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
|
require 'atomic'
require 'metriks/snapshot'
module Metriks
class UniformSample
def initialize(reservoir_size)
@values = Array.new(reservoir_size, 0)
@count = Atomic.new(0)
end
def clear
@values.length.times do |idx|
@values[idx] = 0
end
@count.value = 0
end
def size
count = @count.value
count > @values.length ? @values.length : count
end
def snapshot
Snapshot.new(@values.slice(0, size))
end
def update(value)
new_count = @count.update { |v| v + 1 }
if new_count <= @values.length
@values[new_count - 1] = value
else
idx = rand(new_count)
if idx < @values.length
@values[idx] = value
end
end
end
end
end
|
