third_party/WebKit/Source/core/loader/LinkLoader.h

/*
 * 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER 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 LinkLoader_h
#define LinkLoader_h

#include "core/CoreExport.h"
#include "core/fetch/ResourceClient.h"
#include "core/fetch/ResourceOwner.h"
#include "core/loader/LinkLoaderClient.h"
#include "core/loader/LinkPreloadResourceClients.h"
#include "platform/CrossOriginAttributeValue.h"
#include "platform/PrerenderClient.h"
#include "platform/Timer.h"
#include "platform/heap/Handle.h"

namespace blink {

class Document;
class LinkRelAttribute;
class NetworkHintsInterface;
class PrerenderHandle;
struct ViewportDescriptionWrapper;

// The LinkLoader can load link rel types icon, dns-prefetch, subresource,
// prefetch and prerender.
class CORE_EXPORT LinkLoader final
    : public GarbageCollectedFinalized<LinkLoader>,
      public ResourceOwner<Resource, ResourceClient>,
      public PrerenderClient {
  USING_GARBAGE_COLLECTED_MIXIN(LinkLoader);

 public:
  static LinkLoader* create(LinkLoaderClient* client) {
    return new LinkLoader(client);
  }
  ~LinkLoader() override;

  // from ResourceClient
  void notifyFinished(Resource*) override;
  String debugName() const override { return "LinkLoader"; }

  // from PrerenderClient
  void didStartPrerender() override;
  void didStopPrerender() override;
  void didSendLoadForPrerender() override;
  void didSendDOMContentLoadedForPrerender() override;

  void triggerEvents(const Resource*);

  void released();
  bool loadLink(const LinkRelAttribute&,
                CrossOriginAttributeValue,
                const String& type,
                const String& as,
                const String& media,
                const KURL&,
                Document&,
                const NetworkHintsInterface&);
  enum CanLoadResources {
    OnlyLoadResources,
    DoNotLoadResources,
    LoadResourcesAndPreconnect
  };
  // Media links cannot be preloaded until the first chunk is parsed. The rest
  // can be preloaded at commit time.
  enum MediaPreloadPolicy { LoadAll, OnlyLoadNonMedia, OnlyLoadMedia };
  static void loadLinksFromHeader(const String& headerValue,
                                  const KURL& baseURL,
                                  Document*,
                                  const NetworkHintsInterface&,
                                  CanLoadResources,
                                  MediaPreloadPolicy,
                                  ViewportDescriptionWrapper*);
  static bool getResourceTypeFromAsAttribute(const String& as, Resource::Type&);

  DECLARE_TRACE();

 private:
  explicit LinkLoader(LinkLoaderClient*);

  void linkLoadTimerFired(TimerBase*);
  void linkLoadingErrorTimerFired(TimerBase*);
  void createLinkPreloadResourceClient(Resource*);

  Member<LinkLoaderClient> m_client;

  Timer<LinkLoader> m_linkLoadTimer;
  Timer<LinkLoader> m_linkLoadingErrorTimer;

  Member<PrerenderHandle> m_prerender;
  Member<LinkPreloadResourceClient> m_linkPreloadResourceClient;
};

}  // namespace blink

#endif