PassRefPtrWillBeRawPtr<XSLStyleSheetResource> XSLStyleSheetResource::fetchSynchronously(FetchRequest& request, ResourceFetcher* fetcher)
{
request.mutableResourceRequest().setTimeoutInterval(10);
request.mutableResourceRequest().setRequestContext(WebURLRequest::RequestContextXSLT);
ResourceLoaderOptions options(request.options());
options.synchronousPolicy = RequestSynchronously;
request.setOptions(options);
RefPtrWillBeRawPtr<XSLStyleSheetResource> resource = toXSLStyleSheetResource(fetcher->requestResource(request, XSLStyleSheetResourceFactory()));
if (resource && resource->m_data)
resource->m_sheet = resource->decodedText();
return resource;
}
ResourceFetcher::RevalidationPolicy ResourceFetcher::determineRevalidationPolicy(Resource::Type type, const FetchRequest& fetchRequest, Resource* existingResource) const
{
const ResourceRequest& request = fetchRequest.resourceRequest();
if (!existingResource)
return Load;
// If the same URL has been loaded as a different type, we need to reload.
if (existingResource->type() != type) {
WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to type mismatch.");
return Reload;
}
// Do not load from cache if images are not enabled. The load for this image will be blocked
// in ImageResource::load.
if (FetchRequest::DeferredByClient == fetchRequest.defer())
return Reload;
// Always use data uris.
// FIXME: Extend this to non-images.
if (type == Resource::Image && request.url().protocolIsData())
return Use;
if (!existingResource->canReuse(request))
return Reload;
// Never use cache entries for downloadToFile requests. The caller expects the resource in a file.
if (request.downloadToFile())
return Reload;
// Certain requests (e.g., XHRs) might have manually set headers that require revalidation.
// FIXME: In theory, this should be a Revalidate case. In practice, the MemoryCache revalidation path assumes a whole bunch
// of things about how revalidation works that manual headers violate, so punt to Reload instead.
if (request.isConditional())
return Reload;
// Don't reload resources while pasting.
if (m_allowStaleResources)
return Use;
if (!fetchRequest.options().canReuseRequest(existingResource->options()))
return Reload;
// CachePolicyHistoryBuffer uses the cache no matter what.
CachePolicy cachePolicy = context().cachePolicy(document());
if (cachePolicy == CachePolicyHistoryBuffer)
return Use;
// Don't reuse resources with Cache-control: no-store.
if (existingResource->hasCacheControlNoStoreHeader()) {
WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to Cache-control: no-store.");
return Reload;
}
// If credentials were sent with the previous request and won't be
// with this one, or vice versa, re-fetch the resource.
//
// This helps with the case where the server sends back
// "Access-Control-Allow-Origin: *" all the time, but some of the
// client's requests are made without CORS and some with.
if (existingResource->resourceRequest().allowStoredCredentials() != request.allowStoredCredentials()) {
WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to difference in credentials settings.");
return Reload;
}
// During the initial load, avoid loading the same resource multiple times for a single document,
// even if the cache policies would tell us to.
// We also group loads of the same resource together.
// Raw resources are exempted, as XHRs fall into this category and may have user-set Cache-Control:
// headers or other factors that require separate requests.
if (type != Resource::Raw) {
if (document() && !document()->loadEventFinished() && m_validatedURLs.contains(existingResource->url()))
return Use;
if (existingResource->isLoading())
return Use;
}
// CachePolicyReload always reloads
if (cachePolicy == CachePolicyReload) {
WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to CachePolicyReload.");
return Reload;
}
// We'll try to reload the resource if it failed last time.
if (existingResource->errorOccurred()) {
WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicye reloading due to resource being in the error state");
return Reload;
}
// List of available images logic allows images to be re-used without cache validation. We restrict this only to images
// from memory cache which are the same as the version in the current document.
if (type == Resource::Image && existingResource == cachedResource(request.url()))
return Use;
// Check if the cache headers requires us to revalidate (cache expiration for example).
if (cachePolicy == CachePolicyRevalidate || existingResource->mustRevalidateDueToCacheHeaders()
|| request.cacheControlContainsNoCache()) {
// See if the resource has usable ETag or Last-modified headers.
if (existingResource->canUseCacheValidator())
return Revalidate;
// No, must reload.
