Revert of Revert CL 117933003. Re-add resource speculative prefetching code.

chrome/browser/predictors/resource_prefetch_predictor.h

Index: chrome/browser/predictors/resource_prefetch_predictor.h
diff --git a/chrome/browser/predictors/resource_prefetch_predictor.h b/chrome/browser/predictors/resource_prefetch_predictor.h
deleted file mode 100644
index 5e6157badcbb47a013747c28c5b5b5667a5e72ea..0000000000000000000000000000000000000000
--- a/chrome/browser/predictors/resource_prefetch_predictor.h
+++ /dev/null
@@ -1,314 +0,0 @@
-// 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 <map>
-#include <string>
-#include <vector>
-
-#include "base/gtest_prod_util.h"
-#include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/task/cancelable_task_tracker.h"
-#include "base/time/time.h"
-#include "chrome/browser/history/history_types.h"
-#include "chrome/browser/predictors/resource_prefetch_common.h"
-#include "chrome/browser/predictors/resource_prefetch_predictor_tables.h"
-#include "chrome/browser/predictors/resource_prefetcher.h"
-#include "components/keyed_service/core/keyed_service.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/common/resource_type.h"
-#include "url/gurl.h"
-
-class PredictorsHandler;
-class Profile;
-
-namespace content {
-class WebContents;
-}
-
-namespace net {
-class URLRequest;
-}
-
-namespace predictors {
-
-class ResourcePrefetcherManager;
-
-// Contains logic for learning what can be prefetched and for kicking off
-// speculative prefetching.
-// - The class is a profile keyed service owned by the profile.
-// - All the non-static methods of this class need to be called on the UI
-//   thread.
-//
-// The overall flow of the resource prefetching algorithm is as follows:
-//
-// * ResourcePrefetchPredictorObserver - Listens for URL requests, responses and
-//   redirects on the IO thread (via ResourceDispatcherHostDelegate) and posts
-//   tasks to the ResourcePrefetchPredictor on the UI thread. This is owned by
-//   the ProfileIOData for the profile.
-// * ResourcePrefetchPredictorTables - Persists ResourcePrefetchPredictor data
-//   to a sql database. Runs entirely on the DB thread. Owned by the
-//   PredictorDatabase.
-// * ResourcePrefetchPredictor - Learns about resource requirements per URL in
-//   the UI thread through the ResourcePrefetchPredictorObserver and persists
-//   it to disk in the DB thread through the ResourcePrefetchPredictorTables. It
-//   initiates resource prefetching using the ResourcePrefetcherManager. Owned
-//   by profile.
-// * ResourcePrefetcherManager - Manages the ResourcePrefetchers that do the
-//   prefetching on the IO thread. The manager is owned by the
-//   ResourcePrefetchPredictor and interfaces between the predictor on the UI
-//   thread and the prefetchers on the IO thread.
-// * ResourcePrefetcher - Lives entirely on the IO thread, owned by the
-//   ResourcePrefetcherManager, and issues net::URLRequest to fetch resources.
-//
-// TODO(shishir): Do speculative prefetching for https resources and/or https
-// main frame urls.
-// TODO(zhenw): Currently only main frame requests/redirects/responses are
-// recorded. Consider recording sub-frame responses independently or together
-// with main frame.
-class ResourcePrefetchPredictor
-    : public KeyedService,
-      public content::NotificationObserver,
-      public base::SupportsWeakPtr<ResourcePrefetchPredictor> {
- public:
-  // Stores the data that we need to get from the URLRequest.
-  struct URLRequestSummary {
-    URLRequestSummary();
-    URLRequestSummary(const URLRequestSummary& other);
-    ~URLRequestSummary();
-
-    NavigationID navigation_id;
-    GURL resource_url;
-    content::ResourceType resource_type;
-
-    // Only for responses.
-    std::string mime_type;
-    bool was_cached;
-    GURL redirect_url;  // Empty unless request was redirected to a valid url.
-  };
-
-  ResourcePrefetchPredictor(const ResourcePrefetchPredictorConfig& config,
-                            Profile* profile);
-  virtual ~ResourcePrefetchPredictor();
-
-  // Thread safe.
-  static bool ShouldRecordRequest(net::URLRequest* request,
-                                  content::ResourceType resource_type);
-  static bool ShouldRecordResponse(net::URLRequest* response);
-  static bool ShouldRecordRedirect(net::URLRequest* response);
-
-  // Determines the ResourceType from the mime type, defaulting to the
-  // |fallback| if the ResourceType could not be determined.
-  static content::ResourceType GetResourceTypeFromMimeType(
-      const std::string& mime_type,
-      content::ResourceType fallback);
-
-  // 'ResourcePrefetchPredictorObserver' calls the below functions to inform the
-  // predictor of main frame and resource requests. Should only be called if the
-  // corresponding Should* functions return true.
-  void RecordURLRequest(const URLRequestSummary& request);
-  void RecordURLResponse(const URLRequestSummary& response);
-  void RecordURLRedirect(const URLRequestSummary& response);
-
-  // Called when the main frame of a page completes loading.
-  void RecordMainFrameLoadComplete(const NavigationID& navigation_id);
-
-  // Called by ResourcePrefetcherManager to notify that prefetching has finished
-  // for a navigation. Should take ownership of |requests|.
