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 "content/public/common/resource_type.h"
  13
  14 namespace net {
  15 class URLRequest;
  16 }
  17
  18 namespace prerender {
  19 class PrerenderContents;
  20
  21 // This class implements policy on resource requests in prerenders.  It cancels
  22 // prerenders on certain requests.  It also defers certain requests until after
  23 // the prerender is swapped in.
  24 //
  25 // TODO(davidben): Experiment with deferring network requests that
  26 // would otherwise cancel the prerender.
  27 class PrerenderResourceThrottle
  28     : public content::ResourceThrottle,
  29       public base::SupportsWeakPtr<PrerenderResourceThrottle> {
  30  public:
  31   explicit PrerenderResourceThrottle(net::URLRequest* request);
  32
  33   // content::ResourceThrottle implementation:
  34   virtual void WillStartRequest(bool* defer) override;
  35   virtual void WillRedirectRequest(const GURL& new_url, bool* defer) override;
  36   virtual const char* GetNameForLogging() const override;
  37
  38   // Called by the PrerenderContents when a prerender becomes visible.
  39   // May only be called if currently throttling the resource.
  40   void Resume();
  41
  42   static void OverridePrerenderContentsForTesting(PrerenderContents* contents);
  43
  44  private:
  45   // Helper method to cancel the request. May only be called if currently
  46   // throttling the resource.
  47   void Cancel();
  48
  49   static void WillStartRequestOnUI(
  50       const base::WeakPtr<PrerenderResourceThrottle>& throttle,
  51       const std::string& method,
  52       content::ResourceType resource_type,
  53       int render_process_id,
  54       int render_frame_id,
  55       const GURL& url);
  56
  57   static void WillRedirectRequestOnUI(
  58       const base::WeakPtr<PrerenderResourceThrottle>& throttle,
  59       const std::string& follow_only_when_prerender_shown_header,
  60       content::ResourceType resource_type,
  61       bool async,
  62       int render_process_id,
  63       int render_frame_id,
  64       const GURL& new_url);
  65
  66   // Helper to return the PrerenderContents given a render frame id. May return
  67   // NULL if it's gone.
  68   static PrerenderContents* PrerenderContentsFromRenderFrame(
  69       int render_process_id, int render_frame_id);
  70
  71   net::URLRequest* request_;
  72
  73   DISALLOW_COPY_AND_ASSIGN(PrerenderResourceThrottle);
  74 };
  75
  76 }  // namespace prerender
  77
  78 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_