WTF_LOG(ResourceLoading, "ResourceFetcher::determineRevalidationPolicy reloading due to missing cache validators.");
return Reload;
}
return Use;
}
ResourcePtr<Resource> ResourceFetcher::requestResource(Resource::Type type, FetchRequest& request)
{
ASSERT(request.options().synchronousPolicy == RequestAsynchronously || type == Resource::Raw);
TRACE_EVENT0("blink", "ResourceFetcher::requestResource");
KURL url = request.resourceRequest().url();
WTF_LOG(ResourceLoading, "ResourceFetcher::requestResource '%s', charset '%s', priority=%d, type=%s", url.elidedString().latin1().data(), request.charset().latin1().data(), request.priority(), ResourceTypeName(type));
// If only the fragment identifiers differ, it is the same resource.
url = MemoryCache::removeFragmentIdentifierIfNeeded(url);
if (!url.isValid())
return 0;
if (!canRequest(type, url, request.options(), request.originRestriction()))
return 0;
if (LocalFrame* f = frame())
f->loaderClient()->dispatchWillRequestResource(&request);
// See if we can use an existing resource from the cache.
ResourcePtr<Resource> resource = memoryCache()->resourceForURL(url);
const RevalidationPolicy policy = determineRevalidationPolicy(type, request, resource.get());
switch (policy) {
case Reload:
memoryCache()->remove(resource.get());
// Fall through
case Load:
resource = createResourceForLoading(type, request, request.charset());
break;
case Revalidate:
resource = createResourceForRevalidation(request, resource.get());
break;
case Use:
memoryCache()->updateForAccess(resource.get());
break;
}
if (!resource)
return 0;
if (!resource->hasClients())
m_deadStatsRecorder.update(policy);
if (policy != Use)
resource->setIdentifier(createUniqueIdentifier());
ResourceLoadPriority priority = loadPriority(type, request);
if (priority != resource->resourceRequest().priority()) {
resource->mutableResourceRequest().setPriority(priority);
resource->didChangePriority(priority, 0);
}
if (resourceNeedsLoad(resource.get(), request, policy)) {
if (!shouldLoadNewResource(type)) {
if (memoryCache()->contains(resource.get()))
memoryCache()->remove(resource.get());
return 0;
}
resource->load(this, request.options());
// For asynchronous loads that immediately fail, it's sufficient to return a
// null Resource, as it indicates that something prevented the load from starting.
// If there's a network error, that failure will happen asynchronously. However, if
// a sync load receives a network error, it will have already happened by this point.
// In that case, the requester should have access to the relevant ResourceError, so
// we need to return a non-null Resource.
if (resource->errorOccurred()) {
if (memoryCache()->contains(resource.get()))
memoryCache()->remove(resource.get());
return 0;
}
}
requestLoadStarted(resource.get(), request, policy == Use ? ResourceLoadingFromCache : ResourceLoadingFromNetwork);
ASSERT(resource->url() == url.string());
m_documentResources.set(resource->url(), resource);
return resource;
}
ResourcePtr<ImageResource> ImageResource::fetch(FetchRequest& request, ResourceFetcher* fetcher)
{
if (request.resourceRequest().requestContext() == WebURLRequest::RequestContextUnspecified)
request.mutableResourceRequest().setRequestContext(WebURLRequest::RequestContextImage);
if (fetcher->context().pageDismissalEventBeingDispatched()) {
KURL requestURL = request.resourceRequest().url();
if (requestURL.isValid() && fetcher->context().canRequest(Resource::Image, request.resourceRequest(), requestURL, request.options(), request.forPreload(), request.originRestriction()))
fetcher->context().sendImagePing(requestURL);
return 0;
}
if (fetcher->clientDefersImage(request.resourceRequest().url()))
request.setDefer(FetchRequest::DeferredByClient);
return toImageResource(fetcher->requestResource(request, ImageResourceFactory()));
}