Ruby on rails Can'；t获取ActionController:：Live以更好地使用ActiveSupport:：Notifications_Ruby On Rails_Events_Stream_Notifications_Actioncontroller

Ruby on rails Can'；t获取ActionController:：Live以更好地使用ActiveSupport:：Notifications

ruby-on-rails events stream notifications

Ruby on rails Can'；t获取ActionController:：Live以更好地使用ActiveSupport:：Notifications,ruby-on-rails,events,stream,notifications,actioncontroller,Ruby On Rails,Events,Stream,Notifications,Actioncontroller,我一直在寻找在不使用轮询的情况下使用ActionController:：Live触发服务器端事件的方法。似乎唯一有文档记录的Live发布/订阅解决方案是使用Redis，但我真的希望使用我目前拥有的堆栈。我遇到了ActiveSupport:：Notifications，它似乎正是我想要的然而，当我几乎用它代替Redis时，Live抛出一个IOError，流被关闭。我看不出任何合理的理由来解释为什么会发生这种情况例如，这应该是有效的： def stream response.header

我一直在寻找在不使用轮询的情况下使用ActionController:：Live触发服务器端事件的方法。似乎唯一有文档记录的Live发布/订阅解决方案是使用Redis，但我真的希望使用我目前拥有的堆栈。我遇到了ActiveSupport:：Notifications，它似乎正是我想要的

然而，当我几乎用它代替Redis时，Live抛出一个IOError，流被关闭。我看不出任何合理的理由来解释为什么会发生这种情况

例如，这应该是有效的：

def stream
    response.headers['Content-Type'] = 'text/event-stream'
    redis = Redis.new
    redis.subscribe('namespaced:stream') do |on|
        response.stream.write "hello world\n"
    end
    rescue IOError
        # Client Disconnected
    ensure
        response.stream.close
end

但当我尝试此操作时，会出现IO错误：

def stream
    response.headers['Content-Type'] = 'text/event-stream'
    ActiveSupport::Notifications.subscribe("process_action.action_controller") do |*args|
        response.stream.write "hello world\n"
    end
    rescue IOError
        # Client Disconnected
    ensure
        response.stream.close
end

我真的不知道为什么会这样。服务器日志中没有任何内容表明存在实际问题，否则通知订阅将起作用；我可以说出来，因为即使我得到一个IO错误，我仍然可以得到订阅，以便在出现“process\u action.action\u controller”通知时将字符串放入控制台

当通知没有出现时，连接工作正常，但一旦有通知（我认为应该只在流中写入“hello world”），我就会得到那个愚蠢的IO错误

顺便说一下，我确实计划检测我自己的通知；仅使用现有通知进行测试更容易

哦，这是当我访问使用流控制器方法的路线时终端发生的情况的副本：

IOError (closed stream):
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_dispatch/http/response.rb:76:in `write'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/live.rb:47:in `write'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/live.rb:135:in `rescue in block in process'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/live.rb:145:in `block in process'



IOError (closed stream):
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_dispatch/http/response.rb:76:in `write'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/live.rb:47:in `write'
  /home/benjamin/Desktop/workspace/fremote/app/controllers/remotes_controller.rb:25:in `block in show'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/fanout.rb:125:in `call'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/fanout.rb:125:in `finish'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/fanout.rb:40:in `block in finish'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/fanout.rb:40:in `each'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/fanout.rb:40:in `finish'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/instrumenter.rb:36:in `finish'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications/instrumenter.rb:25:in `instrument'
  /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.2/lib/active_support/notifications.rb:159:in `instrument'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/instrumentation.rb:30:in `process_action'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/abstract_controller/base.rb:136:in `process'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/abstract_controller/rendering.rb:44:in `process'
  /usr/local/lib/ruby/gems/2.0.0/gems/actionpack-4.0.2/lib/action_controller/metal/live.rb:132:in `block in process'

如果我弄错了任何术语，我深表歉意，因为我对SSEs和Rails一般来说都是新手，所以我非常感谢您在这方面提供的帮助

编辑：如果您需要知道，我将使用以下内容：

Rails 4.0.2
Ruby 2.0.0p353（2013-11-22修订版43784）[i686 linux]

  def close
    @response.commit!
    @closed = true
  end


  def write(string)
    raise IOError, "closed stream" if closed?

    @response.commit!
    @buf.push string
  end

，

  self.body, self.header, self.status = body, header, status

body=

def body=(body)
  @blank = true if body == EMPTY

  if body.respond_to?(:to_path)
    @stream = body
  else
    synchronize do
      @stream = build_buffer self, munge_body_object(body)
    end
  end
end

@stream

缓冲区

def build_buffer(response, body)
  Buffer.new response, body
end

response.stream.close