Returns the initial benchmark configuration for Benchee, composed of defaults and an optional custom configuration.

Configuration times are given in seconds, but are converted to microseconds internally.

Possible options:

• time - total run time in seconds of a single benchmark (determines how often it is executed). Defaults to 5.
• warmup - the time in seconds for which the benchmarking function should be run without gathering results. Defaults to 2.
• inputs - a map from descriptive input names to some different input, your benchmarking jobs will then be run with each of these inputs. For this to work your benchmarking function gets the current input passed in as an argument into the function. Defaults to nil, aka no input specified and functions are called without an argument.
• parallel - each the function of each job will be executed in parallel number processes. If parallel is 4 then 4 processes will be spawned that all execute the same function for the given time. When these finish/the time is up 4 new processes will be spawned for the next job/function. This gives you more data in the same time, but also puts a load on the system interfering with benchmark results. For more on the pros and cons of parallel benchmarking check the wiki. Defaults to 1 (no parallel execution).
• formatters - list of formatter functions you’d like to run to output the benchmarking results of the suite when using Benchee.run/2. Functions need to accept one argument (which is the benchmarking suite with all data) and then use that to produce output. Used for plugins. Defaults to the builtin console formatter calling Benchee.Formatters.Console.output/1.

• print - a map from atoms to true or false to configure if the output identified by the atom will be printed. All options are enabled by default (true). Options are:

  • :benchmarking - print when Benchee starts benchmarking a new job (Benchmarking name ..)
  • :configuration - a summary of configured benchmarking options including estimated total run time is printed before benchmarking starts
  • :fast_warning - warnings are displayed if functions are executed too fast leading to inaccurate measures

• console - options for the built-in console formatter. Like the print options the boolean options are also enabled by default:

  • :comparison - if the comparison of the different benchmarking jobs (x times slower than) is shown (true/false)

  • :unit_scaling - the strategy for choosing a unit for durations and counts. When scaling a value, Benchee finds the “best fit” unit (the largest unit for which the result is at least 1). For example, 1_200_000 scales to 1.2 M, while 800_000 scales to 800 K. The unit_scaling strategy determines how Benchee chooses the best fit unit for an entire list of values, when the individual values in the list may have different best fit units. There are four strategies, defaulting to :best:

    • :best - the most frequent best fit unit will be used, a tie will result in the larger unit being selected.
    • :largest - the largest best fit unit will be used (i.e. thousand and seconds if values are large enough).
    • :smallest - the smallest best fit unit will be used (i.e. millisecond and one)
    • :none - no unit scaling will occur. Durations will be displayed in microseconds, and counts will be displayed in ones (this is equivalent to the behaviour Benchee had pre 0.5.0)

Examples

iex> Benchee.init
%Benchee.Suite{
  configuration:
    %Benchee.Configuration{
      parallel: 1,
      time: 5_000_000,
      warmup: 2_000_000,
      inputs: nil,
      formatters: [&Benchee.Formatters.Console.output/1],
      print: %{
        benchmarking: true,
        fast_warning: true,
        configuration: true
      },
      formatter_options: %{
        console: %{ comparison: true, unit_scaling: :best }
      },
      assigns: %{}
    },
  jobs: %{},
  run_times: nil,
  statistics: nil,
  system: nil
}

iex> Benchee.init time: 1, warmup: 0.2
%Benchee.Suite{
  configuration:
    %Benchee.Configuration{
      parallel: 1,
      time: 1_000_000,
      warmup: 200_000.0,
      inputs: nil,
      formatters: [&Benchee.Formatters.Console.output/1],
      print: %{
        benchmarking: true,
        fast_warning: true,
        configuration: true
      },
      formatter_options: %{
        console: %{ comparison: true, unit_scaling: :best }
      },
      assigns: %{}
    },
  jobs: %{},
  run_times: nil,
  statistics: nil,
  system: nil
}

iex> Benchee.init %{time: 1, warmup: 0.2}
%Benchee.Suite{
  configuration:
    %Benchee.Configuration{
      parallel: 1,
      time: 1_000_000,
      warmup: 200_000.0,
      inputs: nil,
      formatters: [&Benchee.Formatters.Console.output/1],
      print: %{
        benchmarking: true,
        fast_warning: true,
        configuration: true
      },
      formatter_options: %{
        console: %{ comparison: true, unit_scaling: :best }
      },
      assigns: %{}
    },
  jobs: %{},
  run_times: nil,
  statistics: nil,
  system: nil
}

iex> Benchee.init(
...>   parallel: 2,
...>   time: 1,
...>   warmup: 0.2,
...>   formatters: [&IO.puts/2],
...>   print: [fast_warning: false],
...>   console: [unit_scaling: :smallest],
...>   inputs: %{"Small" => 5, "Big" => 9999},
...>   formatter_options: [some: "option"])
%Benchee.Suite{
  configuration:
    %Benchee.Configuration{
      parallel: 2,
      time: 1_000_000,
      warmup: 200_000.0,
      inputs: %{"Small" => 5, "Big" => 9999},
      formatters: [&IO.puts/2],
      print: %{
        benchmarking: true,
        fast_warning: false,
        configuration: true
      },
      formatter_options: %{
        console: %{ comparison: true, unit_scaling: :smallest },
        some: "option"
      },
      assigns: %{}
    },
  jobs: %{},
  run_times: nil,
  statistics: nil,
  system: nil
}