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_ANSWERS_CACHE_H_
6#define COMPONENTS_OMNIBOX_ANSWERS_CACHE_H_
7
8#include <list>
9
10#include "base/basictypes.h"
11#include "base/strings/string16.h"
12
13struct 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.
22class 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_ANSWERS_CACHE_H_
47