Class: XRay::LocalReservoir

Inherits:
Object
  • Object
show all
Defined in:
lib/aws-xray-sdk/sampling/local/reservoir.rb

Overview

Keeps track of the number of sampled segments within a single second in the local process. This class is implemented to be thread-safe to achieve accurate sampling.

Instance Method Summary collapse

Constructor Details

#initialize(traces_per_sec: 0) ⇒ LocalReservoir

Returns a new instance of LocalReservoir

Parameters:

  • traces_per_sec (Integer) —

    The number of guranteed sampled segments per second.



8
9
10
11
12
13
 
# File 'lib/aws-xray-sdk/sampling/local/reservoir.rb', line 8

def initialize(traces_per_sec: 0)
  @traces_per_sec = traces_per_sec
  @used_this_sec = 0
  @this_sec = Time.now.to_i
  @lock = Mutex.new
end

Instance Method Details

#take ⇒ Object

Returns true if there are quota left within the current second, otherwise returns false.



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
 
# File 'lib/aws-xray-sdk/sampling/local/reservoir.rb', line 17

def take
  # nothing to provide if reserved is set to 0
  return false if @traces_per_sec.zero?
  @lock.synchronize do
    now = Time.now.to_i
    # refresh time frame
    if now != @this_sec
      @used_this_sec = 0
      @this_sec = now
    end
    # return false if reserved item ran out
    return false unless @used_this_sec < @traces_per_sec
    # otherwise increment used counter and return true
    @used_this_sec += 1
    return true
  end
end