1//
2// Copyright (C) 2012 The Android Open Source Project
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15//
16
17#ifndef SHILL_SCOPE_LOGGER_H_
18#define SHILL_SCOPE_LOGGER_H_
19
20#include <bitset>
21#include <string>
22#include <vector>
23
24#include <base/lazy_instance.h>
25#include <base/macros.h>
26#include <gtest/gtest_prod.h>
27
28#include "shill/callbacks.h"
29
30namespace shill {
31
32// A class that enables logging based on scope and verbose level. It is not
33// intended to be used directly but via the SLOG() macros in shill/logging.h
34class ScopeLogger {
35 public:
36  // Logging scopes.
37  //
38  // Update kScopeNames in scope_logger.cc after changing this enumerated type.
39  // These scope identifiers are sorted by their scope names alphabetically.
40  enum Scope {
41    kBinder = 0,
42    kCellular,
43    kConnection,
44    kCrypto,
45    kDaemon,
46    kDBus,
47    kDevice,
48    kDHCP,
49    kDNS,
50    kEthernet,
51    kHTTP,
52    kHTTPProxy,
53    kInet,
54    kLink,
55    kManager,
56    kMetrics,
57    kModem,
58    kPortal,
59    kPower,
60    kPPP,
61    kPPPoE,
62    kProfile,
63    kProperty,
64    kResolver,
65    kRoute,
66    kRTNL,
67    kService,
68    kStorage,
69    kTask,
70    kVPN,
71    kWiFi,
72    kWiMax,
73    kNumScopes
74  };
75
76  typedef base::Callback<void(bool)> ScopeEnableChangedCallback;
77  typedef std::vector<ScopeEnableChangedCallback>ScopeEnableChangedCallbacks;
78
79  // Returns a singleton of this class.
80  static ScopeLogger* GetInstance();
81
82  ScopeLogger();
83  ~ScopeLogger();
84
85  // Returns true if logging is enabled for |scope| and |verbose_level|, i.e.
86  // scope_enable_[|scope|] is true and |verbose_level| <= |verbose_level_|
87  bool IsLogEnabled(Scope scope, int verbose_level) const;
88
89  // Returns true if logging is enabled for |scope| at any verbosity level.
90  bool IsScopeEnabled(Scope scope) const;
91
92  // Returns a string comprising the names, separated by commas, of all scopes.
93  std::string GetAllScopeNames() const;
94
95  // Returns a string comprising the names, separated by plus signs, of all
96  // scopes that are enabled for logging.
97  std::string GetEnabledScopeNames() const;
98
99  // Enables/disables scopes as specified by |expression|.
100  //
101  // |expression| is a string comprising a sequence of scope names, each
102  // prefixed by a plus '+' or minus '-' sign. A scope prefixed by a plus
103  // sign is enabled for logging, whereas a scope prefixed by a minus sign
104  // is disabled for logging. Scopes that are not mentioned in |expression|
105  // remain the same state.
106  //
107  // To allow resetting the state of all scopes, an exception is made for the
108  // first scope name in the sequence, which may not be prefixed by any sign.
109  // That is considered as an implicit plus sign for that scope and also
110  // indicates that all scopes are first disabled before enabled by
111  // |expression|.
112  //
113  // If |expression| is an empty string, all scopes are disabled. Any unknown
114  // scope name found in |expression| is ignored.
115  void EnableScopesByName(const std::string& expression);
116
117  // Register for log scope enable/disable state changes for |scope|.
118  void RegisterScopeEnableChangedCallback(
119      Scope scope, ScopeEnableChangedCallback callback);
120
121  // Sets the verbose level for all scopes to |verbose_level|.
122  void set_verbose_level(int verbose_level) { verbose_level_ = verbose_level; }
123
124 private:
125  // Required for constructing LazyInstance<ScopeLogger>.
126  friend struct base::DefaultLazyInstanceTraits<ScopeLogger>;
127  friend class ScopeLoggerTest;
128  FRIEND_TEST(ScopeLoggerTest, GetEnabledScopeNames);
129  FRIEND_TEST(ScopeLoggerTest, SetScopeEnabled);
130  FRIEND_TEST(ScopeLoggerTest, SetVerboseLevel);
131
132  // Disables logging for all scopes.
133  void DisableAllScopes();
134
135  // Enables or disables logging for |scope|.
136  void SetScopeEnabled(Scope scope, bool enabled);
137
138  // Boolean values to indicate whether logging is enabled for each scope.
139  std::bitset<kNumScopes> scope_enabled_;
140
141  // Verbose level that is applied to all scopes.
142  int verbose_level_;
143
144  // Hooks to notify interested parties of changes to log scopes.
145  ScopeEnableChangedCallbacks log_scope_callbacks_[kNumScopes];
146
147  DISALLOW_COPY_AND_ASSIGN(ScopeLogger);
148};
149
150}  // namespace shill
151
152#endif  // SHILL_SCOPE_LOGGER_H_
153