigned& nestingLevel, Document* document)
60    : NestingLevelIncrementer(nestingLevel)
61    , ActiveParserSession(document)
62    // Setting processedTokens to INT_MAX causes us to check for yields
63    // after any token during any parse where yielding is allowed.
64    // At that time we'll initialize startTime.
65    , processedTokens(INT_MAX)
66    , startTime(0)
67    , needsYield(false)
68    , didSeeScript(false)
69{
70}
71
72PumpSession::~PumpSession()
73{
74}
75
76HTMLParserScheduler::HTMLParserScheduler(HTMLDocumentParser* parser)
77    : m_parser(parser)
78    , m_continueNextChunkTimer(this, &HTMLParserScheduler::continueNextChunkTimerFired)
79    , m_isSuspendedWithActiveTimer(false)
80{
81}
82
83HTMLParserScheduler::~HTMLParserScheduler()
84{
85    m_continueNextChunkTimer.stop();
86}
87
88void HTMLParserScheduler::continueNextChunkTimerFired(Timer<HTMLParserScheduler>* timer)
89{
90    ASSERT_UNUSED(timer, timer == &m_continueNextChunkTimer);
91    m_parser->resumeParsingAfterYield();
92}
93
94void HTMLParserScheduler::scheduleForResume()
95{
96    m_continueNextChunkTimer.startOneShot(0, FROM_HERE);
97}
98
99void HTMLParserScheduler::suspend()
100{
101    ASSERT(!m_isSuspendedWithActiveTimer);
102    if (!m_continueNextChunkTimer.isActive())
103        return;
104    m_isSuspendedWithActiveTimer = true;
105    m_continueNextChunkTimer.stop();
106}
107
108void HTMLParserScheduler::resume()
109{
110    ASSERT(!m_continueNextChunkTimer.isActive());
111    if (!m_isSuspendedWithActiveTimer)
112        return;
113    m_isSuspendedWithActiveTimer = false;
114    m_continueNextChunkTimer.startOneShot(0, FROM_HERE);
115}
116
117}
118