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# encoding: utf-8
require "eventmachine"
require "amqp/framing/string/frame"
require "amqp/auth_mechanism_adapter"
require "amqp/broker"
require "amqp/channel"
require "amqp/channel_id_allocator"
require "amq/settings"
module AMQP
# AMQP session represents connection to the broker. Session objects let you define callbacks for
# various TCP connection lifecycle events, for instance:
#
# * Connection is established
# * Connection has failed
# * Authentication has failed
# * Connection is lost (there is a network failure)
# * AMQP connection is opened
# * AMQP connection parameters (tuning) are negotiated and accepted by the broker
# * AMQP connection is properly closed
#
# h2. Key methods
#
# * {Session#on_connection}
# * {Session#on_open}
# * {Session#on_disconnection}
# * {Session#on_possible_authentication_failure}
# * {Session#on_tcp_connection_failure}
# * {Session#on_tcp_connection_loss}
# * {Session#reconnect}
# * {Session#connected?}
#
#
# @api public
class Session < EM::Connection
include AMQP::ChannelIdAllocator
#
# Behaviours
#
include Openable
include Callbacks
extend ProtocolMethodHandlers
extend RegisterEntityMixin
register_entity :channel, AMQP::Channel
#
# API
#
attr_accessor :logger
attr_accessor :settings
# @return [Array<#call>]
attr_reader :callbacks
# The locale defines the language in which the server will send reply texts.
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.2)
attr_accessor :locale
# Client capabilities
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.2.1)
attr_accessor :client_properties
# Authentication mechanism used.
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.2)
attr_reader :mechanism
# Authentication mechanisms broker supports.
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.2)
attr_reader :server_authentication_mechanisms
# Channels within this connection.
#
# @see http://bit.ly/amqp091spec AMQP 0.9.1 specification (Section 2.2.5)
attr_reader :channels
# Maximum channel number that the server permits this connection to use.
# Usable channel numbers are in the range 1..channel_max.
# Zero indicates no specified limit.
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Sections 1.4.2.5.1 and 1.4.2.6.1)
attr_accessor :channel_max
# Maximum frame size that the server permits this connection to use.
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Sections 1.4.2.5.2 and 1.4.2.6.2)
attr_accessor :frame_max
attr_accessor :connection_timeout
attr_reader :known_hosts
class << self
# Settings
def settings
@settings ||= AMQ::Settings.default
end
def logger
@logger ||= begin
require "logger"
Logger.new(STDERR)
end
end
def logger=(logger)
methods = AMQP::Logging::REQUIRED_METHODS
unless methods.all? { |method| logger.respond_to?(method) }
raise AMQP::Logging::IncompatibleLoggerError.new(methods)
end
@logger = logger
end
# @return [Boolean] Current value of logging flag.
def logging
settings[:logging]
end
# Turns loggin on or off.
def logging=(boolean)
settings[:logging] = boolean
end
end
# @group Connecting, reconnecting, disconnecting
def initialize(*args, &block)
super(*args)
connection_options_or_string = args.first
other_options = args[1] || {}
self.logger = self.class.logger
# channel => collected frames. MK.
@frames = Hash.new { Array.new }
@channels = Hash.new
@callbacks = Hash.new
opening!
# track TCP connection state, used to detect initial TCP connection failures.
@tcp_connection_established = false
@tcp_connection_failed = false
@intentionally_closing_connection = false
@settings = AMQ::Settings.configure(connection_options_or_string).merge(other_options)
@on_tcp_connection_failure = Proc.new { |settings|
closed!
