prerender_history.h revision eb525c5499e34cc9c4b825d6d9e75bb07cc06ace 
1// Copyright (c) 2011 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 CHROME_BROWSER_PRERENDER_PRERENDER_HISTORY_H_
6#define CHROME_BROWSER_PRERENDER_PRERENDER_HISTORY_H_
7
8#include <list>
9
10#include "base/threading/non_thread_safe.h"
11#include "base/time/time.h"
12#include "chrome/browser/prerender/prerender_final_status.h"
13#include "chrome/browser/prerender/prerender_origin.h"
14#include "url/gurl.h"
15
16namespace base {
17class Value;
18}
19
20namespace prerender {
21
22// PrerenderHistory maintains a per-session history of prerendered pages
23// and their final dispositions. It has a fixed maximum capacity, and old
24// items in history will be removed when the capacity is reached.
25class PrerenderHistory : public base::NonThreadSafe {
26 public:
27  // Entry is an individual entry in the history list. It corresponds to a
28  // specific prerendered page.
29  struct Entry {
30    Entry() : final_status(FINAL_STATUS_MAX), origin(ORIGIN_MAX) {}
31
32    Entry(const GURL& url_arg,
33          FinalStatus final_status_arg,
34          Origin origin_arg,
35          base::Time end_time_arg)
36        : url(url_arg), final_status(final_status_arg),
37          origin(origin_arg),
38          end_time(end_time_arg) {
39    }
40
41    // The URL which was prerendered. This should be the URL included in the
42    // <link rel="prerender"> tag, and not any URLs which it may have redirected
43    // to.
44    GURL url;
45
46    // The FinalStatus describing whether the prerendered page was used or why
47    // it was cancelled.
48    FinalStatus final_status;
49
50    // The Origin describing where the prerender originated from.
51    Origin origin;
52
53    // Time the PrerenderContents was destroyed.
54    base::Time end_time;
55  };
56
57  // Creates a history with capacity for |max_items| entries.
58  explicit PrerenderHistory(size_t max_items);
59  ~PrerenderHistory();
60
61  // Adds |entry| to the history. If at capacity, the oldest entry is dropped.
62  void AddEntry(const Entry& entry);
63
64  // Deletes all history entries.
65  void Clear();
66
67  // Retrieves the entries as a value which can be displayed.
68  base::Value* GetEntriesAsValue() const;
69
70 private:
71  std::list<Entry> entries_;
72  size_t max_items_;
73
74  DISALLOW_COPY_AND_ASSIGN(PrerenderHistory);
75};
76
77}
78#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_HISTORY_H_
79