Class: Bunny::Channel

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

Overview

Channels in RabbitMQ

To quote AMQP 0.9.1 specification:

AMQP 0.9.1 is a multi-channelled protocol. Channels provide a way to multiplex a heavyweight TCP/IP connection into several light weight connections. This makes the protocol more “firewall friendly” since port usage is predictable. It also means that traffic shaping and other network QoS features can be easily employed. Channels are independent of each other and can perform different functions simultaneously with other channels, the available bandwidth being shared between the concurrent activities.

Opening Channels

Channels can be opened either via Bunny::Session#create_channel (sufficient in the majority of cases) or by instantiating Bunny::Channel directly:

conn = Bunny.new
conn.start

ch   = conn.create_channel

This will automatically allocate a channel id.

Closing Channels

Channels are closed via #close. Channels that get a channel-level exception are closed, too. Closed channels can no longer be used. Attempts to use them will raise ChannelAlreadyClosed.

ch = conn.create_channel
ch.close

Higher-level API

Bunny offers two sets of methods on Channel: known as higher-level and lower-level APIs, respectively. Higher-level API mimics amqp gem API where exchanges and queues are objects (instance of Exchange and Queue, respectively). Lower-level API is built around AMQP 0.9.1 methods (commands), where queues and exchanges are passed as strings (à la RabbitMQ Java client, Langohr and Pika).

Queue Operations In Higher-level API

  • #queue is used to declare queues. The rest of the API is in Queue.

Exchange Operations In Higher-level API

Channel Qos (Prefetch Level)

It is possible to control how many messages at most a consumer will be given (before it acknowledges or rejects previously consumed ones). This setting is per channel and controlled via #prefetch.

Channel IDs

Channels are identified by their ids which are integers. Bunny takes care of allocating and releasing them as channels are opened and closed. It is almost never necessary to specify channel ids explicitly.

There is a limit on the maximum number of channels per connection, usually 65536. Note that allocating channels is very cheap on both client and server so having tens, hundreds or even thousands of channels is not a problem.

Channels and Error Handling

Channel-level exceptions are more common than connection-level ones and often indicate issues applications can recover from (such as consuming from or trying to delete a queue that does not exist).

With Bunny, channel-level exceptions are raised as Ruby exceptions, for example, NotFound, that provide access to the underlying channel.close method information.

Examples:

Handling 404 NOT_FOUND

begin
  ch.queue_delete("queue_that_should_not_exist#{rand}")
rescue Bunny::NotFound => e
  puts "Channel-level exception! Code: #{e.channel_close.reply_code}, message: #{e.channel_close.reply_text}"
end

Handling 406 PRECONDITION_FAILED

begin
  ch2 = conn.create_channel
  q   = "bunny.examples.recovery.q#{rand}"

  ch2.queue_declare(q, :durable => false)
  ch2.queue_declare(q, :durable => true)
rescue Bunny::PreconditionFailed => e
  puts "Channel-level exception! Code: #{e.channel_close.reply_code}, message: #{e.channel_close.reply_text}"
ensure
  conn.create_channel.queue_delete(q)
end

See Also:

Consumer and Message operations (basic.*) collapse

MAX_PREFETCH_COUNT =

prefetch_count is of type short in the protocol. MK.

(2 ** 16) - 1

Constant Summary collapse

DEFAULT_CONTENT_TYPE = 
"application/octet-stream".freeze
SHORTSTR_LIMIT = 
255

Instance Attribute Summary collapse

Backwards compatibility with 0.8.0 collapse

Higher-level API for exchange operations collapse

Higher-level API for queue operations collapse

QoS and Flow Control collapse

Message acknowledgements collapse

Consumer and Message operations (basic.*) collapse

Queue operations (queue.*) collapse

Exchange operations (exchange.*) collapse

Flow control (channel.*) collapse

Transactions (tx.*) collapse

Publisher Confirms (confirm.*) collapse

Misc collapse

Network Failure Recovery collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection = nil, id = nil, work_pool = ConsumerWorkPool.new(1)) ⇒ Channel

Returns a new instance of Channel.

Parameters:

  • connection (Bunny::Session) (defaults to: nil) —

    AMQP 0.9.1 connection

  • id (Integer) (defaults to: nil) —

    Channel id, pass nil to make Bunny automatically allocate it

  • work_pool (Bunny::ConsumerWorkPool) (defaults to: ConsumerWorkPool.new(1)) —

    Thread pool for delivery processing, by default of size 1



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# File 'lib/bunny/channel.rb', line 172

def initialize(connection = nil, id = nil, work_pool = ConsumerWorkPool.new(1))
  @connection = connection
  @logger     = connection.logger
  @id         = id || @connection.next_channel_id

  # channel allocator is exhausted
  if @id < 0
    msg = "Cannot open a channel: max number of channels on connection reached. Connection channel_max value: #{@connection.channel_max}"
    @logger.error(msg)

    raise msg
  else
    @logger.debug { "Allocated channel id: #{@id}" }
  end

  @status     = :opening

  @connection.register_channel(self)

  @queues     = Hash.new
  @exchanges  = Hash.new
  @consumers  = Hash.new
  @work_pool  = work_pool

  # synchronizes frameset delivery. MK.
  @publishing_mutex = @connection.mutex_impl.new
  @consumer_mutex   = @connection.mutex_impl.new

  @queue_mutex    = @connection.mutex_impl.new
  @exchange_mutex = @connection.mutex_impl.new

  @unconfirmed_set_mutex = @connection.mutex_impl.new

  self.reset_continuations

  # threads awaiting on continuations. Used to unblock
  # them when network connection goes down so that busy loops
  # that perform synchronous operations can work. MK.
  @threads_waiting_on_continuations           = Set.new
  @threads_waiting_on_confirms_continuations  = Set.new
  @threads_waiting_on_basic_get_continuations = Set.new

  @next_publish_seq_no = 0
  @delivery_tag_offset = 0

  @recoveries_counter = Bunny::Concurrent::AtomicFixnum.new(0)
  @uncaught_exception_handler = Proc.new do |e, consumer|
    @logger.error "Uncaught exception from consumer #{consumer.to_s}: #{e.inspect} @ #{e.backtrace[0]}"
  end
end

Instance Attribute Details

#connection ⇒ Bunny::Session (readonly)

Returns AMQP connection this channel was opened on.

Returns:



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# File 'lib/bunny/channel.rb', line 139

def connection
  @connection
end

#consumers ⇒ Hash<String, Bunny::Consumer> (readonly)

Returns Consumer instances declared on this channel.

Returns:

  • (Hash<String, Bunny::Consumer>) —

    Consumer instances declared on this channel



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# File 'lib/bunny/channel.rb', line 159

def consumers
  @consumers
end

#delivery_tag_offset ⇒ Integer (readonly)

This will be set to the current sequence index during automatic network failure recovery to keep the sequence monotonic for the user and abstract the reset from the protocol

Returns:

  • (Integer) —

    Offset for the confirmations sequence index.



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# File 'lib/bunny/channel.rb', line 149

def delivery_tag_offset
  @delivery_tag_offset
end

#exchanges ⇒ Hash<String, Bunny::Exchange> (readonly)

Returns Exchange instances declared on this channel.

