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 #ifndef HTMLParserScheduler_h 27 #define HTMLParserScheduler_h 28 29 #include "core/html/parser/NestingLevelIncrementer.h" 30 #include "platform/Timer.h" 31 #include "wtf/CurrentTime.h" 32 #include "wtf/PassOwnPtr.h" 33 #include "wtf/RefPtr.h" 34 35 namespace blink { 36 37 class Document; 38 class HTMLDocumentParser; 39 40 class ActiveParserSession { 41 STACK_ALLOCATED(); 42 public: 43 explicit ActiveParserSession(Document*); 44 ~ActiveParserSession(); 45 46 private: 47 RefPtrWillBeMember<Document> m_document; 48 }; 49 50 class PumpSession : public NestingLevelIncrementer, public ActiveParserSession { 51 STACK_ALLOCATED(); 52 public: 53 PumpSession(unsigned& nestingLevel, Document*); 54 ~PumpSession(); 55 56 int processedTokens; 57 double startTime; 58 bool needsYield; 59 bool didSeeScript; 60 }; 61 62 class HTMLParserScheduler { 63 WTF_MAKE_NONCOPYABLE(HTMLParserScheduler); WTF_MAKE_FAST_ALLOCATED; 64 public: create(HTMLDocumentParser * parser)65 static PassOwnPtr<HTMLParserScheduler> create(HTMLDocumentParser* parser) 66 { 67 return adoptPtr(new HTMLParserScheduler(parser)); 68 } 69 ~HTMLParserScheduler(); 70 71 // Inline as this is called after every token in the parser. checkForYieldBeforeToken(PumpSession & session)72 void checkForYieldBeforeToken(PumpSession& session) 73 { 74 if (session.processedTokens > parserChunkSize || session.didSeeScript) { 75 // currentTime() can be expensive. By delaying, we avoided calling 76 // currentTime() when constructing non-yielding PumpSessions. 77 if (!session.startTime) 78 session.startTime = currentTime(); 79 80 session.processedTokens = 0; 81 session.didSeeScript = false; 82 83 double elapsedTime = currentTime() - session.startTime; 84 if (elapsedTime > parserTimeLimit) 85 session.needsYield = true; 86 } 87 ++session.processedTokens; 88 } 89 90 void scheduleForResume(); isScheduledForResume()91 bool isScheduledForResume() const { return m_isSuspendedWithActiveTimer || m_continueNextChunkTimer.isActive(); } 92 93 void suspend(); 94 void resume(); 95 96 private: 97 static const double parserTimeLimit; 98 static const int parserChunkSize; 99 100 HTMLParserScheduler(HTMLDocumentParser*); 101 102 void continueNextChunkTimerFired(Timer<HTMLParserScheduler>*); 103 104 HTMLDocumentParser* m_parser; 105 106 Timer<HTMLParserScheduler> m_continueNextChunkTimer; 107 bool m_isSuspendedWithActiveTimer; 108 }; 109 110 } 111 112 #endif 113