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:

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.

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:

conn = Bunny.new
conn.start

ch   = conn.create_channel

ch  = conn.create_channel
ch.close

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:

Constant Summary

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

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

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 169

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

  @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

  @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.message}"
  end
end

Instance Attribute Details

- (Bunny::Session) connection (readonly)

Returns AMQP connection this channel was opened on

Returns:



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# File 'lib/bunny/channel.rb', line 142

def connection
  @connection
end

- (Hash<String, Bunny::Consumer>) consumers (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 158

def consumers
  @consumers
end

- (Hash<String, Bunny::Exchange>) exchanges (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 152

def exchanges
  @exchanges
end

- (Integer) id

Returns Channel id

Returns:

  • (Integer)

    Channel id



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# File 'lib/bunny/channel.rb', line 140

def id
  @id
end

- (Set<Integer>) nacked_set (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 156

def nacked_set
  @nacked_set
end

- (Integer) next_publish_seq_no (readonly)

Returns Next publisher confirmations sequence index

Returns:

  • (Integer)

    Next publisher confirmations sequence index



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# File 'lib/bunny/channel.rb', line 148

def next_publish_seq_no
  @next_publish_seq_no
end

- (Integer) prefetch_count (readonly)

Returns active basic.qos prefetch value

Returns:

  • (Integer)

    active basic.qos prefetch value



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# File 'lib/bunny/channel.rb', line 161

def prefetch_count
  @prefetch_count
end

- (Hash<String, Bunny::Queue>) queues (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 150

def queues
  @queues
end

- (Object) recoveries_counter (readonly)

Returns the value of attribute recoveries_counter



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# File 'lib/bunny/channel.rb', line 205

def recoveries_counter
  @recoveries_counter
end

- (Symbol) status (readonly)

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

Returns:

  • (Symbol)

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



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# File 'lib/bunny/channel.rb', line 144

def status
  @status
end

- (Set<Integer>) unconfirmed_set (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 154

def unconfirmed_set
  @unconfirmed_set
end

- (Bunny::ConsumerWorkPool) work_pool (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 146

def work_pool
  @work_pool
end

Instance Method Details

- (Object) ack(delivery_tag, multiple = false) 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 466

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

- (Boolean) active

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 261

def active
  open?
end

- (Boolean) any_consumers?

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 935

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

- (NilClass) basic_ack(delivery_tag, multiple)

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)
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", :ack => true)
ch.basic_ack(delivery_info.delivery_tag)

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", :ack => true)
_, _, payload2 = ch.basic_get("bunny.examples.queue3", :ack => true)
delivery_info, properties, payload3 = ch.basic_get("bunny.examples.queue3", :ack => true)
# ack all fetched messages up to payload3
ch.basic_ack(delivery_info.delivery_tag, true)

Parameters:

  • delivery_tag (Integer)

    Delivery tag obtained from delivery info

  • multiple (Boolean)

    Should all deliveries up to this one be acknowledged?

Returns:

  • (NilClass)

    nil

See Also:



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# File 'lib/bunny/channel.rb', line 730

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

  nil
end

- (AMQ::Protocol::Basic::CancelOk) basic_cancel(consumer_tag)

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 921

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

  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_basic_cancel_ok = wait_on_continuations
  end

  maybe_kill_consumer_work_pool! unless any_consumers?

  @last_basic_cancel_ok
end

- (AMQ::Protocol::Basic::ConsumeOk) basic_consume(queue, consumer_tag = generate_consumer_tag, no_ack = false, exclusive = false, arguments = nil, &block) 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 813

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
    Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) 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

- (AMQ::Protocol::Basic::ConsumeOk) basic_consume_with(consumer) 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 869

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
    Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) 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

- (Array) basic_get(queue, opts = {:ack => true})

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", :ack => true)
ch.acknowledge(delivery_info.delivery_tag)

Parameters:

  • queue (String)

    Queue name

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

    Options

Options Hash (opts):

  • :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 582

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

  @connection.send_frame(AMQ::Protocol::Basic::Get.encode(@id, queue, !(opts[: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?
                               wait_on_basic_get_continuations
                             else
                               [nil, nil, nil]
                             end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_basic_get_response
end

- (NilClass) basic_nack(delivery_tag, multiple = false, requeue = false)

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", :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", :ack => true)
_, _, payload2 = ch.basic_get("bunny.examples.queue3", :ack => true)
delivery_info, properties, payload3 = ch.basic_get("bunny.examples.queue3", :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 790

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

  nil
end

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

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 521

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_without_timeout(frames, self)

  self
end

- (AMQ::Protocol::Basic::QosOk) basic_qos(count, global = false)

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)

    (false) Ignored, as it is not supported by RabbitMQ

Returns:

  • (AMQ::Protocol::Basic::QosOk)

    RabbitMQ response

Raises:

  • (ArgumentError)

See Also:



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# File 'lib/bunny/channel.rb', line 612

def basic_qos(count, global = false)
  raise ArgumentError.new("prefetch count must be a positive integer, given: #{prefetch_count}") if count < 0
  raise_if_no_longer_open!

