Splits the OfflinePageModel into and interface and and implementation class.

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 <stdint.h>
 
-#include <map>
 #include <memory>
 #include <set>
+#include <string>
 #include <vector>
 
-#include "base/callback.h"
-#include "base/files/file_path.h"
-#include "base/gtest_prod_util.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_vector.h"
-#include "base/memory/weak_ptr.h"
-#include "base/observer_list.h"
-#include "base/optional.h"
 #include "base/supports_user_data.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/offline_pages/offline_page_archiver.h"
-#include "components/offline_pages/offline_page_metadata_store.h"
 #include "components/offline_pages/offline_page_storage_manager.h"
 #include "components/offline_pages/offline_page_types.h"
 
 class GURL;
 namespace base {
-class SequencedTaskRunner;
 class Time;
-class TimeDelta;
-class TimeTicks;
 }  // namespace base
 
 namespace offline_pages {
 
 static const char* const kBookmarkNamespace = "bookmark";
 static const int64_t kInvalidOfflineId = 0;
 
 struct ClientId;
 struct OfflinePageItem;
 
-class ArchiveManager;
-class ClientPolicyController;
-class OfflinePageMetadataStore;
-class OfflinePageStorageManager;
-
 // Service for saving pages offline, storing the offline copy and metadata, and
 // retrieving them upon request.
 //
 // Example usage:
 //   class ArchiverImpl : public OfflinePageArchiver {
 //     // This is a class that knows how to create archiver
 //     void CreateArchiver(...) override;
 //     ...
 //   }
 //
 //   // In code using the OfflinePagesModel to save a page:
 //   std::unique_ptr<ArchiverImpl> archiver(new ArchiverImpl());
 //   // Callback is of type SavePageCallback.
 //   model->SavePage(url, std::move(archiver), callback);
 //
 // TODO(fgorski): Things to describe:
 // * how to cancel requests and what to expect
 class OfflinePageModel : public KeyedService,

[dewittj, 2016/05/26 16:38:43]

I think that this inheritance is wrong.  OfflinePageModel should be a pure
interface - OffilnePageModelImpl should implement KeyedService and
SupportsUserData.  If that requires extra API methods that's fine with me.

I think we can also get rid of OfflinePageStorageManager::Client altogether now
too.

[dougarnett, 2016/05/26 20:50:34]

Moved inheritances to impl. Have TODO wrt StorageManager subinterface.

[dougarnett, 2016/05/27 15:22:29]

I put StorageManager::Client and SupportsUserData back on this interface class
for now. 

For StorageManager::Client, I think we get rid of it in a follow-up CL that
reworks the mocking for the tests which motivated it in first place (nominating
romax to that). 

For SupportsUserData, I am not sure what is best to do. It only seems to be used
for one key for bridge instance so one idea is to add more specific
SetBridge/GetBridge interface here. Another is to add some GetUserData()
interface to expose the Impl implementation of it. Unless there is some simple
recommendation though, I wonder if this should be a follow-up as well. 

                          public base::SupportsUserData,
                          public OfflinePageStorageManager::Client {
  public:
   // 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 |offline_id| was deleted.
     // In can be invoked as a result of |CheckForExternalFileDeletion|, if a
     // deleted page is detected.
     virtual void OfflinePageDeleted(int64_t offline_id,
                                     const ClientId& client_id) = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
   using CheckPagesExistOfflineResult =

[dewittj, 2016/05/26 16:38:43]

these types can now just be declared here, and we can nuke offline_page_types.h

[dougarnett, 2016/05/26 20:50:34]

captured in https://bugs.chromium.org/p/chromium/issues/detail?id=615165

       offline_pages::CheckPagesExistOfflineResult;
   using MultipleOfflinePageItemResult =
       offline_pages::MultipleOfflinePageItemResult;
   using SingleOfflinePageItemResult =
       offline_pages::SingleOfflinePageItemResult;
-
-  //using DeletePageCallback = offline_pages::DeletePageCallback;
   using DeletePageResult = offline_pages::DeletePageResult;
   using SavePageResult = offline_pages::SavePageResult;
 
-  // Generates a new offline id
-  static int64_t GenerateOfflineId();
-
   // Returns true if an offline copy can be saved for the given URL.
   static bool CanSavePage(const GURL& url);

[dewittj, 2016/05/26 16:38:43]

Not sure that this belongs here now.

