CLI11 2.2.0
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Timer.hpp
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1// Copyright (c) 2017-2022, University of Cincinnati, developed by Henry Schreiner
2// under NSF AWARD 1414736 and by the respective contributors.
3// All rights reserved.
4//
5// SPDX-License-Identifier: BSD-3-Clause
6
7#pragma once
8
9// On GCC < 4.8, the following define is often missing. Due to the
10// fact that this library only uses sleep_for, this should be safe
11#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 5 && __GNUC_MINOR__ < 8
12#define _GLIBCXX_USE_NANOSLEEP
13#endif
14
15#include <array>
16#include <chrono>
17#include <functional>
18#include <iostream>
19#include <string>
20#include <utility>
21
22namespace CLI {
23
25class Timer {
26 protected:
28 using clock = std::chrono::steady_clock;
29
31 using time_point = std::chrono::time_point<clock>;
32
34 using time_print_t = std::function<std::string(std::string, std::string)>;
35
37 std::string title_;
38
41
44
46 std::size_t cycles{1};
47
48 public:
50 static std::string Simple(std::string title, std::string time) { return title + ": " + time; }
51
53 static std::string Big(std::string title, std::string time) {
54 return std::string("-----------------------------------------\n") + "| " + title + " | Time = " + time + "\n" +
55 "-----------------------------------------";
56 }
57
58 public:
60 explicit Timer(std::string title = "Timer", time_print_t time_print = Simple)
61 : title_(std::move(title)), time_print_(std::move(time_print)), start_(clock::now()) {}
62
64 std::string time_it(std::function<void()> f, double target_time = 1) {
65 time_point start = start_;
66 double total_time;
67
68 start_ = clock::now();
69 std::size_t n = 0;
70 do {
71 f();
72 std::chrono::duration<double> elapsed = clock::now() - start_;
73 total_time = elapsed.count();
74 } while(n++ < 100u && total_time < target_time);
75
76 std::string out = make_time_str(total_time / static_cast<double>(n)) + " for " + std::to_string(n) + " tries";
77 start_ = start;
78 return out;
79 }
80
82 std::string make_time_str() const {
83 time_point stop = clock::now();
84 std::chrono::duration<double> elapsed = stop - start_;
85 double time = elapsed.count() / static_cast<double>(cycles);
86 return make_time_str(time);
87 }
88
89 // LCOV_EXCL_START
91 std::string make_time_str(double time) const {
92 auto print_it = [](double x, std::string unit) {
93 const unsigned int buffer_length = 50;
94 std::array<char, buffer_length> buffer;
95 std::snprintf(buffer.data(), buffer_length, "%.5g", x);
96 return buffer.data() + std::string(" ") + unit;
97 };
98
99 if(time < .000001)
100 return print_it(time * 1000000000, "ns");
101 else if(time < .001)
102 return print_it(time * 1000000, "us");
103 else if(time < 1)
104 return print_it(time * 1000, "ms");
105 else
106 return print_it(time, "s");
107 }
108 // LCOV_EXCL_STOP
109
111 std::string to_string() const { return time_print_(title_, make_time_str()); }
112
114 Timer &operator/(std::size_t val) {
115 cycles = val;
116 return *this;
117 }
118};
119
121class AutoTimer : public Timer {
122 public:
124 explicit AutoTimer(std::string title = "Timer", time_print_t time_print = Simple) : Timer(title, time_print) {}
125 // GCC 4.7 does not support using inheriting constructors.
126
128 ~AutoTimer() { std::cout << to_string() << std::endl; }
129};
130
131} // namespace CLI
132
134inline std::ostream &operator<<(std::ostream &in, const CLI::Timer &timer) { return in << timer.to_string(); }
std::ostream & operator<<(std::ostream &in, const CLI::Timer &timer)
This prints out the time if shifted into a std::cout like stream.
Definition Timer.hpp:134
This class prints out the time upon destruction.
Definition Timer.hpp:121
AutoTimer(std::string title="Timer", time_print_t time_print=Simple)
Reimplementing the constructor is required in GCC 4.7.
Definition Timer.hpp:124
~AutoTimer()
This destructor prints the string.
Definition Timer.hpp:128
This is a simple timer with pretty printing. Creating the timer starts counting.
Definition Timer.hpp:25
time_print_t time_print_
This is the function that is used to format most of the timing message.
Definition Timer.hpp:40
Timer(std::string title="Timer", time_print_t time_print=Simple)
Standard constructor, can set title and print function.
Definition Timer.hpp:60
time_point start_
This is the starting point (when the timer was created)
Definition Timer.hpp:43
std::string title_
This is the title of the timer.
Definition Timer.hpp:37
std::string make_time_str() const
This formats the numerical value for the time string.
Definition Timer.hpp:82
std::string to_string() const
This is the main function, it creates a string.
Definition Timer.hpp:111
std::function< std::string(std::string, std::string)> time_print_t
This is the type of a printing function, you can make your own.
Definition Timer.hpp:34
std::size_t cycles
This is the number of times cycles (print divides by this number)
Definition Timer.hpp:46
std::string make_time_str(double time) const
This prints out a time string from a time.
Definition Timer.hpp:91
std::string time_it(std::function< void()> f, double target_time=1)
Time a function by running it multiple times. Target time is the len to target.
Definition Timer.hpp:64
std::chrono::steady_clock clock
This is a typedef to make clocks easier to use.
Definition Timer.hpp:28
Timer & operator/(std::size_t val)
Division sets the number of cycles to divide by (no graphical change)
Definition Timer.hpp:114
static std::string Big(std::string title, std::string time)
This is a fancy print function with — headers.
Definition Timer.hpp:53
std::chrono::time_point< clock > time_point
This typedef is for points in time.
Definition Timer.hpp:31
static std::string Simple(std::string title, std::string time)
Standard print function, this one is set by default.
Definition Timer.hpp:50
Definition App.hpp:34