Class: Bunny::Queue

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

Overview

Represents AMQP 0.9.1 queue.

See Also:

Defined Under Namespace

Modules: Types, XArgs

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(channel, name = AMQ::Protocol::EMPTY_STRING, opts = {}) ⇒ Queue

Returns a new instance of Queue.

Parameters:

  • channel (Bunny::Channel) —

    Channel this queue will use.

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

    Queue name. Pass an empty string to make RabbitMQ generate a unique one.

  • opts (Hash) (defaults to: {}) —

    Queue properties

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)?

  • :type (String) — default: nil —

    Type of the declared queue (classic, quorum or stream)

  • :arguments (Hash) — default: nil —

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

See Also:



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# File 'lib/bunny/queue.rb', line 52

def initialize(channel, name = AMQ::Protocol::EMPTY_STRING, opts = {})
  # old Bunny versions pass a connection here. In that case,
  # we just use default channel from it. MK.
  @channel          = channel
  @name             = name
  @options          = self.class.add_default_options(name, opts)

  @durable          = @options[:durable]
  @exclusive        = @options[:exclusive]
  @server_named     = @name.empty?
  @auto_delete      = @options[:auto_delete]
  @type             = @options[:type]

  @arguments        = if @type and !@type.empty? then
    (@options[:arguments] || {}).merge({XArgs::QUEUE_TYPE => @type})
  else
    @options[:arguments]
  end
  verify_type!(@arguments)
  # reassigns updated and verified arguments because Bunny::Channel#declare_queue
  # accepts a map of options
  @options[:arguments] = @arguments

  @bindings         = Array.new

  @default_consumer = nil

  declare! unless opts[:no_declare]

  @channel.register_queue(self)
end

Instance Attribute Details

#channel ⇒ Bunny::Channel (readonly)

Returns Channel this queue uses.

Returns:



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# File 'lib/bunny/queue.rb', line 32

def channel
  @channel
end

#name ⇒ String (readonly)

Returns Queue name.

Returns:

  • (String) —

    Queue name



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# File 'lib/bunny/queue.rb', line 34

def name
  @name
end

#options ⇒ Hash (readonly)

Returns Options this queue was created with.

Returns:

  • (Hash) —

    Options this queue was created with



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# File 'lib/bunny/queue.rb', line 36

def options
  @options
end

Instance Method Details

#arguments ⇒ Hash

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

Returns:

  • (Hash) —

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



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# File 'lib/bunny/queue.rb', line 114

def arguments
  @arguments
end

#auto_delete? ⇒ Boolean

Returns true if this queue was declared as automatically deleted (deleted as soon as last consumer unbinds).

Returns:

  • (Boolean) —

    true if this queue was declared as automatically deleted (deleted as soon as last consumer unbinds).

See Also:



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# File 'lib/bunny/queue.rb', line 101

def auto_delete?
  @auto_delete
end

#bind(exchange, opts = {}) ⇒ Object

Binds queue to an exchange

Parameters:

  • exchange (Bunny::Exchange, String) —

    Exchange to bind to

  • opts (Hash) (defaults to: {}) —

    Binding properties

Options Hash (opts):

  • :routing_key (String) —

    Routing key

  • :arguments (Hash) — default: {} —

    Additional optional binding arguments

See Also:



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# File 'lib/bunny/queue.rb', line 138

def bind(exchange, opts = {})
  @channel.queue_bind(@name, exchange, opts)

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


  # store bindings for automatic recovery. We need to be very careful to
  # not cause an infinite rebinding loop here when we recover. MK.
  binding = { :exchange => exchange_name, :routing_key => (opts[:routing_key] || opts[:key]), :arguments => opts[:arguments] }
  @bindings.push(binding) unless @bindings.include?(binding)

  self
end

#consumer_count ⇒ Integer

Returns How many active consumers the queue has.

Returns:

  • (Integer) —

    How many active consumers the queue has



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# File 'lib/bunny/queue.rb', line 350

def consumer_count
  s = self.status
  s[:consumer_count]
end

#declare! ⇒ Object 



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# File 'lib/bunny/queue.rb', line 396

def declare!
  queue_declare_ok = @channel.queue_declare(@name, @options)
  @name = queue_declare_ok.queue
end

#delete(opts = {}) ⇒ Object

Deletes the queue

Parameters:

  • 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?

