[Offline pages] Detecting missing offline copy

components/offline_pages/offline_page_model.h

 // Copyright 2015 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 COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 #define COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 85 matching lines @@
   // Observer of the OfflinePageModel.
   class Observer {
    public:
     // Invoked when the model has finished loading.
     virtual void OfflinePageModelLoaded(OfflinePageModel* model) = 0;
 
     // Invoked when the model is being updated, due to adding, removing or
     // updating an offline page.
     virtual void OfflinePageModelChanged(OfflinePageModel* model) = 0;
 
+    // Invoked when an offline copy related to |bookmark_id| was deleted.
+    // In can be invoked as a result of |CheckForExternalFileDeletion|, if a
+    // deleted page is detected.
+    virtual void OfflinePageDeleted(int64 bookmark_id) = 0;
+
    protected:
     virtual ~Observer() {}
   };
 
   typedef base::Callback<void(SavePageResult)> SavePageCallback;
   typedef base::Callback<void(DeletePageResult)> DeletePageCallback;
 
   // All blocking calls/disk access will happen on the provided |task_runner|.
   OfflinePageModel(
       scoped_ptr<OfflinePageMetadataStore> store,
@@ skipping 46 matching lines @@
   const std::vector<OfflinePageItem> GetAllPages() const;
 
   // Gets pages that should be removed to clean up storage. Requires that the
   // model is loaded.
   const std::vector<OfflinePageItem> GetPagesToCleanUp() const;
 
   // Returns an offline page associated with a specified |bookmark_id|. nullptr
   // is returned if not found.
   const OfflinePageItem* GetPageByBookmarkId(int64 bookmark_id) const;
 
-  // Returns an offline page that is stored as |offline_url|. nullptr is
+  // Returns an offline page that is stored as |offline_url|. A nullptr is
   // returned if not found.
   const OfflinePageItem* GetPageByOfflineURL(const GURL& offline_url) const;
 
+  // Checks that all of the offline pages have corresponding offline copies.
+  // If a page is discovered to be missing an offline copy, its offline page
+  // metadata will be removed and |OfflinePageDeleted| will be sent to model
+  // observers.
+  void CheckForExternalFileDeletion();
+
   // Methods for testing only:
   OfflinePageMetadataStore* GetStoreForTesting();
 
   bool is_loaded() const { return is_loaded_; }
 
  private:
   FRIEND_TEST_ALL_PREFIXES(OfflinePageModelTest, MarkPageForDeletion);
 
   typedef ScopedVector<OfflinePageArchiver> PendingArchivers;
 
@@ skipping 36 matching lines @@
       const bool* success);
   void OnRemoveOfflinePagesDone(const std::vector<int64>& bookmark_ids,
                                 const DeletePageCallback& callback,
                                 bool success);
   void InformDeletePageDone(const DeletePageCallback& callback,
                             DeletePageResult result);
 
   void OnMarkPageAccesseDone(const OfflinePageItem& offline_page_item,
                              bool success);
 
-  // Steps for marking an offline page for deletion that can be undo-ed.
+  // Steps for marking an offline page for deletion that can be undone.
   void OnMarkPageForDeletionDone(const OfflinePageItem& offline_page_item,
                                  const DeletePageCallback& callback,
                                  bool success);
   void FinalizePageDeletion();
 
-  // Steps for undoing a offline page deletion.
+  // Steps for undoing an offline page deletion.
   void UndoPageDeletion(int64 bookmark_id);
   void OnUndoOfflinePageDone(const OfflinePageItem& offline_page, bool success);
 
+  // Callbacks for checking if offline pages are missing archive files.
+  void OnFindPagesMissingArchiveFile(
+      const std::vector<int64>* pages_missing_archive_file);
+  void OnRemoveOfflinePagesMissingArchiveFileDone(
+      const std::vector<int64>& bookmark_ids,
+      OfflinePageModel::DeletePageResult result);
+
   // Persistent store for offline page metadata.
   scoped_ptr<OfflinePageMetadataStore> store_;
 
   // The observers.
   base::ObserverList<Observer> observers_;
 
   bool is_loaded_;
 
   // In memory copy of the offline page metadata, keyed by bookmark IDs.
   std::map<int64, OfflinePageItem> offline_pages_;
@@ skipping 10 matching lines @@
       scoped_observer_;
 
   base::WeakPtrFactory<OfflinePageModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OfflinePageModel);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_