1// Copyright 2013 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_EXTENSIONS_ACTIVITY_LOG_COUNTING_POLICY_H_
6#define CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_COUNTING_POLICY_H_
7
8#include <string>
9
10#include "base/containers/hash_tables.h"
11#include "chrome/browser/extensions/activity_log/activity_database.h"
12#include "chrome/browser/extensions/activity_log/activity_log_policy.h"
13#include "chrome/browser/extensions/activity_log/database_string_table.h"
14
15namespace extensions {
16
17// A policy for logging the stream of actions, but with most arguments stripped
18// out (to improve privacy and reduce database size) and with multiple
19// identical rows combined together using a count column to track the total
20// number of repetitions.  Identical rows within the same day are merged, but
21// actions on separate days are kept distinct.  Data is kept for up to a few
22// days then deleted.
23class CountingPolicy : public ActivityLogDatabasePolicy {
24 public:
25  explicit CountingPolicy(Profile* profile);
26  virtual ~CountingPolicy();
27
28  virtual void ProcessAction(scoped_refptr<Action> action) OVERRIDE;
29
30  virtual void ReadFilteredData(
31      const std::string& extension_id,
32      const Action::ActionType type,
33      const std::string& api_name,
34      const std::string& page_url,
35      const std::string& arg_url,
36      const int days_ago,
37      const base::Callback
38          <void(scoped_ptr<Action::ActionVector>)>& callback) OVERRIDE;
39
40  virtual void Close() OVERRIDE;
41
42  // Gets or sets the amount of time that old records are kept in the database.
43  const base::TimeDelta& retention_time() const { return retention_time_; }
44  void set_retention_time(const base::TimeDelta& delta) {
45    retention_time_ = delta;
46  }
47
48  // Clean the URL data stored for this policy.
49  virtual void RemoveURLs(const std::vector<GURL>&) OVERRIDE;
50
51  // Clean the data related to this extension for this policy.
52  virtual void RemoveExtensionData(const std::string& extension_id) OVERRIDE;
53
54  // Delete everything in the database.
55  virtual void DeleteDatabase() OVERRIDE;
56
57  // The main database table, and the name for a read-only view that
58  // decompresses string values for easier parsing.
59  static const char* kTableName;
60  static const char* kReadViewName;
61
62 protected:
63  // The ActivityDatabase::Delegate interface.  These are always called from
64  // the database thread.
65  virtual bool InitDatabase(sql::Connection* db) OVERRIDE;
66  virtual bool FlushDatabase(sql::Connection* db) OVERRIDE;
67  virtual void OnDatabaseFailure() OVERRIDE;
68  virtual void OnDatabaseClose() OVERRIDE;
69
70 private:
71  // A type used to track pending writes to the database.  The key is an action
72  // to write; the value is the amount by which the count field should be
73  // incremented in the database.
74  typedef std::map<scoped_refptr<Action>, int, ActionComparatorExcludingTime>
75      ActionQueue;
76
77  // Adds an Action to those to be written out; this is an internal method used
78  // by ProcessAction and is called on the database thread.
79  void QueueAction(scoped_refptr<Action> action);
80
81  // Internal method to read data from the database; called on the database
82  // thread.
83  scoped_ptr<Action::ActionVector> DoReadFilteredData(
84      const std::string& extension_id,
85      const Action::ActionType type,
86      const std::string& api_name,
87      const std::string& page_url,
88      const std::string& arg_url,
89      const int days_ago);
90
91  // The implementation of RemoveURLs; this must only run on the database
92  // thread.
93  void DoRemoveURLs(const std::vector<GURL>& restrict_urls);
94
95  // The implementation of RemoveExtensionData; this must only run on the
96  // database thread.
97  void DoRemoveExtensionData(const std::string& extension_id);
98
99  // The implementation of DeleteDatabase; called on the database thread.
100  void DoDeleteDatabase();
101
102  // Cleans old records from the activity log database.
103  bool CleanOlderThan(sql::Connection* db, const base::Time& cutoff);
104
105  // Cleans unused interned strings from the database.  This should be run
106  // after deleting rows from the main log table to clean out stale values.
107  bool CleanStringTables(sql::Connection* db);
108
109  // API calls for which complete arguments should be logged.
110  Util::ApiSet api_arg_whitelist_;
111
112  // Tables for mapping strings to integers for shrinking database storage
113  // requirements.  URLs are kept in a separate table from other strings to
114  // make history clearing simpler.
115  DatabaseStringTable string_table_;
116  DatabaseStringTable url_table_;
117
118  // Tracks any pending updates to be written to the database, if write
119  // batching is turned on.  Should only be accessed from the database thread.
120  ActionQueue queued_actions_;
121
122  // All queued actions must fall on the same day, so that we do not
123  // accidentally aggregate actions that should be kept separate.
124  // queued_actions_date_ is the date (timestamp at local midnight) of all the
125  // actions in queued_actions_.
126  base::Time queued_actions_date_;
127
128  // The amount of time old activity log records should be kept in the
129  // database.  This time is subtracted from the current time, rounded down to
130  // midnight, and rows older than this are deleted from the database when
131  // cleaning runs.
132  base::TimeDelta retention_time_;
133
134  // The time at which old activity log records were last cleaned out of the
135  // database (only tracked for this browser session).  Old records are deleted
136  // on the first database flush, and then every 12 hours subsequently.
137  base::Time last_database_cleaning_time_;
138
139  friend class CountingPolicyTest;
140  FRIEND_TEST_ALL_PREFIXES(CountingPolicyTest, EarlyFlush);
141  FRIEND_TEST_ALL_PREFIXES(CountingPolicyTest, MergingAndExpiring);
142  FRIEND_TEST_ALL_PREFIXES(CountingPolicyTest, StringTableCleaning);
143};
144
145}  // namespace extensions
146
147#endif  // CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_COUNTING_POLICY_H_
148