chrome/browser/prerender/prerender_resource_throttle.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_
   6 #define CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "content/public/browser/resource_throttle.h"
  12 #include "webkit/common/resource_type.h"
  13
  14 namespace net {
  15 class URLRequest;
  16 }
  17
  18 namespace prerender {
  19 class PrerenderContents;
  20 class PrerenderTracker;
  21
  22 // This class implements policy on resource requests in prerenders.  It cancels
  23 // prerenders on certain requests.  It also defers certain requests until after
  24 // the prerender is swapped in.
  25 //
  26 // TODO(davidben): Experiment with deferring network requests that
  27 // would otherwise cancel the prerender.
  28 class PrerenderResourceThrottle
  29     : public content::ResourceThrottle,
  30       public base::SupportsWeakPtr<PrerenderResourceThrottle> {
  31  public:
  32   PrerenderResourceThrottle(net::URLRequest* request,
  33                             PrerenderTracker* tracker);
  34
  35   // content::ResourceThrottle implementation:
  36   virtual void WillStartRequest(bool* defer) OVERRIDE;
  37   virtual void WillRedirectRequest(const GURL& new_url, bool* defer) OVERRIDE;
  38   virtual const char* GetNameForLogging() const OVERRIDE;
  39
  40   // Called by the PrerenderTracker when a prerender becomes visible.
  41   // May only be called if currently throttling the resource.
  42   void Resume();
  43
  44   // Called by the PrerenderTracker when a prerender is destroyed.
  45   // May only be called if currently throttling the resource.
  46   void Cancel();
  47
  48   static void OverridePrerenderContentsForTesting(PrerenderContents* contents);
  49
  50  private:
  51   static void WillStartRequestOnUI(
  52       const base::WeakPtr<PrerenderResourceThrottle>& throttle,
  53       const std::string& method,
  54       int render_process_id,
  55       int render_frame_id,
  56       const GURL& url);
  57
  58   static void WillRedirectRequestOnUI(
  59       const base::WeakPtr<PrerenderResourceThrottle>& throttle,
  60       const std::string& follow_only_when_prerender_shown_header,
  61       ResourceType::Type resource_type,
  62       bool async,
  63       int render_process_id,
  64       int render_frame_id,
  65       const GURL& new_url);
  66
  67   // Helper to return the PrerenderContents given a render frame id. May return
  68   // NULL if it's gone.
  69   static PrerenderContents* PrerenderContentsFromRenderFrame(
  70       int render_process_id, int render_frame_id);
  71
  72   // Helper method to call tracker_->AddResourceThrottleOnIOThread.
  73   void AddResourceThrottle();
  74
  75   net::URLRequest* request_;
  76   PrerenderTracker* tracker_;
  77
  78   DISALLOW_COPY_AND_ASSIGN(PrerenderResourceThrottle);
  79 };
  80
  81 }  // namespace prerender
  82
  83 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_