Returns:

  • (Hash<String, Bunny::Exchange>) —

    Exchange instances declared on this channel



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# File 'lib/bunny/channel.rb', line 153

def exchanges
  @exchanges
end

#id ⇒ Integer

Returns Channel id.

Returns:

  • (Integer) —

    Channel id



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# File 'lib/bunny/channel.rb', line 137

def id
  @id
end

#nacked_set ⇒ Set<Integer> (readonly)

Returns Set of nacked message indexes that have been nacked.

Returns:

  • (Set<Integer>) —

    Set of nacked message indexes that have been nacked



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# File 'lib/bunny/channel.rb', line 157

def nacked_set
  @nacked_set
end

#next_publish_seq_no ⇒ Integer (readonly)

Returns Next publisher confirmations sequence index.

Returns:

  • (Integer) —

    Next publisher confirmations sequence index



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# File 'lib/bunny/channel.rb', line 145

def next_publish_seq_no
  @next_publish_seq_no
end

#prefetch_count ⇒ Integer (readonly)

Returns active basic.qos prefetch value.

Returns:

  • (Integer) —

    active basic.qos prefetch value



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# File 'lib/bunny/channel.rb', line 162

def prefetch_count
  @prefetch_count
end

#prefetch_global ⇒ Integer (readonly)

Returns active basic.qos prefetch global mode.

Returns:

  • (Integer) —

    active basic.qos prefetch global mode



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# File 'lib/bunny/channel.rb', line 164

def prefetch_global
  @prefetch_global
end

#queues ⇒ Hash<String, Bunny::Queue> (readonly)

Returns Queue instances declared on this channel.

Returns:

  • (Hash<String, Bunny::Queue>) —

    Queue instances declared on this channel



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# File 'lib/bunny/channel.rb', line 151

def queues
  @queues
end

#recoveries_counter ⇒ Object (readonly)

Returns the value of attribute recoveries_counter.



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# File 'lib/bunny/channel.rb', line 223

def recoveries_counter
  @recoveries_counter
end

#status ⇒ Symbol (readonly)

Returns Channel status (:opening, :open, :closed).

Returns:

  • (Symbol) —

    Channel status (:opening, :open, :closed)



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# File 'lib/bunny/channel.rb', line 141

def status
  @status
end

#unconfirmed_set ⇒ Set<Integer> (readonly)

Returns Set of published message indexes that are currently unconfirmed.

Returns:

  • (Set<Integer>) —

    Set of published message indexes that are currently unconfirmed



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# File 'lib/bunny/channel.rb', line 155

def unconfirmed_set
  @unconfirmed_set
end

#work_pool ⇒ Bunny::ConsumerWorkPool (readonly)

Returns Thread pool delivered messages are dispatched to.

Returns:

  • (Bunny::ConsumerWorkPool) —

    Thread pool delivered messages are dispatched to.



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# File 'lib/bunny/channel.rb', line 143

def work_pool
  @work_pool
end

Instance Method Details

#ack(delivery_tag, multiple = false) ⇒ Object Also known as: acknowledge

Acknowledges a message. Acknowledged messages are completely removed from the queue.

Parameters:

  • delivery_tag (Integer) —

    Delivery tag to acknowledge

  • multiple (Boolean) (defaults to: false) —

    (false) Should all unacknowledged messages up to this be acknowledged as well?

See Also:



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# File 'lib/bunny/channel.rb', line 553

def ack(delivery_tag, multiple = false)
  basic_ack(delivery_tag.to_i, multiple)
end

#active ⇒ Boolean

Returns true if this channel is open.

Returns:

  • (Boolean) —

    true if this channel is open



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# File 'lib/bunny/channel.rb', line 282

def active
  open?
end

#any_consumers? ⇒ Boolean

Returns true if there are consumers on this channel.

Returns:

  • (Boolean) —

    true if there are consumers on this channel



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# File 'lib/bunny/channel.rb', line 1050

def any_consumers?
  @consumer_mutex.synchronize { @consumers.any? }
end

#basic_ack(delivery_tag, multiple = false) ⇒ NilClass

Acknowledges a delivery (message).

Examples:

Ack a message

conn  = Bunny.new
conn.start

ch    = conn.create_channel
q.subscribe do |delivery_info, properties, payload|
  # requeue the message
  ch.basic_ack(delivery_info.delivery_tag.to_i)
end

Ack a message fetched via basic.get

conn  = Bunny.new
conn.start

ch    = conn.create_channel
# we assume the queue exists and has messages
delivery_info, properties, payload = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
ch.basic_ack(delivery_info.delivery_tag.to_i)

Ack multiple messages fetched via basic.get

conn  = Bunny.new
conn.start

ch    = conn.create_channel
# we assume the queue exists and has messages
_, _, payload1 = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
_, _, payload2 = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
delivery_info, properties, payload3 = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
# ack all fetched messages up to payload3
ch.basic_ack(delivery_info.delivery_tag.to_i, true)

Parameters:

  • delivery_tag (Integer) —

    Delivery tag obtained from delivery info

  • multiple (Boolean) (defaults to: false) —

    Should all deliveries up to this one be acknowledged?

Returns:

  • (NilClass) —

    nil

See Also:



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# File 'lib/bunny/channel.rb', line 839

def basic_ack(delivery_tag, multiple = false)
  guarding_against_stale_delivery_tags(delivery_tag) do
    raise_if_no_longer_open!
    @connection.send_frame(AMQ::Protocol::Basic::Ack.encode(@id, delivery_tag, multiple))

    nil
  end
end

#basic_cancel(consumer_tag) ⇒ AMQ::Protocol::Basic::CancelOk

Removes a consumer. Messages for this consumer will no longer be delivered. If the queue it was on is auto-deleted and this consumer was the last one, the queue will be deleted.

Parameters:

  • consumer_tag (String) —

    Consumer tag (unique identifier) to cancel

Returns:

  • (AMQ::Protocol::Basic::CancelOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1034

def basic_cancel(consumer_tag)
  @connection.send_frame(AMQ::Protocol::Basic::Cancel.encode(@id, consumer_tag, false))

  with_continuation_timeout do
    @last_basic_cancel_ok = wait_on_continuations
  end

  # reduces thread usage for channels that don't have any
  # consumers
  @work_pool.shutdown(true) unless self.any_consumers?

  @last_basic_cancel_ok
end

#basic_consume(queue, consumer_tag = generate_consumer_tag, no_ack = false, exclusive = false, arguments = nil, &block) ⇒ AMQ::Protocol::Basic::ConsumeOk Also known as: consume

Registers a consumer for queue. Delivered messages will be handled with the block provided to this method.

Parameters:

  • queue (String, Bunny::Queue) —

    Queue to consume from

  • consumer_tag (String) (defaults to: generate_consumer_tag) —

    Consumer tag (unique identifier), generated by Bunny by default

  • no_ack (Boolean) (defaults to: false) —

    (false) If true, delivered messages will be automatically acknowledged. If false, manual acknowledgements will be necessary.

