Module: EMDextras::Chains

Defined in:
lib/em-dextras/chains.rb

Defined Under Namespace

Modules: Deferrables, SynchronousStage Classes: InvalidStage, JoinedDeferrable, PipeSetup

Class Method Summary collapse

Class Method Details

.create_chain_result(monitoring, options) ⇒ Object 



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# File 'lib/em-dextras/chains.rb', line 94

def self.create_chain_result(monitoring, options)
  EventMachine::DefaultDeferrable.new.
    tap {|d| d.callback { |value| notify_end_of_chain!(value, monitoring, options) }}.
    tap {|d| d.errback  { |value| notify_end_of_chain!(value, monitoring, options) }}
end

.pipe(zero, monitoring, stages, options = {}) ⇒ Object 



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# File 'lib/em-dextras/chains.rb', line 89

def self.pipe(zero, monitoring, stages, options = {})
  result = create_chain_result(monitoring, options)
  run_chain zero, stages, PipeSetup.new(monitoring, options, result)
end

.run_chain(input, stages, pipe_setup) ⇒ Object 



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# File 'lib/em-dextras/chains.rb', line 100

def self.run_chain input, stages, pipe_setup
  return pipe_setup.result.succeed(input) if stages.empty? || input.nil?

  stage, *rest = *stages

  if stage == :split
    split_chain(input, rest, pipe_setup)
    return pipe_setup.result
  end

  deferrable = call(stage, input, pipe_setup)
  check_stage_is_well_behaved!(deferrable, stage, input, deferrable)
  deferrable.callback do |value|
    run_chain value, rest, pipe_setup
  end
  deferrable.errback do |error_value|
    pipe_setup.inform_exception! error_value, stage
    pipe_setup.result.fail(error_value)
  end

  pipe_setup.result
end