class Bunny::Exchange
Represents AMQP 0.9.1 exchanges.
@see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @see rubybunny.info/articles/extensions.html RabbitMQ Extensions guide
Attributes
@return [Bunny::Channel]
@return [String]
Options hash this exchange instance was instantiated with @return [Hash]
@return [Symbol] @api plugin
Type of this exchange (one of: :direct, :fanout, :topic, :headers). @return [Symbol]
Public Class Methods
The default exchange. This exchange is a direct exchange that is predefined by the broker and that cannot be removed. Every queue is bound to this exchange by default with the following routing semantics: messages will be routed to the queue with the same name as the message's routing key. In other words, if a message is published with a routing key of “weather.usa.ca.sandiego” and there is a queue with this name, the message will be routed to the queue.
@param [Bunny::Channel] channel_or_connection Channel
to use. {Bunny::Session} instances
are only supported for backwards compatibility.
@example Publishing a messages to the tasks queue
channel = Bunny::Channel.new(connection) tasks_queue = channel.queue("tasks") Bunny::Exchange.default(channel).publish("make clean", :routing_key => "tasks")
@see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @see www.rabbitmq.com/resources/specs/amqp0-9-1.pdf AMQP 0.9.1 specification (Section 2.1.2.4) @note Do not confuse the default exchange with amq.direct: amq.direct is a pre-defined direct
exchange that doesn't have any special routing semantics.
@return [Exchange] An instance that corresponds to the default exchange (of type direct). @api public
# File lib/bunny/exchange.rb, line 54 def self.default(channel_or_connection) self.new(channel_or_connection, :direct, AMQ::Protocol::EMPTY_STRING, :no_declare => true) end
@param [Bunny::Channel] channel Channel
this exchange will use. @param [Symbol,String] type Exchange
type @param [String] name Exchange
name @param [Hash] opts Exchange
properties
@option opts [Boolean] :durable (false) Should this exchange be durable? @option opts [Boolean] :auto_delete (false) Should this exchange be automatically deleted when it is no longer used? @option opts [Boolean] :arguments ({}) Additional optional arguments (typically used by RabbitMQ extensions and plugins)
@see Bunny::Channel#topic
@see Bunny::Channel#fanout
@see Bunny::Channel#direct
@see Bunny::Channel#headers
@see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @see rubybunny.info/articles/extensions.html RabbitMQ Extensions guide @api public
# File lib/bunny/exchange.rb, line 74 def initialize(channel, type, name, opts = {}) @channel = channel @name = name @type = type @options = self.class.add_default_options(name, opts) @durable = @options[:durable] @auto_delete = @options[:auto_delete] @internal = @options[:internal] @arguments = @options[:arguments] @bindings = Set.new declare! unless opts[:no_declare] || predeclared? || (@name == AMQ::Protocol::EMPTY_STRING) @channel.register_exchange(self) end
Protected Class Methods
@private
# File lib/bunny/exchange.rb, line 258 def self.add_default_options(name, opts) # :nowait is always false for Bunny h = { :queue => name, :nowait => false }.merge(opts) if name.empty? { :passive => false, :durable => false, :auto_delete => false, :internal => false, :arguments => nil }.merge(h) else h end end
Public Instance Methods
@return [Hash] Additional optional arguments (typically used by RabbitMQ extensions and plugins) @api public
# File lib/bunny/exchange.rb, line 112 def arguments @arguments end
@return [Boolean] true if this exchange was declared as automatically deleted (deleted as soon as last consumer unbinds). @api public
# File lib/bunny/exchange.rb, line 100 def auto_delete? @auto_delete end
Binds an exchange to another (source) exchange using exchange.bind AMQP 0.9.1 extension that RabbitMQ provides.
