Class: QueueBus::Heartbeat

Inherits:
Object
  • Object
show all
Defined in:
lib/queue_bus/heartbeat.rb

Overview

publishes event about the current time

Class Method Summary collapse

Class Method Details

.environment_name ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 46

def environment_name
  ENV["RAILS_ENV"] || ENV["RACK_ENV"] || ENV["BUS_ENV"]
end

.get_saved_minute! ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 50

def get_saved_minute!
  key = ::QueueBus.redis { |redis| redis.get(redis_key) }
  return nil if key.nil?
  case environment_name
  when 'development', 'test'
    # only 3 minutes in development; otherwise, TONS of events if not run in a while
    three_ago = Time.now.to_i - 3*60*60
    key = three_ago if key.to_i < three_ago
  end
  return key.to_i
end

.lock! ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 15

def lock!
  now = Time.now.to_i
  timeout = now + lock_seconds + 2

  ::QueueBus.redis do |redis|
    # return true if we successfully acquired the lock
    return timeout if redis.setnx(lock_key, timeout)

    # see if the existing timeout is still valid and return false if it is
    # (we cannot acquire the lock during the timeout period)
    return 0 if now <= redis.get(lock_key).to_i

    # otherwise set the timeout and ensure that no other worker has
    # acquired the lock
    if now > redis.getset(lock_key, timeout).to_i
      return timeout
    else
      return 0
    end
  end
end

.lock_key ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 7

def lock_key
  "bus:heartbeat:lock"
end

.lock_seconds ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 11

def lock_seconds
  60
end

.perform(*args) ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 66

def perform(*args)
  real_now = Time.now.to_i
  run_until = lock! - 2
  return if run_until < real_now

  while((real_now = Time.now.to_i) < run_until)
    minutes = real_now.to_i / 60
    last = get_saved_minute!
    if last
      break if minutes <= last
      minutes = last + 1
    end

    seconds = minutes * (60)
    hours   = minutes / (60)
    days    = minutes / (60*24)

    now     = Time.at(seconds)

    attributes = {}
    attributes["epoch_seconds"] = seconds
    attributes["epoch_minutes"] = minutes
    attributes["epoch_hours"]   = hours
    attributes["epoch_days"]    = days

    attributes["minute"] = now.min
    attributes["hour"]   = now.hour
    attributes["day"]    = now.day
    attributes["month"]  = now.month
    attributes["year"]   = now.year
    attributes["yday"]   = now.yday
    attributes["wday"]   = now.wday

    ::QueueBus.publish("heartbeat_minutes", attributes)
    set_saved_minute!(minutes)
  end

  unlock!
end

.redis_key ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 42

def redis_key
  "bus:heartbeat:timestamp"
end

.set_saved_minute!(epoch_minute) ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 62

def set_saved_minute!(epoch_minute)
  ::QueueBus.redis { |redis| redis.set(redis_key, epoch_minute) }
end

.unlock! ⇒ Object 



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# File 'lib/queue_bus/heartbeat.rb', line 37

def unlock!
  ::QueueBus.redis { |redis| redis.del(lock_key) }
end