Source/core/html/parser/HTMLPreloadScanner.h

/*
 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
 * Copyright (C) 2010 Google Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef HTMLPreloadScanner_h
#define HTMLPreloadScanner_h

#include "core/html/parser/CSSPreloadScanner.h"
#include "core/html/parser/CompactHTMLToken.h"
#include "core/html/parser/HTMLToken.h"
#include "core/platform/text/SegmentedString.h"
#include "wtf/Vector.h"

namespace WebCore {

typedef size_t TokenPreloadScannerCheckpoint;

class HTMLParserOptions;
class HTMLTokenizer;
class SegmentedString;

class TokenPreloadScanner {
    WTF_MAKE_NONCOPYABLE(TokenPreloadScanner); WTF_MAKE_FAST_ALLOCATED;
public:
    TokenPreloadScanner(const KURL& documentURL, float deviceScaleFactor);
    ~TokenPreloadScanner();

    void scan(const HTMLToken&, const SegmentedString&, PreloadRequestStream& requests);
    void scan(const CompactHTMLToken&, const SegmentedString&, PreloadRequestStream& requests);

    void setPredictedBaseElementURL(const KURL& url) { m_predictedBaseElementURL = url; }

    // A TokenPreloadScannerCheckpoint is valid until the next call to rewindTo,
    // at which point all outstanding checkpoints are invalidated.
    TokenPreloadScannerCheckpoint createCheckpoint();
    void rewindTo(TokenPreloadScannerCheckpoint);

    bool isSafeToSendToAnotherThread()
    {
        return m_documentURL.isSafeToSendToAnotherThread()
            && m_predictedBaseElementURL.isSafeToSendToAnotherThread();
    }

private:
    class StartTagScanner;

    template<typename Token>
    inline void scanCommon(const Token&, const SegmentedString&, PreloadRequestStream& requests);

    template<typename Token>
    void updatePredictedBaseURL(const Token&);

    struct Checkpoint {
        Checkpoint(const KURL& predictedBaseElementURL, bool inStyle, size_t templateCount)
            : predictedBaseElementURL(predictedBaseElementURL)
            , inStyle(inStyle)
            , templateCount(templateCount)
        {
        }

        KURL predictedBaseElementURL;
        bool inStyle;
        size_t templateCount;
    };

    CSSPreloadScanner m_cssScanner;
    const KURL m_documentURL;
    KURL m_predictedBaseElementURL;
    bool m_inStyle;
    float m_deviceScaleFactor;
    size_t m_templateCount;

    Vector<Checkpoint> m_checkpoints;
};

class HTMLPreloadScanner {
    WTF_MAKE_NONCOPYABLE(HTMLPreloadScanner); WTF_MAKE_FAST_ALLOCATED;
public:
    HTMLPreloadScanner(const HTMLParserOptions&, const KURL& documentURL, float deviceScaleFactor);
    ~HTMLPreloadScanner();

    void appendToEnd(const SegmentedString&);
    void scan(HTMLResourcePreloader*, const KURL& documentBaseElementURL);

private:
    TokenPreloadScanner m_scanner;
    SegmentedString m_source;
    HTMLToken m_token;
    OwnPtr<HTMLTokenizer> m_tokenizer;
};

}

#endif