Class: Bunny::Client

Inherits:
Qrack::Client show all
Defined in:
lib/bunny/client08.rb

Overview

=== DESCRIPTION:

The Client class provides the major Bunny API methods.

Constant Summary

Constants inherited from Qrack::Client

Qrack::Client::CONNECT_TIMEOUT, Qrack::Client::RETRY_DELAY

Instance Attribute Summary collapse

Attributes inherited from Qrack::Client

#__opts__, #channel, #channels, #connecting, #exchanges, #heartbeat, #host, #logfile, #logging, #message_in, #message_out, #port, #queues, #spec, #status, #vhost

Instance Method Summary collapse

Methods inherited from Qrack::Client

#close, #connected?, #connecting?, #next_payload, #read, #returned_message, #switch_channel, #write

Constructor Details

#initialize(connection_string_or_opts = Hash.new, opts = Hash.new) ⇒ Client

=== DESCRIPTION:

Sets up a Bunny::Client object ready for connection to a broker/server. Client_._status is set to :not_connected.

==== OPTIONS:

  • :host => ‘hostname’ (default = ‘localhost’)
  • :port => portno (default = 5672 or 5671 if :ssl set to true)
  • :vhost => ‘vhostname’ (default = ‘/’)
  • :user => ‘username’ (default = ‘guest’)
  • :pass => ‘password’ (default = ‘guest’)
  • :ssl => true or false (default = false) – If set to true, ssl encryption will be used and port will default to 5671.
  • :verify_ssl => true or false (default = true) – If ssl is enabled, this will cause OpenSSL to validate the server certificate unless this parameter is set to false.
  • :logfile => ‘logfilepath’ (default = nil)
  • :logging => true or false (default) – If set to true, session information is sent to STDOUT if :logfile has not been specified. Otherwise, session information is written to :logfile.
  • :insist => true or false (default) – In a configuration with multiple load-sharing servers, the server may respond to a Connection::Open method with a Connection::Redirect. The insist option, if set to true, tells the server that the client is insisting on a connection to the specified server.
  • :frame_max => maximum frame size in bytes (default = 131072)
  • :channel_max => maximum number of channels (default = 0 no maximum)
  • :heartbeat => number of seconds (default = 0 no heartbeat)
  • :connect_timeout => number of seconds before Qrack::ConnectionTimeout is raised (default = 5)


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# File 'lib/bunny/client08.rb', line 51

def initialize(connection_string_or_opts = Hash.new, opts = Hash.new)
  super
  @spec = '0-8'
  @port = self.__opts__[:port] || (self.__opts__[:ssl] ? Qrack::Protocol::SSL_PORT : Qrack::Protocol::PORT)
  @insist = self.__opts__[:insist]
end

Instance Attribute Details

#ticket ⇒ Object

Returns the value of attribute ticket.



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# File 'lib/bunny/client08.rb', line 15

def ticket
  @ticket
end

Instance Method Details

#check_response(received_method, expected_method, err_msg, err_class = Bunny::ProtocolError) ⇒ Object

=== DESCRIPTION:

Checks response from AMQP methods and takes appropriate action



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# File 'lib/bunny/client08.rb', line 66

def check_response(received_method, expected_method, err_msg, err_class = Bunny::ProtocolError)
  case
  when received_method.is_a?(Qrack::Protocol::Connection::Close)
    # Clean up the socket
    close_socket

    raise Bunny::ForcedConnectionCloseError, "Error Reply Code: #{received_method.reply_code}\nError Reply Text: #{received_method.reply_text}"

  when received_method.is_a?(Qrack::Protocol::Channel::Close)
    # Clean up the channel
    channel.active = false

    raise Bunny::ForcedChannelCloseError, "Error Reply Code: #{received_method.reply_code}\nError Reply Text: #{received_method.reply_text}"

  when !received_method.is_a?(expected_method)
    raise err_class, err_msg

  else
    :response_ok
  end
end

#close_connection ⇒ Object 



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# File 'lib/bunny/client08.rb', line 88

def close_connection
  # Set client channel to zero
  switch_channel(0)

  send_frame(Qrack::Protocol::Connection::Close.new(:reply_code => 200, :reply_text => 'Goodbye', :class_id => 0, :method_id => 0))

  method = next_method

  check_response(method, Qrack::Protocol::Connection::CloseOk, "Error closing connection")
end

