1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
#--
# benchmark.rb - a performance benchmarking library
#
# $Id: benchmark.rb 32269 2011-06-28 06:09:46Z naruse $
#
# Created by Gotoken ([email protected]).
#
# Documentation by Gotoken (original RD), Lyle Johnson (RDoc conversion), and
# Gavin Sinclair (editing).
#++

module Benchmark

  BENCHMARK_VERSION = "2002-04-25" #:nodoc"

  # Invokes the block with a <tt>Benchmark::Report</tt> object, which
  # may be used to collect and report on the results of individual
  # benchmark tests. Reserves <i>label_width</i> leading spaces for
  # labels on each line. Prints _caption_ at the top of the
  # report, and uses _format_ to format each line.
  # Returns an array of Benchmark::Tms objects.
  #
  # If the block returns an array of
  # <tt>Benchmark::Tms</tt> objects, these will be used to format
  # additional lines of output. If _label_ parameters are
  # given, these are used to label these extra lines.
  #
  # _Note_: Other methods provide a simpler interface to this one, and are
  # suitable for nearly all benchmarking requirements.  See the examples in
  # Benchmark, and the #bm and #bmbm methods.
  #
  # Example:
  #
  #     require 'benchmark'
  #     include Benchmark          # we need the CAPTION and FORMAT constants
  #
  #     n = 50000
  #     Benchmark.benchmark(CAPTION, 7, FORMAT, ">total:", ">avg:") do |x|
  #       tf = x.report("for:")   { for i in 1..n; a = "1"; end }
  #       tt = x.report("times:") { n.times do   ; a = "1"; end }
  #       tu = x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
  #       [tf+tt+tu, (tf+tt+tu)/3]
  #     end
  #
  # <i>Generates:</i>
  #
  #                     user     system      total        real
  #        for:     1.016667   0.016667   1.033333 (  0.485749)
  #        times:   1.450000   0.016667   1.466667 (  0.681367)
  #        upto:    1.533333   0.000000   1.533333 (  0.722166)
  #        >total:  4.000000   0.033333   4.033333 (  1.889282)
  #        >avg:    1.333333   0.011111   1.344444 (  0.629761)
  #

  def benchmark(caption = "", label_width = nil, format = nil, *labels) # :yield: report
    sync = STDOUT.sync
    STDOUT.sync = true
    label_width ||= 0
    label_width += 1
    format ||= FORMAT
    print ' '*label_width + caption
    report = Report.new(label_width, format)
    results = yield(report)
    Array === results and results.grep(Tms).each {|t|
      print((labels.shift || t.label || "").ljust(label_width), t.format(format))
    }
    report.list
  ensure
    STDOUT.sync = sync unless sync.nil?
  end


  # A simple interface to the #benchmark method, #bm is generates sequential reports
  # with labels.  The parameters have the same meaning as for #benchmark.
  #
  #     require 'benchmark'
  #
  #     n = 50000
  #     Benchmark.bm(7) do |x|
  #       x.report("for:")   { for i in 1..n; a = "1"; end }
  #       x.report("times:") { n.times do   ; a = "1"; end }
  #       x.report("upto:")  { 1.upto(n) do ; a = "1"; end }
  #     end
  #
  # <i>Generates:</i>
  #
  #                     user     system      total        real
  #        for:     1.050000   0.000000   1.050000 (  0.503462)
  #        times:   1.533333   0.016667   1.550000 (  0.735473)
  #        upto:    1.500000   0.016667   1.516667 (  0.711239)
  #

  def bm(label_width = 0, *labels, &blk) # :yield: report
    benchmark(CAPTION, label_width, FORMAT, *labels, &blk)
  end


  # Sometimes benchmark results are skewed because code executed
  # earlier encounters different garbage collection overheads than
  # that run later. #bmbm attempts to minimize this effect by running
  # the tests twice, the first time as a rehearsal in order to get the
  # runtime environment stable, the second time for
  # real. <tt>GC.start</tt> is executed before the start of each of
  # the real timings; the cost of this is not included in the
  # timings. In reality, though, there's only so much that #bmbm can
  # do, and the results are not guaranteed to be isolated from garbage
  # collection and other effects.
  #
  # Because #bmbm takes two passes through the tests, it can
  # calculate the required label width.
  #
  #       require 'benchmark'
  #
  #       array = (1..1000000).map { rand }
  #
  #       Benchmark.bmbm do |x|
  #         x.report("sort!") { array.dup.sort! }
  #         x.report("sort")  { array.dup.sort  }
  #       end
  #
  # <i>Generates:</i>
  #
  #        Rehearsal -----------------------------------------
  #        sort!  11.928000   0.010000  11.938000 ( 12.756000)
  #        sort   13.048000   0.020000  13.068000 ( 13.857000)
  #        ------------------------------- total: 25.006000sec
  #
  #                    user     system      total        real
  #        sort!  12.959000   0.010000  12.969000 ( 13.793000)
  #        sort   12.007000   0.000000  12.007000 ( 12.791000)
  #
  # #bmbm yields a Benchmark::Job object and returns an array of
  # Benchmark::Tms objects.
  #
  def bmbm(width = 0, &blk) # :yield: job
    job = Job.new(width)
    yield(job)
    width = job.width + 1
    sync = STDOUT.sync
    STDOUT.sync = true