See Also:



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# File 'lib/bunny/queue.rb', line 320

def delete(opts = {})
  @channel.deregister_queue(self)
  @channel.queue_delete(@name, opts)
end

#durable? ⇒ Boolean

Returns true if this queue was declared as durable (will survive broker restart).

Returns:

  • (Boolean) —

    true if this queue was declared as durable (will survive broker restart).

See Also:



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# File 'lib/bunny/queue.rb', line 87

def durable?
  @durable
end

#exclusive? ⇒ Boolean

Returns true if this queue was declared as exclusive (limited to just one consumer).

Returns:

  • (Boolean) —

    true if this queue was declared as exclusive (limited to just one consumer)

See Also:



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# File 'lib/bunny/queue.rb', line 94

def exclusive?
  @exclusive
end

#inspect ⇒ Object 



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# File 'lib/bunny/queue.rb', line 123

def inspect
  to_s
end

#message_count ⇒ Integer

Returns How many messages the queue has ready (e.g. not delivered but not unacknowledged).

Returns:

  • (Integer) —

    How many messages the queue has ready (e.g. not delivered but not unacknowledged)



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# File 'lib/bunny/queue.rb', line 344

def message_count
  s = self.status
  s[:message_count]
end

#pop(opts = {:manual_ack => false}, &block) ⇒ Array Also known as: get

Returns Triple of delivery info, message properties and message content. If the queue is empty, all three will be nils.

Examples:

conn = Bunny.new
conn.start

ch   = conn.create_channel
q = ch.queue("test1")
x = ch.default_exchange
x.publish("Hello, everybody!", :routing_key => 'test1')

delivery_info, properties, payload = q.pop

puts "This is the message: " + payload + "\n\n"
conn.close

Parameters:

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

    Options

Options Hash (opts):

  • :ack (Boolean) — default: false —
    DEPRECATED

    Use :manual_ack instead

  • :manual_ack (Boolean) — default: false —

    Will the message be acknowledged manually?

Returns:

  • (Array) —

    Triple of delivery info, message properties and message content. If the queue is empty, all three will be nils.

See Also:



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# File 'lib/bunny/queue.rb', line 269

def pop(opts = {:manual_ack => false}, &block)
  unless opts[:ack].nil?
    warn "[DEPRECATION] `:ack` is deprecated.  Please use `:manual_ack` instead."
    opts[:manual_ack] = opts[:ack]
  end

  get_response, properties, content = @channel.basic_get(@name, opts)

  if block
    if properties
      di = GetResponse.new(get_response, @channel)
      mp = MessageProperties.new(properties)

      block.call(di, mp, content)
    else
      block.call(nil, nil, nil)
    end
  else
    if properties
      di = GetResponse.new(get_response, @channel)
      mp = MessageProperties.new(properties)
      [di, mp, content]
    else
      [nil, nil, nil]
    end
  end
end

#publish(payload, opts = {}) ⇒ Object

Publishes a message to the queue via default exchange. Takes the same arguments as Exchange#publish

See Also:



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# File 'lib/bunny/queue.rb', line 304

def publish(payload, opts = {})
  @channel.default_exchange.publish(payload, opts.merge(:routing_key => @name))

  self
end

#purge(opts = {}) ⇒ Object

Purges a queue (removes all messages from it)

See Also:



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# File 'lib/bunny/queue.rb', line 328

def purge(opts = {})
  @channel.queue_purge(@name, opts)

  self
end

#recover_bindings ⇒ Object 



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# File 'lib/bunny/queue.rb', line 382

def recover_bindings
  @bindings.each do |b|
    # TODO: inject and use logger
    # puts "Recovering binding #{b.inspect}"
    self.bind(b[:exchange], b)
  end
end

#recover_from_network_failure ⇒ Object 



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# File 'lib/bunny/queue.rb', line 360

def recover_from_network_failure
  if self.server_named?
    old_name = @name.dup
    @name    = AMQ::Protocol::EMPTY_STRING

    @channel.deregister_queue_named(old_name)
  end

  # TODO: inject and use logger
  # puts "Recovering queue #{@name}"
  begin
    declare! unless @options[:no_declare]

    @channel.register_queue(self)
  rescue Exception => e
    # TODO: inject and use logger
    puts "Caught #{e.inspect} while redeclaring and registering #{@name}!"
  end
  recover_bindings
end

#server_named? ⇒ Boolean

Returns true if this queue was declared as server named.