if cb = @settings[:on_tcp_connection_failure]
cb.call(settings)
else
raise self.class.tcp_connection_failure_exception_class.new(settings)
end
}
@on_possible_authentication_failure = @settings[:on_possible_authentication_failure] || Proc.new { |settings|
raise self.class.authentication_failure_exception_class.new(settings)
}
@mechanism = normalize_auth_mechanism(@settings.fetch(:auth_mechanism, "PLAIN"))
@locale = @settings.fetch(:locale, "en_GB")
@client_properties = Settings.client_properties.merge(@settings.fetch(:client_properties, Hash.new))
@auto_recovery = (!!@settings[:auto_recovery])
@connection_timeout = (@settings[:timeout] || @settings[:connection_timeout] || 3).to_f
self.reset
self.set_pending_connect_timeout(@connection_timeout) unless defined?(JRUBY_VERSION)
end # initialize
# @return [Boolean] true if this AMQP connection is currently open
# @api plugin
def connected?
self.opened?
end
# @return [String] Broker hostname this connection uses
# @api public
def hostname
@settings[:host]
end
alias host hostname
# @return [String] Broker port this connection uses
# @api public
def port
@settings[:port]
end
# @return [String] Broker endpoint in the form of HOST:PORT/VHOST
# @api public
def broker_endpoint
"#{self.hostname}:#{self.port}/#{self.vhost}"
end
# @return [String] Username used by this connection
# @api public
def username
@settings[:user]
end # username
alias user username
# Properly close connection with AMQ broker, as described in
# section 2.2.4 of the {https://www.rabbitmq.com/resources/specs/amqp0-9-1.pdf AMQP 0.9.1 specification}.
#
# @api plugin
# @see #close_connection
def disconnect(reply_code = 200, reply_text = "Goodbye", &block)
@intentionally_closing_connection = true
self.on_disconnection do
@frames.clear
block.call if block
end
# ruby-amqp/amqp#66, MK.
if self.open?
closing!
self.send_frame(AMQ::Protocol::Connection::Close.encode(reply_code, reply_text, 0, 0))
elsif self.closing?
# no-op
else
self.disconnection_successful
end
end
alias close disconnect
# @endgroup
# @group Broker information
# Server properties (product information, platform, et cetera)
#
# @return [Hash]
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol documentation (Section 1.4.2.1.3)
attr_reader :server_properties
# Server capabilities (usually used to detect AMQP 0.9.1 extensions like basic.nack, publisher
# confirms and so on)
#
# @return [Hash]
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol documentation (Section 1.4.2.1.3)
attr_reader :server_capabilities
# Locales server supports
#
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol documentation (Section 1.4.2.1.3)
attr_reader :server_locales
# @return [AMQP::Broker] Broker this connection is established with
def broker
@broker ||= AMQP::Broker.new(@server_properties)
end # broker
# @endgroup
# Defines a callback that will be executed when AMQP connection is considered open:
# after client and broker has agreed on max channel identifier and maximum allowed frame
# size and authentication succeeds. You can define more than one callback.
#
# @see #on_closed
# @api public
def on_open(&block)
@connection_deferrable.callback(&block)
end
alias on_connection on_open
# @group Error Handling and Recovery
# Defines a callback that will be run when broker confirms connection termination
# (client receives connection.close-ok). You can define more than one callback.
#
# @see #on_closed
# @api public
def on_closed(&block)
@disconnection_deferrable.callback(&block)
end
alias on_disconnection on_closed
# Defines a callback that will be run when initial TCP connection fails.
# You can define only one callback.
#
# @api public
def on_tcp_connection_failure(&block)
@on_tcp_connection_failure = block
end
# Defines a callback that will be run when TCP connection to AMQP broker is lost (interrupted).
# You can define only one callback.
#
# @api public
def on_tcp_connection_loss(&block)
@on_tcp_connection_loss = block
end
# Defines a callback that will be run when TCP connection is closed before authentication
# finishes. Usually this means authentication failure. You can define only one callback.
#
# @api public
def on_possible_authentication_failure(&block)
