module AMQP
Top-level namespace of amqp gem. Please refer to “See also” section below.
@see AMQP.connect
@see AMQP.start
@see AMQP::Channel
@see AMQP::Exchange
@see AMQP::Queue
Original version is from Qusion project by Daniel DeLeo.
Copyright © 2009 Daniel DeLeo Copyright © 2011 Michael Klishin
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Constants
- BitSet
A forward reference for
AMQP::BitSet
that was extracted to amq-protocol to make it possible to reuse it in Bunny.- Deferrable
- IntAllocator
A forward reference for
AMQP::IntAllocator
that was extracted to amq-protocol to make it possible to reuse it in Bunny.- VERSION
amqp gem version. Not to be confused with the
AMQP
protocol version it implements. For that, see {AMQ::Protocol::VERSION}@see AMQ::Protocol::VERSION @return [String]
AMQP
gem version
Public Class Methods
“Default channel”. A placeholder for apps that only want to use one channel. This channel is not global, not used under the hood by methods like {AMQP::Exchange#initialize} and only shared by exchanges/queues you decide on. To reiterate: this is only a conventience accessor, since many apps (especially Web apps) can get by with just one connection and one channel.
@api public
# File lib/amqp.rb, line 131 def self.channel @channel end
A placeholder for applications that only need one channel. If you use {AMQP.start} to set up default connection, {AMQP.channel} is open on that connection, but can be replaced by your application.
@see AMQP.channel
@api public
# File lib/amqp.rb, line 141 def self.channel=(value) @channel = value end
Indicates that default connection is closing.
@return [Boolean] @api public
# File lib/amqp.rb, line 101 def self.closing? @connection.closing? end
Alias for {AMQP.connection} @deprecated @api public
# File lib/amqp.rb, line 154 def self.conn warn "AMQP.conn will be removed in 1.0. Please use AMQP.connection." @connection end
Alias for {AMQP.connection=} @deprecated @api public
# File lib/amqp.rb, line 162 def self.conn=(value) warn "AMQP.conn= will be removed in 1.0. Please use AMQP.connection=(connection)." self.connection = value end
Connects to AMQP
broker and yields connection object to the block as soon as connection is considered open.
@example Using AMQP.connect
with default connection settings
AMQP.connect do |connection| AMQP::Channel.new(connection) do |channel| # channel is ready: set up your messaging flow by creating exchanges, # queues, binding them together and so on. end end
@example Using AMQP.connect
to connect to a public RabbitMQ instance with connection settings given as a hash
AMQP.connect(:host => "dev.rabbitmq.com", :username => "guest", :password => "guest") do |connection| AMQP::Channel.new(connection) do |channel| # ... end end
@example Using AMQP.connect
to connect to a public RabbitMQ instance with connection settings given as a URI
AMQP.connect "amqp://guest:guest@dev.rabbitmq.com:5672", :on_possible_authentication_failure => Proc.new { puts("Looks like authentication has failed") } do |connection| AMQP::Channel.new(connection) do |channel| # ... end end
@overload connect(connection_string, options = {})
Used to pass connection parameters as a connection string @param [String] :connection_string AMQP connection URI, à la JDBC connection string. For example: amqp://bus.megacorp.internal:5877/qa
@overload connect(connection_options)
Used to pass connection options as a Hash. @param [Hash] :connection_options AMQP connection options (:host, :port, :username, :vhost, :password)
@option connection_options_or_string [String] :host (“localhost”) Host to connect to. @option connection_options_or_string [Integer] :port (5672) Port to connect to. @option connection_options_or_string [String] :vhost (“/”) Virtual host to connect to. @option connection_options_or_string [String] :username (“guest”) Username to use. Also can be specified as :user. @option connection_options_or_string [String] :password (“guest”) Password to use. Also can be specified as :pass. @option connection_options_or_string [Hash] :ssl TLS (SSL) parameters to use. @option connection_options_or_string [Fixnum] :heartbeat (0) Connection heartbeat, in seconds. 0 means no heartbeat. Can also be configured server-side starting with RabbitMQ 3.0. @option connection_options_or_string [#call] :on_tcp_connection_failure A callable object that will be run if connection to server fails @option connection_options_or_string [#call] :on_possible_authentication_failure A callable object that will be run if authentication fails (see Authentication failure section)
h2. Handling authentication failures
AMQP
0.9.1 specification dictates that broker closes TCP connection when it detects that authentication has failed. However, broker does exactly the same thing when other connection-level exception occurs so there is no way to guarantee that connection was closed because of authentication failure.
