Class: Async::Background::Web::Stream

Inherits:
Object
  • Object
show all
Includes:
Clock
Defined in:
lib/async/background/web/stream.rb

Instance Method Summary collapse

Constructor Details

#initialize(hub, heartbeat_seconds:, retry_ms:, poll_seconds:, logger: nil) ⇒ Stream

Returns a new instance of Stream.



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# File 'lib/async/background/web/stream.rb', line 11

def initialize(hub, heartbeat_seconds:, retry_ms:, poll_seconds:, logger: nil)
  @hub = hub
  @heartbeat_seconds = heartbeat_seconds
  @retry_ms = retry_ms
  @poll_seconds = poll_seconds
  @logger = logger
end

Instance Method Details

#each ⇒ Object 



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# File 'lib/async/background/web/stream.rb', line 19

def each
  yield "retry: #{@retry_ms}\n\n"

  version, frame = initial_state
  if version.nil?
    yield EventHub::UNAVAILABLE_FRAME
    return
  end

  yield frame
  last_yield = monotonic_now
  unavailable_announced = false

  loop do
    sleep_for_poll

    begin
      new_version = @hub.current_version

      if new_version != version
        version = new_version
        yield @hub.frame_for(version)
        last_yield = monotonic_now
      elsif (monotonic_now - last_yield) >= @heartbeat_seconds
        yield EventHub::HEARTBEAT_FRAME
        last_yield = monotonic_now
      end

      unavailable_announced = false
    rescue ClosedError
      break
    rescue UnavailableError
      unless unavailable_announced
        yield EventHub::UNAVAILABLE_FRAME
        unavailable_announced = true
        last_yield = monotonic_now
      end
    end
  end
rescue Errno::EPIPE, Errno::ECONNRESET, IOError
  nil
rescue StandardError => error
  @logger&.error(
    "[async-background-web] SSE stream terminated: " \
    "#{error.class}: #{error.message}"
  )
  nil
end