Componentize TopSites, TopSitesBackend, TopSitesDatabase

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>
 #include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/history/history_service.h"
-#include "chrome/browser/history/top_sites.h"
-#include "chrome/browser/history/top_sites_backend.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/history/core/browser/page_usage_data.h"
+#include "components/history/core/browser/top_sites.h"
+#include "components/history/core/browser/top_sites_backend.h"
 #include "components/history/core/common/thumbnail_score.h"
+#include "content/public/browser/notification_observer.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
 
 class Profile;
 
 namespace base {
 class FilePath;
 class RefCountedBytes;
 class RefCountedMemory;
+class SingleThreadTaskRunner;
 }
 
 namespace history {
 
 class TopSitesCache;
 class TopSitesImplTest;
 
 // This class allows requests for most visited urls and thumbnails on any
 // thread. All other methods must be invoked on the UI thread. All mutations
 // to internal state happen on the UI thread and are scheduled to update the
 // db using TopSitesBackend.
-class TopSitesImpl : public TopSites {
+class TopSitesImpl : public TopSites, public content::NotificationObserver {
  public:
-  explicit TopSitesImpl(Profile* profile);
+  TopSitesImpl(Profile* profile,
+               const PrepopulatedPageList& prepopulated_pages);
 
   // Initializes TopSitesImpl.
-  void Init(const base::FilePath& db_name);
+  void Init(const base::FilePath& db_name,
+            const scoped_refptr<base::SingleThreadTaskRunner>& db_task_runner);
 
   bool SetPageThumbnail(const GURL& url,
                         const gfx::Image& thumbnail,
                         const ThumbnailScore& score) override;
   bool SetPageThumbnailToJPEGBytes(const GURL& url,
                                    const base::RefCountedMemory* memory,
                                    const ThumbnailScore& score) override;
   void GetMostVisitedURLs(const GetMostVisitedURLsCallback& callback,
                           bool include_forced_urls) override;
   bool GetPageThumbnail(const GURL& url,
                         bool prefix_match,
                         scoped_refptr<base::RefCountedMemory>* bytes) override;
   bool GetPageThumbnailScore(const GURL& url, ThumbnailScore* score) override;
   bool GetTemporaryPageThumbnailScore(const GURL& url,
                                       ThumbnailScore* score) override;
   void SyncWithHistory() override;
   bool HasBlacklistedItems() const override;
   void AddBlacklistedURL(const GURL& url) override;
   void RemoveBlacklistedURL(const GURL& url) override;
   bool IsBlacklisted(const GURL& url) override;
   void ClearBlacklistedURLs() override;
   base::CancelableTaskTracker::TaskId StartQueryForMostVisited() override;
   bool IsKnownURL(const GURL& url) override;
   const std::string& GetCanonicalURLString(const GURL& url) const override;
   bool IsNonForcedFull() override;
   bool IsForcedFull() override;
-  MostVisitedURLList GetPrepopulatePages() override;
+  PrepopulatedPageList GetPrepopulatedPages() override;

[droger, 2015/01/27 10:08:36]

Could you return a const reference here?

[sdefresne, 2015/01/27 13:55:16]

GetPrepopulatedPages() is a virtual method defined on TopSites pure virtual
interface. Using a const reference in the interface would force a particular
implementation. Returning a copy does not make the code worse than before since
it was already returning a copy.

[sdefresne, 2015/01/27 13:55:16]

GetPrepopulatedPages() is a virtual method defined on TopSites pure virtual
interface. Using a const reference in the interface would force a particular
implementation. Returning a copy does not make the code worse than before since
it was already returning a copy.

   bool loaded() const override;
   bool AddForcedURL(const GURL& url, const base::Time& time) override;
 
   // RefcountedKeyedService:
   void ShutdownOnUIThread() override;
 
  protected:
   ~TopSitesImpl() override;
 
  private:
@@ skipping 155 matching lines @@
   // 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
   // SetNonForcedTopSites call.
   TempImages temp_images_;
 
   // URL List of prepopulated page.
-  std::vector<GURL> prepopulated_page_urls_;
+  PrepopulatedPageList prepopulated_pages_;
 
   // Are we loaded?
   bool loaded_;
 
   DISALLOW_COPY_AND_ASSIGN(TopSitesImpl);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_TOP_SITES_IMPL_H_