transferSize implementation

third_party/WebKit/Source/core/loader/DocumentLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2011 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 89 matching lines @@
                                ClientRedirectPolicy clientRedirectPolicy)
     : m_frame(frame),
       m_fetcher(FrameFetchContext::createContextAndFetcher(this, nullptr)),
       m_originalRequest(req),
       m_substituteData(substituteData),
       m_request(req),
       m_isClientRedirect(clientRedirectPolicy ==
                          ClientRedirectPolicy::ClientRedirect),
       m_replacesCurrentHistoryItem(false),
       m_dataReceived(false),
+      m_mainResourceIdentifier(0),
       m_navigationType(NavigationTypeOther),
       m_documentLoadTiming(*this),
       m_timeOfLastDataReceived(0.0),
       m_applicationCacheHost(ApplicationCacheHost::create(this)),
       m_wasBlockedAfterXFrameOptionsOrCSP(false),
       m_state(NotStarted),
       m_inDataReceived(false),
       m_dataBuffer(SharedBuffer::create()) {
   // The document URL needs to be added to the head of the list as that is
   // where the redirects originated.
@@ skipping 18 matching lines @@
   visitor->trace(m_fetcher);
   visitor->trace(m_mainResource);
   visitor->trace(m_writer);
   visitor->trace(m_documentLoadTiming);
   visitor->trace(m_applicationCacheHost);
   visitor->trace(m_contentSecurityPolicy);
   RawResourceClient::trace(visitor);
 }
 
 unsigned long DocumentLoader::mainResourceIdentifier() const {
-  return m_mainResource ? m_mainResource->identifier() : 0;
+  return m_mainResourceIdentifier;

[Yoav Weiss, 2016/11/29 10:39:32]

Why do we need to store this rather than get the identifier from m_mainResource
as before? Did you see issues related to that?

[sunjian, 2016/11/29 19:33:30]

Yeah, m_mainResource gets reset to nullptr after in clearMainResourceHandle()
after notifyFinished(Resource* resource) gets called. The
mainResourceIdentifier() method was used for logging purpose when they decide
not to continue loading (something went wrong) which will not cause
m_mainResource gets cleared. But when loading finished (success or failure),
they decided that they no longer need to hold on to this object any more. 

+}
+
+ResourceTimingInfo* DocumentLoader::getMainResourceTimingInfo() const {
+  return fetcher()->getMainResourceTimingInfo(mainResourceIdentifier());
 }
 
 const ResourceRequest& DocumentLoader::originalRequest() const {
   return m_originalRequest;
 }
 
 const ResourceRequest& DocumentLoader::request() const {
   return m_request;
 }
 
@@ skipping 551 matching lines @@
   }
 
   DEFINE_STATIC_LOCAL(
       ResourceLoaderOptions, mainResourceLoadOptions,
       (DoNotBufferData, AllowStoredCredentials, ClientRequestedCredentials,
        CheckContentSecurityPolicy, DocumentContext));
   FetchRequest fetchRequest(m_request, FetchInitiatorTypeNames::document,
                             mainResourceLoadOptions);
   m_mainResource =
       RawResource::fetchMainResource(fetchRequest, fetcher(), m_substituteData);
+  m_mainResourceIdentifier = m_mainResource ? m_mainResource->identifier() : 0;
 
   // PlzNavigate:
   // The final access checks are still performed here, potentially rejecting
   // the "provisional" load, but the browser side already expects the renderer
   // to be able to unconditionally commit.
   if (!m_mainResource || (m_frame->settings()->browserSideNavigationEnabled() &&
                           m_mainResource->errorOccurred())) {
     m_request = ResourceRequest(blankURL());
     maybeLoadEmpty();
     return;
@@ skipping 63 matching lines @@
                              m_writer ? m_writer->encoding() : emptyAtom, true,
                              ForceSynchronousParsing);
   if (!source.isNull())
     m_writer->appendReplacingData(source);
   endWriting();
 }
 
 DEFINE_WEAK_IDENTIFIER_MAP(DocumentLoader);
 
 }  // namespace blink