Do conservative prerendering based on the LocalPredictor in Dev/Canary.

chrome/browser/prerender/prerender_local_predictor.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PRERENDER_PRERENDER_LOCAL_PREDICTOR_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_LOCAL_PREDICTOR_H_
 
 #include <vector>
 
 #include "base/hash_tables.h"
+#include "base/memory/weak_ptr.h"
 #include "base/timer.h"
 #include "chrome/browser/common/cancelable_request.h"
 #include "chrome/browser/history/visit_database.h"
 #include "googleurl/src/gurl.h"
 
 class HistoryService;
 
+namespace content {
+class SessionStorageNamespace;
+}
+
+namespace gfx {
+class Size;
+}
+
 namespace prerender {
 
+class PrerenderHandle;
 class PrerenderManager;
 
 // PrerenderLocalPredictor maintains local browsing history to make prerender
 // predictions.
 // At this point, the class is not actually creating prerenders, but just
 // recording timing stats about the effect prerendering would have.
 class PrerenderLocalPredictor : public history::VisitDatabaseObserver {
  public:
+  struct LocalPredictorURLInfo;

[Shishir, 2013/05/08 20:19:20]

Can you make these structs private? Looks like only this class needs them.

[tburkard, 2013/05/08 20:35:47]

can't be made private, used by anonymous helper routines in .cc

+  struct LocalPredictorURLLookupInfo;
   enum Event {
     EVENT_CONSTRUCTED = 0,
     EVENT_INIT_SCHEDULED = 1,
     EVENT_INIT_STARTED = 2,
     EVENT_INIT_FAILED_NO_HISTORY = 3,
     EVENT_INIT_SUCCEEDED = 4,
     EVENT_ADD_VISIT = 5,
     EVENT_ADD_VISIT_INITIALIZED = 6,
     EVENT_ADD_VISIT_PRERENDER_IDENTIFIED = 7,
     EVENT_ADD_VISIT_RELEVANT_TRANSITION = 8,
     EVENT_ADD_VISIT_IDENTIFIED_PRERENDER_CANDIDATE = 9,
     EVENT_ADD_VISIT_PRERENDERING = 10,
     EVENT_GOT_PRERENDER_URL = 11,
     EVENT_ERROR_NO_PRERENDER_URL_FOR_PLT = 12,
     EVENT_ADD_VISIT_PRERENDERING_EXTENDED = 13,
     EVENT_PRERENDER_URL_LOOKUP_RESULT = 14,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_ROOT_PAGE = 15,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_IS_HTTP = 16,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_HAS_QUERY_STRING = 17,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_CONTAINS_LOGOUT = 18,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_CONTAINS_LOGIN = 19,
     EVENT_START_URL_LOOKUP = 20,
     EVENT_ADD_VISIT_NOT_ROOTPAGE = 21,
     EVENT_URL_WHITELIST_ERROR = 22,
     EVENT_URL_WHITELIST_OK = 23,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_ON_WHITELIST = 24,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_ON_WHITELIST_ROOT_PAGE = 25,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_EXTENDED_ROOT_PAGE = 26,
     EVENT_PRERENDER_URL_LOOKUP_RESULT_ROOT_PAGE_HTTP = 27,
+    EVENT_PRERENDER_URL_LOOKUP_FAILED = 28,
+    EVENT_PRERENDER_URL_LOOKUP_NO_SOURCE_WEBCONTENTS_FOUND = 29,
+    EVENT_PRERENDER_URL_LOOKUP_NO_LOGGED_IN_TABLE_FOUND = 30,
+    EVENT_PRERENDER_URL_LOOKUP_ISSUING_LOGGED_IN_LOOKUP = 31,
+    EVENT_CONTINUE_PRERENDER_CHECK_STARTED = 32,
+    EVENT_CONTINUE_PRERENDER_CHECK_NO_URL = 33,
+    EVENT_CONTINUE_PRERENDER_CHECK_PRIORITY_TOO_LOW = 34,
+    EVENT_CONTINUE_PRERENDER_CHECK_URLS_IDENTICAL_BUT_FRAGMENT = 35,
+    EVENT_CONTINUE_PRERENDER_CHECK_HTTPS = 36,
+    EVENT_CONTINUE_PRERENDER_CHECK_ROOT_PAGE = 37,
+    EVENT_CONTINUE_PRERENDER_CHECK_LOGOUT_URL = 38,
+    EVENT_CONTINUE_PRERENDER_CHECK_LOGIN_URL = 39,
+    EVENT_CONTINUE_PRERENDER_CHECK_NOT_LOGGED_IN = 40,
+    EVENT_CONTINUE_PRERENDER_CHECK_FALLTHROUGH_NOT_PRERENDERING = 41,
+    EVENT_CONTINUE_PRERENDER_CHECK_ISSUING_PRERENDER = 42,
+    EVENT_ISSUING_PRERENDER = 43,
+    EVENT_NO_PRERENDER_CANDIDATES = 44,
+    EVENT_GOT_HISTORY_ISSUING_LOOKUP = 45,
     EVENT_MAX_VALUE
   };
 