  • exclusive (Boolean) (defaults to: false) —

    (false) Should this consumer be exclusive?

  • arguments (Hash) (defaults to: nil) —

    (nil) Optional arguments that may be used by RabbitMQ extensions, etc

Returns:

  • (AMQ::Protocol::Basic::ConsumeOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 926

def basic_consume(queue, consumer_tag = generate_consumer_tag, no_ack = false, exclusive = false, arguments = nil, &block)
  raise_if_no_longer_open!
  maybe_start_consumer_work_pool!

  queue_name = if queue.respond_to?(:name)
                 queue.name
               else
                 queue
               end

  # helps avoid race condition between basic.consume-ok and basic.deliver if there are messages
  # in the queue already. MK.
  if consumer_tag && consumer_tag.strip != AMQ::Protocol::EMPTY_STRING
    add_consumer(queue_name, consumer_tag, no_ack, exclusive, arguments, &block)
  end

  @connection.send_frame(AMQ::Protocol::Basic::Consume.encode(@id,
      queue_name,
      consumer_tag,
      false,
      no_ack,
      exclusive,
      false,
      arguments))

  begin
    with_continuation_timeout do
      @last_basic_consume_ok = wait_on_continuations
    end
  rescue Exception => e
    # if basic.consume-ok never arrives, unregister the proactively
    # registered consumer. MK.
    unregister_consumer(@last_basic_consume_ok.consumer_tag)

    raise e
  end

  # in case there is another exclusive consumer and we get a channel.close
  # response here. MK.
  raise_if_channel_close!(@last_basic_consume_ok)

  # covers server-generated consumer tags
  add_consumer(queue_name, @last_basic_consume_ok.consumer_tag, no_ack, exclusive, arguments, &block)

  @last_basic_consume_ok
end

#basic_consume_with(consumer) ⇒ AMQ::Protocol::Basic::ConsumeOk Also known as: consume_with

Registers a consumer for queue as Bunny::Consumer instance.

Parameters:

  • consumer (Bunny::Consumer) —

    Consumer to register. It should already have queue name, consumer tag and other attributes set.

Returns:

  • (AMQ::Protocol::Basic::ConsumeOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 982

def basic_consume_with(consumer)
  raise_if_no_longer_open!
  maybe_start_consumer_work_pool!

  # helps avoid race condition between basic.consume-ok and basic.deliver if there are messages
  # in the queue already. MK.
  if consumer.consumer_tag && consumer.consumer_tag.strip != AMQ::Protocol::EMPTY_STRING
    register_consumer(consumer.consumer_tag, consumer)
  end

  @connection.send_frame(AMQ::Protocol::Basic::Consume.encode(@id,
      consumer.queue_name,
      consumer.consumer_tag,
      false,
      consumer.no_ack,
      consumer.exclusive,
      false,
      consumer.arguments))

  begin
    with_continuation_timeout do
      @last_basic_consume_ok = wait_on_continuations
    end
  rescue Exception => e
    # if basic.consume-ok never arrives, unregister the proactively
    # registered consumer. MK.
    unregister_consumer(@last_basic_consume_ok.consumer_tag)

    raise e
  end

  # in case there is another exclusive consumer and we get a channel.close
  # response here. MK.
  raise_if_channel_close!(@last_basic_consume_ok)

  # covers server-generated consumer tags
  register_consumer(@last_basic_consume_ok.consumer_tag, consumer)

  raise_if_continuation_resulted_in_a_channel_error!

  @last_basic_consume_ok
end

#basic_get(queue, opts = {:manual_ack => true}) ⇒ Array

Synchronously fetches a message from the queue, if there are any. This method is for cases when the convenience of synchronous operations is more important than throughput.

Examples:

Using Bunny::Channel#basic_get with manual acknowledgements

conn = Bunny.new
conn.start
ch   = conn.create_channel
# here we assume the queue already exists and has messages
delivery_info, properties, payload = ch.basic_get("bunny.examples.queue1", :manual_ack => true)
ch.acknowledge(delivery_info.delivery_tag)

Parameters:

  • queue (String) —

    Queue name

  • opts (Hash) (defaults to: {:manual_ack => true}) —

    Options

Options Hash (opts):

  • :ack (Boolean) — default: true —

    [DEPRECATED] Use :manual_ack instead

  • :manual_ack (Boolean) — default: true —

    Will this message be acknowledged manually?

Returns:

  • (Array) —

    A triple of delivery info, message properties and message content

See Also:



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# File 'lib/bunny/channel.rb', line 666

def basic_get(queue, opts = {:manual_ack => true})
  raise_if_no_longer_open!

  unless opts[:ack].nil?
    warn "[DEPRECATION] `:ack` is deprecated.  Please use `:manual_ack` instead."
    opts[:manual_ack] = opts[:ack]
  end

  @connection.send_frame(AMQ::Protocol::Basic::Get.encode(@id, queue, !(opts[:manual_ack])))
  # this is a workaround for the edge case when basic_get is called in a tight loop
  # and network goes down we need to perform recovery. The problem is, basic_get will
  # keep blocking the thread that calls it without clear way to constantly unblock it
  # from the network activity loop (where recovery happens) with the current continuations
  # implementation (and even more correct and convenient ones, such as wait/notify, should
  # we implement them). So we return a triple of nils immediately which apps should be
  # able to handle anyway as "got no message, no need to act". MK.
  last_basic_get_response = if @connection.open?
                              begin
                                wait_on_basic_get_continuations
                              rescue Timeout::Error => e
                                raise_if_continuation_resulted_in_a_channel_error!
                                raise e
                              end
                            else
                              [nil, nil, nil]
                            end

  raise_if_continuation_resulted_in_a_channel_error!
  last_basic_get_response
end

#basic_nack(delivery_tag, multiple = false, requeue = false) ⇒ NilClass

Rejects or requeues messages just like #basic_reject but can do so with multiple messages at once.

Examples:

Requeue a message

conn  = Bunny.new
conn.start

ch    = conn.create_channel
q.subscribe do |delivery_info, properties, payload|
  # requeue the message
  ch.basic_nack(delivery_info.delivery_tag, false, true)
end

Reject a message

conn  = Bunny.new
conn.start

ch    = conn.create_channel
q.subscribe do |delivery_info, properties, payload|
  # requeue the message
  ch.basic_nack(delivery_info.delivery_tag)
end

Requeue a message fetched via basic.get

conn  = Bunny.new
conn.start

ch    = conn.create_channel
# we assume the queue exists and has messages
delivery_info, properties, payload = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
ch.basic_nack(delivery_info.delivery_tag, false, true)

Requeue multiple messages fetched via basic.get

conn  = Bunny.new
conn.start

ch    = conn.create_channel
# we assume the queue exists and has messages
_, _, payload1 = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
_, _, payload2 = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
delivery_info, properties, payload3 = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
# requeue all fetched messages up to payload3
ch.basic_nack(delivery_info.delivery_tag, true, true)

Parameters:

  • delivery_tag (Integer) —

    Delivery tag obtained from delivery info

  • requeue (Boolean) (defaults to: false) —

    Should the message be requeued?

