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_SYNC_UTIL_EXTENSIONS_ACTIVITY_MONITOR_H_
6#define CHROME_BROWSER_SYNC_UTIL_EXTENSIONS_ACTIVITY_MONITOR_H_
7#pragma once
8
9#include <map>
10
11#include "base/message_loop.h"
12#include "base/synchronization/lock.h"
13#include "content/common/notification_observer.h"
14#include "content/common/notification_registrar.h"
15
16namespace browser_sync {
17
18// A class to monitor usage of extensions APIs to send to sync servers, with
19// the ability to purge data once sync servers have acknowledged it (successful
20// commit response).
21//
22// This can be used from any thread (it is a 'monitor' in the synchronization
23// sense as well), HOWEVER
24//
25// *** IT MUST BE DELETED FROM THE UI LOOP ***
26//
27// Consider using MessageLoop::DeleteSoon. (Yes, this means if you allocate
28// an ExtensionsActivityMonitor on a thread other than UI, you must 'new' it).
29class ExtensionsActivityMonitor : public NotificationObserver {
30 public:
31  // A data record of activity performed by extension |extension_id|.
32  struct Record {
33    Record() : bookmark_write_count(0U) {}
34
35    // The human-readable ID identifying the extension responsible
36    // for the activity reported in this Record.
37    std::string extension_id;
38
39    // How many times the extension successfully invoked a write
40    // operation through the bookmarks API since the last CommitMessage.
41    uint32 bookmark_write_count;
42  };
43
44  typedef std::map<std::string, Record> Records;
45
46  // Creates an ExtensionsActivityMonitor to monitor extensions activities on
47  // BrowserThread::UI.
48  ExtensionsActivityMonitor();
49  ~ExtensionsActivityMonitor();
50
51  // Fills |buffer| with snapshot of current records in constant time by
52  // swapping.  This is done mutually exclusively w.r.t methods of this class.
53  void GetAndClearRecords(Records* buffer);
54
55  // Add |records| piece-wise (by extension id) to the set of active records.
56  // This is done mutually exclusively w.r.t the methods of this class.
57  void PutRecords(const Records& records);
58
59  // NotificationObserver implementation.  Called on |ui_loop_|.
60  virtual void Observe(NotificationType type,
61                       const NotificationSource& source,
62                       const NotificationDetails& details);
63 private:
64  Records records_;
65  mutable base::Lock records_lock_;
66
67  // Used only from UI loop.
68  NotificationRegistrar registrar_;
69};
70
71}  // namespace browser_sync
72
73#endif  // CHROME_BROWSER_SYNC_UTIL_EXTENSIONS_ACTIVITY_MONITOR_H_
74