Class: Benchmark::HTTP::Stopwatch

Inherits:
Object
  • Object
show all
Defined in:
lib/benchmark/http/statistics.rb

Direct Known Subclasses

Statistics

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(concurrency = 0) ⇒ Stopwatch

Returns a new instance of Stopwatch.



26
27
28
29
30
31
32
33
34
 
# File 'lib/benchmark/http/statistics.rb', line 26

def initialize(concurrency = 0)
  @samples = []
  
  # The number of currently executing measurements:
  @count = 0
  
  @concurrency = concurrency
  @start_time = nil
end

Instance Attribute Details

#concurrency ⇒ Object (readonly)

The maximum number of executing measurements at any one time.



40
41
42
 
# File 'lib/benchmark/http/statistics.rb', line 40

def concurrency
  @concurrency
end

#samples ⇒ Object (readonly)

The individual samples’ durations.



37
38
39
 
# File 'lib/benchmark/http/statistics.rb', line 37

def samples
  @samples
end

Instance Method Details

#add(duration, result = nil) ⇒ Object 



100
101
102
 
# File 'lib/benchmark/http/statistics.rb', line 100

def add(duration, result = nil)
  @samples << duration
end

#average ⇒ Object 



68
69
70
71
72
 
# File 'lib/benchmark/http/statistics.rb', line 68

def average
  if @samples.any?
    @samples.sum / @samples.size
  end
end

#count ⇒ Object 



50
51
52
 
# File 'lib/benchmark/http/statistics.rb', line 50

def count
  @samples.size
end

#duration ⇒ Object 



42
43
44
 
# File 'lib/benchmark/http/statistics.rb', line 42

def duration
  @samples.sum
end

#latency ⇒ Object 



58
59
60
 
# File 'lib/benchmark/http/statistics.rb', line 58

def latency
  duration.to_f / count.to_f
end

#measure ⇒ Object 



104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
 
# File 'lib/benchmark/http/statistics.rb', line 104

def measure
  @count += 1
  
  if @count > @concurrency
    @concurrency = @count
  end
  
  start_time = Async::Clock.now
  
  unless @start_time
    @start_time = start_time
  end
  
  result = yield
  
  end_time = Async::Clock.now
  
  self.add(end_time - start_time, result)
  
  return result
ensure
  @count -= 1
end

#per_second(duration = self.sequential_duration) ⇒ Object 



54
55
56
 
# File 'lib/benchmark/http/statistics.rb', line 54

def per_second(duration = self.sequential_duration)
  @samples.size.to_f / duration.to_f
end

#print(out = STDOUT) ⇒ Object 



136
137
138
139
140
141
142
 
# File 'lib/benchmark/http/statistics.rb', line 136

def print(out = STDOUT)
  if self.valid?
    out.puts "#{@samples.size} samples. #{per_second} requests per second. S/D: #{Seconds[standard_deviation]}."
  else
    out.puts "Not enough samples."
  end
end

#sample(confidence_factor, &block) ⇒ Object 



128
129
130
131
132
133
134
 
# File 'lib/benchmark/http/statistics.rb', line 128

def sample(confidence_factor, &block)
  yield
  
  begin
    measure(&block)
  end until confident?(confidence_factor)
end

#sequential_duration ⇒ Object 



46
47
48
 
# File 'lib/benchmark/http/statistics.rb', line 46

def sequential_duration
  duration / @concurrency
end

#similar?(other, difference = 2.0) ⇒ Boolean

Returns:

  • (Boolean) 


62
63
64
65
66
 
# File 'lib/benchmark/http/statistics.rb', line 62

def similar?(other, difference = 2.0)
  ratio = other.latency / self.latency
  
  return ratio < difference
end

#standard_deviation ⇒ Object

Population Standard Deviation, σ



88
89
90
91
92
 
# File 'lib/benchmark/http/statistics.rb', line 88

def standard_deviation
  if variance = self.variance
    Math.sqrt(variance.abs)
  end
end

#standard_error ⇒ Object 



94
95
96
97
98
 
# File 'lib/benchmark/http/statistics.rb', line 94

def standard_error
  if standard_deviation = self.standard_deviation
    standard_deviation / Math.sqrt(@samples.size)
  end
end

#valid? ⇒ Boolean

Returns:

  • (Boolean) 


74
75
76
 
# File 'lib/benchmark/http/statistics.rb', line 74

def valid?
  @samples.size > 0
end

#variance ⇒ Object

Computes Population Variance, σ^2.



79
80
81
82
83
84
85
 
# File 'lib/benchmark/http/statistics.rb', line 79

def variance
  if valid?
    average = self.average
    
    return @samples.map{|n| (n - average)**2}.sum / @samples.size
  end
end