  • multiple (Boolean) (defaults to: false) —

    Should all deliveries up to this one be rejected/requeued?

Returns:

  • (NilClass) —

    nil

See Also:



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# File 'lib/bunny/channel.rb', line 901

def basic_nack(delivery_tag, multiple = false, requeue = false)
  guarding_against_stale_delivery_tags(delivery_tag) do
    raise_if_no_longer_open!
    @connection.send_frame(AMQ::Protocol::Basic::Nack.encode(@id,
                                                             delivery_tag,
                                                             multiple,
                                                             requeue))

    nil
  end
end

#basic_publish(payload, exchange, routing_key, opts = {}) ⇒ Bunny::Channel

Publishes a message using basic.publish AMQP 0.9.1 method.

Parameters:

  • payload (String) —

    Message payload. It will never be modified by Bunny or RabbitMQ in any way.

  • exchange (String) —

    Exchange to publish to

  • routing_key (String) —

    Routing key

  • opts (Hash) (defaults to: {}) —

    Publishing options

Options Hash (opts):

  • :persistent (Boolean) —

    Should the message be persisted to disk?

  • :mandatory (Boolean) —

    Should the message be returned if it cannot be routed to any queue?

  • :timestamp (Integer) —

    A timestamp associated with this message

  • :expiration (Integer) —

    Expiration time after which the message will be deleted

  • :type (String) —

    Message type, e.g. what type of event or command this message represents. Can be any string

  • :reply_to (String) —

    Queue name other apps should send the response to

  • :content_type (String) —

    Message content type (e.g. application/json)

  • :content_encoding (String) —

    Message content encoding (e.g. gzip)

  • :correlation_id (String) —

    Message correlated to this one, e.g. what request this message is a reply for

  • :priority (Integer) —

    Message priority, 0 to 9. Not used by RabbitMQ, only applications

  • :message_id (String) —

    Any message identifier

  • :user_id (String) —

    Optional user ID. Verified by RabbitMQ against the actual connection username

  • :app_id (String) —

    Optional application ID

Returns:

Raises:

  • (ArgumentError) 


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# File 'lib/bunny/channel.rb', line 604

def basic_publish(payload, exchange, routing_key, opts = {})
  raise_if_no_longer_open!
  raise ArgumentError, "routing key cannot be longer than #{SHORTSTR_LIMIT} characters" if routing_key && routing_key.size > SHORTSTR_LIMIT

  exchange_name = if exchange.respond_to?(:name)
                    exchange.name
                  else
                    exchange
                  end

  mode = if opts.fetch(:persistent, true)
           2
         else
           1
         end

  opts[:delivery_mode] ||= mode
  opts[:content_type]  ||= DEFAULT_CONTENT_TYPE
  opts[:priority]      ||= 0

  if @next_publish_seq_no > 0
    @unconfirmed_set_mutex.synchronize do
      @unconfirmed_set.add(@next_publish_seq_no)
      @next_publish_seq_no += 1
    end
  end

  frames = AMQ::Protocol::Basic::Publish.encode(@id,
    payload,
    opts,
    exchange_name,
    routing_key,
    opts[:mandatory],
    false,
    @connection.frame_max)
  @connection.send_frameset(frames, self)

  self
end

#basic_qos(count, global = false) ⇒ AMQ::Protocol::Basic::QosOk Also known as: prefetch

Controls message delivery rate using basic.qos AMQP 0.9.1 method.

Parameters:

  • prefetch_count (Integer) —

    How many messages can consumers on this channel be given at a time (before they have to acknowledge or reject one of the earlier received messages)

  • global (Boolean) (defaults to: false) —

    Whether to use global mode for prefetch:

    • +false+: per-consumer
    • +true+: per-channel Note that the default value (+false+) hasn't actually changed, but previous documentation described that as meaning per-channel and unsupported in RabbitMQ, whereas it now actually appears to mean per-consumer and supported (https://www.rabbitmq.com/consumer-prefetch.html).

Returns:

  • (AMQ::Protocol::Basic::QosOk) —

    RabbitMQ response

Raises:

  • (ArgumentError)

See Also:



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# File 'lib/bunny/channel.rb', line 717

def basic_qos(count, global = false)
  raise ArgumentError.new("prefetch count must be a positive integer, given: #{count}") if count < 0
  raise ArgumentError.new("prefetch count must be no greater than #{MAX_PREFETCH_COUNT}, given: #{count}") if count > MAX_PREFETCH_COUNT
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Basic::Qos.encode(@id, 0, count, global))

  with_continuation_timeout do
    @last_basic_qos_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @prefetch_count  = count
  @prefetch_global = global

  @last_basic_qos_ok
end

#basic_recover(requeue) ⇒ AMQ::Protocol::Basic::RecoverOk

Redeliver unacknowledged messages

Parameters:

  • requeue (Boolean) —

    Should messages be requeued?

Returns:

  • (AMQ::Protocol::Basic::RecoverOk) —

    RabbitMQ response



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# File 'lib/bunny/channel.rb', line 741

def basic_recover(requeue)
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Basic::Recover.encode(@id, requeue))
  with_continuation_timeout do
    @last_basic_recover_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_basic_recover_ok
end

#basic_reject(delivery_tag, requeue = false) ⇒ NilClass

Rejects or requeues a message.

Examples:

Requeue a message

conn  = Bunny.new
conn.start

ch    = conn.create_channel
q.subscribe do |delivery_info, properties, payload|
  # requeue the message
  ch.basic_reject(delivery_info.delivery_tag, true)
end

Reject a message

conn  = Bunny.new
conn.start

ch    = conn.create_channel
q.subscribe do |delivery_info, properties, payload|
  # reject the message
  ch.basic_reject(delivery_info.delivery_tag, false)
end

Requeue a message fetched via basic.get

conn  = Bunny.new
conn.start

ch    = conn.create_channel
# we assume the queue exists and has messages
delivery_info, properties, payload = ch.basic_get("bunny.examples.queue3", :manual_ack => true)
ch.basic_reject(delivery_info.delivery_tag, true)

Parameters:

  • delivery_tag (Integer) —

    Delivery tag obtained from delivery info

  • requeue (Boolean) (defaults to: false) —

    Should the message be requeued?

Returns:

  • (NilClass) —

    nil

See Also:



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# File 'lib/bunny/channel.rb', line 791

def basic_reject(delivery_tag, requeue = false)
  guarding_against_stale_delivery_tags(delivery_tag) do
    raise_if_no_longer_open!
    @connection.send_frame(AMQ::Protocol::Basic::Reject.encode(@id, delivery_tag, requeue))

    nil
  end
end

#channel_flow(active) ⇒ AMQ::Protocol::Channel::FlowOk

Note:

Recent (e.g. 2.8.x., 3.x) RabbitMQ will employ TCP/IP-level back pressure on publishers if it detects that consumers do not keep up with them.

Enables or disables message flow for the channel. When message flow is disabled, no new messages will be delivered to consumers on this channel. This is typically used by consumers that cannot keep up with the influx of messages.

