Merge branch 'ismaelJimenez-added_lambdas'

README.md

@@ -142,6 +142,14 @@ BENCHMARK(BM_StringCompare)
     ->RangeMultiplier(2)->Range(1<<10, 1<<18)->Complexity();
 ```
 
+The following code will specify asymptotic complexity with a lambda function,
+that might be used to customize high-order term calculation.
+
+```c++
+BENCHMARK(BM_StringCompare)->RangeMultiplier(2)
+    ->Range(1<<10, 1<<18)->Complexity([](int n)->double{return n; });
+```
+
 ### Templated benchmarks
 Templated benchmarks work the same way: This example produces and consumes
 messages of size `sizeof(v)` `range_x` times. It also outputs throughput in the

include/benchmark/benchmark_api.h

@@ -247,9 +247,14 @@ enum BigO {
   oNCubed,
   oLogN,
   oNLogN,
-  oAuto
+  oAuto,
+  oLambda
 };
 
+// BigOFunc is passed to a benchmark in order to specify the asymptotic 
+// computational complexity for the benchmark.
+typedef double(BigOFunc)(int);
+
 // State is passed to a running Benchmark and contains state for the
 // benchmark to use.
 class State {
@@ -257,7 +262,7 @@ public:
   State(size_t max_iters, bool has_x, int x, bool has_y, int y,
         int thread_i, int n_threads);
 
-  // Returns true iff the benchmark should continue through another iteration.
+  // Returns true if the benchmark should continue through another iteration.
   // NOTE: A benchmark may not return from the test until KeepRunning() has
   // returned false.
   bool KeepRunning() {
@@ -358,7 +363,7 @@ public:
   // family benchmark, then current benchmark will be part of the computation and complexity_n will
   // represent the length of N.
   BENCHMARK_ALWAYS_INLINE
-  void SetComplexityN(size_t complexity_n) {
+  void SetComplexityN(int complexity_n) {
     complexity_n_ = complexity_n;
   }
 
@@ -439,7 +444,7 @@ private:
   size_t bytes_processed_;
   size_t items_processed_;
 
-  size_t complexity_n_;
+  int complexity_n_;
 
 public:
   // FIXME: Make this private somehow.
@@ -538,6 +543,10 @@ public:
   // the asymptotic computational complexity will be shown on the output. 
   Benchmark* Complexity(BigO complexity = benchmark::oAuto);
 
+  // Set the asymptotic computational complexity for the benchmark. If called
+  // the asymptotic computational complexity will be shown on the output.
+  Benchmark* Complexity(BigOFunc* complexity);
+
   // Support for running multiple copies of the same benchmark concurrently
   // in multiple threads.  This may be useful when measuring the scaling
   // of some piece of code.

include/benchmark/reporter.h

@@ -86,6 +86,7 @@ class BenchmarkReporter {
 
     // Keep track of arguments to compute asymptotic complexity
     BigO complexity;
+    BigOFunc* complexity_lambda;
     int complexity_n;
 
     // Inform print function whether the current run is a complexity report
@@ -147,7 +148,7 @@ class BenchmarkReporter {
   // REQUIRES: 'out' is non-null.
