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      1 /*
      2  * Copyright (C) 2000 Peter Kelly (pmk (at) post.com)
      3  * Copyright (C) 2005, 2006 Apple Computer, Inc.
      4  * Copyright (C) 2007 Samuel Weinig (sam (at) webkit.org)
      5  * Copyright (C) 2010 Google, Inc.
      6  *
      7  * This library is free software; you can redistribute it and/or
      8  * modify it under the terms of the GNU Library General Public
      9  * License as published by the Free Software Foundation; either
     10  * version 2 of the License, or (at your option) any later version.
     11  *
     12  * This library is distributed in the hope that it will be useful,
     13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     15  * Library General Public License for more details.
     16  *
     17  * You should have received a copy of the GNU Library General Public License
     18  * along with this library; see the file COPYING.LIB.  If not, write to
     19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     20  * Boston, MA 02110-1301, USA.
     21  *
     22  */
     23 
     24 #ifndef DocumentParser_h
     25 #define DocumentParser_h
     26 
     27 #include "platform/heap/Handle.h"
     28 #include "wtf/Forward.h"
     29 #include "wtf/RefCounted.h"
     30 
     31 namespace WebCore {
     32 
     33 class Document;
     34 class DocumentWriter;
     35 class SegmentedString;
     36 class ScriptableDocumentParser;
     37 class TextResourceDecoder;
     38 
     39 class DocumentParser : public RefCountedWillBeGarbageCollectedFinalized<DocumentParser> {
     40 public:
     41     virtual ~DocumentParser();
     42     virtual void trace(Visitor*);
     43 
     44     virtual ScriptableDocumentParser* asScriptableDocumentParser() { return 0; }
     45 
     46     // http://www.whatwg.org/specs/web-apps/current-work/#insertion-point
     47     virtual bool hasInsertionPoint() { return true; }
     48 
     49     // insert is used by document.write.
     50     virtual void insert(const SegmentedString&) = 0;
     51 
     52     // The below functions are used by DocumentWriter (the loader).
     53     virtual void appendBytes(const char* bytes, size_t length) = 0;
     54     virtual void flush() = 0;
     55     virtual bool needsDecoder() const { return false; }
     56     virtual void setDecoder(PassOwnPtr<TextResourceDecoder>);
     57     virtual TextResourceDecoder* decoder();
     58     virtual void setHasAppendedData() { }
     59 
     60     // pinToMainThread also makes append() not yield before completion of that chunk.
     61     virtual void pinToMainThread() { }
     62 
     63     // FIXME: append() should be private, but DocumentWriter::replaceDocument uses it for now.
     64     // FIXME: This really should take a PassOwnPtr to signify that it expects to take
     65     // ownership of the buffer. The parser expects the PassRefPtr to hold the only ref of the StringImpl.
     66     virtual void append(PassRefPtr<StringImpl>) = 0;
     67 
     68     virtual void finish() = 0;
     69 
     70     // FIXME: processingData() is only used by DocumentLoader::isLoadingInAPISense
     71     // and is very unclear as to what it actually means.  The LegacyHTMLDocumentParser
     72     // used to implement it.
     73     virtual bool processingData() const { return false; }
     74 
     75     // document() will return 0 after detach() is called.
     76     Document* document() const { ASSERT(m_document); return m_document; }
     77 
     78     bool isParsing() const { return m_state == ParsingState; }
     79     bool isStopping() const { return m_state == StoppingState; }
     80     bool isStopped() const { return m_state >= StoppedState; }
     81     bool isDetached() const { return m_state == DetachedState; }
     82 
     83     // FIXME: Is this necessary? Does XMLDocumentParserLibxml2 really need to set this?
     84     virtual void startParsing();
     85 
     86     // prepareToStop() is used when the EOF token is encountered and parsing is to be
     87     // stopped normally.
     88     virtual void prepareToStopParsing();
     89 
     90     // stopParsing() is used when a load is canceled/stopped.
     91     // stopParsing() is currently different from detach(), but shouldn't be.
     92     // It should NOT be ok to call any methods on DocumentParser after either
     93     // detach() or stopParsing() but right now only detach() will ASSERT.
     94     virtual void stopParsing();
     95 
     96     // Document is expected to detach the parser before releasing its ref.
     97     // After detach, m_document is cleared.  The parser will unwind its
     98     // callstacks, but not produce any more nodes.
     99     // It is impossible for the parser to touch the rest of WebCore after
    100     // detach is called.
    101     // Oilpan: We don't need to call detach when a Document is destructed.
    102     virtual void detach();
    103 
    104     void setDocumentWasLoadedAsPartOfNavigation() { m_documentWasLoadedAsPartOfNavigation = true; }
    105     bool documentWasLoadedAsPartOfNavigation() const { return m_documentWasLoadedAsPartOfNavigation; }
    106 
    107     // FIXME: The names are not very accurate :(
    108     virtual void suspendScheduledTasks();
    109     virtual void resumeScheduledTasks();
    110 
    111 protected:
    112     explicit DocumentParser(Document*);
    113 
    114 private:
    115     enum ParserState {
    116         ParsingState,
    117         StoppingState,
    118         StoppedState,
    119         DetachedState
    120     };
    121     ParserState m_state;
    122     bool m_documentWasLoadedAsPartOfNavigation;
    123 
    124     // Every DocumentParser needs a pointer back to the document.
    125     // m_document will be 0 after the parser is stopped.
    126     RawPtrWillBeMember<Document> m_document;
    127 };
    128 
    129 } // namespace WebCore
    130 
    131 #endif // DocumentParser_h
    132