Class: MessageChannel::Redis

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

Instance Method Summary collapse

Constructor Details

#initialize(host: nil, port: nil, db: nil) ⇒ Redis

Returns a new instance of Redis.



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# File 'lib/message_channel/redis.rb', line 8

def initialize( host: nil, port: nil, db: nil )
  @host  =  host  || "127.0.0.1"
  @port  =  ( port  ||  6379 ).to_i
  @db  =  ( db  ||  0 ).to_i
  @redis  =  ::Redis.new( host: @host, port: @port, db: @db )
  @threads  =  {}
end

Instance Method Details

#listen(*patterns, timeout: nil, &block) ⇒ Object 



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# File 'lib/message_channel/redis.rb', line 66

def listen( *patterns, timeout: nil, &block )
  if block_given?
    listen_each( *patterns ) do |topic, items|
      block.call( topic, items )
    end
    return  nil
  end
  if timeout.nil? || ( timeout.is_a?( Numeric ) && timeout >= 0 )
    begin
      Timeout.timeout( timeout ) do
        listen_once( *patterns )
      end
    rescue  Timeout::Error
      return  nil
    end
  else
    raise  ArgumentError, "timeout: %s" % timeout
  end
end

#listen_each(*patterns, &block) ⇒ Object 



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# File 'lib/message_channel/redis.rb', line 45

def listen_each( *patterns, &block )
  patterns.each do |pattern|
    @threads[pattern]  =  ::Thread.start( pattern ) do |pttrn|
      redis  =  ::Redis.new( host: @host, port: @port, db: @db )
      begin
        redis.psubscribe( pttrn ) do |on|
          on.pmessage do |_ptn, channel, message|
            items  =  JSON.parse( message, symbolize_names: true )
            block.call( channel, items )
          end
        end
      rescue  ::Redis::BaseConnectionError => error
        sleep 1
        retry
      ensure
        redis.punsubscribe( pttrn )    rescue  nil
      end
    end
  end
end

#listen_once(*patterns) ⇒ Object 



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# File 'lib/message_channel/redis.rb', line 16

def listen_once( *patterns )
  queue  =  Queue.new
  threads  =  {}
  patterns.each do |pattern|
    threads[pattern]  =  ::Thread.start( pattern ) do |pttrn|
      redis  =  ::Redis.new( host: @host, port: @port, db: @db )
      begin
        redis.psubscribe( pttrn ) do |on|
          on.pmessage do |ptn, channel, message|
            items  =  JSON.parse( message, symbolize_names: true )
            redis.punsubscribe( ptn )    rescue  nil
            queue.push  [channel, items]
          end
        end
      rescue  ::Redis::BaseConnectionError => error
        sleep 1
        retry
      end
    end
  end

  topic, items  =  queue.pop
  patterns.each do |pattern|
    threads[pattern].kill    rescue  nil
    threads.delete( pattern )    rescue  nil
  end
  [topic, items]
end

#notify(topic, **items) ⇒ Object 



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# File 'lib/message_channel/redis.rb', line 93

def notify( topic, **items )
  @redis.publish( topic, items.to_json )
end

#unlisten(*patterns) ⇒ Object 



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# File 'lib/message_channel/redis.rb', line 86

def unlisten( *patterns )
  patterns.each do |pattern|
    @threads[pattern].kill    rescue  nil
    @threads.delete( pattern )    rescue  nil
  end
end