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

  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_basic_qos_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @prefetch_count = count

  @last_basic_qos_ok
end

- (AMQ::Protocol::Basic::RecoverOk) basic_recover(requeue)

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 633

def basic_recover(requeue)
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Basic::Recover.encode(@id, requeue))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_basic_recover_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_basic_recover_ok
end

- (NilClass) basic_reject(delivery_tag, requeue)

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|
  # requeue 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", :ack => true)
ch.basic_reject(delivery_info.delivery_tag, true)

Parameters:

  • delivery_tag (Integer)

    Delivery tag obtained from delivery info

  • requeue (Boolean)

    Should the message be requeued?

Returns:

  • (NilClass)

    nil

See Also:



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# File 'lib/bunny/channel.rb', line 683

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

  nil
end

- (AMQ::Protocol::Channel::FlowOk) channel_flow(active)

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 1265

def channel_flow(active)
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Channel::Flow.encode(@id, active))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_channel_flow_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_channel_flow_ok
end

- (Bunny::Session) client

Returns Connection this channel was opened on

Returns:



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# File 'lib/bunny/channel.rb', line 266

def client
  @connection
end

- (Object) close

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 232

def close
  @connection.close_channel(self)
  closed!
  maybe_kill_consumer_work_pool!
end

- (Boolean) closed?

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 246

def closed?
  @status == :closed
end

- (AMQ::Protocol::Confirm::SelectOk) confirm_select(callback = nil)

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 1354

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
  end

  @confirms_callback = callback

  @connection.send_frame(AMQ::Protocol::Confirm::Select.encode(@id, false))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_confirm_select_ok = wait_on_continuations
  end
  @confirm_mode = true
  raise_if_continuation_resulted_in_a_channel_error!
  @last_confirm_select_ok
end

- (Object) default_exchange

Provides access to the default exchange



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# File 'lib/bunny/channel.rb', line 359

def default_exchange
  self.direct(AMQ::Protocol::EMPTY_STRING, :no_declare => true)
end

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

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 316

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

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

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 377

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

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

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 1176

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]))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_exchange_bind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_bind_ok
end

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

Declares a echange using echange.declare AMQP 0.9.1 method.

Parameters:

  • name (String)

    Exchange name

  • opts (Hash) (defaults to: {})

    Exchange properties

Options Hash (opts):

  • durable (Boolean) — default: false

    Should information about this echange 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 echange 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 1116

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

  @connection.send_frame(AMQ::Protocol::Exchange::Declare.encode(@id,
      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]))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_exchange_declare_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_declare_ok
end

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

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 1146

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

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

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_delete_ok
end

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

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 1220

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]))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_exchange_unbind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_exchange_unbind_ok
end

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

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 298

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

- (Object) flow(active)

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 427

def flow(active)
  channel_flow(active)
end

- (String) generate_consumer_tag(name = "bunny")

Unique string supposed to be used as a consumer tag.

Returns:

  • (String)

    Unique string.



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# File 'lib/bunny/channel.rb', line 1406

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

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

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 352

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

- (Object) nack(delivery_tag, multiple = false, requeue = false)

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 483

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

- (Integer) number

Returns Channel id

Returns:

  • (Integer)

    Channel id



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# File 'lib/bunny/channel.rb', line 256

def number
  self.id
end

- (Object) on_error(&block)

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 1421

def on_error(&block)
  @on_error = block
end

- (Object) on_uncaught_exception(&block)

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



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# File 'lib/bunny/channel.rb', line 1429

def on_uncaught_exception(&block)
  @uncaught_exception_handler = block
end

- (Bunny::Channel) open

Opens the channel and resets its internal state

Returns:



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# File 'lib/bunny/channel.rb', line 215

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

- (Boolean) open?

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 240

def open?
  @status == :open
end

- (Object) prefetch(count)

Sets how many messages will be given to consumers on this channel before they have to acknowledge or reject one of the previously consumed messages

Parameters:

  • prefetch_count (Integer)

    Prefetch (QoS setting) for this channel

See Also:



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# File 'lib/bunny/channel.rb', line 418

def prefetch(count)
  self.basic_qos(count, false)
end

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

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 (Boolean) — 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 400

def queue(name = AMQ::Protocol::EMPTY_STRING, opts = {})
  q = find_queue(name) || Bunny::Queue.new(self, name, opts)

  register_queue(q)
end

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

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 1039

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]))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_queue_bind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_queue_bind_ok
end

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

Declares a queue using queue.declare AMQP 0.9.1 method.