   // A PrerenderLocalPredictor is owned by the PrerenderManager specified
   // in the constructor.  It will be destoryed at the time its owning
   // PrerenderManager is destroyed.
   explicit PrerenderLocalPredictor(PrerenderManager* prerender_manager);
   virtual ~PrerenderLocalPredictor();
 
   void Shutdown();
 
   // history::VisitDatabaseObserver implementation
   virtual void OnAddVisit(const history::BriefVisitInfo& info) OVERRIDE;
 
-  void OnLookupURL(history::URLID url_id, double priority, const GURL& url);
+  void OnLookupURL(scoped_ptr<LocalPredictorURLLookupInfo> info);

[Shishir, 2013/05/08 20:19:20]

make private.

[tburkard, 2013/05/08 20:35:47]

Done.

 
   void OnGetInitialVisitHistory(
       scoped_ptr<std::vector<history::BriefVisitInfo> > visit_history);
 
   void OnPLTEventForURL(const GURL& url, base::TimeDelta page_load_time);
 
  private:
-  struct PrerenderData;
+  struct PrerenderProperties;
   HistoryService* GetHistoryIfExists() const;
   void Init();
-  bool IsPrerenderStillValid(PrerenderData* prerender) const;
-  bool DoesPrerenderMatchPLTRecord(PrerenderData* prerender,
+  bool IsPrerenderStillValid(PrerenderProperties* prerender) const;
+  bool DoesPrerenderMatchPLTRecord(PrerenderProperties* prerender,
                                    const GURL& url,
                                    base::TimeDelta plt) const;
   void RecordEvent(Event event) const;
 
   // Returns whether a new prerender of the specified priority should replace
   // the current prerender (based on whether it exists, whether it has expired,
   // and based on what its priority is).
   bool ShouldReplaceCurrentPrerender(double priority) const;
 
+  void ContinuePrerenderCheck(
+      scoped_refptr<content::SessionStorageNamespace> session_storage_namespace,
+      scoped_ptr<gfx::Size> size,
+      scoped_ptr<LocalPredictorURLLookupInfo> info);
+  void LogCandidateURLStats(const GURL& url) const;
+  void IssuePrerender(scoped_refptr<content::SessionStorageNamespace>
+                      session_storage_namespace,
+                      scoped_ptr<gfx::Size> size,
+                      scoped_ptr<LocalPredictorURLInfo> info);
+
   PrerenderManager* prerender_manager_;
   base::OneShotTimer<PrerenderLocalPredictor> timer_;
 
   // Delay after which to initialize, to avoid putting to much load on the
   // database thread early on when Chrome is starting up.
   static const int kInitDelayMs = 5 * 1000;
 
   // Whether we're registered with the history service as a
   // history::VisitDatabaseObserver.
   bool is_visit_database_observer_;
 
   CancelableRequestConsumer history_db_consumer_;
 
   scoped_ptr<std::vector<history::BriefVisitInfo> > visit_history_;
 
-  scoped_ptr<PrerenderData> current_prerender_;
-  scoped_ptr<PrerenderData> last_swapped_in_prerender_;
+  scoped_ptr<PrerenderProperties> current_prerender_;
+  scoped_ptr<PrerenderProperties> last_swapped_in_prerender_;
+
+  scoped_ptr<PrerenderHandle> prerender_handle_;
+  double current_prerender_priority_;
 
   base::hash_set<int64> url_whitelist_;
 
+  base::WeakPtrFactory<PrerenderLocalPredictor> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(PrerenderLocalPredictor);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_LOCAL_PREDICTOR_H_