1 //===- llvm/Support/Chrono.h - Utilities for Timing Manipulation-*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_SUPPORT_CHRONO_H 11 #define LLVM_SUPPORT_CHRONO_H 12 13 #include "llvm/Support/Compiler.h" 14 #include "llvm/Support/FormatProviders.h" 15 16 #include <chrono> 17 #include <ctime> 18 19 namespace llvm { 20 21 class raw_ostream; 22 23 namespace sys { 24 25 /// A time point on the system clock. This is provided for two reasons: 26 /// - to insulate us agains subtle differences in behavoir to differences in 27 /// system clock precision (which is implementation-defined and differs between 28 /// platforms). 29 /// - to shorten the type name 30 /// The default precision is nanoseconds. If need a specific precision specify 31 /// it explicitly. If unsure, use the default. If you need a time point on a 32 /// clock other than the system_clock, use std::chrono directly. 33 template <typename D = std::chrono::nanoseconds> 34 using TimePoint = std::chrono::time_point<std::chrono::system_clock, D>; 35 36 /// Convert a TimePoint to std::time_t 37 LLVM_ATTRIBUTE_ALWAYS_INLINE inline std::time_t toTimeT(TimePoint<> TP) { 38 using namespace std::chrono; 39 return system_clock::to_time_t( 40 time_point_cast<system_clock::time_point::duration>(TP)); 41 } 42 43 /// Convert a std::time_t to a TimePoint 44 LLVM_ATTRIBUTE_ALWAYS_INLINE inline TimePoint<std::chrono::seconds> 45 toTimePoint(std::time_t T) { 46 using namespace std::chrono; 47 return time_point_cast<seconds>(system_clock::from_time_t(T)); 48 } 49 50 } // namespace sys 51 52 raw_ostream &operator<<(raw_ostream &OS, sys::TimePoint<> TP); 53 54 /// Format provider for TimePoint<> 55 /// 56 /// The options string is a strftime format string, with extensions: 57 /// - %L is millis: 000-999 58 /// - %f is micros: 000000-999999 59 /// - %N is nanos: 000000000 - 999999999 60 /// 61 /// If no options are given, the default format is "%Y-%m-%d %H:%M:%S.%N". 62 template <> 63 struct format_provider<sys::TimePoint<>> { 64 static void format(const sys::TimePoint<> &TP, llvm::raw_ostream &OS, 65 StringRef Style); 66 }; 67 68 /// Implementation of format_provider<T> for duration types. 69 /// 70 /// The options string of a duration type has the grammar: 71 /// 72 /// duration_options ::= [unit][show_unit [number_options]] 73 /// unit ::= `h`|`m`|`s`|`ms|`us`|`ns` 74 /// show_unit ::= `+` | `-` 75 /// number_options ::= options string for a integral or floating point type 76 /// 77 /// Examples 78 /// ================================= 79 /// | options | Input | Output | 80 /// ================================= 81 /// | "" | 1s | 1 s | 82 /// | "ms" | 1s | 1000 ms | 83 /// | "ms-" | 1s | 1000 | 84 /// | "ms-n" | 1s | 1,000 | 85 /// | "" | 1.0s | 1.00 s | 86 /// ================================= 87 /// 88 /// If the unit of the duration type is not one of the units specified above, 89 /// it is still possible to format it, provided you explicitly request a 90 /// display unit or you request that the unit is not displayed. 91 92 namespace detail { 93 template <typename Period> struct unit { static const char value[]; }; 94 template <typename Period> const char unit<Period>::value[] = ""; 95 96 template <> struct unit<std::ratio<3600>> { static const char value[]; }; 97 template <> struct unit<std::ratio<60>> { static const char value[]; }; 98 template <> struct unit<std::ratio<1>> { static const char value[]; }; 99 template <> struct unit<std::milli> { static const char value[]; }; 100 template <> struct unit<std::micro> { static const char value[]; }; 101 template <> struct unit<std::nano> { static const char value[]; }; 102 } // namespace detail 103 104 template <typename Rep, typename Period> 105 struct format_provider<std::chrono::duration<Rep, Period>> { 106 private: 107 typedef std::chrono::duration<Rep, Period> Dur; 108 typedef typename std::conditional< 109 std::chrono::treat_as_floating_point<Rep>::value, double, intmax_t>::type 110 InternalRep; 111 112 template <typename AsPeriod> static InternalRep getAs(const Dur &D) { 113 using namespace std::chrono; 114 return duration_cast<duration<InternalRep, AsPeriod>>(D).count(); 115 } 116 117 static std::pair<InternalRep, StringRef> consumeUnit(StringRef &Style, 118 const Dur &D) { 119 using namespace std::chrono; 120 if (Style.consume_front("ns")) 121 return {getAs<std::nano>(D), "ns"}; 122 if (Style.consume_front("us")) 123 return {getAs<std::micro>(D), "us"}; 124 if (Style.consume_front("ms")) 125 return {getAs<std::milli>(D), "ms"}; 126 if (Style.consume_front("s")) 127 return {getAs<std::ratio<1>>(D), "s"}; 128 if (Style.consume_front("m")) 129 return {getAs<std::ratio<60>>(D), "m"}; 130 if (Style.consume_front("h")) 131 return {getAs<std::ratio<3600>>(D), "h"}; 132 return {D.count(), detail::unit<Period>::value}; 133 } 134 135 static bool consumeShowUnit(StringRef &Style) { 136 if (Style.empty()) 137 return true; 138 if (Style.consume_front("-")) 139 return false; 140 if (Style.consume_front("+")) 141 return true; 142 assert(0 && "Unrecognised duration format"); 143 return true; 144 } 145 146 public: 147 static void format(const Dur &D, llvm::raw_ostream &Stream, StringRef Style) { 148 InternalRep count; 149 StringRef unit; 150 std::tie(count, unit) = consumeUnit(Style, D); 151 bool show_unit = consumeShowUnit(Style); 152 153 format_provider<InternalRep>::format(count, Stream, Style); 154 155 if (show_unit) { 156 assert(!unit.empty()); 157 Stream << " " << unit; 158 } 159 } 160 }; 161 162 } // namespace llvm 163 164 #endif // LLVM_SUPPORT_CHRONO_H 165
