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
|
require 'benchmark/ips'
def yield_control
yield
end
def capture_block_and_yield(&block)
yield
end
def capture_block_and_call(&block)
block.call
end
puts "Using the block directly"
Benchmark.ips do |x|
x.report("yield ") do
yield_control { }
end
x.report("capture block and yield") do
capture_block_and_yield { }
end
x.report("capture block and call ") do
capture_block_and_call { }
end
end
puts "Forwarding the block to another method"
def tap_with_yield
5.tap { |i| yield i }
end
def tap_with_forwarded_block(&block)
5.tap(&block)
end
Benchmark.ips do |x|
x.report("tap { |i| yield i }") do
tap_with_yield { |i| }
end
x.report("tap(&block) ") do
tap_with_forwarded_block { |i| }
end
end
def yield_n_times(n)
n.times { yield }
end
def forward_block_to_n_times(n, &block)
n.times(&block)
end
def call_block_n_times(n, &block)
n.times { block.call }
end
[10, 25, 50, 100, 1000, 10000].each do |count|
puts "Invoking the block #{count} times"
Benchmark.ips do |x|
x.report("#{count}.times { yield } ") do
yield_n_times(count) { }
end
x.report("#{count}.times(&block) ") do
forward_block_to_n_times(count) { }
end
x.report("#{count}.times { block.call }") do
call_block_n_times(count) { }
end
end
end
__END__
This benchmark demonstrates that capturing a block (e.g. `&block`) has
a high constant cost, taking about 5x longer than a single `yield`
(even if the block is never used!).
However, fowarding a captured block can be faster than using `yield`
if the block is used many times (the breakeven point is at about 20-25
invocations), so it appears that he per-invocation cost of `yield`
is higher than that of a captured-and-forwarded block.
Note that there is no circumstance where using `block.call` is faster.
See also `flat_map_vs_inject.rb`, which appears to contradict these
results a little bit.
Using the block directly
Calculating -------------------------------------
yield
91.539k i/100ms
capture block and yield
50.945k i/100ms
capture block and call
50.923k i/100ms
-------------------------------------------------
yield
4.757M (± 6.0%) i/s - 23.709M
capture block and yield
1.112M (±20.7%) i/s - 5.349M
capture block and call
964.475k (±20.3%) i/s - 4.634M
Forwarding the block to another method
Calculating -------------------------------------
tap { |i| yield i } 74.620k i/100ms
tap(&block) 51.382k i/100ms
-------------------------------------------------
tap { |i| yield i } 3.213M (± 6.3%) i/s - 16.043M
tap(&block) 970.418k (±18.6%) i/s - 4.727M
Invoking the block 10 times
Calculating -------------------------------------
10.times { yield }
49.151k i/100ms
10.times(&block)
40.682k i/100ms
10.times { block.call }
27.576k i/100ms
-------------------------------------------------
10.times { yield }
908.673k (± 4.9%) i/s - 4.571M
10.times(&block)
674.565k (±16.1%) i/s - 3.336M
10.times { block.call }
385.056k (±10.3%) i/s - 1.930M
Invoking the block 25 times
Calculating -------------------------------------
25.times { yield }
29.874k i/100ms
25.times(&block)
30.934k i/100ms
25.times { block.call }
17.119k i/100ms
-------------------------------------------------
25.times { yield }
416.342k (± 3.6%) i/s - 2.091M
25.times(&block)
446.108k (±10.6%) i/s - 2.227M
25.times { block.call }
201.264k (± 7.2%) i/s - 1.010M
Invoking the block 50 times
Calculating -------------------------------------
50.times { yield }
17.690k i/100ms
50.times(&block)
21.760k i/100ms
50.times { block.call }
9.961k i/100ms
-------------------------------------------------
50.times { yield }
216.195k (± 5.7%) i/s - 1.079M
50.times(&block)
280.217k (± 9.9%) i/s - 1.393M
50.times { block.call }
112.754k (± 5.6%) i/s - 567.777k
Invoking the block 100 times
Calculating -------------------------------------
100.times { yield }
10.143k i/100ms
100.times(&block)
13.688k i/100ms
100.times { block.call }
5.551k i/100ms
-------------------------------------------------
100.times { yield }
111.700k (± 3.6%) i/s - 568.008k
100.times(&block)
163.638k (± 7.7%) i/s - 821.280k
100.times { block.call }
58.472k (± 5.6%) i/s - 294.203k
Invoking the block 1000 times
Calculating -------------------------------------
1000.times { yield }
1.113k i/100ms
1000.times(&block)
1.817k i/100ms
1000.times { block.call }
603.000 i/100ms
-------------------------------------------------
1000.times { yield }
11.156k (± 8.4%) i/s - 56.763k
1000.times(&block)
18.551k (±10.1%) i/s - 92.667k
1000.times { block.call }
6.206k (± 3.5%) i/s - 31.356k
Invoking the block 10000 times
Calculating -------------------------------------
10000.times { yield }
113.000 i/100ms
10000.times(&block)
189.000 i/100ms
10000.times { block.call }
61.000 i/100ms
-------------------------------------------------
10000.times { yield }
1.150k (± 3.6%) i/s - 5.763k
10000.times(&block)
1.896k (± 6.9%) i/s - 9.450k
10000.times { block.call }
624.401 (± 3.0%) i/s - 3.172k
|
