Class: SimplePubSub::Server

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hostname, raw_reg = 'simplepubsub.xml') ⇒ Server

Returns a new instance of Server.



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# File 'lib/simplepubsub.rb', line 60

def initialize(hostname, raw_reg='simplepubsub.xml')


  h = {DWSRegistry: ->{raw_reg}, String: ->{DWSRegistry.new raw_reg}}

  @reg = h[raw_reg.class.to_s.to_sym].call

  # try to read the subscribers
  topics = @reg.get_key 'hkey_apps/simplepubsub/subscription_topics'
  
  @subscribers = {'#' => []}     
        
  if topics then
    topics.elements.each do |topic_element|
      topic = topic_element.name
      @subscribers[topic] ||= []
      @subscribers[topic] = topic_element.elements[0].elements.map(&:value)
    end
  end      
        
  @hostname = hostname

  @bridges = {'#' => []}
end

Instance Attribute Details

#bridges ⇒ Object (readonly)

Returns the value of attribute bridges.



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# File 'lib/simplepubsub.rb', line 58

def bridges
  @bridges
end

#subscribers ⇒ Object (readonly)

Returns the value of attribute subscribers.



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# File 'lib/simplepubsub.rb', line 58

def subscribers
  @subscribers
end

Instance Method Details

#add_bridge(topic, hostname, address) ⇒ Object 



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# File 'lib/simplepubsub.rb', line 144

def add_bridge(topic, hostname, address)
  @bridges[topic] ||= {}
  @bridges[topic].merge!(hostname => address)
end

#bridge_deliver(topic, message, excluded_host = nil) ⇒ Object 



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# File 'lib/simplepubsub.rb', line 149

def bridge_deliver(topic, message, excluded_host=nil)
  
  return 'no matching topic' unless @bridges.has_key? topic
  
  if excluded_host  then
    bridges = @bridges[topic].select{|x| x != excluded_host}
  else
    bridges = @bridges[topic]
  end
  
  bridges.values.each do |address|
    url = "http://%s/do/simplepubsub/bridgepub?topic=%s&hostname=%s&message=%s" % \
        [address, URI.escape(topic), @hostname, URI.escape(message)]
    r = open(url, 'UserAgent' => USER_AGENT)
  end
  'bridge delivered'
end

#deliver(topic, msg) ⇒ Object 



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# File 'lib/simplepubsub.rb', line 98

def deliver(topic, msg)
  
  topic.sub!('/','_')
  
  if not @subscribers.include?(topic) and \
      not @subscribers.include?('#') then
    return 'no topic subscribers' 
  end
             

  DRb.start_service

  topic_subscribers = @subscribers[topic]
  
  if topic_subscribers then
  
    topic_subscribers.each do |uri|
    
      next if @subscribers['#'].include? uri              
      echo = DRbObject.new nil, uri
      
      begin
        echo.message topic, msg
      rescue DRb::DRbConnError => e             
        @subscribers[topic].delete uri
        key = "hkey_apps/simplepubsub/subscription_topics/%s/subscribers/%s" % \
            [topic, uri[/[^\/]+$/].sub(':','')]
        @reg.delete_key key
      end          
      
    end
  end            

  @subscribers['#'].each do |uri|
  
    echo = DRbObject.new nil, uri
    
    begin
      echo.message topic, msg
    rescue DRb::DRbConnError => e             
      @subscribers['#'].delete uri
    end          

  end
end

#subscribe(topic, uri) ⇒ Object 



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# File 'lib/simplepubsub.rb', line 85

def subscribe(topic, uri)
  
  topic.sub!('/','_')
  @subscribers[topic] ||= []
  @subscribers[topic] << uri      
  
  # e.g. 'hkey_apps/simplepubsub/subscription_topics/magic/subscribers/niko', 
  #         'druby://niko:353524'
  key = "hkey_apps/simplepubsub/subscription_topics/%s/subscribers/%s" % \
      [topic, uri[/[^\/]+$/].sub(':','')]
  @reg.set_key key, uri
end