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Vector Packet Processing
logger.hpp
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1 /*
2  * Copyright (c) 2017 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef __VOM_LOGGER_H__
17 #define __VOM_LOGGER_H__
18 
19 #include <fstream>
20 #include <iostream>
21 #include <sstream>
22 
23 #include "vom/enum_base.hpp"
24 
25 namespace VOM {
26 struct log_level_t : enum_base<log_level_t>
27 {
28  const static log_level_t CRITICAL;
29  const static log_level_t ERROR;
30  const static log_level_t WARNING;
31  const static log_level_t INFO;
32  const static log_level_t DEBUG;
33 
34 private:
35  /**
36  * Private constructor taking the value and the string name
37  */
38  log_level_t(int v, const std::string& s);
39 
40  /*
41  * not allowed to construct
42  */
43  log_level_t() = delete;
44 };
45 
46 /**
47  * Ideally we'd use the boost logger but that is not prevelent
48  * in many distros. So something simple here instead.
49  */
50 class log_t
51 {
52 public:
53  /**
54  *
55  */
56  class handler
57  {
58  public:
59  /**
60  * Default Constructor
61  */
62  handler() = default;
63 
64  /**
65  * Default Destructor
66  */
67  virtual ~handler() = default;
68 
69  /**
70  * Handle a log message
71  */
72  virtual void handle_message(const std::string& file,
73  const int line,
74  const std::string& function,
75  const log_level_t& level,
76  const std::string& message) = 0;
77  };
78 
79  /**
80  * Construct a logger
81  */
82  log_t(handler* h);
83  log_t();
84 
85  /**
86  * The configured level
87  */
88  const log_level_t& level() const;
89 
90  /**
91  * set the logging level
92  */
93  void set(const log_level_t& level);
94 
95  /**
96  * set a file to receive the logging data
97  */
98  void set(handler* h);
99 
100  /**
101  * An entry in the log
102  */
103  class entry
104  {
105  public:
106  entry(const char* file,
107  const char* function,
108  int line,
109  const log_level_t& level);
110  ~entry();
111 
112  std::stringstream& stream();
113 
114  private:
115  const std::string m_file;
116  const std::string m_function;
117  const log_level_t m_level;
118  const int m_line;
119 
120  std::stringstream m_stream;
121  };
122  /**
123  * Register a log handler to receive the log output
124  */
125  void register_handler(handler& h);
126 
127 private:
128  void write(const std::string& file,
129  const int line,
130  const std::string& function,
131  const log_level_t& level,
132  const std::string& message);
133 
134  /**
135  * the configured logging level
136  */
137  log_level_t m_level;
138 
139  /**
140  * Pointer to a registered handler. Null if no handler registerd
141  */
142  handler* m_handler;
143 };
144 
146 {
147 public:
148  file_handler(const std::string& ofile);
149  ~file_handler();
150 
151  virtual void handle_message(const std::string& file,
152  const int line,
153  const std::string& function,
154  const log_level_t& level,
155  const std::string& message);
156 
157 private:
158  /**
159  * Opened file for debugging
160  */
161  std::ofstream m_file_stream;
162 };
163 
165 {
166 public:
167  cout_handler() = default;
168  ~cout_handler() = default;
169  virtual void handle_message(const std::string& file,
170  const int line,
171  const std::string& function,
172  const log_level_t& level,
173  const std::string& message);
174 };
175 
176 /**
177  * Return a log object into which VPP objects can write
178  */
179 log_t& logger();
180 
181 #define VOM_LOG(lvl) \
182  if (lvl >= logger().level()) \
183  log_t::entry(__FILE__, __FUNCTION__, __LINE__, lvl).stream()
184 };
185 
186 /*
187  * fd.io coding-style-patch-verification: ON
188  *
189  * Local Variables:
190  * eval: (c-set-style "mozilla")
191  * End:
192  */
193 
194 #endif
A template base class for all enum types.
Definition: enum_base.hpp:30
static const log_level_t DEBUG
Definition: logger.hpp:32
An entry in the log.
Definition: logger.hpp:103
static const log_level_t CRITICAL
Definition: logger.hpp:28
#define v
Definition: acl.c:491
static const log_level_t WARNING
Definition: logger.hpp:30
static const log_level_t INFO
Definition: logger.hpp:31
Ideally we&#39;d use the boost logger but that is not prevelent in many distros.
Definition: logger.hpp:50
static const log_level_t ERROR
Definition: logger.hpp:29
The VPP Object Model (VOM) library.
Definition: acl_binding.cpp:19
log_t & logger()
Return a log object into which VPP objects can write.
Definition: logger.cpp:39