    # rehearsal
    puts 'Rehearsal '.ljust(width+CAPTION.length,'-')
    ets = job.list.inject(Tms.new) { |sum,(label,item)|
      print label.ljust(width)
      res = Benchmark.measure(&item)
      print res.format
      sum + res
    }.format("total: %tsec")
    print " #{ets}\n\n".rjust(width+CAPTION.length+2,'-')

    # take
    print ' '*width + CAPTION
    job.list.map { |label,item|
      GC.start
      print label.ljust(width)
      Benchmark.measure(label, &item).tap { |res| print res }
    }
  ensure
    STDOUT.sync = sync unless sync.nil?
  end

  #
  # Returns the time used to execute the given block as a
  # Benchmark::Tms object.
  #
  def measure(label = "") # :yield:
    t0, r0 = Process.times, Time.now
    yield
    t1, r1 = Process.times, Time.now
    Benchmark::Tms.new(t1.utime  - t0.utime,
                       t1.stime  - t0.stime,
                       t1.cutime - t0.cutime,
                       t1.cstime - t0.cstime,
                       r1.to_f - r0.to_f,
                       label)
  end

  #
  # Returns the elapsed real time used to execute the given block.
  #
  def realtime # :yield:
    r0 = Time.now
    yield
    Time.now - r0
  end

  module_function :benchmark, :measure, :realtime, :bm, :bmbm

  #
  # A Job is a sequence of labelled blocks to be processed by the
  # Benchmark.bmbm method.  It is of little direct interest to the user.
  #
  class Job # :nodoc:
    #
    # Returns an initialized Job instance.
    # Usually, one doesn't call this method directly, as new
    # Job objects are created by the #bmbm method.
    # _width_ is a initial value for the label offset used in formatting;
    # the #bmbm method passes its _width_ argument to this constructor.
    #
    def initialize(width)
      @width = width
      @list = []
    end

    #
    # Registers the given label and block pair in the job list.
    #
    def item(label = "", &blk) # :yield:
      raise ArgumentError, "no block" unless block_given?
      label = label.to_s
      w = label.length
      @width = w if @width < w
      @list << [label, blk]
      self
    end

    alias report item

    # An array of 2-element arrays, consisting of label and block pairs.
    attr_reader :list

    # Length of the widest label in the #list.
    attr_reader :width
  end

  #
  # This class is used by the Benchmark.benchmark and Benchmark.bm methods.
  # It is of little direct interest to the user.
  #
  class Report # :nodoc:
    #
    # Returns an initialized Report instance.
    # Usually, one doesn't call this method directly, as new
    # Report objects are created by the #benchmark and #bm methods.
    # _width_ and _format_ are the label offset and
    # format string used by Tms#format.
    #
    def initialize(width = 0, format = nil)
      @width, @format, @list = width, format, []
    end

    #
    # Prints the _label_ and measured time for the block,
    # formatted by _format_. See Tms#format for the
    # formatting rules.
    #
    def item(label = "", *format, &blk) # :yield:
      print label.to_s.ljust(@width)
      @list << res = Benchmark.measure(label, &blk)
      print res.format(@format, *format)
      res
    end

    alias report item

    # An array of Benchmark::Tms objects representing each item.
    attr_reader :list
  end



  #
  # A data object, representing the times associated with a benchmark
  # measurement.
  #
  class Tms

    # Default caption, see also Benchmark::CAPTION
    CAPTION = "      user     system      total        real\n"

    # Default format string, see also Benchmark::FORMAT
    FORMAT = "%10.6u %10.6y %10.6t %10.6r\n"

    # User CPU time
    attr_reader :utime

    # System CPU time
    attr_reader :stime

    # User CPU time of children
    attr_reader :cutime

    # System CPU time of children
    attr_reader :cstime

    # Elapsed real time
    attr_reader :real

    # Total time, that is _utime_ + _stime_ + _cutime_ + _cstime_
    attr_reader :total

    # Label
    attr_reader :label

    #
    # Returns an initialized Tms object which has
    # _utime_ as the user CPU time, _stime_ as the system CPU time,
    # _cutime_ as the children's user CPU time, _cstime_ as the children's
    # system CPU time, _real_ as the elapsed real time and _label_ as the label.
    #
    def initialize(utime = 0.0, stime = 0.0, cutime = 0.0, cstime = 0.0, real = 0.0, label = nil)
      @utime, @stime, @cutime, @cstime, @real, @label = utime, stime, cutime, cstime, real, label.to_s
      @total = @utime + @stime + @cutime + @cstime
    end

    #
    # Returns a new Tms object whose times are the sum of the times for this
    # Tms object, plus the time required to execute the code block (_blk_).
    #
    def add(&blk) # :yield:
      self + Benchmark.measure(&blk)
    end