[dougarnett, 2016/05/26 20:50:34]

captured in https://bugs.chromium.org/p/chromium/issues/detail?id=615165

 
-  static base::TimeDelta GetFinalDeletionDelayForTesting();
-
-  // All blocking calls/disk access will happen on the provided |task_runner|.
-  OfflinePageModel(std::unique_ptr<OfflinePageMetadataStore> store,
-                   const base::FilePath& archives_dir,
-                   const scoped_refptr<base::SequencedTaskRunner>& task_runner);
+  OfflinePageModel();

[dewittj, 2016/05/26 16:38:43]

OfflinePageModel() = default;

[dougarnett, 2016/05/26 20:50:34]

Done.

   ~OfflinePageModel() override;

[dewittj, 2016/05/26 16:38:43]

If we make this just an interface, this can become
 virtual ~OfflinePageModel() = default;

[dougarnett, 2016/05/26 20:50:34]

Done.

 
-  void AddObserver(Observer* observer);
-  void RemoveObserver(Observer* observer);
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
 
   // Attempts to save a page addressed by |url| offline. Requires that the model
   // is loaded.  Generates a new offline id and returns it.
-  void SavePage(const GURL& url,
-                const ClientId& client_id,
-                std::unique_ptr<OfflinePageArchiver> archiver,
-                const SavePageCallback& callback);
+  virtual void SavePage(const GURL& url,
+                        const ClientId& client_id,
+                        std::unique_ptr<OfflinePageArchiver> archiver,
+                        const SavePageCallback& callback) = 0;
 
   // Marks that the offline page related to the passed |offline_id| has been
   // accessed. Its access info, including last access time and access count,
   // will be updated. Requires that the model is loaded.
-  void MarkPageAccessed(int64_t offline_id);
+  virtual void MarkPageAccessed(int64_t offline_id) = 0;
 
-  // Deletes an offline page related to the passed |offline_id|.
-  void DeletePageByOfflineId(int64_t offline_id,
-                             const DeletePageCallback& callback);
-
-  // Deletes offline pages related to the passed |offline_ids|.
-  void DeletePagesByOfflineId(const std::vector<int64_t>& offline_ids,
-                              const DeletePageCallback& callback) override;
+  // TODO(romax): Pull this interface up from OfflinePageStorageManager::Client

[dewittj, 2016/05/26 16:38:43]

Probably should just do that in this refactor.

[dougarnett, 2016/05/26 20:50:34]

captured in https://bugs.chromium.org/p/chromium/issues/detail?id=615165

+  // void DeletePagesByOfflineId(const std::vector<int64_t>& offline_ids,
+  //                             const DeletePageCallback& callback);
 
   // Wipes out all the data by deleting all saved files and clearing the store.
-  void ClearAll(const base::Closure& callback);
+  virtual void ClearAll(const base::Closure& callback) = 0;
 
   // Deletes offline pages matching the URL predicate.
-  void DeletePagesByURLPredicate(const UrlPredicate& predicate,
-                                 const DeletePageCallback& callback);
+  virtual void DeletePagesByURLPredicate(
+      const UrlPredicate& predicate,
+      const DeletePageCallback& callback) = 0;
 
   // Returns true via callback if there are offline pages in the given
   // |name_space|.
-  void HasPages(const std::string& name_space,
-                const HasPagesCallback& callback);
+  virtual void HasPages(const std::string& name_space,
+                        const HasPagesCallback& callback) = 0;
 
