scope_logger.h revision 1a212a6b98b22ad1d69652bb26a9e94138635476 
1// Copyright (c) 2012 The Chromium OS 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 SHILL_SCOPE_LOGGER_H_
6#define SHILL_SCOPE_LOGGER_H_
7
8#include <bitset>
9#include <string>
10#include <vector>
11
12#include <base/lazy_instance.h>
13#include <base/macros.h>
14#include <gtest/gtest_prod.h>
15
16#include "shill/callbacks.h"
17
18namespace shill {
19
20// A class that enables logging based on scope and verbose level. It is not
21// intended to be used directly but via the SLOG() macros in shill/logging.h
22class ScopeLogger {
23 public:
24  // Logging scopes.
25  //
26  // Update kScopeNames in scope_logger.cc after changing this enumerated type.
27  // These scope identifiers are sorted by their scope names alphabetically.
28  enum Scope {
29    kCellular = 0,
30    kConnection,
31    kCrypto,
32    kDaemon,
33    kDBus,
34    kDevice,
35    kDHCP,
36    kDNS,
37    kEthernet,
38    kHTTP,
39    kHTTPProxy,
40    kInet,
41    kLink,
42    kManager,
43    kMetrics,
44    kModem,
45    kPortal,
46    kPower,
47    kPPP,
48    kPPPoE,
49    kProfile,
50    kProperty,
51    kResolver,
52    kRoute,
53    kRTNL,
54    kService,
55    kStorage,
56    kTask,
57    kVPN,
58    kWiFi,
59    kWiMax,
60    kNumScopes
61  };
62
63  typedef base::Callback<void(bool)> ScopeEnableChangedCallback;
64  typedef std::vector<ScopeEnableChangedCallback>ScopeEnableChangedCallbacks;
65
66  // Returns a singleton of this class.
67  static ScopeLogger* GetInstance();
68
69  ~ScopeLogger();
70
71  // Returns true if logging is enabled for |scope| and |verbose_level|, i.e.
72  // scope_enable_[|scope|] is true and |verbose_level| <= |verbose_level_|
73  bool IsLogEnabled(Scope scope, int verbose_level) const;
74
75  // Returns true if logging is enabled for |scope| at any verbosity level.
76  bool IsScopeEnabled(Scope scope) const;
77
78  // Returns a string comprising the names, separated by commas, of all scopes.
79  std::string GetAllScopeNames() const;
80
81  // Returns a string comprising the names, separated by plus signs, of all
82  // scopes that are enabled for logging.
83  std::string GetEnabledScopeNames() const;
84
85  // Enables/disables scopes as specified by |expression|.
86  //
87  // |expression| is a string comprising a sequence of scope names, each
88  // prefixed by a plus '+' or minus '-' sign. A scope prefixed by a plus
89  // sign is enabled for logging, whereas a scope prefixed by a minus sign
90  // is disabled for logging. Scopes that are not mentioned in |expression|
91  // remain the same state.
92  //
93  // To allow resetting the state of all scopes, an exception is made for the
94  // first scope name in the sequence, which may not be prefixed by any sign.
95  // That is considered as an implicit plus sign for that scope and also
96  // indicates that all scopes are first disabled before enabled by
97  // |expression|.
98  //
99  // If |expression| is an empty string, all scopes are disabled. Any unknown
100  // scope name found in |expression| is ignored.
101  void EnableScopesByName(const std::string& expression);
102
103  // Register for log scope enable/disable state changes for |scope|.
104  void RegisterScopeEnableChangedCallback(
105      Scope scope, ScopeEnableChangedCallback callback);
106
107  // Sets the verbose level for all scopes to |verbose_level|.
108  void set_verbose_level(int verbose_level) { verbose_level_ = verbose_level; }
109
110 private:
111  // Required for constructing LazyInstance<ScopeLogger>.
112  friend struct base::DefaultLazyInstanceTraits<ScopeLogger>;
113  friend class ScopeLoggerTest;
114  FRIEND_TEST(ScopeLoggerTest, GetEnabledScopeNames);
115  FRIEND_TEST(ScopeLoggerTest, SetScopeEnabled);
116  FRIEND_TEST(ScopeLoggerTest, SetVerboseLevel);
117
118  // Disables logging for all scopes.
119  void DisableAllScopes();
120
121  // Enables or disables logging for |scope|.
122  void SetScopeEnabled(Scope scope, bool enabled);
123
124  // Boolean values to indicate whether logging is enabled for each scope.
125  std::bitset<kNumScopes> scope_enabled_;
126
127  // Verbose level that is applied to all scopes.
128  int verbose_level_;
129
130  // Hooks to notify interested parties of changes to log scopes.
131  ScopeEnableChangedCallbacks log_scope_callbacks_[kNumScopes];
132
133  DISALLOW_IMPLICIT_CONSTRUCTORS(ScopeLogger);
134};
135
136}  // namespace shill
137
138#endif  // SHILL_SCOPE_LOGGER_H_
139