reporter.h revision 6429348e0d986315d95a0582eb8f57a6a4488ac1 
1// Copyright 2015 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14#ifndef BENCHMARK_REPORTER_H_
15#define BENCHMARK_REPORTER_H_
16
17#include <string>
18#include <utility>
19#include <vector>
20
21#include "benchmark_api.h" // For forward declaration of BenchmarkReporter
22
23namespace benchmark {
24
25// Interface for custom benchmark result printers.
26// By default, benchmark reports are printed to stdout. However an application
27// can control the destination of the reports by calling
28// RunSpecifiedBenchmarks and passing it a custom reporter object.
29// The reporter object must implement the following interface.
30class BenchmarkReporter {
31 public:
32  struct Context {
33    int num_cpus;
34    double mhz_per_cpu;
35    bool cpu_scaling_enabled;
36
37    // The number of chars in the longest benchmark name.
38    size_t name_field_width;
39  };
40
41  struct Run {
42    Run() :
43      iterations(1),
44      real_accumulated_time(0),
45      cpu_accumulated_time(0),
46      bytes_per_second(0),
47      items_per_second(0),
48      max_heapbytes_used(0) {}
49
50    std::string benchmark_name;
51    std::string report_label;  // Empty if not set by benchmark.
52    size_t iterations;
53    double real_accumulated_time;
54    double cpu_accumulated_time;
55
56    // Zero if not set by benchmark.
57    double bytes_per_second;
58    double items_per_second;
59
60    // This is set to 0.0 if memory tracing is not enabled.
61    double max_heapbytes_used;
62  };
63
64  // Called once for every suite of benchmarks run.
65  // The parameter "context" contains information that the
66  // reporter may wish to use when generating its report, for example the
67  // platform under which the benchmarks are running. The benchmark run is
68  // never started if this function returns false, allowing the reporter
69  // to skip runs based on the context information.
70  virtual bool ReportContext(const Context& context) = 0;
71
72  // Called once for each group of benchmark runs, gives information about
73  // cpu-time and heap memory usage during the benchmark run.
74  // Note that all the grouped benchmark runs should refer to the same
75  // benchmark, thus have the same name.
76  virtual void ReportRuns(const std::vector<Run>& report) = 0;
77
78  // Called once and only once after ever group of benchmarks is run and
79  // reported.
80  virtual void Finalize();
81
82  virtual ~BenchmarkReporter();
83protected:
84    static void ComputeStats(std::vector<Run> const& reports, Run* mean, Run* stddev);
85};
86
87// Simple reporter that outputs benchmark data to the console. This is the
88// default reporter used by RunSpecifiedBenchmarks().
89class ConsoleReporter : public BenchmarkReporter {
90 public:
91  virtual bool ReportContext(const Context& context);
92  virtual void ReportRuns(const std::vector<Run>& reports);
93protected:
94  virtual void PrintRunData(const Run& report);
95
96  size_t name_field_width_;
97};
98
99class JSONReporter : public BenchmarkReporter {
100public:
101  JSONReporter() : first_report_(true) {}
102  virtual bool ReportContext(const Context& context);
103  virtual void ReportRuns(const std::vector<Run>& reports);
104  virtual void Finalize();
105
106private:
107  void PrintRunData(const Run& report);
108
109  bool first_report_;
110};
111
112} // end namespace benchmark
113#endif // BENCHMARK_REPORTER_H_
114