   static void PrintBasicContext(std::ostream* out, Context const& context);
 
-private:
+ private:
   std::ostream* output_stream_;
   std::ostream* error_stream_;
 };
@@ -159,31 +160,31 @@ class ConsoleReporter : public BenchmarkReporter {
   virtual bool ReportContext(const Context& context);
   virtual void ReportRuns(const std::vector<Run>& reports);
 
-protected:
+ protected:
   virtual void PrintRunData(const Run& report);
 
   size_t name_field_width_;
 };
 
 class JSONReporter : public BenchmarkReporter {
-public:
+ public:
   JSONReporter() : first_report_(true) {}
   virtual bool ReportContext(const Context& context);
   virtual void ReportRuns(const std::vector<Run>& reports);
   virtual void Finalize();
 
-private:
+ private:
   void PrintRunData(const Run& report);
 
   bool first_report_;
 };
 
 class CSVReporter : public BenchmarkReporter {
-public:
+ public:
   virtual bool ReportContext(const Context& context);
   virtual void ReportRuns(const std::vector<Run>& reports);
 
-private:
+ private:
   void PrintRunData(const Run& report);
 };
 

src/benchmark.cc

@@ -317,6 +317,7 @@ struct Benchmark::Instance {
   bool           use_real_time;
   bool           use_manual_time;
   BigO           complexity;
+  BigOFunc*      complexity_lambda;
   bool           last_benchmark_instance;
   int            repetitions;
   double         min_time;
@@ -362,6 +363,7 @@ public:
   void UseRealTime();
   void UseManualTime();
   void Complexity(BigO complexity);
+  void ComplexityLambda(BigOFunc* complexity);
   void Threads(int t);
   void ThreadRange(int min_threads, int max_threads);
   void ThreadPerCpu();
@@ -382,6 +384,7 @@ private:
   bool use_real_time_;
   bool use_manual_time_;
   BigO complexity_;
+  BigOFunc* complexity_lambda_;
   std::vector<int> thread_counts_;
 
   BenchmarkImp& operator=(BenchmarkImp const&);
@@ -446,6 +449,7 @@ bool BenchmarkFamilies::FindBenchmarks(
         instance.use_real_time = family->use_real_time_;
         instance.use_manual_time = family->use_manual_time_;
         instance.complexity = family->complexity_;
+        instance.complexity_lambda = family->complexity_lambda_;
         instance.threads = num_threads;
         instance.multithreaded = !(family->thread_counts_.empty());
 
@@ -573,6 +577,10 @@ void BenchmarkImp::Complexity(BigO complexity){
   complexity_ = complexity;
 }
 
+void BenchmarkImp::ComplexityLambda(BigOFunc* complexity) {
+  complexity_lambda_ = complexity;
+}
+
 void BenchmarkImp::Threads(int t) {
   CHECK_GT(t, 0);
   thread_counts_.push_back(t);
@@ -697,6 +705,12 @@ Benchmark* Benchmark::Complexity(BigO complexity) {
   return this;
 }
 
+Benchmark* Benchmark::Complexity(BigOFunc* complexity) {
+  imp_->Complexity(oLambda);
+  imp_->ComplexityLambda(complexity);
+  return this;
+}
+
 Benchmark* Benchmark::Threads(int t) {
   imp_->Threads(t);
   return this;
@@ -855,6 +869,7 @@ void RunBenchmark(const benchmark::internal::Benchmark::Instance& b,
           report.items_per_second = items_per_second;
           report.complexity_n = total.complexity_n;
           report.complexity = b.complexity;
+          report.complexity_lambda = b.complexity_lambda;
           if(report.complexity != oNone)
             complexity_reports.push_back(report);
         }

src/complexity.cc

@@ -17,31 +17,30 @@
 
 #include "benchmark/benchmark_api.h"
 
-#include "complexity.h"
+#include <algorithm>
+#include <cmath>
 #include "check.h"
+#include "complexity.h"
 #include "stat.h"
-#include <cmath>
-#include <algorithm>
-#include <functional>
 
 namespace benchmark {
 
 // Internal function to calculate the different scalability forms
-std::function<double(int)> FittingCurve(BigO complexity) {
+BigOFunc* FittingCurve(BigO complexity) {
   switch (complexity) {
     case oN:
-      return [](int n) {return n; };
+      return [](int n) -> double { return n; };
     case oNSquared:
-      return [](int n) {return n*n; };
+      return [](int n) -> double { return n * n; };
     case oNCubed:
-      return [](int n) {return n*n*n; };
+      return [](int n) -> double { return n * n * n; };
     case oLogN:
-      return [](int n) {return log2(n); };
+      return [](int n) { return log2(n); };
     case oNLogN:
-      return [](int n) {return n * log2(n); };
+      return [](int n) { return n * log2(n); };
     case o1:
     default:
-      return [](int) {return 1; };
+      return [](int) { return 1.0; };
   }
 }
 
@@ -49,19 +48,19 @@ std::function<double(int)> FittingCurve(BigO complexity) {
 std::string GetBigOString(BigO complexity) {
   switch (complexity) {
     case oN:
-      return "* N";
+      return "N";
     case oNSquared:
-      return "* N**2";
+      return "N^2";
     case oNCubed:
-      return "* N**3";
+      return "N^3";
     case oLogN:
-      return "* lgN";
+      return "lgN";
     case oNLogN:
-      return "* NlgN";
+      return "NlgN";
     case o1:
-      return "* 1";
+      return "(1)";
     default:
-      return "";
+      return "f(N)";
   }
 }
 
@@ -75,21 +74,9 @@ std::string GetBigOString(BigO complexity) {
 // For a deeper explanation on the algorithm logic, look the README file at
 // http://github.com/ismaelJimenez/Minimal-Cpp-Least-Squared-Fit
 
-// This interface is currently not used from the oustide, but it has been 
-// provided for future upgrades. If in the future it is not needed to support 
-// Cxx03, then all the calculations could be upgraded to use lambdas because 
-// they are more powerful and provide a cleaner inferface than enumerators, 
-// but complete implementation with lambdas will not work for Cxx03 
-// (e.g. lack of std::function).
