Class: CircuitB::Fuse

Inherits:
Object
  • Object
show all
Defined in:
lib/circuit_b/fuse.rb

Constant Summary collapse

DEFAULT_BREAK_HANDLER_TIMEOUT =

Maximum time the handler is allowed to execute

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STANDARD_HANDLERS =

Standard handlers that can be refered by their names

{
  :rails_log => lambda { |fuse| RAILS_DEFAULT_LOGGER.error("CircuitB: Fuse '#{fuse.name}' has broken") }
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, state_storage, config) ⇒ Fuse

Returns a new instance of Fuse.



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# File 'lib/circuit_b/fuse.rb', line 17

def initialize(name, state_storage, config)
  raise "Name must be specified" if name.nil?
  raise "Storage must be specified" if state_storage.nil?
  raise "Storage must be of CircuitB::Storage::Base kind" unless state_storage.kind_of?(CircuitB::Storage::Base)
  raise "Config must be specified" if config.nil?
  
  @name          = name
  @state_storage = state_storage
  @config        = config
  
  @break_handler_timeout = DEFAULT_BREAK_HANDLER_TIMEOUT
end

Instance Attribute Details

#break_handler_timeout ⇒ Object

Returns the value of attribute break_handler_timeout.



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# File 'lib/circuit_b/fuse.rb', line 15

def break_handler_timeout
  @break_handler_timeout
end

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/circuit_b/fuse.rb', line 14

def config
  @config
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/circuit_b/fuse.rb', line 14

def name
  @name
end

Instance Method Details

#failures ⇒ Object 



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# File 'lib/circuit_b/fuse.rb', line 59

def failures
  get(:failures)
end

#open? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/circuit_b/fuse.rb', line 55

def open?
  get(:state) == :open
end

#wrap(&block) ⇒ Object

Raises:



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# File 'lib/circuit_b/fuse.rb', line 30

def wrap(&block)
  close_if_cooled_off if open?
  raise CircuitB::FastFailure if open?
  
  begin
    if @config[:timeout] && @config[:timeout].to_f > 0
      Timeout::timeout(@config[:timeout].to_f) { block.call }
    else
      block.call
    end

    put(:failures, 0)
  rescue Exception => e
    # Save the time of the last failure
    put(:last_failure_at, Time.now.to_i)
  
    # Increment the number of failures and open if the limit has been reached
    failures = inc(:failures)
    open if failures >= @config[:allowed_failures]
  
    # Re-raise the original exception
    raise e
  end
end