LCOV - code coverage report
Current view: top level - include/llvm/Support - Chrono.h (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 24 28 85.7 %
Date: 2017-09-14 15:23:50 Functions: 24 24 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       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      503168 :       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     1043790 :   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             : /// Implementation of format_provider<T> for duration types.
      55             : ///
      56             : /// The options string of a duration  type has the grammar:
      57             : ///
      58             : ///   duration_options  ::= [unit][show_unit [number_options]]
      59             : ///   unit              ::= `h`|`m`|`s`|`ms|`us`|`ns`
      60             : ///   show_unit         ::= `+` | `-`
      61             : ///   number_options    ::= options string for a integral or floating point type
      62             : ///
      63             : ///   Examples
      64             : ///   =================================
      65             : ///   |  options  | Input | Output    |
      66             : ///   =================================
      67             : ///   | ""        | 1s    | 1 s       |
      68             : ///   | "ms"      | 1s    | 1000 ms   |
      69             : ///   | "ms-"     | 1s    | 1000      |
      70             : ///   | "ms-n"    | 1s    | 1,000     |
      71             : ///   | ""        | 1.0s  | 1.00 s    |
      72             : ///   =================================
      73             : ///
      74             : ///  If the unit of the duration type is not one of the units specified above,
      75             : ///  it is still possible to format it, provided you explicitly request a
      76             : ///  display unit or you request that the unit is not displayed.
      77             : 
      78             : namespace detail {
      79             : template <typename Period> struct unit { static const char value[]; };
      80             : template <typename Period> const char unit<Period>::value[] = "";
      81             : 
      82             : template <> struct unit<std::ratio<3600>> { static const char value[]; };
      83             : template <> struct unit<std::ratio<60>> { static const char value[]; };
      84             : template <> struct unit<std::ratio<1>> { static const char value[]; };
      85             : template <> struct unit<std::milli> { static const char value[]; };
      86             : template <> struct unit<std::micro> { static const char value[]; };
      87             : template <> struct unit<std::nano> { static const char value[]; };
      88             : } // namespace detail
      89             : 
      90             : template <typename Rep, typename Period>
      91             : struct format_provider<std::chrono::duration<Rep, Period>> {
      92             : private:
      93             :   typedef std::chrono::duration<Rep, Period> Dur;
      94             :   typedef typename std::conditional<
      95             :       std::chrono::treat_as_floating_point<Rep>::value, double, intmax_t>::type
      96             :       InternalRep;
      97             : 
      98             :   template <typename AsPeriod> static InternalRep getAs(const Dur &D) {
      99             :     using namespace std::chrono;
     100           5 :     return duration_cast<duration<InternalRep, AsPeriod>>(D).count();
     101             :   }
     102             : 
     103          20 :   static std::pair<InternalRep, StringRef> consumeUnit(StringRef &Style,
     104             :                                                         const Dur &D) {
     105             :     using namespace std::chrono;
     106          20 :     if (Style.consume_front("ns"))
     107           0 :       return {getAs<std::nano>(D), "ns"};
     108          21 :     if (Style.consume_front("us"))
     109           2 :       return {getAs<std::micro>(D), "us"};
     110          23 :     if (Style.consume_front("ms"))
     111           8 :       return {getAs<std::milli>(D), "ms"};
     112          15 :     if (Style.consume_front("s"))
     113           0 :       return {getAs<std::ratio<1>>(D), "s"};
     114          15 :     if (Style.consume_front("m"))
     115           0 :       return {getAs<std::ratio<60>>(D), "m"};
     116          15 :     if (Style.consume_front("h"))
     117           0 :       return {getAs<std::ratio<3600>>(D), "h"};
     118          30 :     return {D.count(), detail::unit<Period>::value};
     119             :   }
     120             : 
     121          20 :   static bool consumeShowUnit(StringRef &Style) {
     122          20 :     if (Style.empty())
     123             :       return true;
     124          16 :     if (Style.consume_front("-"))
     125             :       return false;
     126           4 :     if (Style.consume_front("+"))
     127             :       return true;
     128             :     assert(0 && "Unrecognised duration format");
     129             :     return true;
     130             :   }
     131             : 
     132             : public:
     133          20 :   static void format(const Dur &D, llvm::raw_ostream &Stream, StringRef Style) {
     134             :     InternalRep count;
     135             :     StringRef unit;
     136          60 :     std::tie(count, unit) = consumeUnit(Style, D);
     137          20 :     bool show_unit = consumeShowUnit(Style);
     138             : 
     139          20 :     format_provider<InternalRep>::format(count, Stream, Style);
     140             : 
     141          20 :     if (show_unit) {
     142             :       assert(!unit.empty());
     143          14 :       Stream << " " << unit;
     144             :     }
     145          20 :   }
     146             : };
     147             : 
     148             : } // namespace llvm
     149             : 
     150             : #endif // LLVM_SUPPORT_CHRONO_H

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