Module: Backrub

Extended by:
Backrub
Included in:
Backrub
Defined in:
lib/backrub.rb

Constant Summary collapse

VERSION = 
"1.0.0"
DEFAULT_BACKLOG_SIZE = 
100

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#backlog_size ⇒ Object 



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

def backlog_size
  @backlog_size || DEFAULT_BACKLOG_SIZE
end

#redis ⇒ Object 



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# File 'lib/backrub.rb', line 16

def redis
  @redis ||= new_redis
end

#redis_config ⇒ Object 



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# File 'lib/backrub.rb', line 12

def redis_config
  @redis_config ||= {}
end

Instance Method Details

#publish(channel, message) ⇒ Object 



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# File 'lib/backrub.rb', line 52

def publish(channel, message)
  redis.multi do
    redis.publish(channel, message)
    redis.lpush(channel, message)
    redis.ltrim(channel, 0, backlog_size - 1)
  end
end

#subscribe(*channels) ⇒ Object 



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# File 'lib/backrub.rb', line 20

def subscribe(*channels)
  raise ArgumentError.new "You have to pass at least one channel" if channels.count.zero?

  if channels.count == 1 && channels.first.is_a?(Hash)
    hash = channels.first

    hash.each do |channel, offset|
      if offset > 0
        backlog = redis.lrange(channel, 0, offset - 1)

        backlog.reverse_each do |message|
          yield channel.to_s, message
        end
      end
    end

    channels = hash.keys
  end

  begin
    # Open a new connection because the connection blocks, causing other threads to be unable to use it
    local_redis = new_redis
    local_redis.subscribe(*channels) do |on|
      on.message do |channel, message|
        yield channel, message
      end
    end
  ensure
    local_redis.quit
  end
end