@on_possible_authentication_failure = block
end
# Defines a callback that will be executed after TCP connection is interrupted (typically because of a network failure).
# Only one callback can be defined (the one defined last replaces previously added ones).
#
# @api public
def on_connection_interruption(&block)
self.redefine_callback(:after_connection_interruption, &block)
end
alias after_connection_interruption on_connection_interruption
# Defines a callback that will be executed when connection is closed after
# connection-level exception. Only one callback can be defined (the one defined last
# replaces previously added ones).
#
# @api public
def on_error(&block)
self.redefine_callback(:error, &block)
end
# Defines a callback that will be executed after TCP connection has recovered after a network failure
# but before AMQP connection is re-opened.
# Only one callback can be defined (the one defined last replaces previously added ones).
#
# @api public
def before_recovery(&block)
self.redefine_callback(:before_recovery, &block)
end
# Defines a callback that will be executed after AMQP connection has recovered after a network failure..
# Only one callback can be defined (the one defined last replaces previously added ones).
#
# @api public
def on_recovery(&block)
self.redefine_callback(:after_recovery, &block)
end
alias after_recovery on_recovery
# @return [Boolean] whether connection is in the automatic recovery mode
# @api public
def auto_recovering?
!!@auto_recovery
end
alias auto_recovery? auto_recovering?
# Performs recovery of channels that are in the automatic recovery mode.
#
# @see Channel#auto_recover
# @see Queue#auto_recover
# @see Exchange#auto_recover
# @api plugin
def auto_recover
@channels.select { |channel_id, ch| ch.auto_recovering? }.each { |n, ch| ch.auto_recover }
end # auto_recover
# @endgroup
# @group Blocked connection notifications
def on_blocked(&fn)
@on_blocked = fn
end
def on_unblocked(&fn)
@on_unblocked = fn
end
# @endgroup
#
# Implementation
#
# Overrides TCP connection failure exception to one that inherits from AMQP::Error
# and thus is backwards compatible.
#
# @private
# @api plugin
# @return [Class] AMQP::TCPConnectionFailed
def self.tcp_connection_failure_exception_class
@tcp_connection_failure_exception_class ||= AMQP::TCPConnectionFailed
end # self.tcp_connection_failure_exception_class
# Overrides authentication failure exception to one that inherits from AMQP::Error
# and thus is backwards compatible.
#
# @private
# @api plugin
# @return [Class] AMQP::PossibleAuthenticationFailureError
def self.authentication_failure_exception_class
@authentication_failure_exception_class ||= AMQP::PossibleAuthenticationFailureError
end # self.authentication_failure_exception_class
# @group Connection operations
# Initiates connection to AMQP broker. If callback is given, runs it when (and if) AMQP connection
# succeeds.
#
# @option settings [String] :host ("127.0.0.1") Hostname AMQ broker runs on.
# @option settings [String] :port (5672) Port AMQ broker listens on.
# @option settings [String] :vhost ("/") Virtual host to use.
# @option settings [String] :user ("guest") Username to use for authentication.
# @option settings [String] :pass ("guest") Password to use for authentication.
# @option settings [String] :auth_mechanism ("PLAIN") SASL authentication mechanism to use.
# @option settings [String] :ssl (false) Should be use TLS (SSL) for connection?
# @option settings [String] :timeout (nil) Connection timeout.
# @option settings [Fixnum] :heartbeat (0) Connection heartbeat, in seconds.
# @option settings [Fixnum] :frame_max (131072) Maximum frame size to use. If broker cannot support frames this large, broker's maximum value will be used instead.
