Class: EventSource::EventStore::HTTP::Get

Inherits:
Object
  • Object
show all
Includes:
Log::Dependency
Defined in:
lib/event_source/event_store/http/get.rb,
lib/event_source/event_store/http/get/last.rb,
lib/event_source/event_store/http/get/result.rb,
lib/event_source/event_store/http/get/assertions.rb

Defined Under Namespace

Modules: Assertions, Defaults, Result Classes: Last

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.build(batch_size: nil, precedence: nil, long_poll_duration: nil, session: nil) ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 18

def self.build(batch_size: nil, precedence: nil, long_poll_duration: nil, session: nil)
  instance = new batch_size, precedence, long_poll_duration

  session = Session.configure instance, session: session
  ::EventStore::HTTP::ReadStream.configure instance, session: session

  instance.configure
  instance
end

.call(stream_name, position: nil, **build_arguments) ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 28

def self.call(stream_name, position: nil, **build_arguments)
  instance = build **build_arguments
  instance.(stream_name, position: position)
end

Instance Method Details

#call(stream_name, position: nil) ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 42

def call(stream_name, position: nil)
  stream_name = StreamName.canonize stream_name

  logger.trace { "Reading stream (StreamName: #{stream_name}, Position: #{position || '(start)'}, Direction: #{direction}, BatchSize: #{batch_size})" }

  if precedence == :desc
    position = desc_position stream_name, position

    if position < 0
      logger.debug { "Reading backward across start of stream (StreamName: #{stream_name}, Position: #{position || '(start)'}, Direction: #{direction}, BatchSize: #{batch_size}, Events: 0)" }
      return []
    end
  end

  begin
    events = read_stream.(
      stream_name,
      position: position,
      direction: direction,
      batch_size: batch_size
    )
  rescue ::EventStore::HTTP::ReadStream::StreamNotFoundError
    events = []
  end

  events.reverse! if precedence == :desc

  logger.debug { "Done reading stream (StreamName: #{stream_name}, Position: #{position || '(start)'}, Direction: #{direction}, BatchSize: #{batch_size}, Events: #{events.count})" }

  events
end

#configure ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 33

def configure
  read_stream.embed_body
  read_stream.output_schema = Result

  unless long_poll_duration.nil?
    read_stream.enable_long_poll long_poll_duration
  end
end

#desc_position(stream_name, position) ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 74

def desc_position(stream_name, position)
  begin
    head_event, * = read_stream.(
      stream_name,
      position: :head,
      direction: :backward,
      batch_size: 1
    )
  rescue ::EventStore::HTTP::ReadStream::StreamNotFoundError
    return -1
  end

  if position.nil?
    head_event.position
  else
    head_event.position - position
  end
end

#direction ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 93

def direction
  if precedence == :asc
    :forward
  else
    :backward
  end
end

#precedence ⇒ Object 



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# File 'lib/event_source/event_store/http/get.rb', line 11

def precedence
  @precedence ||= Defaults.precedence
end