Returns:

  • (Boolean) —

    true if this queue was declared as server named.

See Also:



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# File 'lib/bunny/queue.rb', line 108

def server_named?
  @server_named
end

#status ⇒ Hash

Returns A hash with information about the number of queue messages and consumers.

Returns:

  • (Hash) —

    A hash with information about the number of queue messages and consumers

See Also:



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

def status
  queue_declare_ok = @channel.queue_declare(@name, @options.merge(:passive => true))
  {:message_count => queue_declare_ok.message_count,
    :consumer_count => queue_declare_ok.consumer_count}
end

#subscribe(opts = { :consumer_tag => @channel.generate_consumer_tag, :manual_ack => false, :exclusive => false, :block => false, :on_cancellation => nil }, &block) ⇒ Object

Adds a consumer to the queue (subscribes for message deliveries).

Parameters:

  • opts (Hash) (defaults to: { :consumer_tag => @channel.generate_consumer_tag, :manual_ack => false, :exclusive => false, :block => false, :on_cancellation => nil }) —

    Options

Options Hash (opts):

  • :ack (Boolean) — default: false —
    DEPRECATED

    Use :manual_ack instead

  • :manual_ack (Boolean) — default: false —

    Will this consumer use manual acknowledgements?

  • :exclusive (Boolean) — default: false —

    Should this consumer be exclusive for this queue?

  • :on_cancellation (#call) —

    Block to execute when this consumer is cancelled remotely (e.g. via the RabbitMQ Management plugin)

  • :consumer_tag (String) —

    Unique consumer identifier. It is usually recommended to let Bunny generate it for you.

  • :arguments (Hash) — default: {} —

    Additional (optional) arguments, typically used by RabbitMQ extensions

See Also:



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# File 'lib/bunny/queue.rb', line 195

def subscribe(opts = {
                :consumer_tag    => @channel.generate_consumer_tag,
                :manual_ack      => false,
                :exclusive       => false,
                :block           => false,
                :on_cancellation => nil
              }, &block)

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

  ctag       = opts.fetch(:consumer_tag, @channel.generate_consumer_tag)
  consumer   = Consumer.new(@channel,
                            self,
                            ctag,
                            !opts[:manual_ack],
                            opts[:exclusive],
                            opts[:arguments])

  consumer.on_delivery(&block)
  consumer.on_cancellation(&opts[:on_cancellation]) if opts[:on_cancellation]

  @channel.basic_consume_with(consumer)
  if opts[:block]
    # joins current thread with the consumers pool, will block
    # the current thread for as long as the consumer pool is active
    @channel.work_pool.join
  end

  consumer
end

#subscribe_with(consumer, opts = {:block => false}) ⇒ Object

Adds a consumer object to the queue (subscribes for message deliveries).

Parameters:

  • consumer (Bunny::Consumer) —

    a Consumer subclass that implements consumer interface

  • opts (Hash) (defaults to: {:block => false}) —

    Options

Options Hash (opts):

  • block (Boolean) — default: false —

    Should the call block calling thread?

See Also:



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# File 'lib/bunny/queue.rb', line 238

def subscribe_with(consumer, opts = {:block => false})
  @channel.basic_consume_with(consumer)

  @channel.work_pool.join if opts[:block]
  consumer
end

#to_s ⇒ Object 



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# File 'lib/bunny/queue.rb', line 118

def to_s
  oid = ("0x%x" % (self.object_id << 1))
  "<#{self.class.name}:#{oid} @name=\"#{name}\" channel=#{@channel.to_s} @durable=#{@durable} @auto_delete=#{@auto_delete} @exclusive=#{@exclusive} @arguments=#{@arguments}>"
end

#unbind(exchange, opts = {}) ⇒ Object

Unbinds queue from an exchange

Parameters:

  • exchange (Bunny::Exchange, String) —

    Exchange to unbind from

  • opts (Hash) (defaults to: {}) —

    Binding properties

Options Hash (opts):

  • :routing_key (String) —

    Routing key

  • :arguments (Hash) — default: {} —

    Additional optional binding arguments

See Also:



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# File 'lib/bunny/queue.rb', line 167

def unbind(exchange, opts = {})
  @channel.queue_unbind(@name, exchange, opts)

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


  @bindings.delete_if { |b| b[:exchange] == exchange_name && b[:routing_key] == (opts[:routing_key] || opts[:key]) && b[:arguments] == opts[:arguments] }

  self
end