-// In case lambdas are implemented, the interface would be like :
-//   -> Complexity([](int n) {return n;};)
-// and any arbitrary and valid  equation would be allowed, but the option to 
-// calculate the best fit to the most common scalability curves will still 
-// be kept.
-
-LeastSq CalculateLeastSq(const std::vector<int>& n, 
+LeastSq MinimalLeastSq(const std::vector<int>& n,
                        const std::vector<double>& time,
-                         std::function<double(int)> fitting_curve) {
+                       BigOFunc* fitting_curve) {
   double sigma_gn = 0.0;
   double sigma_gn_squared = 0.0;
   double sigma_time = 0.0;
@@ -105,6 +92,7 @@ LeastSq CalculateLeastSq(const std::vector<int>& n,
   }
 
   LeastSq result;
+  result.complexity = oLambda;
 
   // Calculate complexity.
   result.coef = sigma_time_gn / sigma_gn_squared;
@@ -134,29 +122,29 @@ LeastSq MinimalLeastSq(const std::vector<int>& n,
                        const std::vector<double>& time,
                        const BigO complexity) {
   CHECK_EQ(n.size(), time.size());
-  CHECK_GE(n.size(), 2);  // Do not compute fitting curve is less than two benchmark runs are given
+  CHECK_GE(n.size(), 2);  // Do not compute fitting curve is less than two
+                          // benchmark runs are given
   CHECK_NE(complexity, oNone);
 
   LeastSq best_fit;
 
-  if(complexity == oAuto) {
-    std::vector<BigO> fit_curves = {
-      oLogN, oN, oNLogN, oNSquared, oNCubed };
+  if (complexity == oAuto) {
+    std::vector<BigO> fit_curves = {oLogN, oN, oNLogN, oNSquared, oNCubed};
 
     // Take o1 as default best fitting curve
-    best_fit = CalculateLeastSq(n, time, FittingCurve(o1));
+    best_fit = MinimalLeastSq(n, time, FittingCurve(o1));
     best_fit.complexity = o1;
 
     // Compute all possible fitting curves and stick to the best one
     for (const auto& fit : fit_curves) {
-      LeastSq current_fit = CalculateLeastSq(n, time, FittingCurve(fit));
+      LeastSq current_fit = MinimalLeastSq(n, time, FittingCurve(fit));
       if (current_fit.rms < best_fit.rms) {
         best_fit = current_fit;
         best_fit.complexity = fit;
       }
     }
   } else {
-    best_fit = CalculateLeastSq(n, time, FittingCurve(complexity));
+    best_fit = MinimalLeastSq(n, time, FittingCurve(complexity));
     best_fit.complexity = complexity;
   }
 
@@ -164,14 +152,13 @@ LeastSq MinimalLeastSq(const std::vector<int>& n,
 }
 
 std::vector<BenchmarkReporter::Run> ComputeStats(
-    const std::vector<BenchmarkReporter::Run>& reports)
-{
+    const std::vector<BenchmarkReporter::Run>& reports) {
   typedef BenchmarkReporter::Run Run;
   std::vector<Run> results;
 
-  auto error_count = std::count_if(
-      reports.begin(), reports.end(),
-      [](Run const& run) {return run.error_occurred;});
+  auto error_count =
+      std::count_if(reports.begin(), reports.end(),
+                    [](Run const& run) { return run.error_occurred; });
 
   if (reports.size() - error_count < 2) {
     // We don't report aggregated data if there was a single run.