-  virtual void FinishedPrefetchForNavigation(
-      const NavigationID& navigation_id,
-      PrefetchKeyType key_type,
-      ResourcePrefetcher::RequestVector* requests);
-
- private:
-  friend class ::PredictorsHandler;
-  friend class ResourcePrefetchPredictorTest;
-
-  FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, DeleteUrls);
-  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, OnMainFrameRequest);
-  FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest, OnMainFrameRedirect);
-  FRIEND_TEST_ALL_PREFIXES(ResourcePrefetchPredictorTest,
-                           OnSubresourceResponse);
-
-  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;
-    scoped_ptr<ResourcePrefetcher::RequestVector> requests;
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(Result);
-  };
-
-  typedef ResourcePrefetchPredictorTables::ResourceRow ResourceRow;
-  typedef ResourcePrefetchPredictorTables::ResourceRows ResourceRows;
-  typedef ResourcePrefetchPredictorTables::PrefetchData PrefetchData;
-  typedef ResourcePrefetchPredictorTables::PrefetchDataMap PrefetchDataMap;
-  typedef std::map<NavigationID, linked_ptr<std::vector<URLRequestSummary> > >
-      NavigationMap;
-  typedef std::map<NavigationID, 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);
-
-  // Returns true if the request (should have a response in it) is cacheable.
-  static bool IsCacheable(const net::URLRequest* request);
-
-  // content::NotificationObserver methods OVERRIDE.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  // KeyedService methods OVERRIDE.
-  virtual void Shutdown() OVERRIDE;
-
-  // Functions called on different network events pertaining to the loading of
-  // main frame resource or sub resources.
-  void OnMainFrameRequest(const URLRequestSummary& request);
-  void OnMainFrameResponse(const URLRequestSummary& response);
-  void OnMainFrameRedirect(const URLRequestSummary& response);
-  void OnSubresourceResponse(const URLRequestSummary& response);
-
-  // Called when onload completes for a navigation. We treat this point as the
-  // "completion" of the navigation. The resources requested by the page upto
-  // this point are the only ones considered for prefetching.
-  void OnNavigationComplete(const NavigationID& navigation_id);
-
-  // Returns true if there is PrefetchData that can be used for the
-  // navigation and fills in the |prefetch_data| to resources that need to be
-  // prefetched.
-  bool GetPrefetchData(const NavigationID& navigation_id,
-                       ResourcePrefetcher::RequestVector* prefetch_requests,
-                       PrefetchKeyType* key_type);
-
-  // Converts a PrefetchData into a ResourcePrefetcher::RequestVector.
-  void PopulatePrefetcherRequest(const PrefetchData& data,
-                                 ResourcePrefetcher::RequestVector* requests);
-
-  // Starts prefetching if it is enabled and prefetching data exists for the
-  // NavigationID either at the URL or at the host level.
-  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|.
-  void CreateCaches(scoped_ptr<PrefetchDataMap> url_data_map,
-                    scoped_ptr<PrefetchDataMap> host_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);
-
-  // Removes the oldest entry in the input |data_map|, also deleting it from the
-  // predictor database.
-  void RemoveOldestEntryInPrefetchDataMap(PrefetchKeyType key_type,
-                                          PrefetchDataMap* data_map);
-
-  // Merges resources in |new_resources| into the |data_map| and correspondingly
-  // updates the predictor database.
-  void LearnNavigation(const std::string& key,
-                       PrefetchKeyType key_type,
-                       const std::vector<URLRequestSummary>& new_resources,
-                       size_t max_data_map_size,
-                       PrefetchDataMap* data_map);
-
-  // Reports accuracy by comparing prefetched resources with resources that are
-  // actually used by the page.
-  void ReportAccuracyStats(PrefetchKeyType key_type,
-                           const std::vector<URLRequestSummary>& actual,
-                           ResourcePrefetcher::RequestVector* prefetched) const;
-
-  // Reports predicted accuracy i.e. by comparing resources that are actually
-  // used by the page with those that may have been prefetched.
-  void ReportPredictedAccuracyStats(
-      PrefetchKeyType key_type,
-      const std::vector<URLRequestSummary>& actual,
-      const ResourcePrefetcher::RequestVector& predicted) const;
-  void ReportPredictedAccuracyStatsHelper(
-      PrefetchKeyType key_type,
-      const ResourcePrefetcher::RequestVector& predicted,
-      const std::map<GURL, bool>& actual,
-      size_t total_resources_fetched_from_network,
-      size_t max_assumed_prefetched) const;
-
-  // Used for testing to inject mock tables.
-  void set_mock_tables(scoped_refptr<ResourcePrefetchPredictorTables> tables) {
-    tables_ = tables;
-  }
-
-  Profile* const profile_;
-  ResourcePrefetchPredictorConfig const config_;
-  InitializationState initialization_state_;
-  scoped_refptr<ResourcePrefetchPredictorTables> tables_;
-  scoped_refptr<ResourcePrefetcherManager> prefetch_manager_;
-  content::NotificationRegistrar notification_registrar_;
-  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.
-  scoped_ptr<PrefetchDataMap> url_table_cache_;
-  scoped_ptr<PrefetchDataMap> host_table_cache_;
-
-  ResultsMap results_map_;
-  STLValueDeleter<ResultsMap> results_map_deleter_;
-
-  DISALLOW_COPY_AND_ASSIGN(ResourcePrefetchPredictor);
-};
-
-}  // namespace predictors
-
-#endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_H_