Class: Wakame::EventDispatcher

Inherits:
Object
  • Object
show all
Includes:
ThreadImmutable
Defined in:
lib/wakame/event_dispatcher.rb

Constant Summary collapse

FIRE_EVENT_LOG_IGNORE_EVENTS = 
[Wakame::Event::AgentPong]

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ThreadImmutable

#bind_thread, included, #target_thread, #target_thread?, #thread_check

Constructor Details

#initialize ⇒ EventDispatcher

Returns a new instance of EventDispatcher.



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# File 'lib/wakame/event_dispatcher.rb', line 43

def initialize
  @event_handlers = {}
  @tickets = {}

  @unsubscribe_queue = []
end

Class Method Details

.fire_event(event_obj) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 31

def fire_event(event_obj)
  self.instance.fire_event(event_obj)
end

.instance ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 6

def instance
  if @instance.nil?
    @instance = self.new
  end
  @instance
end

.reset ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 35

def reset
  @instance = nil
end

.subscribe(event_class, *args, &blk) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 13

def subscribe(event_class, *args, &blk)
  self.instance.subscribe(event_class, *args, &blk)
end

.subscribe_once(event_class, *args, &blk) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 21

def subscribe_once(event_class, *args, &blk)
  tkt = self.subscribe(event_class, *args) { |event|
    begin
      blk.call(event) if blk
    ensure
      self.unsubscribe(tkt)
    end
  }
end

.unsubscribe(ticket) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 17

def unsubscribe(ticket)
  self.instance.unsubscribe(ticket)
end

Instance Method Details

#fire_event(event_obj) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/wakame/event_dispatcher.rb', line 100

def fire_event(event_obj)
  raise ArgumentError unless event_obj.is_a?(Event::Base)

  if Wakame.log.level == 'DEBUG' && !FIRE_EVENT_LOG_IGNORE_EVENTS.member?(event_obj.class)
    Wakame.log.debug("Event #{event_obj.class} has been fired:" + (event_obj.log_message.nil? ? "" : event_obj.log_message) )
  end
  tlist = @event_handlers[event_obj.class]
  return if tlist.nil?

  run_callbacks = proc {
    @unsubscribe_queue.each { |t|
      @tickets.delete(t)
      tlist.delete(t)
    }

    tlist.each { |t|
      ary = @tickets[t]
      c = ary[1]
      if c.nil?
        next
      end
      
      begin 
        c.call(event_obj)
      rescue => e
        Wakame.log.error(e)
        #raise e
      end
    }
    
    @unsubscribe_queue.each { |t|
      @tickets.delete(t)
      tlist.delete(t)
    }
  }

  #@handler_run_queue.push(run_handlers)
  
  StatusDB.barrier {
    begin 
      run_callbacks.call
    rescue => e
      Wakame.log.error(e)
    end
  }
end

#reset(event_class = nil) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 147

def reset(event_class=nil)
  if event_class.nil?
    @event_handlers.clear
    @tickets.clear
  else
    unless @event_handlers[event_class.to_s].nil?
      @event_handlers[event_class.to_s].each_key { |k|
        @tickets.delete(k)
      }
      @event_handlers[event_class.to_s].clear
    end
  end
end

#subscribe(event_class, *args, &blk) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 50

def subscribe(event_class, *args, &blk)
  event_class = case event_class
                when Class
                  event_class
                when String
                  Util.str2const(event_class)
                else
                  raise ArgumentError, "event_class has to be a form of String or Class type"
                end

  StatusDB.barrier {
    tlist = @event_handlers[event_class]
    if tlist.nil?
      tlist = @event_handlers[event_class] = []
    end
    
    tickets = []
    args.each { |o|
      tickets << Util.gen_id
      @tickets.store(tickets.last, [event_class, o])
      tlist << tickets.last
    }
    
    if blk
      tickets << Util.gen_id
      @tickets.store(tickets.last, [event_class, blk])
      tlist << tickets.last
    end
    
    # Return in array if num of ticket to be returned is more than or equal 2.
    tickets.size > 1 ? tickets : tickets.first
  }
end

#unsubscribe(ticket) ⇒ Object 



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# File 'lib/wakame/event_dispatcher.rb', line 84

def unsubscribe(ticket)
  unless @tickets.has_key?(ticket)
    #Wakame.log.warn("EventHander.unsubscribe(#{ticket}) has been tried but the ticket was not registered.")
    return nil
  end
  
  StatusDB.barrier {
    Wakame.log.debug("#{self.class}.unsubscribe(#{ticket})")

    @unsubscribe_queue << ticket
    ticket
  }
end