Class: Reqless::Subscriber

Inherits:
Object
  • Object
show all
Defined in:
lib/reqless/subscriber.rb

Overview

A class used for subscribing to messages in a thread

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(client, channel, options = {}, &message_received_callback) ⇒ Subscriber

Returns a new instance of Subscriber.



15
16
17
18
19
20
21
22
23
24
25
26
 
# File 'lib/reqless/subscriber.rb', line 15

def initialize(client, channel, options = {}, &message_received_callback)
  @channel = channel
  @message_received_callback = message_received_callback
  @log = options.fetch(:log) { ::Logger.new($stderr) }

  # pub/sub blocks the connection so we must use a different redis
  # connection
  @client_redis   = client.redis
  @listener_redis = client.new_redis_connection

  @my_channel = Reqless.generate_jid
end

Instance Attribute Details

#channel ⇒ Object (readonly)

Returns the value of attribute channel.



13
14
15
 
# File 'lib/reqless/subscriber.rb', line 13

def channel
  @channel
end

#redis ⇒ Object (readonly)

Returns the value of attribute redis.



13
14
15
 
# File 'lib/reqless/subscriber.rb', line 13

def redis
  @redis
end

Class Method Details

.start(*args, &block) ⇒ Object 



9
10
11
 
# File 'lib/reqless/subscriber.rb', line 9

def self.start(*args, &block)
  new(*args, &block).tap(&:start)
end

Instance Method Details

#start ⇒ Object

Start a thread listening



29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
 
# File 'lib/reqless/subscriber.rb', line 29

def start
  queue = ::Queue.new

  @thread = Thread.start do
    begin
      @listener_redis.subscribe(@channel, @my_channel) do |on|
        on.subscribe do |channel|
          # insert nil into the queue to indicate we've
          # successfully subscribed
          queue << nil if channel == @channel
        end

        on.message do |channel, message|
          handle_message(channel, message)
        end
      end
    # Watch for any exceptions so we don't block forever if
    # subscribing to the channel fails
    rescue Exception => e
      queue << e
    end
  end

  if (exception = queue.pop)
    raise exception
  end
end

#stop ⇒ Object 



57
58
59
60
 
# File 'lib/reqless/subscriber.rb', line 57

def stop
  @client_redis.publish(@my_channel, 'disconnect')
  @thread.join
end