//===- llvm/Support/Chrono.h - Utilities for Timing Manipulation-*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef LLVM_SUPPORT_CHRONO_H #define LLVM_SUPPORT_CHRONO_H #include "llvm/Support/Compiler.h" #include "llvm/Support/FormatProviders.h" #include #include namespace llvm { class raw_ostream; namespace sys { /// A time point on the system clock. This is provided for two reasons: /// - to insulate us agains subtle differences in behavoir to differences in /// system clock precision (which is implementation-defined and differs between /// platforms). /// - to shorten the type name /// The default precision is nanoseconds. If need a specific precision specify /// it explicitly. If unsure, use the default. If you need a time point on a /// clock other than the system_clock, use std::chrono directly. template using TimePoint = std::chrono::time_point; /// Convert a TimePoint to std::time_t inline std::time_t toTimeT(TimePoint<> TP) { using namespace std::chrono; return system_clock::to_time_t( time_point_cast(TP)); } /// Convert a std::time_t to a TimePoint inline TimePoint toTimePoint(std::time_t T) { using namespace std::chrono; return time_point_cast(system_clock::from_time_t(T)); } /// Convert a std::time_t + nanoseconds to a TimePoint inline TimePoint<> toTimePoint(std::time_t T, uint32_t nsec) { using namespace std::chrono; return time_point_cast(system_clock::from_time_t(T)) + nanoseconds(nsec); } } // namespace sys raw_ostream &operator<<(raw_ostream &OS, sys::TimePoint<> TP); /// Format provider for TimePoint<> /// /// The options string is a strftime format string, with extensions: /// - %L is millis: 000-999 /// - %f is micros: 000000-999999 /// - %N is nanos: 000000000 - 999999999 /// /// If no options are given, the default format is "%Y-%m-%d %H:%M:%S.%N". template <> struct format_provider> { static void format(const sys::TimePoint<> &TP, llvm::raw_ostream &OS, StringRef Style); }; /// Implementation of format_provider for duration types. /// /// The options string of a duration type has the grammar: /// /// duration_options ::= [unit][show_unit [number_options]] /// unit ::= `h`|`m`|`s`|`ms|`us`|`ns` /// show_unit ::= `+` | `-` /// number_options ::= options string for a integral or floating point type /// /// Examples /// ================================= /// | options | Input | Output | /// ================================= /// | "" | 1s | 1 s | /// | "ms" | 1s | 1000 ms | /// | "ms-" | 1s | 1000 | /// | "ms-n" | 1s | 1,000 | /// | "" | 1.0s | 1.00 s | /// ================================= /// /// If the unit of the duration type is not one of the units specified above, /// it is still possible to format it, provided you explicitly request a /// display unit or you request that the unit is not displayed. namespace detail { template struct unit { static const char value[]; }; template const char unit::value[] = ""; template <> struct unit> { static const char value[]; }; template <> struct unit> { static const char value[]; }; template <> struct unit> { static const char value[]; }; template <> struct unit { static const char value[]; }; template <> struct unit { static const char value[]; }; template <> struct unit { static const char value[]; }; } // namespace detail template struct format_provider> { private: typedef std::chrono::duration Dur; typedef typename std::conditional< std::chrono::treat_as_floating_point::value, double, intmax_t>::type InternalRep; template static InternalRep getAs(const Dur &D) { using namespace std::chrono; return duration_cast>(D).count(); } static std::pair consumeUnit(StringRef &Style, const Dur &D) { using namespace std::chrono; if (Style.consume_front("ns")) return {getAs(D), "ns"}; if (Style.consume_front("us")) return {getAs(D), "us"}; if (Style.consume_front("ms")) return {getAs(D), "ms"}; if (Style.consume_front("s")) return {getAs>(D), "s"}; if (Style.consume_front("m")) return {getAs>(D), "m"}; if (Style.consume_front("h")) return {getAs>(D), "h"}; return {D.count(), detail::unit::value}; } static bool consumeShowUnit(StringRef &Style) { if (Style.empty()) return true; if (Style.consume_front("-")) return false; if (Style.consume_front("+")) return true; assert(0 && "Unrecognised duration format"); return true; } public: static void format(const Dur &D, llvm::raw_ostream &Stream, StringRef Style) { InternalRep count; StringRef unit; std::tie(count, unit) = consumeUnit(Style, D); bool show_unit = consumeShowUnit(Style); format_provider::format(count, Stream, Style); if (show_unit) { assert(!unit.empty()); Stream << " " << unit; } } }; } // namespace llvm #endif // LLVM_SUPPORT_CHRONO_H