Redirect handling in the resource_prefetch_predictor.

chrome/browser/predictors/resource_prefetch_predictor.h

 // Copyright 2014 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_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_H_
 #define CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 81 matching lines @@
 
     bool has_validators;
     bool always_revalidate;
 
     // Initializes a |URLRequestSummary| from a |URLRequest| response.
     // Returns true for success.
     static bool SummarizeResponse(const net::URLRequest& request,
                                   URLRequestSummary* summary);
   };
 
+  // Stores information about inflight navigations.
+  struct Navigation {

[pasko, 2016/09/22 14:27:09]

The name 'Navigation' looks a bit generic, so it slightly complicates reading
resource_prefetch_predictor.cc. RedirectChain would be more readable, at least
to me.

[alexilin, 2016/09/22 16:48:19]

I don't think that 'RedirectChain' is also a good name.
Because this structure holds the all information that
'ResourcePrefetchPredictor' collects within single navigation.
'subresource_requests' contains all requests to subresources as well, so
'RedirectChain' name isn't relevant.

Actually, this struct could be moved in private section, because it isn't used
outside 'ResourcePrefetchPredictor'. So then we could keep 'NavigationInfo' or
'NavigationData' name.

[pasko, 2016/09/26 12:28:15]

I would also prefer moving it into the implementation if it is possible.

How about 'PageRequestSummary' or 'PageLoadRequestInfo' or some variation of
these? My understanding of 'Navigation' does not include subresources, only
remotely relevant.

[alexilin, 2016/09/27 14:52:45]

Renamed to 'PageRequestSummary' and moved into private section of
ResourcePrefetchPredictor class.
Done.

+    explicit Navigation(const GURL& initial_url);
+    ~Navigation();
+
+    GURL initial_url;
+    std::vector<URLRequestSummary> subresource_requests;
+  };
+
   ResourcePrefetchPredictor(const ResourcePrefetchPredictorConfig& config,
                             Profile* profile);
   ~ResourcePrefetchPredictor() override;
 
   // Thread safe.
   static bool ShouldRecordRequest(net::URLRequest* request,
                                   content::ResourceType resource_type);
   static bool ShouldRecordResponse(net::URLRequest* response);
   static bool ShouldRecordRedirect(net::URLRequest* response);
 
@@ skipping 34 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
                            LazilyInitializeEmpty);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
                            LazilyInitializeWithData);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
                            NavigationNotRecorded);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, NavigationUrlInDB);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, NavigationUrlNotInDB);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
                            NavigationUrlNotInDBAndDBFull);
+  FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, RedirectUrlNotInDB);
+  FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, RedirectUrlInDB);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, OnMainFrameRequest);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, OnMainFrameRedirect);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
                            OnSubresourceResponse);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, GetCorrectPLT);
   FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, HandledResourceTypes);
 
   enum InitializationState {
     NOT_INITIALIZED = 0,
     INITIALIZING = 1,
     INITIALIZED = 2
   };
 
   // Stores prefetching results.
   struct Result {
     // Takes ownership of requests.
     Result(PrefetchKeyType key_type,
            ResourcePrefetcher::RequestVector* requests);
     ~Result();
 
     PrefetchKeyType key_type;
     std::unique_ptr<ResourcePrefetcher::RequestVector> requests;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(Result);
   };
 
   typedef ResourcePrefetchPredictorTables::PrefetchData PrefetchData;
   typedef ResourcePrefetchPredictorTables::PrefetchDataMap PrefetchDataMap;
-  typedef std::map<NavigationID, linked_ptr<std::vector<URLRequestSummary> > >
-      NavigationMap;
+
+  typedef ResourcePrefetchPredictorTables::RedirectDataMap RedirectDataMap;
+
+  typedef std::map<NavigationID, std::unique_ptr<Navigation>> NavigationMap;
   typedef std::map<NavigationID, std::unique_ptr<Result>> ResultsMap;
 
   // Returns true if the main page request is supported for prediction.
   static bool IsHandledMainPage(net::URLRequest* request);
 
   // Returns true if the subresource request is supported for prediction.
   static bool IsHandledSubresource(net::URLRequest* request,
                                    content::ResourceType resource_type);
 
   // Returns true if the subresource has a supported type.
@@ skipping 34 matching lines @@
   void StartPrefetching(const NavigationID& navigation_id);
 
