Offline blacklisting for SuggestionsService.

chrome/browser/search/suggestions/blacklist_store.h

+// Copyright 2014 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_SEARCH_SUGGESTIONS_BLACKLIST_STORE_H_
+#define CHROME_BROWSER_SEARCH_SUGGESTIONS_BLACKLIST_STORE_H_
+
+#include "base/macros.h"
+#include "chrome/browser/search/suggestions/proto/suggestions.pb.h"
+#include "url/gurl.h"
+
+class PrefService;
+
+namespace user_prefs {
+class PrefRegistrySyncable;
+}  // namespace user_prefs
+
+namespace suggestions {
+
+// A helper class for reading, writing and modifying a small blacklist stored
+// in the Profile preferences. It also handles SuggestionsProfile
+// filtering based on the stored blacklist.
+class BlacklistStore {
+ public:
+  explicit BlacklistStore(PrefService* profile_prefs);
+  virtual ~BlacklistStore();
+
+  // Returns true if successful or |url| was already in the blacklist.
+  virtual bool BlacklistUrl(const GURL& url);
+
+  // Sets |url| to the first URL from the blacklist. Returns false if the
+  // blacklist is empty.
+  virtual bool GetFirstUrlFromBlacklist(GURL* url);
+
+  // Removes |url| from the stored blacklist. Returns true if successful or if
+  // |url| is not in the blacklist.
+  virtual bool RemoveUrl(const GURL& url);
+
+  // Applies the blacklist to |suggestions|.
+  virtual void FilterSuggestions(SuggestionsProfile* suggestions);
+
+  // Register BlacklistStore related prefs in the Profile prefs.
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+ protected:
+  // Test seam. For simplicity of mock creation.
+  BlacklistStore() {}
+
+  // Loads the blacklist data from the Profile preferences into
+  // |blacklist|. If there is a problem with loading, the pref value is
+  // cleared, false is returned and |blacklist| is cleared. If successful,
+  // |blacklist| will contain the loaded data and true is returned.
+  bool LoadBlacklist(SuggestionsBlacklist* blacklist);
+
+  // Stores the provided |blacklist| to the Profile preferences, using
+  // a base64 encoding of its protobuf serialization.
+  bool StoreBlacklist(const SuggestionsBlacklist& blacklist);
+
+  // Clears any blacklist data from the profile's preferences.
+  void ClearBlacklist();
+
+ private:
+  // The pref service used to persist the suggestions blacklist.
+  PrefService* pref_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlacklistStore);
+};
+
+}  // namespace suggestions
+
+#endif  // CHROME_BROWSER_SEARCH_SUGGESTIONS_BLACKLIST_STORE_H_