Add <link rel=preconnect> support to the HTMLPreloadScanner

Source/core/html/parser/HTMLPreloadScanner.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
  * 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.
@@ skipping 93 matching lines @@
     RefPtrWillBeRawPtr<MediaQuerySet> mediaQueries = MediaQuerySet::createOffMainThread(attributeValue);
     MediaQueryEvaluator mediaQueryEvaluator(mediaValues);
     return mediaQueryEvaluator.eval(mediaQueries.get());
 }
 
 class TokenPreloadScanner::StartTagScanner {
 public:
     StartTagScanner(const StringImpl* tagImpl, PassRefPtr<MediaValues> mediaValues)
         : m_tagImpl(tagImpl)
         , m_linkIsStyleSheet(false)
+        , m_linkIsPreconnect(false)
         , m_matchedMediaAttribute(true)
         , m_inputIsImage(false)
         , m_sourceSize(0)
         , m_sourceSizeSet(false)
         , m_isCORSEnabled(false)
         , m_defer(FetchRequest::NoDefer)
         , m_allowCredentials(DoNotAllowStoredCredentials)
         , m_mediaValues(mediaValues)
     {
         ASSERT(m_mediaValues->isCached());
@@ skipping 37 matching lines @@
     void handlePictureSourceURL(String& sourceURL)
     {
         if (match(m_tagImpl, sourceTag) && m_matchedMediaAttribute && sourceURL.isEmpty())
             sourceURL = m_srcsetImageCandidate.toString();
         else if (match(m_tagImpl, imgTag) && !sourceURL.isEmpty())
             setUrlToLoad(sourceURL, AllowURLReplacement);
     }
 
     PassOwnPtr<PreloadRequest> createPreloadRequest(const KURL& predictedBaseURL, const SegmentedString& source, const ClientHintsPreferences& clientHintsPreferences)
     {
-        if (!shouldPreload() || !m_matchedMediaAttribute)
+        PreloadRequest::RequestType requestType = PreloadRequest::RequestTypePreload;
+        if (shouldPreconnect())
+            requestType = PreloadRequest::RequestTypePreconnect;
+        else if (!shouldPreload() || !m_matchedMediaAttribute)
             return nullptr;
 
         TextPosition position = TextPosition(source.currentLine(), source.currentColumn());
         FetchRequest::ResourceWidth resourceWidth;
         if (m_sourceSizeSet && m_srcsetImageCandidate.resourceWidth() != UninitializedDescriptor) {
             resourceWidth.width = m_sourceSize;
             resourceWidth.isSet = true;
         }
-        OwnPtr<PreloadRequest> request = PreloadRequest::create(initiatorFor(m_tagImpl), position, m_urlToLoad, predictedBaseURL, resourceType(), resourceWidth, clientHintsPreferences);
+        OwnPtr<PreloadRequest> request = PreloadRequest::create(initiatorFor(m_tagImpl), position, m_urlToLoad, predictedBaseURL, resourceType(), resourceWidth, clientHintsPreferences, requestType);
         if (isCORSEnabled())
             request->setCrossOriginEnabled(allowStoredCredentials());
         request->setCharset(charset());
         request->setDefer(m_defer);
         return request.release();
     }
 
 private:
     template<typename NameType>
     void processScriptAttribute(const NameType& attributeName, const String& attributeValue)
@@ skipping 28 matching lines @@
                 m_srcsetImageCandidate = bestFitSourceForSrcsetAttribute(m_mediaValues->devicePixelRatio(), m_sourceSize, m_srcsetAttributeValue);
                 setUrlToLoad(bestFitSourceForImageAttributes(m_mediaValues->devicePixelRatio(), m_sourceSize, m_imgSrcUrl, m_srcsetImageCandidate), AllowURLReplacement);
             }
         }
     }
 
     template<typename NameType>
     void processLinkAttribute(const NameType& attributeName, const String& attributeValue)
     {
         // FIXME - Don't set rel/media/crossorigin multiple times.
-        if (match(attributeName, hrefAttr))
+        if (match(attributeName, hrefAttr)) {
             setUrlToLoad(attributeValue, DisallowURLReplacement);
-        else if (match(attributeName, relAttr))
-            m_linkIsStyleSheet = relAttributeIsStyleSheet(attributeValue);
-        else if (match(attributeName, mediaAttr))
+        } else if (match(attributeName, relAttr)) {
+            LinkRelAttribute rel(attributeValue);
+            m_linkIsStyleSheet = rel.isStyleSheet() && !rel.isAlternate() && rel.iconType() == InvalidIcon && !rel.isDNSPrefetch();
+            m_linkIsPreconnect = rel.isPreconnect();
+        } else if (match(attributeName, mediaAttr)) {
             m_matchedMediaAttribute = mediaAttributeMatches(*m_mediaValues, attributeValue);
-        else if (match(attributeName, crossoriginAttr))
+        } else if (match(attributeName, crossoriginAttr)) {
             setCrossOriginAllowed(attributeValue);
+        }
     }
 