#create_channel ⇒ Object 



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# File 'lib/bunny/client08.rb', line 99

def create_channel
  channels.each do |c|
    return c if (!c.open? and c.number != 0)
  end
  # If no channel to re-use instantiate new one
  Bunny::Channel.new(self)
end

#exchange(name, opts = {}) ⇒ Object

=== DESCRIPTION:

Declares an exchange to the broker/server. If the exchange does not exist, a new one is created using the arguments passed in. If the exchange already exists, the existing object is returned. If an error occurs a Bunny_::_ProtocolError is raised.

==== OPTIONS:

  • :type => one of :direct (default), :fanout, :topic, :headers
  • :passive => true or false – If set to true, the server will not create the exchange. The client can use this to check whether an exchange exists without modifying the server state.
  • :durable => true or false (default) – If set to true when creating a new exchange, the exchange will be marked as durable. Durable exchanges remain active when a server restarts. Non-durable exchanges (transient exchanges) are purged if/when a server restarts.
  • :auto_delete => true or false (default) – If set to true, the exchange is deleted when all queues have finished using it.
  • :nowait => true or false (default) – Ignored by Bunny, always false.

==== RETURNS:

Exchange



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# File 'lib/bunny/client08.rb', line 133

def exchange(name, opts = {})
  exchanges[name] || Bunny::Exchange.new(self, name, opts)
end

#init_connection ⇒ Object 



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# File 'lib/bunny/client08.rb', line 137

def init_connection
  write(Qrack::Protocol::HEADER)
  write([1, 1, Qrack::Protocol::VERSION_MAJOR, Qrack::Protocol::VERSION_MINOR].pack('C4'))

  frame = next_frame
  if frame.nil? or !frame.payload.is_a?(Qrack::Protocol::Connection::Start)
    raise Bunny::ProtocolError, 'Connection initiation failed'
  end
end

#next_frame(opts = {}) ⇒ Object

Raises:



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# File 'lib/bunny/client08.rb', line 147

def next_frame(opts = {})
  frame = nil

  case
  when channel.frame_buffer.size > 0
    frame = channel.frame_buffer.shift
  when (timeout = opts[:timeout]) && timeout > 0
    Bunny::Timer::timeout(timeout, Qrack::FrameTimeout) do
      frame = Qrack::Transport::Frame.parse(buffer)
    end
  else
    frame = Qrack::Transport::Frame.parse(buffer)
  end

  @logger.info("received") { frame } if @logging

  raise Bunny::ConnectionError, 'No connection to server' if (frame.nil? and !connecting?)

  # Monitor server activity and discard heartbeats
  @message_in = true

  case
  when frame.is_a?(Qrack::Transport::Heartbeat)
    next_frame(opts)
  when frame.nil?
    frame
  when ((frame.channel != channel.number) and (frame.channel != 0))
    channel.frame_buffer << frame
    next_frame(opts)
  else
    frame
  end
end

#open_connection ⇒ Object

Raises:



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# File 'lib/bunny/client08.rb', line 181

def open_connection
  client_opts = { :platform => 'Ruby', :product => 'Bunny', :information => 'http://github.com/ruby-amqp/bunny', :version => VERSION }

  send_frame(Qrack::Protocol::Connection::StartOk.new(client_opts, 'AMQPLAIN', {:LOGIN => @user, :PASSWORD => @pass}, 'en_US'))

  frame = next_frame
  raise Bunny::ProtocolError, "Connection failed - user: #{@user}" if frame.nil?