Returns:

  • (AMQ::Protocol::Channel::FlowOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1398

def channel_flow(active)
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Channel::Flow.encode(@id, active))
  with_continuation_timeout do
    @last_channel_flow_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_channel_flow_ok
end

#client ⇒ Bunny::Session

Returns Connection this channel was opened on.

Returns:



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# File 'lib/bunny/channel.rb', line 287

def client
  @connection
end

#close ⇒ Object

Closes the channel. Closed channels can no longer be used (this includes associated Queue, Exchange and Bunny::Consumer instances.



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# File 'lib/bunny/channel.rb', line 250

def close
  # see bunny#528
  raise_if_no_longer_open!

  @connection.close_channel(self)
  @status = :closed
  @work_pool.shutdown
  maybe_kill_consumer_work_pool!
end

#closed? ⇒ Boolean

Returns true if this channel is closed (manually or because of an exception), false otherwise.

Returns:

  • (Boolean) —

    true if this channel is closed (manually or because of an exception), false otherwise



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# File 'lib/bunny/channel.rb', line 268

def closed?
  @status == :closed
end

#confirm_select(callback = nil) ⇒ AMQ::Protocol::Confirm::SelectOk

Enables publisher confirms for the channel.

Returns:

  • (AMQ::Protocol::Confirm::SelectOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1487

def confirm_select(callback = nil)
  raise_if_no_longer_open!

  if @next_publish_seq_no == 0
    @confirms_continuations = new_continuation
    @unconfirmed_set        = Set.new
    @nacked_set             = Set.new
    @next_publish_seq_no    = 1
    @only_acks_received = true
  end

  @confirms_callback = callback

  @connection.send_frame(AMQ::Protocol::Confirm::Select.encode(@id, false))
  with_continuation_timeout do
    @last_confirm_select_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!
  @last_confirm_select_ok
end

#default_exchange ⇒ Object

Provides access to the default exchange

See Also:



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# File 'lib/bunny/channel.rb', line 380

def default_exchange
  @default_exchange ||= Exchange.default(self)
end

#direct(name, opts = {}) ⇒ Bunny::Exchange

Declares a direct exchange or looks it up in the cache of previously declared exchanges.

Parameters:

  • name (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Exchange parameters

Options Hash (opts):

  • :durable (Boolean) — default: false —

    Should the exchange be durable?

  • :auto_delete (Boolean) — default: false —

    Should the exchange be automatically deleted when no longer in use?

  • :arguments (Hash) — default: {} —

    Optional exchange arguments (used by RabbitMQ extensions)

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 337

def direct(name, opts = {})
  find_exchange(name) || Exchange.new(self, :direct, name, opts)
end

#durable_queue(name, type = "classic", opts = {}) ⇒ Bunny::Queue

Declares a new server-named queue that is automatically deleted when the connection is closed.

Parameters:

  • name (String) —

    Queue name. Empty (server-generated) names are not supported by this method.

  • opts (Hash) (defaults to: {}) —

    Queue properties and other options. Durability, exclusivity, auto-deletion options will be ignored.

Options Hash (opts):

  • :arguments (Hash) — default: {} —

    Additional optional arguments (typically used by RabbitMQ extensions and plugins)

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 480

def durable_queue(name, type = "classic", opts = {})
  throw ArgumentError.new("queue name must not be nil") if name.nil?
  throw ArgumentError.new("queue name must not be empty (server-named durable queues do not make sense)") if name.empty?

  final_opts = opts.merge({
    :type        => type,
    :durable     => true,
    # exclusive or auto-delete QQs do not make much sense
    :exclusive   => false,
    :auto_delete => false
  })
  q = find_queue(name) || Bunny::Queue.new(self, name, final_opts)

  register_queue(q)
end

#exchange(name, opts = {}) ⇒ Bunny::Exchange

Declares a headers exchange or looks it up in the cache of previously declared exchanges.

Parameters:

  • name (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Exchange parameters

Options Hash (opts):

  • :type (String, Symbol) — default: :direct —

    Exchange type, e.g. :fanout or "x-consistent-hash"

  • :durable (Boolean) — default: false —

    Should the exchange be durable?

  • :auto_delete (Boolean) — default: false —

    Should the exchange be automatically deleted when no longer in use?

  • :arguments (Hash) — default: {} —

    Optional exchange arguments

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 398

def exchange(name, opts = {})
  find_exchange(name) || Exchange.new(self, opts.fetch(:type, :direct), name, opts)
end

#exchange_bind(source, destination, opts = {}) ⇒ AMQ::Protocol::Exchange::BindOk

Binds an exchange to another exchange using exchange.bind AMQP 0.9.1 extension that RabbitMQ provides.

Parameters:

  • source (String) —

    Source exchange name

  • destination (String) —

    Destination exchange name

  • opts (Hash) (defaults to: {}) —

    Options

Options Hash (opts):

  • routing_key (String) — default: nil —

    Routing key used for binding

  • arguments (Hash) — default: {} —

    Optional arguments

Returns:

  • (AMQ::Protocol::Exchange::BindOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1309

def exchange_bind(source, destination, opts = {})
  raise_if_no_longer_open!

  source_name = if source.respond_to?(:name)
                  source.name
                else
                  source
                end

  destination_name = if destination.respond_to?(:name)
                       destination.name
                     else
                       destination
                     end

  @connection.send_frame(AMQ::Protocol::Exchange::Bind.encode(@id,
      destination_name,
      source_name,
      opts[:routing_key],
      false,
      opts[:arguments]))
  with_continuation_timeout do
    @last_exchange_bind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_bind_ok
end

#exchange_declare(name, type, opts = {}) ⇒ AMQ::Protocol::Exchange::DeclareOk

Declares a exchange using exchange.declare AMQP 0.9.1 method.

Parameters:

  • name (String) —

    The name of the exchange. Note that LF and CR characters will be stripped from the value.

  • type (String, Symbol) —

    Exchange type, e.g. :fanout or :topic

  • opts (Hash) (defaults to: {}) —

    Exchange properties

Options Hash (opts):

  • durable (Boolean) — default: false —

    Should information about this exchange be persisted to disk so that it can survive broker restarts? Typically set to true for long-lived exchanges.

  • auto_delete (Boolean) — default: false —

    Should this exchange be deleted when it is no longer used?

  • passive (Boolean) — default: false —

    If true, exchange will be checked for existence. If it does not exist, NotFound will be raised.

Returns:

  • (AMQ::Protocol::Exchange::DeclareOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1246

def exchange_declare(name, type, opts = {})
  raise_if_no_longer_open!