    #
    # An in-place version of #add.
    #
    def add!(&blk)
      t = Benchmark.measure(&blk)
      @utime  = utime + t.utime
      @stime  = stime + t.stime
      @cutime = cutime + t.cutime
      @cstime = cstime + t.cstime
      @real   = real + t.real
      self
    end

    #
    # Returns a new Tms object obtained by memberwise summation
    # of the individual times for this Tms object with those of the other
    # Tms object.
    # This method and #/() are useful for taking statistics.
    #
    def +(other); memberwise(:+, other) end

    #
    # Returns a new Tms object obtained by memberwise subtraction
    # of the individual times for the other Tms object from those of this
    # Tms object.
    #
    def -(other); memberwise(:-, other) end

    #
    # Returns a new Tms object obtained by memberwise multiplication
    # of the individual times for this Tms object by _x_.
    #
    def *(x); memberwise(:*, x) end

    #
    # Returns a new Tms object obtained by memberwise division
    # of the individual times for this Tms object by _x_.
    # This method and #+() are useful for taking statistics.
    #
    def /(x); memberwise(:/, x) end

    #
    # Returns the contents of this Tms object as
    # a formatted string, according to a format string
    # like that passed to Kernel.format. In addition, #format
    # accepts the following extensions:
    #
    # <tt>%u</tt>::     Replaced by the user CPU time, as reported by Tms#utime.
    # <tt>%y</tt>::     Replaced by the system CPU time, as reported by #stime (Mnemonic: y of "s*y*stem")
    # <tt>%U</tt>::     Replaced by the children's user CPU time, as reported by Tms#cutime
    # <tt>%Y</tt>::     Replaced by the children's system CPU time, as reported by Tms#cstime
    # <tt>%t</tt>::     Replaced by the total CPU time, as reported by Tms#total
    # <tt>%r</tt>::     Replaced by the elapsed real time, as reported by Tms#real
    # <tt>%n</tt>::     Replaced by the label string, as reported by Tms#label (Mnemonic: n of "*n*ame")
    #
    # If _format_ is not given, FORMAT is used as default value, detailing the
    # user, system and real elapsed time.
    #
    def format(format = nil, *args)
      str = (format || FORMAT).dup
      str.gsub!(/(%[-+\.\d]*)n/) { "#{$1}s" % label }
      str.gsub!(/(%[-+\.\d]*)u/) { "#{$1}f" % utime }
      str.gsub!(/(%[-+\.\d]*)y/) { "#{$1}f" % stime }
      str.gsub!(/(%[-+\.\d]*)U/) { "#{$1}f" % cutime }
      str.gsub!(/(%[-+\.\d]*)Y/) { "#{$1}f" % cstime }
      str.gsub!(/(%[-+\.\d]*)t/) { "#{$1}f" % total }
      str.gsub!(/(%[-+\.\d]*)r/) { "(#{$1}f)" % real }
      format ? str % args : str
    end

    #
    # Same as #format.
    #
    def to_s
      format
    end

    #
    # Returns a new 6-element array, consisting of the
    # label, user CPU time, system CPU time, children's
    # user CPU time, children's system CPU time and elapsed
    # real time.
    #
    def to_a
      [@label, @utime, @stime, @cutime, @cstime, @real]
    end

    protected
    
    #
    # Returns a new Tms object obtained by memberwise operation +op+
    # of the individual times for this Tms object with those of the other
    # Tms object.
    #
    # +op+ can be a mathematical operation such as <tt>+</tt>, <tt>-</tt>,
    # <tt>*</tt>, <tt>/</tt>
    #
    def memberwise(op, x)
      case x
      when Benchmark::Tms
        Benchmark::Tms.new(utime.__send__(op, x.utime),
                           stime.__send__(op, x.stime),
                           cutime.__send__(op, x.cutime),
                           cstime.__send__(op, x.cstime),
                           real.__send__(op, x.real)
                           )
      else
        Benchmark::Tms.new(utime.__send__(op, x),
                           stime.__send__(op, x),
                           cutime.__send__(op, x),
                           cstime.__send__(op, x),
                           real.__send__(op, x)
                           )
      end
    end
  end

  # The default caption string (heading above the output times).
  CAPTION = Benchmark::Tms::CAPTION

  # The default format string used to display times.  See also Benchmark::Tms#format.
  FORMAT = Benchmark::Tms::FORMAT
end

if __FILE__ == $0
  include Benchmark

  n = ARGV[0].to_i.nonzero? || 50000
  puts %Q([#{n} times iterations of `a = "1"'])
  benchmark("       " + CAPTION, 7, FORMAT) do |x|
    x.report("for:")   {for _ in 1..n; _ = "1"; end} # Benchmark.measure
    x.report("times:") {n.times do   ; _ = "1"; end}
    x.report("upto:")  {1.upto(n) do ; _ = "1"; end}
  end

  benchmark do
    [
      measure{for _ in 1..n; _ = "1"; end},  # Benchmark.measure
      measure{n.times do   ; _ = "1"; end},
      measure{1.upto(n) do ; _ = "1"; end}
    ]
  end
end