Because of that, AMQP
gem follows Java client example and hints at possibility of authentication failure. To handle it, pass a callable object (a proc, a lambda, an instance of a class that responds to call) with :on_possible_authentication_failure option.
@note This method assumes that EventMachine even loop is already running. If it is not the case or you are not sure, we recommend you use {AMQP.start} instead.
It takes exactly the same parameters.
@return [AMQP::Session] @api public
# File lib/amqp.rb, line 232 def self.connect(connection_options_or_string = ENV['RABBITMQ_URL'], other_options = {}, &block) AMQP::Session.connect(connection_options_or_string, other_options, &block) end
Default connection. When you do not pass connection instance to methods like {Channel#initialize}, AMQP
gem will use this default connection.
@api public
# File lib/amqp.rb, line 121 def self.connection @connection end
Sets global connection object. @api public
# File lib/amqp.rb, line 147 def self.connection=(value) @connection = value end
@return [Boolean] Current global logging value @api public
# File lib/amqp.rb, line 107 def self.logging self.settings[:logging] end
@return [Boolean] Sets current global logging value @api public
# File lib/amqp.rb, line 113 def self.logging=(value) self.settings[:logging] = !!value end
Alias for {AMQP.start} @api public
# File lib/amqp.rb, line 67 def self.run(*args, &block) self.start(*args, &block) end
@return [Hash] Default AMQP
connection settings. This hash may be modified. @api public
# File lib/amqp.rb, line 238 def self.settings @settings ||= AMQ::Settings.default.merge(logging: false) end
Starts EventMachine event loop unless it is already running and connects to AMQP
broker using {AMQP.connect}. It is generally a good idea to start EventMachine event loop in a separate thread and use {AMQP.connect} (for Web applications that do not use Thin or Goliath, it is the only option).
See {AMQP.connect} for information about arguments this method takes and information about relevant topics such as authentication failure handling.
@example Using AMQP.start
to connect to AMQP
broker, EventMachine loop isn't yet running
AMQP.start do |connection| # default is to connect to localhost:5672, to root ("/") vhost as guest/guest # this block never exits unless either AMQP.stop or EM.stop # is called. AMQP::Channel(connection) do |channel| channel.queue("", :auto_delete => true).bind(channel.fanout("amq.fanout")).subscribe do |headers, payload| # handle deliveries here end end end
@api public
# File lib/amqp.rb, line 55 def self.start(connection_options_or_string = {}, other_options = {}, &block) EM.run do if !@connection || @connection.closed? || @connection.closing? @connection = connect(connection_options_or_string, other_options, &block) end @channel = Channel.new(@connection) @connection end end
Properly closes default AMQP
connection and then underlying TCP connection. Pass it a block if you want a piece of code to be run once default connection is successfully closed.
@note If default connection was never established or is in the closing state already,
this method has no effect.
@api public
# File lib/amqp.rb, line 78 def self.stop(reply_code = 200, reply_text = "Goodbye", &block) return if @connection.nil? || self.closing? EM.next_tick do if AMQP.channel and AMQP.channel.open? and AMQP.channel.connection.open? AMQP.channel.close end AMQP.channel = nil shim = Proc.new { block.call AMQP.connection = nil } @connection.disconnect(reply_code, reply_text, &shim) end end