@@ -190,12 +177,11 @@ std::vector<BenchmarkReporter::Run> ComputeStats(
   for (Run const& run : reports) {
     CHECK_EQ(reports[0].benchmark_name, run.benchmark_name);
     CHECK_EQ(run_iterations, run.iterations);
-    if (run.error_occurred)
-      continue;
+    if (run.error_occurred) continue;
     real_accumulated_time_stat +=
-        Stat1_d(run.real_accumulated_time/run.iterations, run.iterations);
+        Stat1_d(run.real_accumulated_time / run.iterations, run.iterations);
     cpu_accumulated_time_stat +=
-        Stat1_d(run.cpu_accumulated_time/run.iterations, run.iterations);
+        Stat1_d(run.cpu_accumulated_time / run.iterations, run.iterations);
     items_per_second_stat += Stat1_d(run.items_per_second, run.iterations);
     bytes_per_second_stat += Stat1_d(run.bytes_per_second, run.iterations);
   }
@@ -204,10 +190,10 @@ std::vector<BenchmarkReporter::Run> ComputeStats(
   Run mean_data;
   mean_data.benchmark_name = reports[0].benchmark_name + "_mean";
   mean_data.iterations = run_iterations;
-  mean_data.real_accumulated_time = real_accumulated_time_stat.Mean() *
-                                     run_iterations;
-  mean_data.cpu_accumulated_time = cpu_accumulated_time_stat.Mean() *
-                                    run_iterations;
+  mean_data.real_accumulated_time =
+      real_accumulated_time_stat.Mean() * run_iterations;
+  mean_data.cpu_accumulated_time =
+      cpu_accumulated_time_stat.Mean() * run_iterations;
   mean_data.bytes_per_second = bytes_per_second_stat.Mean();
   mean_data.items_per_second = items_per_second_stat.Mean();
 
@@ -224,10 +210,8 @@ std::vector<BenchmarkReporter::Run> ComputeStats(
   stddev_data.benchmark_name = reports[0].benchmark_name + "_stddev";
   stddev_data.report_label = mean_data.report_label;
   stddev_data.iterations = 0;
-  stddev_data.real_accumulated_time =
-      real_accumulated_time_stat.StdDev();
-  stddev_data.cpu_accumulated_time =
-      cpu_accumulated_time_stat.StdDev();
+  stddev_data.real_accumulated_time = real_accumulated_time_stat.StdDev();
+  stddev_data.cpu_accumulated_time = cpu_accumulated_time_stat.StdDev();
   stddev_data.bytes_per_second = bytes_per_second_stat.StdDev();
   stddev_data.items_per_second = items_per_second_stat.StdDev();
 
@@ -237,8 +221,7 @@ std::vector<BenchmarkReporter::Run> ComputeStats(
 }
 
 std::vector<BenchmarkReporter::Run> ComputeBigO(
-    const std::vector<BenchmarkReporter::Run>& reports)
-{
+    const std::vector<BenchmarkReporter::Run>& reports) {
   typedef BenchmarkReporter::Run Run;
   std::vector<Run> results;
 
@@ -252,19 +235,22 @@ std::vector<BenchmarkReporter::Run> ComputeBigO(
   // Populate the accumulators.
   for (const Run& run : reports) {
     n.push_back(run.complexity_n);
-    real_time.push_back(run.real_accumulated_time/run.iterations);
-    cpu_time.push_back(run.cpu_accumulated_time/run.iterations);
+    real_time.push_back(run.real_accumulated_time / run.iterations);
+    cpu_time.push_back(run.cpu_accumulated_time / run.iterations);
   }
 
-  LeastSq result_cpu = MinimalLeastSq(n, cpu_time, reports[0].complexity);
-
-  // result_cpu.complexity is passed as parameter to result_real because in case
-  // reports[0].complexity is oAuto, the noise on the measured data could make
-  // the best fit function of Cpu and Real differ. In order to solve this, we
-  // take the best fitting function for the Cpu, and apply it to Real data.
