llvm/tools/llvm-exegesis/lib/ProgressMeter.h

   1 //===-- ProgressMeter.h -----------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_TOOLS_LLVM_EXEGESIS_PROGRESSMETER_H
  10 #define LLVM_TOOLS_LLVM_EXEGESIS_PROGRESSMETER_H
  11
  12 #include "llvm/Support/Format.h"
  13 #include "llvm/Support/raw_ostream.h"
  14 #include <cassert>
  15 #include <chrono>
  16 #include <cmath>
  17 #include <optional>
  18 #include <type_traits>
  19
  20 namespace llvm {
  21 namespace exegesis {
  22
  23 /// Represents `\sum_{i=1..accumulated}{step_i} / accumulated`,
  24 /// where `step_i` is the value passed to the `i`-th call to `step()`,
  25 /// and `accumulated` is the total number of calls to `step()`.
  26 template <typename NumTy, typename DenTy = int> class SimpleMovingAverage {
  27   NumTy Accumulated = NumTy(0);
  28   DenTy Steps = 0;
  29
  30 public:
  31   SimpleMovingAverage() = default;
  32
  33   SimpleMovingAverage(const SimpleMovingAverage &) = delete;
  34   SimpleMovingAverage(SimpleMovingAverage &&) = delete;
  35   SimpleMovingAverage &operator=(const SimpleMovingAverage &) = delete;
  36   SimpleMovingAverage &operator=(SimpleMovingAverage &&) = delete;
  37
  38   inline void step(NumTy Quantity) {
  39     Accumulated += Quantity;
  40     ++Steps;
  41   }
  42
  43   inline NumTy getAccumulated() const { return Accumulated; }
  44
  45   inline DenTy getNumSteps() const { return Steps; }
  46
  47   template <typename AvgTy = NumTy>
  48   inline std::optional<AvgTy> getAverage() const {
  49     if (Steps == 0)
  50       return std::nullopt;
  51     return AvgTy(Accumulated) / Steps;
  52   }
  53 };
  54
  55 template <typename ClockTypeTy = std::chrono::steady_clock,
  56           typename = std::enable_if_t<ClockTypeTy::is_steady>>
  57 class ProgressMeter {
  58 public:
  59   using ClockType = ClockTypeTy;
  60   using TimePointType = std::chrono::time_point<ClockType>;
  61   using DurationType = std::chrono::duration<typename ClockType::rep,
  62                                              typename ClockType::period>;
  63   using CompetionPercentage = int;
  64   using Sec = std::chrono::duration<double, std::chrono::seconds::period>;
  65
  66 private:
  67   raw_ostream &Out;
  68   const int NumStepsTotal;
  69   SimpleMovingAverage<DurationType> ElapsedTotal;
  70
  71 public:
  72   friend class ProgressMeterStep;
  73   class ProgressMeterStep {
  74     ProgressMeter *P;
  75     const TimePointType Begin;
  76
  77   public:
  78     inline ProgressMeterStep(ProgressMeter *P_)
  79         : P(P_), Begin(P ? ProgressMeter<ClockType>::ClockType::now()
  80                          : TimePointType()) {}
  81
  82     inline ~ProgressMeterStep() {
  83       if (!P)
  84         return;
  85       const TimePointType End = ProgressMeter<ClockType>::ClockType::now();
  86       P->step(End - Begin);
  87     }
  88
  89     ProgressMeterStep(const ProgressMeterStep &) = delete;
  90     ProgressMeterStep(ProgressMeterStep &&) = delete;
  91     ProgressMeterStep &operator=(const ProgressMeterStep &) = delete;
  92     ProgressMeterStep &operator=(ProgressMeterStep &&) = delete;
  93   };
  94
  95   ProgressMeter(int NumStepsTotal_, raw_ostream &out_ = llvm::errs())
  96       : Out(out_), NumStepsTotal(NumStepsTotal_) {
  97     assert(NumStepsTotal > 0 && "No steps are planned?");
  98   }
  99
 100   ProgressMeter(const ProgressMeter &) = delete;
 101   ProgressMeter(ProgressMeter &&) = delete;
 102   ProgressMeter &operator=(const ProgressMeter &) = delete;
 103   ProgressMeter &operator=(ProgressMeter &&) = delete;
 104
 105 private:
 106   void step(DurationType Elapsed) {
 107     assert((ElapsedTotal.getNumSteps() < NumStepsTotal) && "Step overflow!");
 108     assert(Elapsed.count() >= 0 && "Negative time drift detected.");
 109
 110     auto [OldProgress, OldEta] = eta();
 111     ElapsedTotal.step(Elapsed);
 112     auto [NewProgress, NewEta] = eta();
 113
 114     if (NewProgress < OldProgress + 1)
 115       return;
 116
 117     Out << format("Processing... %*d%%", 3, NewProgress);
 118     if (NewEta) {
 119       int SecondsTotal = std::ceil(NewEta->count());
 120       int Seconds = SecondsTotal % 60;
 121       int MinutesTotal = SecondsTotal / 60;
 122
 123       Out << format(", ETA %02d:%02d", MinutesTotal, Seconds);
 124     }
 125     Out << "\n";
 126     Out.flush();
 127   }
 128
 129   inline std::pair<CompetionPercentage, std::optional<Sec>> eta() const {
 130     CompetionPercentage Progress =
 131         (100 * ElapsedTotal.getNumSteps()) / NumStepsTotal;
 132
 133     std::optional<Sec> ETA;
 134     if (std::optional<Sec> AverageStepDuration =
 135             ElapsedTotal.template getAverage<Sec>())
 136       ETA = (NumStepsTotal - ElapsedTotal.getNumSteps()) * *AverageStepDuration;
 137
 138     return {Progress, ETA};
 139   }
 140 };
 141
 142 } // namespace exegesis
 143 } // namespace llvm
 144
 145 #endif