   // Returns via callback all GURLs in |urls| that are equal to the online URL
   // of any offline page.
-  void CheckPagesExistOffline(const std::set<GURL>& urls,
-                              const CheckPagesExistOfflineCallback& callback);
-
-  // Gets all available offline pages.
-  void GetAllPages(const MultipleOfflinePageItemCallback& callback) override;
+  virtual void CheckPagesExistOffline(
+      const std::set<GURL>& urls,
+      const CheckPagesExistOfflineCallback& callback) = 0;
 
   // Gets all offline ids where the offline page has the matching client id.
-  void GetOfflineIdsForClientId(const ClientId& client_id,
-                                const MultipleOfflineIdCallback& callback);
+  virtual void GetOfflineIdsForClientId(
+      const ClientId& client_id,
+      const MultipleOfflineIdCallback& callback) = 0;
 
   // Gets all offline ids where the offline page has the matching client id.
   // Requires that the model is loaded.  May not return matching IDs depending
-  // on the internal state of the model.
+  // on the internal state of the model.#include <algorithm>

[dewittj, 2016/05/26 16:38:43]

copy/paste error?

[dougarnett, 2016/05/26 20:50:34]

Done.

   //
   // This function is deprecated.  Use |GetOfflineIdsForClientId| instead.
-  const std::vector<int64_t> MaybeGetOfflineIdsForClientId(
-      const ClientId& client_id) const;
+  virtual const std::vector<int64_t> MaybeGetOfflineIdsForClientId(
+      const ClientId& client_id) const = 0;
 
   // Returns zero or one offline pages associated with a specified |offline_id|.
-  void GetPageByOfflineId(int64_t offline_id,
-                          const SingleOfflinePageItemCallback& callback);
+  virtual void GetPageByOfflineId(
+      int64_t offline_id,
+      const SingleOfflinePageItemCallback& callback) = 0;
 
   // Returns an offline page associated with a specified |offline_id|. nullptr
   // is returned if not found.
-  const OfflinePageItem* MaybeGetPageByOfflineId(int64_t offline_id) const;
+  virtual const OfflinePageItem* MaybeGetPageByOfflineId(
+      int64_t offline_id) const = 0;
 
   // Returns the offline page that is stored under |offline_url|, if any.
-  void GetPageByOfflineURL(const GURL& offline_url,
-                           const SingleOfflinePageItemCallback& callback);
+  virtual void GetPageByOfflineURL(
+      const GURL& offline_url,
+      const SingleOfflinePageItemCallback& callback) = 0;
 
   // Returns an offline page that is stored as |offline_url|. A nullptr is
   // returned if not found.
   //
   // This function is deprecated, and may return |nullptr| even if a page
   // exists, depending on the implementation details of OfflinePageModel.
   // Use |GetPageByOfflineURL| instead.
-  const OfflinePageItem* MaybeGetPageByOfflineURL(
-      const GURL& offline_url) const;
+  virtual const OfflinePageItem* MaybeGetPageByOfflineURL(
+      const GURL& offline_url) const = 0;
 
   // Returns the offline pages that are stored under |online_url|.
-  void GetPagesByOnlineURL(const GURL& online_url,
-                           const MultipleOfflinePageItemCallback& callback);
+  virtual void GetPagesByOnlineURL(
+      const GURL& online_url,
+      const MultipleOfflinePageItemCallback& callback) = 0;
 
   // Returns via callback an offline page saved for |online_url|, if any. The
   // best page is chosen based on creation date; a more recently created offline
   // page will be preferred over an older one. This API function does not
   // respect namespaces, as it is used to choose which page is rendered in a
   // tab. Today all namespaces are treated equally for the purposes of this
   // selection.
-  void GetBestPageForOnlineURL(const GURL& online_url,
-                               const SingleOfflinePageItemCallback callback);
+  virtual void GetBestPageForOnlineURL(
+      const GURL& online_url,
+      const SingleOfflinePageItemCallback callback) = 0;
 