   // Stops prefetching that may be in progress corresponding to |navigation_id|.
   void StopPrefetching(const NavigationID& navigation_id);
 
   // Starts initialization by posting a task to the DB thread to read the
   // predictor database.
   void StartInitialization();
 
   // Callback for task to read predictor database. Takes ownership of
-  // |url_data_map| and |host_data_map|.
+  // all arguments.
   void CreateCaches(std::unique_ptr<PrefetchDataMap> url_data_map,
-                    std::unique_ptr<PrefetchDataMap> host_data_map);
+                    std::unique_ptr<PrefetchDataMap> host_data_map,
+                    std::unique_ptr<RedirectDataMap> url_redirect_data_map,
+                    std::unique_ptr<RedirectDataMap> host_redirect_data_map);
 
   // Called during initialization when history is read and the predictor
   // database has been read.
   void OnHistoryAndCacheLoaded();
 
   // Removes data for navigations where the onload never fired. Will cleanup
   // inflight_navigations_ and results_map_.
   void CleanupAbandonedNavigations(const NavigationID& navigation_id);
 
   // Deletes all URLs from the predictor database, the caches and removes all
   // inflight navigations.
   void DeleteAllUrls();
 
   // Deletes data for the input |urls| and their corresponding hosts from the
   // predictor database and caches.
   void DeleteUrls(const history::URLRows& urls);
 
   // Callback for GetUrlVisitCountTask.
   void OnVisitCountLookup(size_t visit_count,
                           const NavigationID& navigation_id,
-                          const std::vector<URLRequestSummary>& requests);
+                          const Navigation& navigation);
 
   // Removes the oldest entry in the input |data_map|, also deleting it from the
   // predictor database.
   void RemoveOldestEntryInPrefetchDataMap(PrefetchKeyType key_type,
                                           PrefetchDataMap* data_map);
 
+  void RemoveOldestEntryInRedirectDataMap(PrefetchKeyType key_type,
+                                          RedirectDataMap* data_map);
+
   // Merges resources in |new_resources| into the |data_map| and correspondingly
-  // updates the predictor database.
+  // updates the predictor database. Also calls LearnRedirect if relevant.
   void LearnNavigation(const std::string& key,
                        PrefetchKeyType key_type,
                        const std::vector<URLRequestSummary>& new_resources,
                        size_t max_data_map_size,
-                       PrefetchDataMap* data_map);
+                       PrefetchDataMap* data_map,
+                       const std::string& redirect_origin_key,
+                       RedirectDataMap* redirect_map);
+
+  // Updates information about final redirect destination for |key| in
+  // |redirect_map| and correspondingly updates the predictor database
+  void LearnRedirect(const std::string& key,
+                     PrefetchKeyType key_type,
+                     const std::string& final_redirect,
+                     size_t max_redirect_map_size,
+                     RedirectDataMap* redirect_map);
 
   // Reports overall page load time.
   void ReportPageLoadTimeStats(base::TimeDelta plt) const;
 
   // Reports page load time for prefetched and not prefetched pages
   void ReportPageLoadTimePrefetchStats(
       base::TimeDelta plt,
       bool prefetched,
       base::Callback<void(int)> report_network_type_callback,
       PrefetchKeyType key_type) const;
@@ skipping 35 matching lines @@
     tables_ = tables;
   }
 
   Profile* const profile_;
   ResourcePrefetchPredictorConfig const config_;
   InitializationState initialization_state_;
   scoped_refptr<ResourcePrefetchPredictorTables> tables_;
   scoped_refptr<ResourcePrefetcherManager> prefetch_manager_;
   base::CancelableTaskTracker history_lookup_consumer_;
 
-  // Map of all the navigations in flight to their resource requests.
-  NavigationMap inflight_navigations_;
-
   // Copy of the data in the predictor tables.
   std::unique_ptr<PrefetchDataMap> url_table_cache_;
   std::unique_ptr<PrefetchDataMap> host_table_cache_;
+  std::unique_ptr<RedirectDataMap> url_redirect_table_cache_;
+  std::unique_ptr<RedirectDataMap> host_redirect_table_cache_;
 
+  NavigationMap inflight_navigations_;
   ResultsMap results_map_;
 
   ScopedObserver<history::HistoryService, history::HistoryServiceObserver>
       history_service_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourcePrefetchPredictor);
 };
 
 }  // namespace predictors
 
 #endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_H_