#
# @param [Hash] settings
# def self.connect(settings = {}, &block)
def self.connect(connection_string_or_opts = ENV['RABBITMQ_URL'], other_options = {}, &block)
@settings = AMQ::Settings.configure(connection_string_or_opts).merge(other_options)
instance = EventMachine.connect(@settings[:host], @settings[:port], self, @settings)
instance.register_connection_callback(&block)
instance
end
# Reconnect after a period of wait.
#
# @param [Fixnum] period Period of time, in seconds, to wait before reconnection attempt.
# @param [Boolean] force If true, enforces immediate reconnection.
# @api public
def reconnect(force = false, period = 5)
if @reconnecting and not force
EventMachine::Timer.new(period) {
reconnect(true, period)
}
return
end
if !@reconnecting
@reconnecting = true
self.reset
end
EventMachine.reconnect(@settings[:host], @settings[:port], self)
end
# Similar to #reconnect, but uses different connection settings
# @see #reconnect
# @api public
def reconnect_to(connection_string_or_options, period = 5)
settings = AMQ::Settings.configure(connection_string_or_opts)
if !@reconnecting
@reconnecting = true
self.reset
end
@settings = Settings.configure(settings)
EventMachine.reconnect(@settings[:host], @settings[:port], self)
end
# Periodically try to reconnect.
#
# @param [Fixnum] period Period of time, in seconds, to wait before reconnection attempt.
# @param [Boolean] force If true, enforces immediate reconnection.
# @api public
def periodically_reconnect(period = 5)
@reconnecting = true
self.reset
@periodic_reconnection_timer = EventMachine::PeriodicTimer.new(period) {
EventMachine.reconnect(@settings[:host], @settings[:port], self)
}
end
# @endgroup
# @see #on_open
# @private
def register_connection_callback(&block)
unless block.nil?
# delay calling block we were given till after we receive
# connection.open-ok. Connection will notify us when
# that happens.
self.on_open do
block.call(self)
end
end
end
alias close disconnect
# Whether we are in authentication state (after TCP connection was estabilished
# but before broker authenticated us).
#
# @return [Boolean]
# @api public
def authenticating?
@authenticating
end # authenticating?
# IS TCP connection estabilished and currently active?
# @return [Boolean]
# @api public
def tcp_connection_established?
@tcp_connection_established
end # tcp_connection_established?
#
# Implementation
#
# Backwards compatibility with 0.7.0.a25. MK.
Deferrable = EventMachine::DefaultDeferrable
alias send_raw send_data
# EventMachine reactor callback. Is run when TCP connection is estabilished
# but before resumption of the network loop. Note that this includes cases
# when TCP connection has failed.
# @private
def post_init
reset
# note that upgrading to TLS in #connection_completed causes
# Erlang SSL app that RabbitMQ relies on to report
# error on TCP connection <0.1465.0>:{ssl_upgrade_error,"record overflow"}
# and close TCP connection down. Investigation of this issue is likely
# to take some time and to not be worth in as long as #post_init
# works fine. MK.
upgrade_to_tls_if_necessary
rescue Exception => error
raise error
end # post_init
# Called by EventMachine reactor once TCP connection is successfully estabilished.
# @private
def connection_completed
# we only can safely set this value here because EventMachine is a lovely piece of
# software that calls #post_init before #unbind even when TCP connection
# fails. MK.
@tcp_connection_established = true
@periodic_reconnection_timer.cancel if @periodic_reconnection_timer
# again, this is because #unbind is called in different situations
# and there is no easy way to tell initial connection failure
# from connection loss. Not in EventMachine 0.12.x, anyway. MK.
if @had_successfully_connected_before
@recovered = true
self.start_automatic_recovery
self.upgrade_to_tls_if_necessary
end
# now we can set it. MK.
@had_successfully_connected_before = true
@reconnecting = false
@handling_skipped_heartbeats = false
@last_server_heartbeat = Time.now
self.handshake
end
# @private
def close_connection(*args)
@intentionally_closing_connection = true
super(*args)
end
# Called by EventMachine reactor when
#
# * We close TCP connection down
# * Our peer closes TCP connection down
# * There is a network connection issue
# * Initial TCP connection fails
# @private
def unbind(exception = nil)
if !@tcp_connection_established && !@had_successfully_connected_before && !@intentionally_closing_connection
@tcp_connection_failed = true
logger.error "[amqp] Detected TCP connection failure: #{exception}"
self.tcp_connection_failed
end
closing!