   // Returns an offline page saved for |online_url|. A nullptr is returned if
   // not found.  See |GetBestPageForOnlineURL| for selection criteria.
-  const OfflinePageItem* MaybeGetBestPageForOnlineURL(
-      const GURL& online_url) const;
+  virtual const OfflinePageItem* MaybeGetBestPageForOnlineURL(
+      const GURL& online_url) const = 0;
 
   // 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();
+  virtual void CheckForExternalFileDeletion() = 0;
 
   // Marks pages as expired and removes their respective files from the archive
   // directory.
-  void ExpirePages(const std::vector<int64_t>& offline_ids,
-                   const base::Time& expiration_time);
+  virtual void ExpirePages(const std::vector<int64_t>& offline_ids,
+                           const base::Time& expiration_time) = 0;
 
   // Returns the policy controller.
-  ClientPolicyController* GetPolicyController();
+  virtual ClientPolicyController* GetPolicyController() = 0;
 
-  // Methods for testing only:
-  OfflinePageMetadataStore* GetStoreForTesting();
-
-  OfflinePageStorageManager* GetStorageManager();
-
-  bool is_loaded() const;
-
- protected:
-  // Adding a protected constructor for testing-only purposes in
-  // offline_page_storage_manager_unittest.cc
-  OfflinePageModel();
+  // Method for testing only:
+  virtual bool is_loaded() const = 0;

[dewittj, 2016/05/26 16:38:43]

Since there will only be tests for the impl, this can be moved to the subclass
now.

Although I can't find any usage of this function.  Let's just nuke it!

[dougarnett, 2016/05/26 20:50:34]

Will fix comment. Removing it captured in
https://bugs.chromium.org/p/chromium/issues/detail?id=615165