  method = frame.payload

  if method.is_a?(Qrack::Protocol::Connection::Tune)
    send_frame(Qrack::Protocol::Connection::TuneOk.new( :channel_max => @channel_max, :frame_max => @frame_max, :heartbeat => @heartbeat))
  end

  send_frame(Qrack::Protocol::Connection::Open.new(:virtual_host => @vhost, :capabilities => '', :insist => @insist))

  case method = next_method
  when Qrack::Protocol::Connection::OpenOk
    :ok
  when Qrack::Protocol::Connection::Redirect
    raise Bunny::ConnectionError, "Cannot connect to the specified server - host: #{@host}, port: #{@port}" if @insist

    @host, @port = method.host.split(':')
    close_socket
  else
    raise Bunny::ProtocolError, 'Cannot open connection'
  end
end

#qos(opts = {}) ⇒ Object

=== DESCRIPTION:

Requests a specific quality of service. The QoS can be specified for the current channel or for all channels on the connection. The particular properties and semantics of a QoS method always depend on the content class semantics. Though the QoS method could in principle apply to both peers, it is currently meaningful only for the server.

==== Options:

  • :prefetch_size => size in no. of octets (default = 0) – The client can request that messages be sent in advance so that when the client finishes processing a message, the following message is already held locally, rather than needing to be sent down the channel. Prefetching gives a performance improvement. This field specifies the prefetch window size in octets. The server will send a message in advance if it is equal to or smaller in size than the available prefetch size (and also falls into other prefetch limits). May be set to zero, meaning “no specific limit”, although other prefetch limits may still apply. The prefetch-size is ignored if the no-ack option is set.
  • :prefetch_count => no. messages (default = 1) – Specifies a prefetch window in terms of whole messages. This field may be used in combination with the prefetch-size field; a message will only be sent in advance if both prefetch windows (and those at the channel and connection level) allow it. The prefetch-count is ignored if the no-ack option is set.
  • :global => true or false (default) – By default the QoS settings apply to the current channel only. If set to true, they are applied to the entire connection.

==== RETURNS:

:qos_ok if successful.



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# File 'lib/bunny/client08.rb', line 242

def qos(opts = {})
  send_frame(Qrack::Protocol::Basic::Qos.new({ :prefetch_size => 0, :prefetch_count => 1, :global => false }.merge(opts)))

  method = next_method

  check_response(method, Qrack::Protocol::Basic::QosOk, "Error specifying Quality of Service")

  # return confirmation
  :qos_ok
end

#queue(name = nil, opts = {}) ⇒ Object

=== DESCRIPTION:

Declares a queue to the broker/server. If the queue does not exist, a new one is created using the arguments passed in. If the queue already exists, a reference to it is created, provided that the arguments passed in do not conflict with the existing attributes of the queue. If an error occurs a Bunny_::_ProtocolError is raised.

==== OPTIONS:

  • :passive => true or false (default) – If set to true, the server will not create the queue. The client can use this to check whether a queue exists without modifying the server state.
  • :durable => true or false (default) – If set to true when creating a new queue, the queue will be marked as durable. Durable queues remain active when a server restarts. Non-durable queues (transient queues) are purged if/when a server restarts. Note that durable queues do not necessarily hold persistent messages, although it does not make sense to send persistent messages to a transient queue.
  • :exclusive => true or false (default) – If set to true, requests an exclusive queue. Exclusive queues may only be consumed from by the current connection. Setting the ‘exclusive’ flag always implies ‘auto-delete’.
  • :auto_delete => true or false (default) – If set to true, the queue is deleted when all consumers have finished using it. Last consumer can be cancelled either explicitly or because its channel is closed. If there has never been a consumer on the queue, it is not deleted.
  • :nowait => true or false (default) – Ignored by Bunny, always false.

==== RETURNS:

Queue



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# File 'lib/bunny/client08.rb', line 287

def queue(name = nil, opts = {})
  if name.is_a?(Hash)
    opts = name
    name = nil
  end

  # Queue is responsible for placing itself in the list of queues
  queues[name] || Bunny::Queue.new(self, name, opts)
end

#recover(opts = {}) ⇒ Object

=== DESCRIPTION:

Asks the broker to redeliver all unacknowledged messages on a specified channel. Zero or more messages may be redelivered.

