Adding support for forced URLs to TopSites.

chrome/browser/history/top_sites_impl.h

 // Copyright (c) 2013 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_HISTORY_TOP_SITES_IMPL_H_
 #define CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 37 matching lines @@
 // to internal state happen on the UI thread and are scheduled to update the
 // db using TopSitesBackend.
 class TopSitesImpl : public TopSites {
  public:
   explicit TopSitesImpl(Profile* profile);
 
   // Initializes TopSitesImpl.
   void Init(const base::FilePath& db_name);
 
   virtual bool SetPageThumbnail(const GURL& url,
-                        const gfx::Image& thumbnail,
-                        const ThumbnailScore& score) OVERRIDE;
+                                const gfx::Image& thumbnail,
+                                const ThumbnailScore& score) OVERRIDE;
   virtual bool SetPageThumbnailToJPEGBytes(
       const GURL& url,
       const base::RefCountedMemory* memory,
       const ThumbnailScore& score) OVERRIDE;
   virtual void GetMostVisitedURLs(
-      const GetMostVisitedURLsCallback& callback) OVERRIDE;
+      const GetMostVisitedURLsCallback& callback,
+      bool include_forced_urls) OVERRIDE;
   virtual bool GetPageThumbnail(
       const GURL& url,
       bool prefix_match,
       scoped_refptr<base::RefCountedMemory>* bytes) OVERRIDE;
   virtual bool GetPageThumbnailScore(const GURL& url,
                                      ThumbnailScore* score) OVERRIDE;
   virtual bool GetTemporaryPageThumbnailScore(const GURL& url,
                                               ThumbnailScore* score) OVERRIDE;
   virtual void SyncWithHistory() OVERRIDE;
   virtual bool HasBlacklistedItems() const OVERRIDE;
   virtual void AddBlacklistedURL(const GURL& url) OVERRIDE;
   virtual void RemoveBlacklistedURL(const GURL& url) OVERRIDE;
   virtual bool IsBlacklisted(const GURL& url) OVERRIDE;
   virtual void ClearBlacklistedURLs() OVERRIDE;
   virtual void Shutdown() OVERRIDE;
   virtual CancelableRequestProvider::Handle StartQueryForMostVisited() OVERRIDE;
   virtual bool IsKnownURL(const GURL& url) OVERRIDE;
   virtual const std::string& GetCanonicalURLString(
       const GURL& url) const OVERRIDE;
-  virtual bool IsFull() OVERRIDE;
+  virtual bool IsNonForcedFull() OVERRIDE;
+  virtual bool IsForcedFull() OVERRIDE;
   virtual MostVisitedURLList GetPrepopulatePages() OVERRIDE;
   virtual bool loaded() const OVERRIDE;
 
  protected:
   virtual ~TopSitesImpl();
 
  private:
   friend class TopSitesImplTest;
   FRIEND_TEST_ALL_PREFIXES(TopSitesImplTest, DiffMostVisited);
+  FRIEND_TEST_ALL_PREFIXES(TopSitesImplTest, DiffMostVisitedWithForced);
+
+  typedef base::Callback<void(const MostVisitedURLList&,
+                              const MostVisitedURLList&)> PendingCallback;
 
   typedef std::pair<GURL, Images> TempImage;
   typedef std::list<TempImage> TempImages;
+  typedef std::vector<PendingCallback> PendingCallbacks;
 
   // Generates the diff of things that happened between "old" and "new."
   //
+  // This treats forced URLs separately than non-forced URLs.
+  //
   // The URLs that are in "new" but not "old" will be have their index into
-  // "new" put in |added_urls|. The URLs that are in "old" but not "new" will
-  // have their index into "old" put into |deleted_urls|.
+  // "new" put in |added_urls|. The non-forced URLs that are in "old" but not
+  // "new" will have their index into "old" put into |deleted_urls|.
   //
   // URLs appearing in both old and new lists but having different indices will
   // have their index into "new" be put into |moved_urls|.
   static void DiffMostVisited(const MostVisitedURLList& old_list,
                               const MostVisitedURLList& new_list,
                               TopSitesDelta* delta);
 
