Fetch incremental updates. Store new state in V4Store.

components/safe_browsing_db/v4_database.h

Index: components/safe_browsing_db/v4_database.h
diff --git a/components/safe_browsing_db/v4_database.h b/components/safe_browsing_db/v4_database.h
index 8e634492e6537955f1b31f736bec2fddfe6a74e7..85dbd375bf33f8d2f747abbabfbbc4fa26bf3381 100644
--- a/components/safe_browsing_db/v4_database.h
+++ b/components/safe_browsing_db/v4_database.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_SAFE_BROWSING_DB_V4_DATABASE_H_
 #define COMPONENTS_SAFE_BROWSING_DB_V4_DATABASE_H_
 
+#include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner.h"
@@ -19,15 +20,10 @@ class V4Database;
 typedef base::Callback<void(std::unique_ptr<V4Database>)>
     NewDatabaseReadyCallback;
 
-// This defines a hash_map that is used to create the backing files for the
-// stores that contain the hash-prefixes. The map key identifies the list that
-// we're interested in and the value represents the ASCII file-name that'll be
-// created on-disk to store the hash-prefixes for that list. This file is
-// created inside the user's profile directory.
-// For instance, the UpdateListIdentifier could be for URL expressions for UwS
-// on Windows platform, and the corresponding file on disk could be named:
-// "uws_win_url.store"
-typedef base::hash_map<UpdateListIdentifier, std::string> ListInfoMap;
+// This callback is Run once the database has finished processing the update
+// requests for all stores and is ready to process the next set of update
+// requests.
+typedef base::Callback<void()> DatabaseUpdatedCallback;
 
 // This hash_map maps the UpdateListIdentifiers to their corresponding in-memory
 // stores, which contain the hash prefixes for that UpdateListIdentifier as well
@@ -42,7 +38,7 @@ class V4DatabaseFactory {
   virtual V4Database* CreateV4Database(
       const scoped_refptr<base::SequencedTaskRunner>& db_task_runner,
       const base::FilePath& base_dir_path,
-      const ListInfoMap& list_info_map) = 0;
+      const StoreFileNameMap& store_file_name_map) = 0;
 };
 
 // The on-disk databases are shared among all profiles, as it doesn't contain
@@ -55,12 +51,19 @@ class V4DatabaseFactory {
 class V4Database {
  public:
   // Factory method to create a V4Database. It creates the database on the
-  // provided |db_task_runner|. When the database creation is complete, it calls
-  // the NewDatabaseReadyCallback on the same thread as it was called.
-  static void Create(
+  // provided |db_task_runner| containing stores for which the filename has
+  // been specified in \store_file_name_map\. The created V4Database runs
+  // |db_updated_callback| after processing updates passed to the ApplyUpdate
+  // method. When the database creation is complete, it runs the
+  // NewDatabaseReadyCallback on the same thread as it was called. If the
+  // |base_path| argument isn't an absolute path or if the
+  // |store_file_name_map| is empty, it returns false right away and doesn't
+  // attempt to create the database at all.
+  static bool Create(
       const scoped_refptr<base::SequencedTaskRunner>& db_task_runner,
       const base::FilePath& base_path,
-      const ListInfoMap& list_info_map,
+      const StoreFileNameMap& store_file_name_map,
+      DatabaseUpdatedCallback db_updated_callback,
       NewDatabaseReadyCallback callback);
 
   // Destroys the provided v4_database on its task_runner since this may be a
@@ -69,12 +72,19 @@ class V4Database {
 
   virtual ~V4Database();
 
+  // Updates the stores with the reponse received from the SafeBrowsing service

[Nathan Parker, 2016/06/15 21:24:13]

nit: response

[vakh (use Gerrit instead), 2016/06/16 01:07:35]

Done.

+  // and calls the db_updated_callback_ when done.
+  void ApplyUpdate(const std::vector<ListUpdateResponse>&);
+
+  const StoreStateMap* store_state_map() { return store_state_map_.get(); }
+
   // Deletes the current database and creates a new one.
   virtual bool ResetDatabase();
 
  protected:
   V4Database(const scoped_refptr<base::SequencedTaskRunner>& db_task_runner,
-             std::unique_ptr<StoreMap> store_map);
+             std::unique_ptr<StoreMap> store_map,
+             DatabaseUpdatedCallback db_updated_callback);
 
  private:
   friend class SafeBrowsingV4DatabaseTest;
@@ -82,6 +92,12 @@ class V4Database {
                            TestSetupDatabaseWithFakeStores);
   FRIEND_TEST_ALL_PREFIXES(SafeBrowsingV4DatabaseTest,
                            TestSetupDatabaseWithFakeStoresFailsReset);
+  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingV4DatabaseTest,
+                           TestApplyUpdateWithNewStates);
+  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingV4DatabaseTest,
+                           TestApplyUpdateWithNoNewState);
+  FRIEND_TEST_ALL_PREFIXES(SafeBrowsingV4DatabaseTest,
+                           TestApplyUpdateWithEmptyUpdate);
 
   // Makes the passed |factory| the factory used to instantiate a V4Store. Only
   // for tests.
@@ -94,18 +110,37 @@ class V4Database {
   static void CreateOnTaskRunner(
       const scoped_refptr<base::SequencedTaskRunner>& db_task_runner,
       const base::FilePath& base_path,
-      const ListInfoMap& list_info_map,
+      const StoreFileNameMap& store_file_name_map,
+      DatabaseUpdatedCallback db_updated_callback,
       const scoped_refptr<base::SingleThreadTaskRunner>& callback_task_runner,
       NewDatabaseReadyCallback callback);
 
+  // Callback called when a new store has been created and is ready to be used.
+  // This method updates the store_map_ to point to the new store, which causes
+  // the old store to get deleted.
+  void UpdatedStoreReady(UpdateListIdentifier, std::unique_ptr<V4Store>);

[Nathan Parker, 2016/06/15 21:24:15]

missing argument names.

[vakh (use Gerrit instead), 2016/06/16 01:07:35]

Done.

+
+  // Updates the store state map after reading the stores from disk on startup.
+  void UpdateStoreStateMap();
+
   const scoped_refptr<base::SequencedTaskRunner> db_task_runner_;
 
   // Map of UpdateListIdentifier to the V4Store.
   const std::unique_ptr<StoreMap> store_map_;
 
+  // Map of UpdateListIdentifier to the state of the V4Store it represents.
+  const std::unique_ptr<StoreStateMap> store_state_map_;

[Nathan Parker, 2016/06/15 21:24:14]

Could this be just a StoreStateMap, and not a ptr?

[vakh (use Gerrit instead), 2016/06/16 01:07:35]

Done.

+
+  DatabaseUpdatedCallback db_updated_callback_;
+
   // The factory that controls the creation of V4Store objects.
   static V4StoreFactory* factory_;
 
+  // The number of stores for which the update request is pending. When this
+  // goes down to 0, that indicates that the database has updated all the stores
+  // that needed updating and is ready for the next update.
+  unsigned pending_store_updates_;
+
   DISALLOW_COPY_AND_ASSIGN(V4Database);
 };