Module: MessageStore::Read::Iterator

Included in:
Controls::Iterator::Example, Substitute
Defined in:
lib/message_store/read/iterator.rb

Defined Under Namespace

Modules: Build, Configure Classes: Substitute

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#batch ⇒ Object

Returns the value of attribute batch.



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# File 'lib/message_store/read/iterator.rb', line 20

def batch
  @batch
end

#batch_index ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 22

def batch_index
  @batch_index ||= 0
end

#starting_position ⇒ Object

Returns the value of attribute starting_position.



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# File 'lib/message_store/read/iterator.rb', line 19

def starting_position
  @starting_position
end

Class Method Details

.included(cls) ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 4

def self.included(cls)
  cls.class_exec do
    cls.extend Build
    cls.extend Configure

    include Log::Dependency

    dependency :get, Get

    initializer :stream_name

    abstract :last_position
  end
end

Instance Method Details

#advance_batch_index ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 59

def advance_batch_index
  logger.trace { "Advancing batch index (Batch Index: #{batch_index})" }
  self.batch_index += 1
  logger.debug { "Advanced batch index (Batch Index: #{batch_index})" }
end

#batch_depleted? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/message_store/read/iterator.rb', line 65

def batch_depleted?
  if batch.nil?
    logger.debug { "Batch is depleted (Batch is nil)" }
    return true
  end

  if batch.empty?
    logger.debug { "Batch is depleted (Batch is empty)" }
    return true
  end

  if batch_index == batch.length
    logger.debug { "Batch is depleted (Batch Index: #{batch_index}, Batch Length: #{batch.length})" }
    return true
  end

  false
end

#get_batch ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 93

def get_batch
  position = next_batch_starting_position

  logger.trace "Getting batch (Position: #{position.inspect})"

  batch = []
  if position.nil? || position >= 0
    batch = get.(stream_name, position: position)
  end

  logger.debug { "Finished getting batch (Count: #{batch.length}, Position: #{position.inspect})" }

  batch
end

#next ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 44

def next
  logger.trace { "Getting next message data (Batch Length: #{(batch &.length).inspect}, Batch Index: #{batch_index})" }

  resupply if batch_depleted?

  message_data = batch[batch_index]

  logger.debug(tags: [:data, :message_data]) { "Next message data: #{message_data.pretty_inspect}" }
  logger.debug { "Done getting next message data (Batch Length: #{(batch &.length).inspect}, Batch Index: #{batch_index})" }

  advance_batch_index

  message_data
end

#next_batch_starting_position ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 108

def next_batch_starting_position
  if batch.nil?
    logger.debug { "Batch is nil (Next batch starting position: #{starting_position.inspect})" }
    return starting_position
  end

  previous_position = last_position
  next_position = previous_position + 1
  logger.debug { "End of batch (Next starting position: #{next_position}, Previous Position: #{previous_position})" }

  next_position
end

#reset(batch) ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 121

def reset(batch)
  logger.trace { "Resetting batch" }

  self.batch = batch
  self.batch_index = 0

  logger.debug(tags: [:data, :batch]) { "Batch set to: \n#{batch.pretty_inspect}" }
  logger.debug(tags: [:data, :batch]) { "Batch position set to: #{batch_index.inspect}" }
  logger.debug { "Done resetting batch" }
end

#resupply ⇒ Object 



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# File 'lib/message_store/read/iterator.rb', line 84

def resupply
  logger.trace { "Resupplying batch (Current Batch Length: #{(batch &.length).inspect})" }

  batch = get_batch
  reset(batch)

  logger.debug { "Batch resupplied (Next Batch Length: #{(batch &.length).inspect})" }
end