==== Options:

  • :requeue => true or false (default) – If set to false, the message will be redelivered to the original recipient. If set to true, the server will attempt to requeue the message, potentially then delivering it to an alternative subscriber.


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# File 'lib/bunny/client08.rb', line 312

def recover(opts = {})
  send_frame(Qrack::Protocol::Basic::Recover.new({ :requeue => false }.merge(opts)))
end

#request_access ⇒ Object 



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# File 'lib/bunny/client08.rb', line 316

def request_access
  send_frame(Qrack::Protocol::Access::Request.new(:realm => '/data', :read => true, :write => true, :active => true, :passive => true))

  method = next_method

  check_response(method, Qrack::Protocol::Access::RequestOk, "Access denied")

  self.ticket = method.ticket
end

#send_frame(*args) ⇒ Object 



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# File 'lib/bunny/client08.rb', line 326

def send_frame(*args)
  args.each do |data|
    data.ticket  = ticket if ticket and data.respond_to?(:ticket=)
    data         = data.to_frame(channel.number) unless data.is_a?(Qrack::Transport::Frame)
    data.channel = channel.number

    @logger.info("send") { data } if @logging
    write(data.to_s)

    # Monitor client activity for heartbeat purposes
    @message_out = true
  end

  nil
end

#send_heartbeat ⇒ Object 



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# File 'lib/bunny/client08.rb', line 342

def send_heartbeat
  # Create a new heartbeat frame
  hb = Qrack::Transport::Heartbeat.new('')
  # Channel 0 must be used
  switch_channel(0) if @channel.number > 0
  # Send the heartbeat to server
  send_frame(hb)
end

#start_session ⇒ Object Also known as: start

=== DESCRIPTION:

Opens a communication channel and starts a connection. If an error occurs, a Bunny_::_ProtocolError is raised. If successful, Client_._status is set to :connected.

==== RETURNS:

:connected if successful.



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# File 'lib/bunny/client08.rb', line 364

def start_session
  @connecting = true

  loop do
    # Create/get socket
    socket

    # Initiate connection
    init_connection

    # Open connection
    break if open_connection == :ok
  end

  # Open another channel because channel zero is used for specific purposes
  c = create_channel()
  c.open

  # Get access ticket
  request_access

  @connecting = false

  # return status
  @status = :connected
end

#tx_commit ⇒ Object

=== DESCRIPTION: This method commits all messages published and acknowledged in the current transaction. A new transaction starts immediately after a commit.

==== RETURNS:

:commit_ok if successful.



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# File 'lib/bunny/client08.rb', line 406

def tx_commit
  send_frame(Qrack::Protocol::Tx::Commit.new())

  method = next_method

  check_response(method, Qrack::Protocol::Tx::CommitOk, "Error commiting transaction")

  # return confirmation
  :commit_ok
end

#tx_rollback ⇒ Object

=== DESCRIPTION: This method abandons all messages published and acknowledged in the current transaction. A new transaction starts immediately after a rollback.

==== RETURNS:

:rollback_ok if successful.



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# File 'lib/bunny/client08.rb', line 430

def tx_rollback
  send_frame(Qrack::Protocol::Tx::Rollback.new())

  method = next_method

  check_response(method, Qrack::Protocol::Tx::RollbackOk, "Error rolling back transaction")

  # return confirmation
  :rollback_ok
end

#tx_select ⇒ Object

=== DESCRIPTION: This method sets the channel to use standard transactions. The client must use this method at least once on a channel before using the Commit or Rollback methods.

==== RETURNS:

:select_ok if successful.



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# File 'lib/bunny/client08.rb', line 454

def tx_select
  send_frame(Qrack::Protocol::Tx::Select.new())

  method = next_method

  check_response(method, Qrack::Protocol::Tx::SelectOk, "Error initiating transactions for current channel")

  # return confirmation
  :select_ok
end