Bitcoin Core  0.18.99
P2P Digital Currency
bench.h
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1 // Copyright (c) 2015-2018 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_BENCH_BENCH_H
6 #define BITCOIN_BENCH_BENCH_H
7 
8 #include <functional>
9 #include <limits>
10 #include <map>
11 #include <string>
12 #include <vector>
13 #include <chrono>
14 
15 #include <boost/preprocessor/cat.hpp>
16 #include <boost/preprocessor/stringize.hpp>
17 
18 // Simple micro-benchmarking framework; API mostly matches a subset of the Google Benchmark
19 // framework (see https://github.com/google/benchmark)
20 // Why not use the Google Benchmark framework? Because adding Yet Another Dependency
21 // (that uses cmake as its build system and has lots of features we don't need) isn't
22 // worth it.
23 
24 /*
25  * Usage:
26 
27 static void CODE_TO_TIME(benchmark::State& state)
28 {
29  ... do any setup needed...
30  while (state.KeepRunning()) {
31  ... do stuff you want to time...
32  }
33  ... do any cleanup needed...
34 }
35 
36 // default to running benchmark for 5000 iterations
37 BENCHMARK(CODE_TO_TIME, 5000);
38 
39  */
40 
41 namespace benchmark {
42 // In case high_resolution_clock is steady, prefer that, otherwise use steady_clock.
43 struct best_clock {
44  using hi_res_clock = std::chrono::high_resolution_clock;
45  using steady_clock = std::chrono::steady_clock;
46  using type = std::conditional<hi_res_clock::is_steady, hi_res_clock, steady_clock>::type;
47 };
51 
52 class Printer;
53 
54 class State
55 {
56 public:
57  std::string m_name;
58  uint64_t m_num_iters_left;
59  const uint64_t m_num_iters;
60  const uint64_t m_num_evals;
61  std::vector<double> m_elapsed_results;
63 
64  bool UpdateTimer(time_point finish_time);
65 
66  State(std::string name, uint64_t num_evals, double num_iters, Printer& printer) : m_name(name), m_num_iters_left(0), m_num_iters(num_iters), m_num_evals(num_evals)
67  {
68  }
69 
70  inline bool KeepRunning()
71  {
72  if (m_num_iters_left--) {
73  return true;
74  }
75 
76  bool result = UpdateTimer(clock::now());
77  // measure again so runtime of UpdateTimer is not included
78  m_start_time = clock::now();
79  return result;
80  }
81 };
82 
83 typedef std::function<void(State&)> BenchFunction;
84 
86 {
87  struct Bench {
88  BenchFunction func;
90  };
91  typedef std::map<std::string, Bench> BenchmarkMap;
92  static BenchmarkMap& benchmarks();
93 
94 public:
95  BenchRunner(std::string name, BenchFunction func, uint64_t num_iters_for_one_second);
96 
97  static void RunAll(Printer& printer, uint64_t num_evals, double scaling, const std::string& filter, bool is_list_only);
98 };
99 
100 // interface to output benchmark results.
101 class Printer
102 {
103 public:
104  virtual ~Printer() {}
105  virtual void header() = 0;
106  virtual void result(const State& state) = 0;
107  virtual void footer() = 0;
108 };
109 
110 // default printer to console, shows min, max, median.
111 class ConsolePrinter : public Printer
112 {
113 public:
114  void header() override;
115  void result(const State& state) override;
116  void footer() override;
117 };
118 
119 // creates box plot with plotly.js
120 class PlotlyPrinter : public Printer
121 {
122 public:
123  PlotlyPrinter(std::string plotly_url, int64_t width, int64_t height);
124  void header() override;
125  void result(const State& state) override;
126  void footer() override;
127 
128 private:
129  std::string m_plotly_url;
130  int64_t m_width;
131  int64_t m_height;
132 };
133 }
134 
135 
136 // BENCHMARK(foo, num_iters_for_one_second) expands to: benchmark::BenchRunner bench_11foo("foo", num_iterations);
137 // Choose a num_iters_for_one_second that takes roughly 1 second. The goal is that all benchmarks should take approximately
138 // the same time, and scaling factor can be used that the total time is appropriate for your system.
139 #define BENCHMARK(n, num_iters_for_one_second) \
140  benchmark::BenchRunner BOOST_PP_CAT(bench_, BOOST_PP_CAT(__LINE__, n))(BOOST_PP_STRINGIZE(n), n, (num_iters_for_one_second));
141 
142 #endif // BITCOIN_BENCH_BENCH_H
const uint64_t m_num_iters
Definition: bench.h:59
std::string m_plotly_url
Definition: bench.h:129
std::chrono::steady_clock steady_clock
Definition: bench.h:45
std::vector< double > m_elapsed_results
Definition: bench.h:61
bool KeepRunning()
Definition: bench.h:70
time_point m_start_time
Definition: bench.h:62
uint64_t m_num_iters_left
Definition: bench.h:58
best_clock::type clock
Definition: bench.h:48
const char * name
Definition: rest.cpp:39
clock::duration duration
Definition: bench.h:50
BenchFunction func
Definition: bench.h:88
State(std::string name, uint64_t num_evals, double num_iters, Printer &printer)
Definition: bench.h:66
const uint64_t m_num_evals
Definition: bench.h:60
std::function< void(State &)> BenchFunction
Definition: bench.h:83
std::chrono::high_resolution_clock hi_res_clock
Definition: bench.h:44
std::map< std::string, Bench > BenchmarkMap
Definition: bench.h:91
std::conditional< hi_res_clock::is_steady, hi_res_clock, steady_clock >::type type
Definition: bench.h:46
std::string m_name
Definition: bench.h:57
uint64_t num_iters_for_one_second
Definition: bench.h:89
clock::time_point time_point
Definition: bench.h:49
virtual ~Printer()
Definition: bench.h:104