Class: Magick::CircuitBreaker

Inherits:
Object
  • Object
show all
Defined in:
lib/magick/circuit_breaker.rb

Constant Summary collapse

DEFAULT_FAILURE_THRESHOLD = 
5
DEFAULT_TIMEOUT = 
60

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(failure_threshold: DEFAULT_FAILURE_THRESHOLD, timeout: DEFAULT_TIMEOUT) ⇒ CircuitBreaker

Returns a new instance of CircuitBreaker.



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# File 'lib/magick/circuit_breaker.rb', line 10

def initialize(failure_threshold: DEFAULT_FAILURE_THRESHOLD, timeout: DEFAULT_TIMEOUT)
  @failure_threshold = failure_threshold
  @timeout = timeout
  @failure_count = 0
  @last_failure_time = nil
  @state = :closed
  @mutex = Mutex.new
end

Instance Attribute Details

#failure_count ⇒ Object (readonly)

Returns the value of attribute failure_count.



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# File 'lib/magick/circuit_breaker.rb', line 8

def failure_count
  @failure_count
end

#last_failure_time ⇒ Object (readonly)

Returns the value of attribute last_failure_time.



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# File 'lib/magick/circuit_breaker.rb', line 8

def last_failure_time
  @last_failure_time
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'lib/magick/circuit_breaker.rb', line 8

def state
  @state
end

Instance Method Details

#call ⇒ Object 



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# File 'lib/magick/circuit_breaker.rb', line 19

def call
  return false if open?

  begin
    result = yield
    record_success
    result
  rescue StandardError => e
    record_failure
    raise e
  end
end

#open? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magick/circuit_breaker.rb', line 32

def open?
  @mutex.synchronize do
    if @state == :open
      if Time.now.to_i - @last_failure_time.to_i > @timeout
        @state = :half_open
        @failure_count = 0
        false
      else
        true
      end
    else
      false
    end
  end
end