Parameters:

  • name (String)

    Queue name

  • 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 961

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

  @connection.send_frame(AMQ::Protocol::Queue::Declare.encode(@id,
      name,
      opts.fetch(:passive, false),
      opts.fetch(:durable, false),
      opts.fetch(:exclusive, false),
      opts.fetch(:auto_delete, false),
      false,
      opts[:arguments]))
  @last_queue_declare_ok = wait_on_continuations

  raise_if_continuation_resulted_in_a_channel_error!

  @last_queue_declare_ok
end

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

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 990

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))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_queue_delete_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_queue_delete_ok
end

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

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 1013

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

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

  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_queue_purge_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_queue_purge_ok
end

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

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 1075

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]))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_queue_unbind_ok = wait_on_continuations
  end

  raise_if_continuation_resulted_in_a_channel_error!
  @last_queue_unbind_ok
end

- (Object) recover(ignored = true)

Tells RabbitMQ to redeliver unacknowledged messages



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# File 'lib/bunny/channel.rb', line 433

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

- (Object) recover_cancelled_consumers!



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# File 'lib/bunny/channel.rb', line 1522

def recover_cancelled_consumers!
  @recover_cancelled_consumers = true
end

- (Object) recover_confirm_mode

Recovers publisher confirms mode. Used by the Automatic Network Failure Recovery feature.



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# File 'lib/bunny/channel.rb', line 1469

def recover_confirm_mode
  confirm_select if @confirm_mode
end

- (Object) recover_consumers

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



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# File 'lib/bunny/channel.rb', line 1506

def recover_consumers
  unless @consumers.empty?
    @work_pool = ConsumerWorkPool.new(@work_pool.size)
    @work_pool.start
  end
  @consumers.values.dup.each do |c|
    c.recover_from_network_failure
  end
end

- (Object) recover_exchanges

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



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# File 'lib/bunny/channel.rb', line 1485

def recover_exchanges
  @exchanges.values.dup.each do |x|
    x.recover_from_network_failure
  end
end

- (Object) recover_from_network_failure

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 1443

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

- (Object) recover_prefetch_setting

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



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# File 'lib/bunny/channel.rb', line 1461

def recover_prefetch_setting
  basic_qos(@prefetch_count) if @prefetch_count
end

- (Object) recover_queues

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



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# File 'lib/bunny/channel.rb', line 1495

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

- (Object) recover_tx_mode

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



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# File 'lib/bunny/channel.rb', line 1477

def recover_tx_mode
  tx_select if @tx_mode
end

- (Boolean) recovers_cancelled_consumers?

Returns:

  • (Boolean)


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# File 'lib/bunny/channel.rb', line 1527

def recovers_cancelled_consumers?
  !!@recover_cancelled_consumers
end

- (Object) reject(delivery_tag, requeue = false)

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 453

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

- (Object) synchronize(&block)

Synchronizes given block using this channel's mutex.



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

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

- (String) to_s

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 1535

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

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

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 334

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

- (AMQ::Protocol::Tx::CommitOk) tx_commit

Commits current transaction

Returns:

  • (AMQ::Protocol::Tx::CommitOk)

    RabbitMQ response



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# File 'lib/bunny/channel.rb', line 1302

def tx_commit
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Tx::Commit.encode(@id))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_tx_commit_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_tx_commit_ok
end

- (AMQ::Protocol::Tx::RollbackOk) tx_rollback

Rolls back current transaction

Returns:

  • (AMQ::Protocol::Tx::RollbackOk)

    RabbitMQ response



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# File 'lib/bunny/channel.rb', line 1317

def tx_rollback
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Tx::Rollback.encode(@id))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) do
    @last_tx_rollback_ok = wait_on_continuations
  end
  raise_if_continuation_resulted_in_a_channel_error!

  @last_tx_rollback_ok
end

- (AMQ::Protocol::Tx::SelectOk) tx_select

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 1286

def tx_select
  raise_if_no_longer_open!

  @connection.send_frame(AMQ::Protocol::Tx::Select.encode(@id))
  Bunny::Timeout.timeout(read_write_timeout, ClientTimeout) 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

- (Boolean) using_publisher_confirmations? 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 1342

def using_publisher_confirmations?
  @next_publish_seq_no > 0
end

- (Boolean) using_tx?

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 1330

def using_tx?
  !!@tx_mode
end

- (Boolean) wait_for_confirms

Blocks calling thread until confirms are received for all currently unacknowledged published messages.

Returns:

  • (Boolean)

    true if all messages were acknowledged positively, false otherwise

See Also:



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# File 'lib/bunny/channel.rb', line 1384

def wait_for_confirms
  @only_acks_received = true
  wait_on_confirms_continuations

  @only_acks_received
end