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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 "wtf/Forward.h"
     28 #include "wtf/RefCounted.h"
     29 
     30 namespace WebCore {
     31 
     32 class Document;
     33 class DocumentWriter;
     34 class SegmentedString;
     35 class ScriptableDocumentParser;
     36 
     37 class DocumentParser : public RefCounted<DocumentParser> {
     38 public:
     39     virtual ~DocumentParser();
     40 
     41     virtual ScriptableDocumentParser* asScriptableDocumentParser() { return 0; }
     42 
     43     // http://www.whatwg.org/specs/web-apps/current-work/#insertion-point
     44     virtual bool hasInsertionPoint() { return true; }
     45 
     46     // insert is used by document.write.
     47     virtual void insert(const SegmentedString&) = 0;
     48 
     49     // appendBytes and flush are used by DocumentWriter (the loader).
     50     virtual size_t appendBytes(const char* bytes, size_t length) = 0;
     51     virtual size_t flush() = 0;
     52     virtual bool needsDecoder() const { return false; }
     53 
     54     // pinToMainThread also makes append() not yield before completion of that chunk.
     55     virtual void pinToMainThread() { }
     56 
     57     // FIXME: append() should be private, but DocumentWriter::replaceDocument uses it for now.
     58     // FIXME: This really should take a PassOwnPtr to signify that it expects to take
     59     // ownership of the buffer. The parser expects the PassRefPtr to hold the only ref of the StringImpl.
     60     virtual void append(PassRefPtr<StringImpl>) = 0;
     61 
     62     virtual void finish() = 0;
     63 
     64     // FIXME: processingData() is only used by DocumentLoader::isLoadingInAPISense
     65     // and is very unclear as to what it actually means.  The LegacyHTMLDocumentParser
     66     // used to implement it.
     67     virtual bool processingData() const { return false; }
     68 
     69     // document() will return 0 after detach() is called.
     70     Document* document() const { ASSERT(m_document); return m_document; }
     71 
     72     bool isParsing() const { return m_state == ParsingState; }
     73     bool isStopping() const { return m_state == StoppingState; }
     74     bool isStopped() const { return m_state >= StoppedState; }
     75     bool isDetached() const { return m_state == DetachedState; }
     76 
     77     // FIXME: Is this necessary? Does XMLDocumentParserLibxml2 really need to set this?
     78     virtual void startParsing();
     79 
     80     // prepareToStop() is used when the EOF token is encountered and parsing is to be
     81     // stopped normally.
     82     virtual void prepareToStopParsing();
     83 
     84     // stopParsing() is used when a load is canceled/stopped.
     85     // stopParsing() is currently different from detach(), but shouldn't be.
     86     // It should NOT be ok to call any methods on DocumentParser after either
     87     // detach() or stopParsing() but right now only detach() will ASSERT.
     88     virtual void stopParsing();
     89 
     90     // Document is expected to detach the parser before releasing its ref.
     91     // After detach, m_document is cleared.  The parser will unwind its
     92     // callstacks, but not produce any more nodes.
     93     // It is impossible for the parser to touch the rest of WebCore after
     94     // detach is called.
     95     virtual void detach();
     96 
     97     void setDocumentWasLoadedAsPartOfNavigation() { m_documentWasLoadedAsPartOfNavigation = true; }
     98     bool documentWasLoadedAsPartOfNavigation() const { return m_documentWasLoadedAsPartOfNavigation; }
     99 
    100     // FIXME: The names are not very accurate :(
    101     virtual void suspendScheduledTasks();
    102     virtual void resumeScheduledTasks();
    103 
    104 protected:
    105     explicit DocumentParser(Document*);
    106 
    107 private:
    108     enum ParserState {
    109         ParsingState,
    110         StoppingState,
    111         StoppedState,
    112         DetachedState
    113     };
    114     ParserState m_state;
    115     bool m_documentWasLoadedAsPartOfNavigation;
    116 
    117     // Every DocumentParser needs a pointer back to the document.
    118     // m_document will be 0 after the parser is stopped.
    119     Document* m_document;
    120 };
    121 
    122 } // namespace WebCore
    123 
    124 #endif // DocumentParser_h
    125