@tcp_connection_established = false
self.handle_connection_interruption if @reconnecting
@disconnection_deferrable.succeed
closed!
self.tcp_connection_lost if !@intentionally_closing_connection && @had_successfully_connected_before
# since AMQP spec dictates that authentication failure is a protocol exception
# and protocol exceptions result in connection closure, check whether we are
# in the authentication stage. If so, it is likely to signal an authentication
# issue. Java client behaves the same way. MK.
if authenticating? && !@intentionally_closing_connection
@on_possible_authentication_failure.call(@settings) if @on_possible_authentication_failure
end
end # unbind
#
# EventMachine receives data in chunks, sometimes those chunks are smaller
# than the size of AMQP frame. That's why you need to add some kind of buffer.
#
# @private
def receive_data(chunk)
@chunk_buffer << chunk
while frame = get_next_frame
self.receive_frame(AMQP::Framing::String::Frame.decode(frame))
end
end
# Called by AMQP::Connection after we receive connection.open-ok.
# @api public
def connection_successful
@authenticating = false
opened!
@connection_deferrable.succeed
end # connection_successful
# Called by AMQP::Connection after we receive connection.close-ok.
#
# @api public
def disconnection_successful
@disconnection_deferrable.succeed
# true for "after writing buffered data"
self.close_connection(true)
self.reset
closed!
end # disconnection_successful
# Called when time since last server heartbeat received is greater or equal to the
# heartbeat interval set via :heartbeat_interval option on connection.
#
# @api plugin
def handle_skipped_heartbeats
if !@handling_skipped_heartbeats && @tcp_connection_established && !@intentionally_closing_connection
@handling_skipped_heartbeats = true
self.cancel_heartbeat_sender
self.run_skipped_heartbeats_callbacks
end
end
# @private
def initialize_heartbeat_sender
@last_server_heartbeat = Time.now
@heartbeats_timer = EventMachine::PeriodicTimer.new(self.heartbeat_interval, &method(:send_heartbeat))
end
# @private
def cancel_heartbeat_sender
@heartbeats_timer.cancel if @heartbeats_timer
end
# Sends AMQ protocol header (also known as preamble).
#
# @note This must be implemented by all AMQP clients.
# @api plugin
# @see http://bit.ly/amqp091spec AMQP 0.9.1 specification (Section 2.2)
def send_preamble
self.send_raw(AMQ::Protocol::PREAMBLE)
end
# Sends frame to the peer, checking that connection is open.
#
# @raise [ConnectionClosedError]
def send_frame(frame)
if closed?
raise ConnectionClosedError.new(frame)
else
self.send_raw(frame.encode)
end
end
# Sends multiple frames, one by one. For thread safety this method takes a channel
# object and synchronizes on it.
#
# @api public
def send_frameset(frames, channel)
# some (many) developers end up sharing channels between threads and when multiple
# threads publish on the same channel aggressively, at some point frames will be
# delivered out of order and broker will raise 505 UNEXPECTED_FRAME exception.
# If we synchronize on the channel, however, this is both thread safe and pretty fine-grained
# locking. Note that "single frame" methods do not need this kind of synchronization. MK.
channel.synchronize do
frames.each { |frame| self.send_frame(frame) }
end
end # send_frameset(frames)
# Returns heartbeat interval this client uses, in seconds.
# This value may or may not be used depending on broker capabilities.
# Zero means the server does not want a heartbeat.
#
# @return [Fixnum] Heartbeat interval this client uses, in seconds.
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.6)
def heartbeat_interval
@heartbeat_interval
end # heartbeat_interval
# Returns true if heartbeats are enabled (heartbeat interval is greater than 0)
# @return [Boolean]
def heartbeats_enabled?
