benchmark  1.7.0
log.h
1 #ifndef BENCHMARK_LOG_H_
2 #define BENCHMARK_LOG_H_
3 
4 #include <iostream>
5 #include <ostream>
6 
7 #include "benchmark/benchmark.h"
8 
9 namespace benchmark {
10 namespace internal {
11 
12 typedef std::basic_ostream<char>&(EndLType)(std::basic_ostream<char>&);
13 
14 class LogType {
15  friend LogType& GetNullLogInstance();
16  friend LogType& GetErrorLogInstance();
17 
18  // FIXME: Add locking to output.
19  template <class Tp>
20  friend LogType& operator<<(LogType&, Tp const&);
21  friend LogType& operator<<(LogType&, EndLType*);
22 
23  private:
24  LogType(std::ostream* out) : out_(out) {}
25  std::ostream* out_;
26  BENCHMARK_DISALLOW_COPY_AND_ASSIGN(LogType);
27 };
28 
29 template <class Tp>
30 LogType& operator<<(LogType& log, Tp const& value) {
31  if (log.out_) {
32  *log.out_ << value;
33  }
34  return log;
35 }
36 
37 inline LogType& operator<<(LogType& log, EndLType* m) {
38  if (log.out_) {
39  *log.out_ << m;
40  }
41  return log;
42 }
43 
44 inline int& LogLevel() {
45  static int log_level = 0;
46  return log_level;
47 }
48 
49 inline LogType& GetNullLogInstance() {
50  static LogType log(nullptr);
51  return log;
52 }
53 
54 inline LogType& GetErrorLogInstance() {
55  static LogType log(&std::clog);
56  return log;
57 }
58 
59 inline LogType& GetLogInstanceForLevel(int level) {
60  if (level <= LogLevel()) {
61  return GetErrorLogInstance();
62  }
63  return GetNullLogInstance();
64 }
65 
66 } // end namespace internal
67 } // end namespace benchmark
68 
69 // clang-format off
70 #define BM_VLOG(x) \
71  (::benchmark::internal::GetLogInstanceForLevel(x) << "-- LOG(" << x << "):" \
72  " ")
73 // clang-format on
74 #endif
Definition: log.h:14