DESCRIPTION:

Asks the server to start a "consumer", which is a transient request for messages from a specific queue. Consumers last as long as the channel they were created on, or until the client cancels them with an unsubscribe. Every time a message reaches the queue it is passed to the blk for processing. If error occurs, Bunny::ProtocolError is raised.

OPTIONS:

• :consumer_tag => ‘tag‘ - Specifies the identifier for the consumer. The consumer tag is local to a connection, so two clients can use the same consumer tags. If this option is not specified a server generated name is used.
• :ack => false (default) or true - If set to false, the server does not expect an acknowledgement message from the client. If set to true, the server expects an acknowledgement message from the client and will re-queue the message if it does not receive one within a time specified by the server.
• :exclusive => true or false (default) - Request exclusive consumer access, meaning only this consumer can access the queue.
• :nowait => true or false (default) - Ignored by Bunny, always false.
• <tt>:timeout => number of seconds - The subscribe loop will continue to wait for messages until terminated (Ctrl-C or kill command) or this timeout interval is reached.
• :message_max => max number messages to process - When the required number of messages is processed subscribe loop is exited.

OPERATION:

Passes a hash of message information to the block, if one has been supplied. The hash contains :header, :payload and :delivery_details. The structure of the data is as follows -

:header has instance variables -

  @klass
  @size
  @weight
  @properties is a hash containing -
    :content_type
    :delivery_mode
    :priority

:payload contains the message contents

:delivery details is a hash containing -

  :consumer_tag
  :delivery_tag
  :redelivered
  :exchange
  :routing_key

If the :timeout option is specified then Qrack::ClientTimeout is raised if method times out waiting to receive the next message from the queue.

EXAMPLES

my_queue.subscribe(:timeout => 5) {|msg| puts msg[:payload]}

my_queue.subscribe(:message_max => 10, :ack => true) {|msg| puts msg[:payload]}