components/omnibox/browser/answers_cache.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_OMNIBOX_BROWSER_ANSWERS_CACHE_H_
   6 #define COMPONENTS_OMNIBOX_BROWSER_ANSWERS_CACHE_H_
   7
   8 #include <list>
   9
  10 #include "base/basictypes.h"
  11 #include "base/strings/string16.h"
  12
  13 struct AnswersQueryData {
  14   AnswersQueryData();
  15   AnswersQueryData(const base::string16& full_query_text,
  16                    const base::string16& query_type);
  17   base::string16 full_query_text;
  18   base::string16 query_type;
  19 };
  20
  21 // Cache for the most-recently seen answer for Answers in Suggest.
  22 class AnswersCache {
  23  public:
  24   explicit AnswersCache(size_t max_entries);
  25   ~AnswersCache();
  26
  27   // Gets the top answer query completion for the query term. The query data
  28   // will contain empty query text and type if no matching data was found.
  29   AnswersQueryData GetTopAnswerEntry(const base::string16& query);
  30
  31   // Registers a query that received an answer suggestion.
  32   void UpdateRecentAnswers(const base::string16& full_query_text,
  33                            const base::string16& query_type);
  34
  35   // Signals if cache is empty.
  36   bool empty() const { return cache_.empty(); }
  37
  38  private:
  39   size_t max_entries_;
  40   typedef std::list<AnswersQueryData> Cache;
  41   Cache cache_;
  42
  43   DISALLOW_COPY_AND_ASSIGN(AnswersCache);
  44 };
  45
  46 #endif  // COMPONENTS_OMNIBOX_BROWSER_ANSWERS_CACHE_H_