@heartbeat_interval && (@heartbeat_interval > 0)
end
# vhost this connection uses. Default is "/", a historically estabilished convention
# of RabbitMQ and amqp gem.
#
# @return [String] vhost this connection uses
# @api public
def vhost
@settings.fetch(:vhost, "/")
end # vhost
# @group Error Handling and Recovery
# Called when initial TCP connection fails.
# @api public
def tcp_connection_failed
@recovered = false
@on_tcp_connection_failure.call(@settings) if @on_tcp_connection_failure
end
# Called when previously established TCP connection fails.
# @api public
def tcp_connection_lost
@recovered = false
@on_tcp_connection_loss.call(self, @settings) if @on_tcp_connection_loss
self.handle_connection_interruption
end
# @return [Boolean]
def reconnecting?
@reconnecting
end # reconnecting?
# @private
# @api plugin
def handle_connection_interruption
self.cancel_heartbeat_sender
@channels.each { |n, c| c.handle_connection_interruption }
self.exec_callback_yielding_self(:after_connection_interruption)
end
# @private
def run_before_recovery_callbacks
self.exec_callback_yielding_self(:before_recovery, @settings)
@channels.each { |n, ch| ch.run_before_recovery_callbacks }
end
# @private
def run_after_recovery_callbacks
self.exec_callback_yielding_self(:after_recovery, @settings)
@channels.each { |n, ch| ch.run_after_recovery_callbacks }
end
# Performs recovery of channels that are in the automatic recovery mode. "before recovery" callbacks
# are run immediately, "after recovery" callbacks are run after AMQP connection is re-established and
# auto recovery is performed (using #auto_recover).
#
# Use this method if you want to run automatic recovery process after handling a connection-level exception,
# for example, 320 CONNECTION_FORCED (used by RabbitMQ when it is shut down gracefully).
#
# @see Channel#auto_recover
# @see Queue#auto_recover
# @see Exchange#auto_recover
# @api plugin
def start_automatic_recovery
self.run_before_recovery_callbacks
self.register_connection_callback do
# always run automatic recovery, because it is per-channel
# and connection has to start it. Channels that did not opt-in for
# autorecovery won't be selected. MK.
self.auto_recover
self.run_after_recovery_callbacks
end
end # start_automatic_recovery
# Defines a callback that will be executed after time since last broker heartbeat is greater
# than or equal to the heartbeat interval (skipped heartbeat is detected).
# Only one callback can be defined (the one defined last replaces previously added ones).
#
# @api public
def on_skipped_heartbeats(&block)
self.redefine_callback(:skipped_heartbeats, &block)
end # on_skipped_heartbeats(&block)
# @private
def run_skipped_heartbeats_callbacks
self.exec_callback_yielding_self(:skipped_heartbeats, @settings)
end
# @endgroup
#
# Implementation
#
# Sends connection preamble to the broker.
# @api plugin
def handshake
@authenticating = true
self.send_preamble
end
# Sends connection.open to the server.
#
# @api plugin
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.7)
def open(vhost = "/")
self.send_frame(AMQ::Protocol::Connection::Open.encode(vhost))
end
# Resets connection state.
#
# @api plugin
def reset_state!
# no-op by default
end # reset_state!
# @api plugin
# @see http://tools.ietf.org/rfc/rfc2595.txt RFC 2595
def encode_credentials(username, password)
auth_mechanism_adapter.encode_credentials(username, password)
end # encode_credentials(username, password)
# Retrieves an AuthMechanismAdapter that will encode credentials for
# this Adapter.
#
# @api plugin
def auth_mechanism_adapter
@auth_mechanism_adapter ||= AuthMechanismAdapter.for_adapter(self)
end
# Processes a single frame.
#
# @param [AMQ::Protocol::Frame] frame
# @api plugin
def receive_frame(frame)
@frames[frame.channel] ||= Array.new
@frames[frame.channel] << frame
if frameset_complete?(@frames[frame.channel])
begin
receive_frameset(@frames[frame.channel])
ensure # Ensure that frames always will be cleared
# for channel.close, frame.channel will be nil. MK.
clear_frames_on(frame.channel) if @frames[frame.channel]
end
end
end
# Processes a frameset by finding and invoking a suitable handler.
# Heartbeat frames are treated in a special way: they simply update @last_server_heartbeat
# value.
#
# @param [Array<AMQ::Protocol::Frame>] frames
# @api plugin
def receive_frameset(frames)
if self.heartbeats_enabled?
