Class: Teakflake::IdWorker

Inherits:
Object
  • Object
show all
Defined in:
lib/teakflake/id_worker.rb

Defined Under Namespace

Classes: BackwardsTimeError

Instance Method Summary collapse

Constructor Details

#initialize(worker_id_assigner) ⇒ IdWorker

Returns a new instance of IdWorker.



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# File 'lib/teakflake/id_worker.rb', line 25

def initialize(worker_id_assigner)
  @clock = worker_id_assigner.clock
  @sequence = 0
  @worker_id_assigner = worker_id_assigner
  @datacenter_id = worker_id_assigner.datacenter_id
  @last_time = 0
end

Instance Method Details

#id(requested_count = 1) ⇒ Object 



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# File 'lib/teakflake/id_worker.rb', line 33

def id(requested_count = 1)
  if requested_count < 1
    raise 'Must request at least one id'
  end

  time = @clock.millis
  if time < @last_time
    raise BackwardsTimeError, "Clocked moved backwards. Refusing to generate id for #{@last_time - time} milliseconds"
  end

  worker_id = @worker_id_assigner.assert(time)

  @sequence = 0 if time > @last_time

  if Id::MAX_SEQUENCE == @sequence
    time = til_next_millis
    @sequence = 0
  end

  available_count = Id::MAX_SEQUENCE - @sequence
  requested_count =
    if available_count < requested_count
      available_count
    else
      requested_count
    end

  next_sequence = @sequence + requested_count

  @last_time = time
  timestamp_part = time - Id::EPOCH

  response = Array.new(requested_count) do |i|
    timestamp_part << Id::TIMESTAMP_SHIFT |
      @datacenter_id << Id::DATACENTER_ID_SHIFT |
      worker_id << Id::WORKER_ID_SHIFT |
      @sequence + i
  end

  @sequence = next_sequence
  response
end

#til_next_millis ⇒ Object 



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# File 'lib/teakflake/id_worker.rb', line 76

def til_next_millis
  loop do
    time = @clock.millis
    if time < @last_time
      raise BackwardsTimeError, "Clocked moved backwards. Refusing to generate id for #{@last_time - time} milliseconds"
    elsif time > @last_time
      break time
    end
  end
end