-  LeastSq result_real = MinimalLeastSq(n, real_time, result_cpu.complexity);
+  LeastSq result_cpu;
+  LeastSq result_real;
 
-  std::string benchmark_name = reports[0].benchmark_name.substr(0, reports[0].benchmark_name.find('/'));
+  if (reports[0].complexity == oLambda) {
+    result_cpu = MinimalLeastSq(n, cpu_time, reports[0].complexity_lambda);
+    result_real = MinimalLeastSq(n, real_time, reports[0].complexity_lambda);
+  } else {
+    result_cpu = MinimalLeastSq(n, cpu_time, reports[0].complexity);
+    result_real = MinimalLeastSq(n, real_time, result_cpu.complexity);
+  }
+  std::string benchmark_name =
+      reports[0].benchmark_name.substr(0, reports[0].benchmark_name.find('/'));
 
   // Get the data from the accumulator to BenchmarkReporter::Run's.
   Run big_o;

src/complexity.h

@@ -60,11 +60,5 @@ struct LeastSq {
 // Function to return an string for the calculated complexity
 std::string GetBigOString(BigO complexity);
 
-// Find the coefficient for the high-order term in the running time, by
-// minimizing the sum of squares of relative error.
-LeastSq MinimalLeastSq(const std::vector<int>& n,
-                       const std::vector<double>& time,
-                       const BigO complexity = oAuto);
-
 } // end namespace benchmark
 #endif // COMPLEXITY_H_

src/console_reporter.cc

@@ -15,9 +15,9 @@
 #include "benchmark/reporter.h"
 #include "complexity.h"
 
+#include <algorithm>
 #include <cstdint>
 #include <cstdio>
-#include <algorithm>
 #include <iostream>
 #include <string>
 #include <tuple>
@@ -62,8 +62,8 @@ void ConsoleReporter::ReportRuns(const std::vector<Run>& reports) {
 void ConsoleReporter::PrintRunData(const Run& result) {
   auto& Out = GetOutputStream();
 
-  auto name_color = (result.report_big_o || result.report_rms)
-      ? COLOR_BLUE : COLOR_GREEN;
+  auto name_color =
+      (result.report_big_o || result.report_rms) ? COLOR_BLUE : COLOR_GREEN;
   ColorPrintf(Out, name_color, "%-*s ", name_field_width_,
               result.benchmark_name.c_str());
 
@@ -89,20 +89,20 @@ void ConsoleReporter::PrintRunData(const Run& result) {
   const double real_time = result.GetAdjustedRealTime();
   const double cpu_time = result.GetAdjustedCPUTime();
 
-  if(result.report_big_o) {
-    std::string big_o = result.report_big_o ? GetBigOString(result.complexity) : "";
-    ColorPrintf(Out, COLOR_YELLOW, "%10.4f %s %10.4f %s ",
-                real_time, big_o.c_str(), cpu_time, big_o.c_str());
-  } else if(result.report_rms) {
-    ColorPrintf(Out, COLOR_YELLOW, "%10.0f %% %10.0f %% ",
-                real_time * 100, cpu_time * 100);
+  if (result.report_big_o) {
+    std::string big_o = GetBigOString(result.complexity);
+    ColorPrintf(Out, COLOR_YELLOW, "%10.2f %s %10.2f %s ", real_time,
+                big_o.c_str(), cpu_time, big_o.c_str());
+  } else if (result.report_rms) {
+    ColorPrintf(Out, COLOR_YELLOW, "%10.0f %% %10.0f %% ", real_time * 100,
+                cpu_time * 100);
   } else {
     const char* timeLabel = GetTimeUnitString(result.time_unit);
-    ColorPrintf(Out, COLOR_YELLOW, "%10.0f %s %10.0f %s ",
-                real_time, timeLabel, cpu_time, timeLabel);
+    ColorPrintf(Out, COLOR_YELLOW, "%10.0f %s %10.0f %s ", real_time, timeLabel,
+                cpu_time, timeLabel);
   }
 
-  if(!result.report_big_o && !result.report_rms) {
+  if (!result.report_big_o && !result.report_rms) {
     ColorPrintf(Out, COLOR_CYAN, "%10lld", result.iterations);
   }
 

src/csv_reporter.cc

@@ -13,9 +13,10 @@
 // limitations under the License.