# treat incoming traffic as heartbeats.
# this operation is pretty expensive under heavy traffic but heartbeats can be disabled
# (and are also disabled by default). MK.
@last_server_heartbeat = Time.now
end
frame = frames.first
if AMQ::Protocol::HeartbeatFrame === frame
# no-op
else
if callable = AMQP::HandlersRegistry.find(frame.method_class)
f = frames.shift
callable.call(self, f, frames)
else
raise MissingHandlerError.new(frames.first)
end
end
end
# Clears frames that were received but not processed on given channel. Needs to be called
# when the channel is closed.
# @private
def clear_frames_on(channel_id)
raise ArgumentError, "channel id cannot be nil!" if channel_id.nil?
@frames[channel_id].clear
end
# Sends a heartbeat frame if connection is open.
# @api plugin
def send_heartbeat
if tcp_connection_established? && !@handling_skipped_heartbeats && @last_server_heartbeat
if @last_server_heartbeat < (Time.now - (self.heartbeat_interval * 2)) && !reconnecting?
logger.error "[amqp] Detected missing server heartbeats"
self.handle_skipped_heartbeats
end
send_frame(AMQ::Protocol::HeartbeatFrame)
end
end # send_heartbeat
# Handles connection.start.
#
# @api plugin
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.1.)
def handle_start(connection_start)
@server_properties = connection_start.server_properties
@server_capabilities = @server_properties["capabilities"]
@server_authentication_mechanisms = (connection_start.mechanisms || "").split(" ")
@server_locales = Array(connection_start.locales)
username = @settings[:user] || @settings[:username]
password = @settings[:pass] || @settings[:password]
# It's not clear whether we should transition to :opening state here
# or in #open but in case authentication fails, it would be strange to have
# @status undefined. So lets do this. MK.
opening!
self.send_frame(AMQ::Protocol::Connection::StartOk.encode(@client_properties, mechanism, self.encode_credentials(username, password), @locale))
end
# Handles Connection.Tune-Ok.
#
# @api plugin
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.6)
def handle_tune(connection_tune)
@channel_max = connection_tune.channel_max.freeze
@frame_max = connection_tune.frame_max.freeze
client_heartbeat = @settings[:heartbeat] || @settings[:heartbeat_interval] || 0
@heartbeat_interval = negotiate_heartbeat_value(client_heartbeat, connection_tune.heartbeat)
self.send_frame(AMQ::Protocol::Connection::TuneOk.encode(@channel_max, [settings[:frame_max], @frame_max].min, @heartbeat_interval))
self.initialize_heartbeat_sender if heartbeats_enabled?
end # handle_tune(method)
# Handles Connection.Open-Ok.
#
# @api plugin
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.8.)
def handle_open_ok(open_ok)
@known_hosts = open_ok.known_hosts.dup.freeze
opened!
self.connection_successful if self.respond_to?(:connection_successful)
end
# Handles connection.close. When broker detects a connection level exception, this method is called.
#
# @api plugin
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.5.2.9)
def handle_close(conn_close)
closed!
# getting connection.close during connection negotiation means authentication
# has failed (RabbitMQ 3.2+):
# http://www.rabbitmq.com/auth-notification.html
if authenticating?