  # strip trailing new line and carriage returns
  # just like RabbitMQ does
  safe_name = name.gsub(/[\r\n]/, "")
  @connection.send_frame(AMQ::Protocol::Exchange::Declare.encode(@id,
      safe_name,
      type.to_s,
      opts.fetch(:passive, false),
      opts.fetch(:durable, false),
      opts.fetch(:auto_delete, false),
      opts.fetch(:internal, false),
      false, # nowait
      opts[:arguments]))
  with_continuation_timeout do
    @last_exchange_declare_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_declare_ok
end

#exchange_delete(name, opts = {}) ⇒ AMQ::Protocol::Exchange::DeleteOk

Deletes a exchange using exchange.delete AMQP 0.9.1 method

Parameters:

  • name (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Options

Options Hash (opts):

  • if_unused (Boolean) — default: false —

    Should this exchange be deleted only if it is no longer used

Returns:

  • (AMQ::Protocol::Exchange::DeleteOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1279

def exchange_delete(name, opts = {})
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Exchange::Delete.encode(@id,
      name,
      opts[:if_unused],
      false))
  with_continuation_timeout do
    @last_exchange_delete_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_delete_ok
end

#exchange_unbind(source, destination, opts = {}) ⇒ AMQ::Protocol::Exchange::UnbindOk

Unbinds an exchange from another exchange using exchange.unbind AMQP 0.9.1 extension that RabbitMQ provides.

Parameters:

  • source (String) —

    Source exchange name

  • destination (String) —

    Destination exchange name

  • opts (Hash) (defaults to: {}) —

    Options

Options Hash (opts):

  • routing_key (String) — default: nil —

    Routing key used for binding

  • arguments (Hash) — default: {} —

    Optional arguments

Returns:

  • (AMQ::Protocol::Exchange::UnbindOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1353

def exchange_unbind(source, destination, opts = {})
  raise_if_no_longer_open!

  source_name = if source.respond_to?(:name)
                  source.name
                else
                  source
                end

  destination_name = if destination.respond_to?(:name)
                       destination.name
                     else
                       destination
                     end

  @connection.send_frame(AMQ::Protocol::Exchange::Unbind.encode(@id,
      destination_name,
      source_name,
      opts[:routing_key],
      false,
      opts[:arguments]))
  with_continuation_timeout do
    @last_exchange_unbind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_unbind_ok
end

#fanout(name, opts = {}) ⇒ Bunny::Exchange

Declares a fanout exchange or looks it up in the cache of previously declared exchanges.

Parameters:

  • name (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Exchange parameters

Options Hash (opts):

  • :durable (Boolean) — default: false —

    Should the exchange be durable?

  • :auto_delete (Boolean) — default: false —

    Should the exchange be automatically deleted when no longer in use?

  • :arguments (Hash) — default: {} —

    Optional exchange arguments (used by RabbitMQ extensions)

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 319

def fanout(name, opts = {})
  find_exchange(name) || Exchange.new(self, :fanout, name, opts)
end

#flow(active) ⇒ Object

Flow control. When set to false, RabbitMQ will stop delivering messages on this channel.

Parameters:

  • active (Boolean) —

    Should messages to consumers on this channel be delivered?



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# File 'lib/bunny/channel.rb', line 516

def flow(active)
  channel_flow(active)
end

#generate_consumer_tag(name = "bunny") ⇒ String

Unique string supposed to be used as a consumer tag.

Returns:

  • (String) —

    Unique string.



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# File 'lib/bunny/channel.rb', line 1538

def generate_consumer_tag(name = "bunny")
  "#{name}-#{Time.now.to_i * 1000}-#{Kernel.rand(999_999_999_999)}"
end

#headers(name, opts = {}) ⇒ Bunny::Exchange

Declares a headers exchange or looks it up in the cache of previously declared exchanges.

Parameters:

  • name (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Exchange parameters

Options Hash (opts):

  • :durable (Boolean) — default: false —

    Should the exchange be durable?

  • :auto_delete (Boolean) — default: false —

    Should the exchange be automatically deleted when no longer in use?

  • :arguments (Hash) — default: {} —

    Optional exchange arguments

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 373

def headers(name, opts = {})
  find_exchange(name) || Exchange.new(self, :headers, name, opts)
end

#inspect ⇒ Object 



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# File 'lib/bunny/channel.rb', line 1679

def inspect
  to_s
end

#nack(delivery_tag, multiple = false, requeue = false) ⇒ Object

Rejects a message. A rejected message can be requeued or dropped by RabbitMQ. This method is similar to #reject but supports rejecting multiple messages at once, and is usually preferred.

Parameters:

  • delivery_tag (Integer) —

    Delivery tag to reject

  • multiple (Boolean) (defaults to: false) —

    (false) Should all unacknowledged messages up to this be rejected as well?

  • requeue (Boolean) (defaults to: false) —

    (false) Should this message be requeued instead of dropping it?

See Also:



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# File 'lib/bunny/channel.rb', line 568

def nack(delivery_tag, multiple = false, requeue = false)
  basic_nack(delivery_tag.to_i, multiple, requeue)
end

#number ⇒ Integer

Returns Channel id.

Returns:

  • (Integer) —

    Channel id



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# File 'lib/bunny/channel.rb', line 277

def number
  self.id
end

#on_error(&block) ⇒ Object

Defines a handler for errors that are not responses to a particular operations (e.g. basic.ack, basic.reject, basic.nack).



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# File 'lib/bunny/channel.rb', line 1553

def on_error(&block)
  @on_error = block
end

#on_uncaught_exception(&block) ⇒ Object

Defines a handler for uncaught exceptions in consumers (e.g. delivered message handlers).



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# File 'lib/bunny/channel.rb', line 1561

def on_uncaught_exception(&block)
  @uncaught_exception_handler = block
end

#open ⇒ Bunny::Channel

Opens the channel and resets its internal state

Returns:



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# File 'lib/bunny/channel.rb', line 233

def open
  @threads_waiting_on_continuations           = Set.new
  @threads_waiting_on_confirms_continuations  = Set.new
  @threads_waiting_on_basic_get_continuations = Set.new

  @connection.open_channel(self)
  # clear last channel error
  @last_channel_error = nil

  @status = :open

  self
end

#open? ⇒ Boolean

Returns true if this channel is open, false otherwise.

Returns:

  • (Boolean) —

    true if this channel is open, false otherwise



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# File 'lib/bunny/channel.rb', line 262

def open?
  @status == :open
end

#queue(name = AMQ::Protocol::EMPTY_STRING, opts = {}) ⇒ Bunny::Queue

Declares a queue or looks it up in the per-channel cache.

Parameters:

  • name (String) (defaults to: AMQ::Protocol::EMPTY_STRING) —

    Queue name. Pass an empty string to declare a server-named queue (make RabbitMQ generate a unique name).

  • opts (Hash) (defaults to: {}) —

    Queue properties and other options

Options Hash (opts):

  • :durable (Boolean) — default: false —

    Should this queue be durable?

  • :auto-delete (Boolean) — default: false —

    Should this queue be automatically deleted when the last consumer disconnects?

  • :exclusive (Boolean) — default: false —

    Should this queue be exclusive (only can be used by this connection, removed when the connection is closed)?