 
 #include "benchmark/reporter.h"
+#include "complexity.h"
 
-#include <cstdint>
 #include <algorithm>
+#include <cstdint>
 #include <iostream>
 #include <string>
 #include <tuple>
@@ -79,7 +80,7 @@ void CSVReporter::PrintRunData(const Run & run) {
   }
 
   // Do not print iteration on bigO and RMS report
-  if(!run.report_big_o && !run.report_rms) {
+  if (!run.report_big_o && !run.report_rms) {
     Out << run.iterations;
   }
   Out << ",";
@@ -87,8 +88,10 @@ void CSVReporter::PrintRunData(const Run & run) {
   Out << run.GetAdjustedRealTime() << ",";
   Out << run.GetAdjustedCPUTime() << ",";
 
-  // Do not print timeLabel on RMS report
-  if(!run.report_rms) {
+  // Do not print timeLabel on bigO and RMS report
+  if (run.report_big_o) {
+    Out << GetBigOString(run.complexity);
+  } else if (!run.report_rms) {
     Out << GetTimeUnitString(run.time_unit);
   }
   Out << ",";

src/json_reporter.cc

@@ -13,9 +13,10 @@
 // limitations under the License.
 
 #include "benchmark/reporter.h"
+#include "complexity.h"
 
-#include <cstdint>
 #include <algorithm>
+#include <cstdint>
 #include <iostream>
 #include <string>
 #include <tuple>
@@ -128,30 +129,47 @@ void JSONReporter::PrintRunData(Run const& run) {
             << FormatKV("error_message", run.error_message)
             << ",\n";
     }
-    if(!run.report_big_o && !run.report_rms) {
+  if (!run.report_big_o && !run.report_rms) {
         out << indent
             << FormatKV("iterations", run.iterations)
             << ",\n";
-    }
         out << indent
             << FormatKV("real_time", RoundDouble(run.GetAdjustedRealTime()))
             << ",\n";
         out << indent
             << FormatKV("cpu_time", RoundDouble(run.GetAdjustedCPUTime()));
-    if(!run.report_rms) {
         out << ",\n" << indent
             << FormatKV("time_unit", GetTimeUnitString(run.time_unit));
+  } else if (run.report_big_o) {
+    out << indent
+        << FormatKV("cpu_coefficient", RoundDouble(run.GetAdjustedCPUTime()))
+        << ",\n";
+    out << indent
+        << FormatKV("real_coefficient", RoundDouble(run.GetAdjustedRealTime()))
+        << ",\n";
+    out << indent
+            << FormatKV("big_o", GetBigOString(run.complexity))
+            << ",\n";
+        out << indent
+            << FormatKV("time_unit", GetTimeUnitString(run.time_unit));
+    } else if(run.report_rms) {
+        out << indent
+            << FormatKV("rms", RoundDouble(run.GetAdjustedCPUTime()*100))
+            << '%';
   }
   if (run.bytes_per_second > 0.0) {
-        out << ",\n" << indent
+    out << ",\n"
+        << indent
         << FormatKV("bytes_per_second", RoundDouble(run.bytes_per_second));
   }
   if (run.items_per_second > 0.0) {
-        out << ",\n" << indent
+    out << ",\n"
+        << indent
         << FormatKV("items_per_second", RoundDouble(run.items_per_second));
   }
   if (!run.report_label.empty()) {
-        out << ",\n" << indent
+    out << ",\n"
+        << indent
         << FormatKV("label", run.report_label);
   }
   out << '\n';

test/reporter_output_test.cc

@@ -189,7 +189,7 @@ void BM_Complexity_O1(benchmark::State& state) {
 }
 BENCHMARK(BM_Complexity_O1)->Range(1, 1<<18)->Complexity(benchmark::o1);
 
-std::string bigOStr = "[0-9]+\\.[0-9]+ \\* [0-9]+";
+std::string bigOStr = "[0-9]+\\.[0-9]+ \\([0-9]+\\)";
 
 ADD_CASES(&ConsoleOutputTests, {
    {join("^BM_Complexity_O1_BigO", bigOStr, bigOStr) + "[ ]*$"},