Refactoring starting a resource load

third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
     Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 192 matching lines @@
     , m_imagesEnabled(true)
     , m_allowStaleResources(false)
 {
     ThreadState::current()->registerPreFinalizer(this);
 }
 
 ResourceFetcher::~ResourceFetcher()
 {
 }
 
-WebTaskRunner* ResourceFetcher::loadingTaskRunner()
-{
-    if (!m_context)
-        return nullptr;
-
-    return m_context->loadingTaskRunner();
-}
-
 Resource* ResourceFetcher::cachedResource(const KURL& resourceURL) const
 {
     KURL url = MemoryCache::removeFragmentIdentifierIfNeeded(resourceURL);
     const WeakMember<Resource>& resource = m_documentResources.get(url);
     return resource.get();
 }
 
 bool ResourceFetcher::canAccessResource(Resource* resource, SecurityOrigin* sourceOrigin, const KURL& url, AccessControlLoggingDecision logErrorsDecision) const
 {
     // Redirects can change the response URL different from one of request.
@@ skipping 251 matching lines @@
     }
 
     // If only the fragment identifiers differ, it is the same resource.
     ASSERT(equalIgnoringFragmentIdentifier(resource->url(), url));
     requestLoadStarted(resource, request, policy == Use ? ResourceLoadingFromCache : ResourceLoadingFromNetwork, isStaticData);
     m_documentResources.set(urlWithoutFragment, resource);
 
     if (!resourceNeedsLoad(resource, request, policy))
         return resource;
 
-    if (!context().shouldLoadNewResource(factory.type())) {
+    if (!startLoad(resource)) {
         if (memoryCache()->contains(resource))
             memoryCache()->remove(resource);
         return nullptr;
     }
-
-    resource->load(this);
     ASSERT(!resource->errorOccurred() || request.options().synchronousPolicy == RequestSynchronously);
     return resource;
 }
 
 void ResourceFetcher::resourceTimingReportTimerFired(Timer<ResourceFetcher>* timer)
 {
     ASSERT_UNUSED(timer, timer == &m_resourceTimingReportTimer);
     Vector<OwnPtr<ResourceTimingInfo>> timingReports;
     timingReports.swap(m_scheduledResourceTimingReports);
     for (const auto& timingInfo : timingReports)
@@ skipping 305 matching lines @@
 
 bool ResourceFetcher::shouldDeferImageLoad(const KURL& url) const
 {
     return !context().allowImage(m_imagesEnabled, url) || !m_autoLoadImages;
 }
 
 void ResourceFetcher::reloadImagesIfNotDeferred()
 {
     for (Resource* resource : m_documentResources.values()) {
         if (resource->getType() == Resource::Image && resource->stillNeedsLoad() && !shouldDeferImageLoad(resource->url()))
-            const_cast<Resource*>(resource)->load(this);
+            startLoad(resource);
     }
 }
 
+bool ResourceFetcher::startLoad(Resource* resource)
+{
+    ASSERT(resource->stillNeedsLoad());

[Yoav Weiss, 2016/04/20 08:52:08]

I believe ASSERT is now deprecated and DCHECK is the new way to go here. Also,
can you DCHECK that resource is non-null?

[Nate Chapin, 2016/05/18 23:56:04]

Done.

+    if (!context().shouldLoadNewResource(resource->getType()))
+        return false;
+
+    ResourceRequest& request(resource->prepareRequestForLoadStart());
+    KURL url = request.url();
+
+    ResourceLoader* loader = ResourceLoader::create(this, resource);
+    resource->setLoader(loader);
+    willStartLoadingResource(resource, loader, request);
+    loader->start(request, context().loadingTaskRunner(), context().defersLoading());
+
+    // If the request reference is null (i.e., a synchronous revalidation will
+    // null the request), don't make the request non-null by setting the url.
+    if (!request.isNull())
+        request.setURL(url);
+    return true;
+}
+
 void ResourceFetcher::didLoadResource(Resource* resource)
 {
     context().didLoadResource(resource);
 }
 
 int ResourceFetcher::requestCount() const
 {
     return m_loaders ? m_loaders->size() : 0;
 }
 
@@ skipping 113 matching lines @@
 void ResourceFetcher::moveResourceLoaderToNonBlocking(ResourceLoader* loader)
 {
     if (!m_nonBlockingLoaders)
         m_nonBlockingLoaders = ResourceLoaderSet::create();
     m_nonBlockingLoaders->add(loader);
     m_loaders->remove(loader);
 }
 
 void ResourceFetcher::willStartLoadingResource(Resource* resource, ResourceLoader* loader, ResourceRequest& request)
 {
-    if (loader->cachedResource()->shouldBlockLoadEvent()) {
+    if (resource->shouldBlockLoadEvent()) {
         if (!m_loaders)
             m_loaders = ResourceLoaderSet::create();
         m_loaders->add(loader);
     } else {
         if (!m_nonBlockingLoaders)
             m_nonBlockingLoaders = ResourceLoaderSet::create();
         m_nonBlockingLoaders->add(loader);
     }
 
     context().willStartLoadingResource(resource, request);
@@ skipping 203 matching lines @@
     visitor->trace(m_context);
     visitor->trace(m_archive);
     visitor->trace(m_loaders);
     visitor->trace(m_nonBlockingLoaders);
     visitor->trace(m_documentResources);
     visitor->trace(m_preloads);
     visitor->trace(m_resourceTimingInfoMap);
 }
 
 } // namespace blink