  • :arguments (Hash) — default: {} —

    Additional optional arguments (typically used by RabbitMQ extensions and plugins)

Returns:

  • (Bunny::Queue) —

    Queue that was declared or looked up in the cache

See Also:



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# File 'lib/bunny/channel.rb', line 421

def queue(name = AMQ::Protocol::EMPTY_STRING, opts = {})
  throw ArgumentError.new("queue name must not be nil") if name.nil?

  q = find_queue(name) || Bunny::Queue.new(self, name, opts)

  register_queue(q)
end

#queue_bind(name, exchange, opts = {}) ⇒ AMQ::Protocol::Queue::BindOk

Binds a queue to an exchange using queue.bind AMQP 0.9.1 method

Parameters:

  • name (String) —

    Queue name

  • exchange (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Options

Options Hash (opts):

  • routing_key (String) — default: nil —

    Routing key used for binding

  • arguments (Hash) — default: {} —

    Optional arguments

Returns:

  • (AMQ::Protocol::Queue::BindOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1167

def queue_bind(name, exchange, opts = {})
  raise_if_no_longer_open!

  exchange_name = if exchange.respond_to?(:name)
                    exchange.name
                  else
                    exchange
                  end

  @connection.send_frame(AMQ::Protocol::Queue::Bind.encode(@id,
      name,
      exchange_name,
      (opts[:routing_key] || opts[:key]),
      false,
      opts[:arguments]))
  with_continuation_timeout do
    @last_queue_bind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_queue_bind_ok
end

#queue_declare(name, opts = {}) ⇒ AMQ::Protocol::Queue::DeclareOk

Declares a queue using queue.declare AMQP 0.9.1 method.

Parameters:

  • name (String) —

    The name of the queue or an empty string to let RabbitMQ generate a name. Note that LF and CR characters will be stripped from the value.

  • opts (Hash) (defaults to: {}) —

    Queue properties

Options Hash (opts):

  • durable (Boolean) — default: false —

    Should information about this queue be persisted to disk so that it can survive broker restarts? Typically set to true for long-lived queues.

  • auto_delete (Boolean) — default: false —

    Should this queue be deleted when the last consumer is cancelled?

  • exclusive (Boolean) — default: false —

    Should only this connection be able to use this queue? If true, the queue will be automatically deleted when this connection is closed

  • passive (Boolean) — default: false —

    If true, queue will be checked for existence. If it does not exist, NotFound will be raised.

Returns:

  • (AMQ::Protocol::Queue::DeclareOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1077

def queue_declare(name, opts = {})
  raise_if_no_longer_open!

  # strip trailing new line and carriage returns
  # just like RabbitMQ does
  safe_name = name.gsub(/[\r\n]/, "")
  @pending_queue_declare_name = safe_name
  @connection.send_frame(
    AMQ::Protocol::Queue::Declare.encode(@id,
      @pending_queue_declare_name,
      opts.fetch(:passive, false),
      opts.fetch(:durable, false),
      opts.fetch(:exclusive, false),
      opts.fetch(:auto_delete, false),
      false,
      opts[:arguments]))

  begin
    with_continuation_timeout do
      @last_queue_declare_ok = wait_on_continuations
    end
  ensure
    # clear pending continuation context if it belongs to us
    @pending_queue_declare_name = nil if @pending_queue_declare_name == safe_name
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_queue_declare_ok
end

#queue_delete(name, opts = {}) ⇒ AMQ::Protocol::Queue::DeleteOk

Deletes a queue using queue.delete AMQP 0.9.1 method

Parameters:

  • name (String) —

    Queue name

  • opts (Hash) (defaults to: {}) —

    Options

Options Hash (opts):

  • if_unused (Boolean) — default: false —

    Should this queue be deleted only if it has no consumers?

  • if_empty (Boolean) — default: false —

    Should this queue be deleted only if it has no messages?

Returns:

  • (AMQ::Protocol::Queue::DeleteOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1118

def queue_delete(name, opts = {})
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Queue::Delete.encode(@id,
      name,
      opts[:if_unused],
      opts[:if_empty],
      false))
  with_continuation_timeout do
    @last_queue_delete_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_queue_delete_ok
end

#queue_purge(name, opts = {}) ⇒ AMQ::Protocol::Queue::PurgeOk

Purges a queue (removes all messages from it) using queue.purge AMQP 0.9.1 method.

Parameters:

  • name (String) —

    Queue name

Returns:

  • (AMQ::Protocol::Queue::PurgeOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1141

def queue_purge(name, opts = {})
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Queue::Purge.encode(@id, name, false))

  with_continuation_timeout do
    @last_queue_purge_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_queue_purge_ok
end

#queue_unbind(name, exchange, opts = {}) ⇒ AMQ::Protocol::Queue::UnbindOk

Unbinds a queue from an exchange using queue.unbind AMQP 0.9.1 method

Parameters:

  • name (String) —

    Queue name

  • exchange (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Options

Options Hash (opts):

  • routing_key (String) — default: nil —

    Routing key used for binding

  • arguments (Hash) — default: {} —

    Optional arguments

Returns:

  • (AMQ::Protocol::Queue::UnbindOk) —

    RabbitMQ response

See Also:



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# File 'lib/bunny/channel.rb', line 1203

def queue_unbind(name, exchange, opts = {})
  raise_if_no_longer_open!

  exchange_name = if exchange.respond_to?(:name)
                    exchange.name
                  else
                    exchange
                  end

  @connection.send_frame(AMQ::Protocol::Queue::Unbind.encode(@id,
      name,
      exchange_name,
      opts[:routing_key],
      opts[:arguments]))
  with_continuation_timeout do
    @last_queue_unbind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_queue_unbind_ok
end

#quorum_queue(name, opts = {}) ⇒ Bunny::Queue

Declares a new client-named quorum queue.

Parameters:

  • name (String) —

    Queue name. Empty (server-generated) names are not supported by this method.

  • opts (Hash) (defaults to: {}) —

    Queue properties and other options. Durability, exclusivity, auto-deletion options will be ignored.

Options Hash (opts):

  • :arguments (Hash) — default: {} —

    Additional optional arguments (typically used by RabbitMQ extensions and plugins)

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 440

def quorum_queue(name, opts = {})
  throw ArgumentError.new("quorum queue name must not be nil") if name.nil?
  throw ArgumentError.new("quorum queue name must not be empty (server-named QQs do not make sense)") if name.empty?

  durable_queue(name, Bunny::Queue::Types::QUORUM, opts)
end

#recover(ignored = true) ⇒ Object

Tells RabbitMQ to redeliver unacknowledged messages



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# File 'lib/bunny/channel.rb', line 522

def recover(ignored = true)
  # RabbitMQ only supports basic.recover with requeue = true
  basic_recover(true)
end

#recover_cancelled_consumers! ⇒ Object 



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# File 'lib/bunny/channel.rb', line 1662

def recover_cancelled_consumers!
  @recover_cancelled_consumers = true
end

#recover_confirm_mode ⇒ Object

Recovers publisher confirms mode. Used by the Automatic Network Failure Recovery feature. Set the offset to the previous publish sequence index as the protocol will reset the index to after recovery.