@param [String] source Source exchange name @param [Hash] opts Options
@option opts [String] routing_key (nil) Routing key used for binding @option opts [Hash] arguments ({}) Optional arguments
@return [Bunny::Exchange] Self @see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @see rubybunny.info/articles/bindings.html Bindings guide @see rubybunny.info/articles/extensions.html RabbitMQ Extensions guide @api public
# File lib/bunny/exchange.rb, line 174 def bind(source, opts = {}) @channel.exchange_bind(source, self, opts) @bindings.add(source: source, opts: opts) self end
Deletes the exchange unless it is predeclared
@param [Hash] opts Options
@option opts [Boolean] if_unused (false) Should this exchange be deleted only if it is no longer used
@see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @api public
# File lib/bunny/exchange.rb, line 155 def delete(opts = {}) @channel.deregister_exchange(self) @channel.exchange_delete(@name, opts) unless predeclared? end
@return [Boolean] true if this exchange was declared as durable (will survive broker restart). @api public
# File lib/bunny/exchange.rb, line 94 def durable? @durable end
@private
# File lib/bunny/exchange.rb, line 236 def handle_return(basic_return, properties, content) if @on_return @on_return.call(basic_return, properties, content) else # TODO: log a warning end end
@return [Boolean] true if this exchange is internal (used solely for exchange-to-exchange
bindings and cannot be published to by clients)
# File lib/bunny/exchange.rb, line 106 def internal? @internal end
Defines a block that will handle returned messages @see rubybunny.info/articles/exchanges.html @api public
# File lib/bunny/exchange.rb, line 205 def on_return(&block) @on_return = block self end
@return [Boolean] true if this exchange is a pre-defined one (amq.direct, amq.fanout, amq.match and so on)
# File lib/bunny/exchange.rb, line 245 def predefined? (@name == AMQ::Protocol::EMPTY_STRING) || !!(@name =~ /^amq\.(direct|fanout|topic|headers|match)/i) end
Publishes a message
@param [String] payload Message payload. It will never be modified by Bunny
or RabbitMQ in any way. @param [Hash] opts Message properties (metadata) and delivery settings
@option opts [String] :routing_key Routing key @option opts [Boolean] :persistent Should the message be persisted to disk? @option opts [Boolean] :mandatory Should the message be returned if it cannot be routed to any queue? @option opts [Integer] :timestamp A timestamp associated with this message @option opts [Integer] :expiration Expiration time after which the message will be deleted @option opts [String] :type Message type, e.g. what type of event or command this message represents. Can be any string @option opts [String] :reply_to Queue
name other apps should send the response to @option opts [String] :content_type Message content type (e.g. application/json) @option opts [String] :content_encoding Message content encoding (e.g. gzip) @option opts [String] :correlation_id Message correlated to this one, e.g. what request this message is a reply for @option opts [Integer] :priority Message priority, 0 to 9. Not used by RabbitMQ, only applications @option opts [String] :message_id Any message identifier @option opts [String] :user_id Optional user ID. Verified by RabbitMQ against the actual connection username @option opts [String] :app_id Optional application ID
@return [Bunny::Exchange] Self @see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @api public
# File lib/bunny/exchange.rb, line 140 def publish(payload, opts = {}) @channel.basic_publish(payload, self.name, (opts.delete(:routing_key) || opts.delete(:key)), opts) self end
@private
# File lib/bunny/exchange.rb, line 222 def recover_from_network_failure declare! unless @options[:no_declare] ||predefined? @bindings.each do |b| bind(b[:source], b[:opts]) end end
Unbinds an exchange from another (source) exchange using exchange.unbind AMQP 0.9.1 extension that RabbitMQ provides.
@param [String] source Source exchange name @param [Hash] opts Options
@option opts [String] routing_key (nil) Routing key used for binding @option opts [Hash] arguments ({}) Optional arguments
@return [Bunny::Exchange] Self @see rubybunny.info/articles/exchanges.html Exchanges and Publishing guide @see rubybunny.info/articles/bindings.html Bindings guide @see rubybunny.info/articles/extensions.html RabbitMQ Extensions guide @api public
# File lib/bunny/exchange.rb, line 195 def unbind(source, opts = {}) @channel.exchange_unbind(source, self, opts) @bindings.delete(source: source, opts: opts) self end
Waits until all outstanding publisher confirms on the channel arrive.
This is a convenience method that delegates to {Bunny::Channel#wait_for_confirms}
@api public
# File lib/bunny/exchange.rb, line 217 def wait_for_confirms @channel.wait_for_confirms end
Protected Instance Methods
@private
# File lib/bunny/exchange.rb, line 253 def declare! @channel.exchange_declare(@name, @type, @options) end