     template<typename NameType>
     void processInputAttribute(const NameType& attributeName, const String& attributeValue)
     {
         // FIXME - Don't set type multiple times.
         if (match(attributeName, srcAttr))
             setUrlToLoad(attributeValue, DisallowURLReplacement);
         else if (match(attributeName, typeAttr))
             m_inputIsImage = equalIgnoringCase(attributeValue, InputTypeNames::image);
@@ skipping 37 matching lines @@
         else if (match(m_tagImpl, linkTag))
             processLinkAttribute(attributeName, attributeValue);
         else if (match(m_tagImpl, inputTag))
             processInputAttribute(attributeName, attributeValue);
         else if (match(m_tagImpl, sourceTag))
             processSourceAttribute(attributeName, attributeValue);
         else if (match(m_tagImpl, videoTag))
             processVideoAttribute(attributeName, attributeValue);
     }
 
-    static bool relAttributeIsStyleSheet(const String& attributeValue)
-    {
-        LinkRelAttribute rel(attributeValue);
-        return rel.isStyleSheet() && !rel.isAlternate() && rel.iconType() == InvalidIcon && !rel.isDNSPrefetch();
-    }
-
     void setUrlToLoad(const String& value, URLReplacement replacement)
     {
         // We only respect the first src/href, per HTML5:
         // http://www.whatwg.org/specs/web-apps/current-work/multipage/tokenization.html#attribute-name-state
         if (replacement == DisallowURLReplacement && !m_urlToLoad.isEmpty())
             return;
         String url = stripLeadingAndTrailingHTMLSpaces(value);
         if (url.isEmpty())
             return;
         m_urlToLoad = url;
     }
 
     const String& charset() const
     {
         // FIXME: Its not clear that this if is needed, the loader probably ignores charset for image requests anyway.
         if (match(m_tagImpl, imgTag) || match(m_tagImpl, videoTag))
             return emptyString();
         return m_charset;
     }
 
     Resource::Type resourceType() const
     {
         if (match(m_tagImpl, scriptTag))
             return Resource::Script;
         if (match(m_tagImpl, imgTag) || match(m_tagImpl, videoTag) || (match(m_tagImpl, inputTag) && m_inputIsImage))
             return Resource::Image;
         if (match(m_tagImpl, linkTag) && m_linkIsStyleSheet)
             return Resource::CSSStyleSheet;
+        if (m_linkIsPreconnect)
+            return Resource::Raw;
         ASSERT_NOT_REACHED();
         return Resource::Raw;
     }
 
+    bool shouldPreconnect() const
+    {
+        return match(m_tagImpl, linkTag) && m_linkIsPreconnect && !m_urlToLoad.isEmpty();
+    }
+
     bool shouldPreload() const
     {
         if (m_urlToLoad.isEmpty())
             return false;
         if (match(m_tagImpl, linkTag) && !m_linkIsStyleSheet)
             return false;
         if (match(m_tagImpl, inputTag) && !m_inputIsImage)
             return false;
         return true;
     }
@@ skipping 25 matching lines @@
     bool defer() const
     {
         return m_defer;
     }
 
     const StringImpl* m_tagImpl;
     String m_urlToLoad;
     ImageCandidate m_srcsetImageCandidate;
     String m_charset;
     bool m_linkIsStyleSheet;
+    bool m_linkIsPreconnect;
     bool m_matchedMediaAttribute;
     bool m_inputIsImage;
     String m_imgSrcUrl;
     String m_srcsetAttributeValue;
     float m_sourceSize;
     bool m_sourceSizeSet;
     bool m_isCORSEnabled;
     FetchRequest::DeferOption m_defer;
     StoredCredentials m_allowCredentials;
     RefPtr<MediaValues> m_mediaValues;
@@ skipping 213 matching lines @@
         mediaValues = givenMediaValues;
     else
         mediaValues = MediaValuesCached::create(*document);
     ASSERT(mediaValues->isSafeToSendToAnotherThread());
     defaultViewportMinWidth = document->viewportDefaultMinWidth();
     viewportMetaZeroValuesQuirk = document->settings() && document->settings()->viewportMetaZeroValuesQuirk();
     viewportMetaEnabled = document->settings() && document->settings()->viewportMetaEnabled();
 }
 
 }