@on_possible_authentication_failure.call(@settings) if @on_possible_authentication_failure
end
self.exec_callback_yielding_self(:error, conn_close)
end
# Handles Connection.Close-Ok.
#
# @api plugin
# @see https://www.rabbitmq.com/resources/specs/amqp-xml-doc0-9-1.pdf AMQP 0.9.1 protocol reference (Section 1.4.2.10)
def handle_close_ok(close_ok)
closed!
self.disconnection_successful
end # handle_close_ok(close_ok)
def handle_connection_blocked(connection_blocked)
@on_blocked.call(self, connection_blocked) if @on_blocked
end
def handle_connection_unblocked(connection_unblocked)
@on_unblocked.call(self, connection_unblocked) if @on_unblocked
end
protected
def negotiate_heartbeat_value(client_value, server_value)
if client_value == 0 || server_value == 0
[client_value, server_value].max
else
[client_value, server_value].min
end
end
# Returns next frame from buffer whenever possible
#
# @api private
def get_next_frame
return nil unless @chunk_buffer.size > 7 # otherwise, cannot read the length
# octet + short
offset = 3 # 1 + 2
# length
payload_length = @chunk_buffer[offset, 4].unpack(AMQ::Protocol::PACK_UINT32).first
# 4 bytes for long payload length, 1 byte final octet
frame_length = offset + payload_length + 5
if frame_length <= @chunk_buffer.size
@chunk_buffer.slice!(0, frame_length)
else
nil
end
end # def get_next_frame
# Utility methods
# Determines, whether the received frameset is ready to be further processed
def frameset_complete?(frames)
return false if frames.empty?
first_frame = frames[0]
first_frame.final? || (first_frame.method_class.has_content? && content_complete?(frames[1..-1]))
end
# Determines, whether given frame array contains full content body
def content_complete?(frames)
return false if frames.empty?
header = frames[0]
raise "Not a content header frame first: #{header.inspect}" unless header.kind_of?(AMQ::Protocol::HeaderFrame)
header.body_size == frames[1..-1].inject(0) {|sum, frame| sum + frame.payload.size }
end
self.handle(AMQ::Protocol::Connection::Start) do |connection, frame|
connection.handle_start(frame.decode_payload)
end
self.handle(AMQ::Protocol::Connection::Tune) do |connection, frame|
connection.handle_tune(frame.decode_payload)
connection.open(connection.vhost)
end
self.handle(AMQ::Protocol::Connection::OpenOk) do |connection, frame|
connection.handle_open_ok(frame.decode_payload)
end
self.handle(AMQ::Protocol::Connection::Close) do |connection, frame|
connection.handle_close(frame.decode_payload)
end
self.handle(AMQ::Protocol::Connection::CloseOk) do |connection, frame|
connection.handle_close_ok(frame.decode_payload)
end
self.handle(AMQ::Protocol::Connection::Blocked) do |connection, frame|
connection.handle_connection_blocked(frame.decode_payload)
end
self.handle(AMQ::Protocol::Connection::Unblocked) do |connection, frame|
connection.handle_connection_unblocked(frame.decode_payload)
end
protected
def reset
@size = 0
@payload = ""
@frames = Array.new
@chunk_buffer = ""
@connection_deferrable = EventMachine::DefaultDeferrable.new
@disconnection_deferrable = EventMachine::DefaultDeferrable.new
# used to track down whether authentication succeeded. AMQP 0.9.1 dictates
# that on authentication failure broker must close TCP connection without sending
# any more data. This is why we need to explicitly track whether we are past
# authentication stage to signal possible authentication failures.
@authenticating = false
end
def upgrade_to_tls_if_necessary
tls_options = @settings[:ssl]
if tls_options.is_a?(Hash)
start_tls(tls_options)
elsif tls_options
start_tls
end
end # upgrade_to_tls_if_necessary
private
def normalize_auth_mechanism(value)
case value
when [] then
"PLAIN"
when nil then
"PLAIN"
else
value
end
end
end # Session
end # AMQP
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