Class: TorqueBox::Messaging::Future

Inherits:
Object
  • Object
show all
Defined in:
lib/torquebox/messaging/future.rb

Overview

A Future encapsulates the result of a long running process, and is used in conjunction with a FutureResponder.

Constant Summary collapse

NO_TIMEOUT =

We can’t really do no timeout - 1ms is as close as we can get.

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Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(response_queue, options = { }) ⇒ Future

Returns a new instance of Future.

Parameters:

  • response_queue (TorqueBox::Messaging::Queue) —

    The queue where response messages are to be received.

  • options (Hash) (defaults to: { }) —

    Additional options

Options Hash (options):

  • :correlation_id (String) — default: Future.unique_id —

    The correlation_id used on the messages to uniquely identify the call they are for.

  • :default_result_timeout (Integer) — default: 30_000 —

    The timeout used by default for the receive call. The processing must at least start before the timeout expires, and finish before 2x this timeout.



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# File 'lib/torquebox/messaging/future.rb', line 43

def initialize(response_queue, options = { })
  @queue = response_queue
  @correlation_id = options[:correlation_id] || self.class.unique_id
  @default_result_timeout = options[:default_result_timeout] || 30_000
  @all_statuses = []
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object

Delegates to #result with the default timeout.



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# File 'lib/torquebox/messaging/future.rb', line 95

def method_missing(method, *args, &block)
  result.send( method, *args, &block )
end

Instance Attribute Details

#all_statuses ⇒ Object (readonly)

Returns all of the statuses seen by this future as an array.



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# File 'lib/torquebox/messaging/future.rb', line 32

def all_statuses
  @all_statuses
end

#correlation_id ⇒ Object (readonly)

Returns the value of attribute correlation_id.



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# File 'lib/torquebox/messaging/future.rb', line 28

def correlation_id
  @correlation_id
end

#default_result_timeout ⇒ Object

Returns the value of attribute default_result_timeout.



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# File 'lib/torquebox/messaging/future.rb', line 29

def default_result_timeout
  @default_result_timeout
end

#error ⇒ Object (readonly)

Returns the remote error (if any)



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# File 'lib/torquebox/messaging/future.rb', line 27

def error
  @error
end

Class Method Details

.unique_id ⇒ String

Returns a unique id useful for correlating a result to its call.

Returns:

  • (String) —

    a unique id useful for correlating a result to its call



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# File 'lib/torquebox/messaging/future.rb', line 101

def self.unique_id
  java.util.UUID.randomUUID.to_s
end

Instance Method Details

#complete? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/torquebox/messaging/future.rb', line 55

def complete?
  receive unless @complete || @error
  !!@complete
end

#error? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/torquebox/messaging/future.rb', line 60

def error?
  receive unless @complete || @error
  !!@error
end

#result(timeout = default_result_timeout) ⇒ Object

Attempts to return the remote result.

Parameters:

  • timeout (Integer) (defaults to: default_result_timeout) —

    The processing must at least start before the timeout expires, and finish before 2x this timeout.

Returns:

  • the remote result

Raises:



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# File 'lib/torquebox/messaging/future.rb', line 85

def result(timeout = default_result_timeout)
  receive( timeout ) unless @started
  raise TimeoutException.new( "timeout expired waiting for processing to start" ) unless @started
  receive( timeout ) unless @complete || @error
  raise TimeoutException.new( "timeout expired waiting for processing to finish" ) unless @complete || @error
  raise @error if @error
  @result
end

#started? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/torquebox/messaging/future.rb', line 50

def started?
  receive unless @started
  !!@started
end

#status ⇒ Object

Returns the latest response from the remote processor, if any. Status reporting is optional, and must be handled by the processed task itself.

See Also:

  • FutureResponder#status


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# File 'lib/torquebox/messaging/future.rb', line 69

def status
  @prior_status = retrieve_status
end

#status_changed? ⇒ Boolean

Returns true if the status has changed since the last call to #status.

Returns:

  • (Boolean) 


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# File 'lib/torquebox/messaging/future.rb', line 75

def status_changed?
  @prior_status != retrieve_status
end