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# File 'lib/bunny/channel.rb', line 1602

def recover_confirm_mode
  if using_publisher_confirmations?
    @unconfirmed_set_mutex.synchronize do
      @unconfirmed_set.clear
      @delivery_tag_offset = @next_publish_seq_no - 1
    end
    confirm_select(@confirms_callback)
  end
end

#recover_consumers ⇒ Object

Recovers consumers. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1645

def recover_consumers
  unless @consumers.empty?
    @work_pool = ConsumerWorkPool.new(@work_pool.size, @work_pool.abort_on_exception)
    @work_pool.start
  end

  @consumer_mutex.synchronize { @consumers.values }.each do |c|
    c.recover_from_network_failure
  end
end

#recover_exchanges ⇒ Object

Recovers exchanges. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1624

def recover_exchanges
  @exchange_mutex.synchronize { @exchanges.values }.each do |x|
    x.recover_from_network_failure
  end
end

#recover_from_network_failure ⇒ Object

Recovers basic.qos setting, exchanges, queues and consumers. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1575

def recover_from_network_failure
  @logger.debug { "Recovering channel #{@id} after network failure" }
  release_all_continuations

  recover_prefetch_setting
  recover_confirm_mode
  recover_tx_mode
  recover_exchanges
  # this includes recovering bindings
  recover_queues
  recover_consumers
  increment_recoveries_counter
end

#recover_prefetch_setting ⇒ Object

Recovers basic.qos setting. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1593

def recover_prefetch_setting
  basic_qos(@prefetch_count, @prefetch_global) if @prefetch_count
end

#recover_queues ⇒ Object

Recovers queues and bindings. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1634

def recover_queues
  @queue_mutex.synchronize { @queues.values }.each do |q|
    @logger.debug { "Recovering queue #{q.name}" }
    q.recover_from_network_failure
  end
end

#recover_tx_mode ⇒ Object

Recovers transaction mode. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1616

def recover_tx_mode
  tx_select if @tx_mode
end

#recovers_cancelled_consumers? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/bunny/channel.rb', line 1667

def recovers_cancelled_consumers?
  !!@recover_cancelled_consumers
end

#reject(delivery_tag, requeue = false) ⇒ Object

Rejects a message. A rejected message can be requeued or dropped by RabbitMQ.

Parameters:

  • delivery_tag (Integer) —

    Delivery tag to reject

  • requeue (Boolean) (defaults to: false) —

    Should this message be requeued instead of dropping it?

See Also:



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# File 'lib/bunny/channel.rb', line 542

def reject(delivery_tag, requeue = false)
  basic_reject(delivery_tag.to_i, requeue)
end

#stream(name, opts = {}) ⇒ Bunny::Queue

Declares a new client-named stream (that Bunny can use as if it was a queue). Note that Bunny would still use AMQP 0-9-1 to perform operations on this "queue". To use stream-specific operations and to gain from stream protocol efficiency and partitioning, use a Ruby client for the RabbitMQ stream protocol.

Parameters:

  • name (String) —

    Stream name. Empty (server-generated) names are not supported by this method.

  • opts (Hash) (defaults to: {}) —

    Queue properties and other options. Durability, exclusivity, auto-deletion options will be ignored.

Options Hash (opts):

  • :arguments (Hash) — default: {} —

    Additional optional arguments (typically used by RabbitMQ extensions and plugins)

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 462

def stream(name, opts = {})
  throw ArgumentError.new("stream name must not be nil") if name.nil?
  throw ArgumentError.new("stream name must not be empty (server-named QQs do not make sense)") if name.empty?

  durable_queue(name, Bunny::Queue::Types::STREAM, opts)
end

#synchronize(&block) ⇒ Object

Synchronizes given block using this channel's mutex.



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# File 'lib/bunny/channel.rb', line 1530

def synchronize(&block)
  @publishing_mutex.synchronize(&block)
end

#temporary_queue(opts = {}) ⇒ Bunny::Queue

Declares a new server-named queue that is automatically deleted when the connection is closed.

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 502

def temporary_queue(opts = {})
  queue("", opts.merge(:exclusive => true))
end

#to_s ⇒ String

Returns Brief human-readable representation of the channel.

Returns:

  • (String) —

    Brief human-readable representation of the channel



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# File 'lib/bunny/channel.rb', line 1675

def to_s
  "#<#{self.class.name}:#{object_id} @id=#{self.number} @connection=#{@connection.to_s} @open=#{open?}>"
end

#topic(name, opts = {}) ⇒ Bunny::Exchange

Declares a topic exchange or looks it up in the cache of previously declared exchanges.

Parameters:

  • name (String) —

    Exchange name

  • opts (Hash) (defaults to: {}) —

    Exchange parameters

Options Hash (opts):

  • :durable (Boolean) — default: false —

    Should the exchange be durable?

  • :auto_delete (Boolean) — default: false —

    Should the exchange be automatically deleted when no longer in use?

  • :arguments (Hash) — default: {} —

    Optional exchange arguments (used by RabbitMQ extensions)

Returns:

See Also:



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# File 'lib/bunny/channel.rb', line 355

def topic(name, opts = {})
  find_exchange(name) || Exchange.new(self, :topic, name, opts)
end

#tx_commit ⇒ AMQ::Protocol::Tx::CommitOk

Commits current transaction

Returns:

  • (AMQ::Protocol::Tx::CommitOk) —

    RabbitMQ response



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# File 'lib/bunny/channel.rb', line 1435

def tx_commit
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Tx::Commit.encode(@id))
  with_continuation_timeout do
    @last_tx_commit_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_tx_commit_ok
end

#tx_rollback ⇒ AMQ::Protocol::Tx::RollbackOk

Rolls back current transaction

Returns:

  • (AMQ::Protocol::Tx::RollbackOk) —

    RabbitMQ response



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# File 'lib/bunny/channel.rb', line 1450

def tx_rollback
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Tx::Rollback.encode(@id))
  with_continuation_timeout do
    @last_tx_rollback_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_tx_rollback_ok
end

#tx_select ⇒ AMQ::Protocol::Tx::SelectOk

Puts the channel into transaction mode (starts a transaction)

Returns:

  • (AMQ::Protocol::Tx::SelectOk) —

    RabbitMQ response



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# File 'lib/bunny/channel.rb', line 1419

def tx_select
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Tx::Select.encode(@id))
  with_continuation_timeout do
    @last_tx_select_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!
  @tx_mode = true

  @last_tx_select_ok
end

#using_publisher_confirmations? ⇒ Boolean Also known as: using_publisher_confirms?

Returns true if this channel has Publisher Confirms enabled, false otherwise.

Returns:

  • (Boolean) —

    true if this channel has Publisher Confirms enabled, false otherwise



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# File 'lib/bunny/channel.rb', line 1475

def using_publisher_confirmations?
  @next_publish_seq_no > 0
end

#using_tx? ⇒ Boolean

Returns true if this channel has transactions enabled.

Returns:

  • (Boolean) —

    true if this channel has transactions enabled



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# File 'lib/bunny/channel.rb', line 1463

def using_tx?
  !!@tx_mode
end

#wait_for_confirms ⇒ Boolean

Blocks calling thread until confirms are received for all currently unacknowledged published messages. Returns immediately if there are no outstanding confirms.

Returns:

  • (Boolean) —

    true if all messages were acknowledged positively since the last time this method was called, false otherwise

See Also:



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# File 'lib/bunny/channel.rb', line 1518

def wait_for_confirms
  wait_on_confirms_continuations
  read_and_reset_only_acks_received
end