 
  private:
-  FRIEND_TEST_ALL_PREFIXES(OfflinePageModelTest, MarkPageForDeletion);
-
-  typedef ScopedVector<OfflinePageArchiver> PendingArchivers;
-
-  // Callback for ensuring archive directory is created.
-  void OnEnsureArchivesDirCreatedDone(const base::TimeTicks& start_time);
-
-  void GetAllPagesAfterLoadDone(
-      const MultipleOfflinePageItemCallback& callback);
-  void CheckPagesExistOfflineAfterLoadDone(
-      const std::set<GURL>& urls,
-      const CheckPagesExistOfflineCallback& callback);
-  void GetOfflineIdsForClientIdWhenLoadDone(
-      const ClientId& client_id,
-      const MultipleOfflineIdCallback& callback) const;
-  void GetPageByOfflineIdWhenLoadDone(
-      int64_t offline_id,
-      const SingleOfflinePageItemCallback& callback) const;
-  void GetPagesByOnlineURLWhenLoadDone(
-      const GURL& offline_url,
-      const MultipleOfflinePageItemCallback& callback) const;
-  void GetPageByOfflineURLWhenLoadDone(
-      const GURL& offline_url,
-      const SingleOfflinePageItemCallback& callback) const;
-  void GetBestPageForOnlineURLWhenLoadDone(
-      const GURL& online_url,
-      const SingleOfflinePageItemCallback& callback) const;
-
-  // Callback for checking whether we have offline pages.
-  void HasPagesAfterLoadDone(const std::string& name_space,
-                             const HasPagesCallback& callback) const;
-
-  // Callback for loading pages from the offline page metadata store.
-  void OnLoadDone(const base::TimeTicks& start_time,
-                  OfflinePageMetadataStore::LoadStatus load_status,
-                  const std::vector<OfflinePageItem>& offline_pages);
-
-  // Steps for saving a page offline.
-  void OnCreateArchiveDone(const GURL& requested_url,
-                           int64_t offline_id,
-                           const ClientId& client_id,
-                           const base::Time& start_time,
-                           const SavePageCallback& callback,
-                           OfflinePageArchiver* archiver,
-                           OfflinePageArchiver::ArchiverResult result,
-                           const GURL& url,
-                           const base::FilePath& file_path,
-                           int64_t file_size);
-  void OnAddOfflinePageDone(OfflinePageArchiver* archiver,
-                            const SavePageCallback& callback,
-                            const OfflinePageItem& offline_page,
-                            bool success);
-  void InformSavePageDone(const SavePageCallback& callback,
-                          SavePageResult result,
-                          const ClientId& client_id,
-                          int64_t offline_id);
-  void DeletePendingArchiver(OfflinePageArchiver* archiver);
-
-  // Steps for deleting files and data for an offline page.
-  void OnDeleteArchiveFilesDone(const std::vector<int64_t>& offline_ids,
-                                const DeletePageCallback& callback,
-                                bool success);
-  void OnRemoveOfflinePagesDone(const std::vector<int64_t>& offline_ids,
-                                const DeletePageCallback& callback,
-                                bool success);
-  void InformDeletePageDone(const DeletePageCallback& callback,
-                            DeletePageResult result);
-
-  void OnMarkPageAccesseDone(const OfflinePageItem& offline_page_item,
-                             bool success);
-
-  // Callbacks for checking if offline pages are missing archive files.
-  void ScanForMissingArchiveFiles(
-      const std::set<base::FilePath>& archive_paths);
-  void OnRemoveOfflinePagesMissingArchiveFileDone(
-      const std::vector<std::pair<int64_t, ClientId>>& offline_client_id_pairs,
-      DeletePageResult result);
-
-  // Steps for clearing all.
-  void OnRemoveAllFilesDoneForClearAll(const base::Closure& callback,
-                                       DeletePageResult result);
-  void OnResetStoreDoneForClearAll(const base::Closure& callback, bool success);
-  void OnReloadStoreDoneForClearAll(
-      const base::Closure& callback,
-      OfflinePageMetadataStore::LoadStatus load_status,
-      const std::vector<OfflinePageItem>& offline_pages);
-
-  void CacheLoadedData(const std::vector<OfflinePageItem>& offline_pages);
-
-  // Actually does the work of deleting, requires the model is loaded.
-  void DoDeletePagesByOfflineId(const std::vector<int64_t>& offline_ids,
-                                const DeletePageCallback& callback);
-
-  // Similar to DoDeletePagesByOfflineId, does actual work of deleting, and
-  // requires that the model is loaded.
-  void DoDeletePagesByURLPredicate(const UrlPredicate& predicate,
-                                   const DeletePageCallback& callback);
-
-  // Callback completing page expiration.
-  void OnExpirePageDone(int64_t offline_id,
-                        const base::Time& expiration_time,
-                        bool success);
-
-  void RunWhenLoaded(const base::Closure& job);
-
-  // Persistent store for offline page metadata.
-  std::unique_ptr<OfflinePageMetadataStore> store_;
-
-  // Location where all of the archive files will be stored.
-  base::FilePath archives_dir_;
-
-  // The observers.
-  base::ObserverList<Observer> observers_;
-
-  bool is_loaded_;
-
-  // In memory copy of the offline page metadata, keyed by bookmark IDs.
-  std::map<int64_t, OfflinePageItem> offline_pages_;
-
-  // Pending archivers owned by this model.
-  PendingArchivers pending_archivers_;
-
-  // Delayed tasks that should be invoked after the loading is done.
-  std::vector<base::Closure> delayed_tasks_;
-
-  // Controller of the client policies.
-  std::unique_ptr<ClientPolicyController> policy_controller_;
-
-  // Manager for the storage consumed by archives and responsible for
-  // automatic page clearing.
-  std::unique_ptr<OfflinePageStorageManager> storage_manager_;
-
-  // Manager for the offline archive files and directory.
-  std::unique_ptr<ArchiveManager> archive_manager_;
-
-  base::WeakPtrFactory<OfflinePageModel> weak_ptr_factory_;
-
   DISALLOW_COPY_AND_ASSIGN(OfflinePageModel);

[Dmitry Titov, 2016/05/26 18:27:29]

Don't think this is needed for pure abstract interfaces that this will become.

[dougarnett, 2016/05/26 20:50:34]

Done.

 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_OFFLINE_PAGE_MODEL_H_