class Bunny::Subscription09

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.

@option opts [String] :consumer_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.

@option opts [Boolean] :ack (false)

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.

@option opts [Boolean] :exclusive (false)

Request exclusive consumer access, meaning only this consumer can access the queue.

@option opts [Boolean] :nowait (false)

Ignored by Bunny, always @false@.

@option opts [Numeric] :timeout

The subscribe loop will continue to wait for messages
until terminated (Ctrl-C or kill command) or this timeout interval is reached.

@option opts [Integer] :message_max

When the required number of messages is processed subscribe loop is exited.

h2. 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 the subscription will automatically cease if the given number of seconds passes with no message arriving.

@example

my_queue.subscribe(timeout: 5) { |msg| puts msg[:payload] }
my_queue.subscribe(message_max: 10, ack: true) { |msg| puts msg[:payload] }

Public Instance Methods

setup_consumer() click to toggle source
# File lib/bunny/subscription09.rb, line 65
def setup_consumer
  subscription_options = {
    :deprecated_ticket => 0,
    :queue => queue.name,
    :consumer_tag => consumer_tag,
    :no_ack => !ack,
    :exclusive => exclusive,
    :nowait => false
  }.merge(@opts)

  client.send_frame(Qrack::Protocol09::Basic::Consume.new(subscription_options))

  method = client.next_method

  client.check_response(method, Qrack::Protocol09::Basic::ConsumeOk, "Error subscribing to queue #{queue.name}")

  @consumer_tag = method.consumer_tag
end