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      1 // Copyright (c) 2012 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_LINK_MANAGER_H_
      6 #define CHROME_BROWSER_PRERENDER_PRERENDER_LINK_MANAGER_H_
      7 
      8 #include <list>
      9 
     10 #include "base/basictypes.h"
     11 #include "base/gtest_prod_util.h"
     12 #include "base/time/time.h"
     13 #include "chrome/browser/prerender/prerender_handle.h"
     14 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
     15 #include "url/gurl.h"
     16 
     17 class Profile;
     18 
     19 namespace content {
     20 struct Referrer;
     21 }
     22 
     23 namespace gfx {
     24 class Size;
     25 }
     26 
     27 FORWARD_DECLARE_TEST(WebViewTest, NoPrerenderer);
     28 
     29 namespace prerender {
     30 
     31 class PrerenderHandle;
     32 class PrerenderManager;
     33 
     34 // PrerenderLinkManager implements the API on Link elements for all documents
     35 // being rendered in this chrome instance.  It receives messages from the
     36 // renderer indicating addition, cancelation and abandonment of link elements,
     37 // and controls the PrerenderManager accordingly.
     38 class PrerenderLinkManager : public BrowserContextKeyedService,
     39                              public PrerenderHandle::Observer {
     40  public:
     41   explicit PrerenderLinkManager(PrerenderManager* manager);
     42   virtual ~PrerenderLinkManager();
     43 
     44   // A <link rel=prerender ...> element has been inserted into the document.
     45   // The |prerender_id| must be unique per |child_id|, and is assigned by the
     46   // WebPrerendererClient.
     47   void OnAddPrerender(int child_id,
     48                       int prerender_id,
     49                       const GURL& url,
     50                       const content::Referrer& referrer,
     51                       const gfx::Size& size,
     52                       int render_view_route_id);
     53 
     54   // A <link rel=prerender ...> element has been explicitly removed from a
     55   // document.
     56   void OnCancelPrerender(int child_id, int prerender_id);
     57 
     58   // A renderer launching <link rel=prerender ...> has navigated away from the
     59   // launching page, the launching renderer process has crashed, or perhaps the
     60   // renderer process was fast-closed when the last render view in it was
     61   // closed.
     62   void OnAbandonPrerender(int child_id, int prerender_id);
     63 
     64   // If a renderer channel closes (crash, fast exit, etc...), that's effectively
     65   // an abandon of any prerenders launched by that child.
     66   void OnChannelClosing(int child_id);
     67 
     68  private:
     69   friend class PrerenderBrowserTest;
     70   friend class PrerenderTest;
     71   // WebViewTest.NoPrerenderer needs to access the private IsEmpty() method.
     72   FRIEND_TEST_ALL_PREFIXES(::WebViewTest, NoPrerenderer);
     73 
     74   struct LinkPrerender {
     75     LinkPrerender(int launcher_child_id,
     76                   int prerender_id,
     77                   const GURL& url,
     78                   const content::Referrer& referrer,
     79                   const gfx::Size& size,
     80                   int render_view_route_id,
     81                   base::TimeTicks creation_time);
     82     ~LinkPrerender();
     83 
     84     // Parameters from PrerenderLinkManager::OnAddPrerender():
     85     int launcher_child_id;
     86     int prerender_id;
     87     GURL url;
     88     content::Referrer referrer;
     89     gfx::Size size;
     90     int render_view_route_id;
     91 
     92     // The time at which this Prerender was added to PrerenderLinkManager.
     93     base::TimeTicks creation_time;
     94 
     95     // Initially NULL, |handle| is set once we start this prerender. It is owned
     96     // by this struct, and must be deleted before destructing this struct.
     97     PrerenderHandle* handle;
     98   };
     99 
    100   bool IsEmpty() const;
    101 
    102   // Returns a count of currently running prerenders.
    103   size_t CountRunningPrerenders() const;
    104 
    105   // Start any prerenders that can be started, respecting concurrency limits for
    106   // the system and per launcher.
    107   void StartPrerenders();
    108 
    109   LinkPrerender* FindByLauncherChildIdAndPrerenderId(int child_id,
    110                                                      int prerender_id);
    111 
    112   LinkPrerender* FindByPrerenderHandle(PrerenderHandle* prerender_handle);
    113 
    114   void RemovePrerender(LinkPrerender* prerender);
    115 
    116   // From BrowserContextKeyedService:
    117   virtual void Shutdown() OVERRIDE;
    118 
    119   // From PrerenderHandle::Observer:
    120   virtual void OnPrerenderStart(PrerenderHandle* prerender_handle) OVERRIDE;
    121   virtual void OnPrerenderStopLoading(PrerenderHandle* prerender_handle)
    122       OVERRIDE;
    123   virtual void OnPrerenderStop(PrerenderHandle* prerender_handle) OVERRIDE;
    124 
    125   bool has_shutdown_;
    126 
    127   PrerenderManager* manager_;
    128 
    129   // All prerenders known to this PrerenderLinkManager. Insertions are always
    130   // made at the back, so the oldest prerender is at the front, and the youngest
    131   // at the back.
    132   std::list<LinkPrerender> prerenders_;
    133 
    134   DISALLOW_COPY_AND_ASSIGN(PrerenderLinkManager);
    135 };
    136 
    137 }  // namespace prerender
    138 
    139 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_LINK_MANAGER_H_
    140 
    141