   // Sets the thumbnail without writing to the database. Useful when
   // reading last known top sites from the DB.
   // Returns true if the thumbnail was set, false if the existing one is better.
@@ skipping 25 matching lines @@
   void TimerFired();
 
   // Finds the given URL in the redirect chain for the given TopSite, and
   // returns the distance from the destination in hops that the given URL is.
   // The URL is assumed to be in the list. The destination is 0.
   static int GetRedirectDistanceForURL(const MostVisitedURL& most_visited,
                                        const GURL& url);
 
   // Add prepopulated pages: 'welcome to Chrome' and themes gallery to |urls|.
   // Returns true if any pages were added.
-  bool AddPrepopulatedPages(MostVisitedURLList* urls);
+  bool AddPrepopulatedPages(MostVisitedURLList* urls,
+                            size_t num_forced_urls);
+
+  // Add all the forced URLs from |cache_| into |new_list|, making sure not to
+  // add any URL that's already in |new_list|'s non-forced URLs. The forced URLs
+  // in |cache_| and |new_list| are assumed to appear at the front of the list
+  // and be sorted in increasing |last_forced_time|. This will still be true
+  // after the call. If the list of forced URLs overflows the older ones are
+  // dropped. Returns the number of forced URLs after the merge.
+  size_t MergeCachedForcedURLs(MostVisitedURLList* new_list);
 
   // Takes |urls|, produces it's copy in |out| after removing blacklisted URLs.
+  // Also ensures we respect the maximum number of forced URLs and non-forced
+  // URLs.
   void ApplyBlacklist(const MostVisitedURLList& urls, MostVisitedURLList* out);
 
   // Returns an MD5 hash of the URL. Hashing is required for blacklisted URLs.
   std::string GetURLHash(const GURL& url);
 
   // Returns the delay until the next update of history is needed.
   // Uses num_urls_changed
   base::TimeDelta GetUpdateDelay();
 
   // Implementation of content::NotificationObserver.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // Resets top_sites_ and updates the db (in the background). All mutations to
-  // top_sites_ *must* go through this. Should be called from the UI thread.
+  // Updates URLs in |cache_| and the db (in the background).
+  // The non-forced URLs in |new_top_sites| replace those in |cache_|.
+  // The forced URLs of |new_top_sites| are merged with those in |cache_|,
+  // if the list of forced URLs overflows, the oldest ones are dropped.
+  // All mutations to cache_ *must* go through this. Should
+  // be called from the UI thread.
   void SetTopSites(const MostVisitedURLList& new_top_sites);
 
-  // Returns the number of most visted results to request from history. This
+  // Returns the number of most visited results to request from history. This
   // changes depending upon how many urls have been blacklisted. Should be
   // called from the UI thread.
   int num_results_to_request_from_history() const;
 
   // Invoked when transitioning to LOADED. Notifies any queued up callbacks.
   // Should be called from the UI thread.
   void MoveStateToLoaded();
 
   void ResetThreadSafeCache();
 
@@ skipping 46 matching lines @@
   size_t last_num_urls_changed_;
 
   // The pending requests for the top sites list. Can only be non-empty at
   // startup. After we read the top sites from the DB, we'll always have a
   // cached list and be able to run callbacks immediately.
   PendingCallbacks pending_callbacks_;
 
   // Stores thumbnails for unknown pages. When SetPageThumbnail is
   // called, if we don't know about that URL yet and we don't have
   // enough Top Sites (new profile), we store it until the next
-  // SetTopSites call.
+  // SetNonForcedTopSites call.
   TempImages temp_images_;
 
   // URL List of prepopulated page.
   std::vector<GURL> prepopulated_page_urls_;
 
   // Are we loaded?
   bool loaded_;
 
   DISALLOW_COPY_AND_ASSIGN(TopSitesImpl);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_