class Bunny::Client

DESCRIPTION:

The Client class provides the major Bunny API methods.

Attributes

ticket[RW]

Public Class Methods

new(connection_string_or_opts = Hash.new, opts = Hash.new) click to toggle source

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)

# File lib/bunny/client08.rb, line 50
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

Public Instance Methods

check_response(received_method, expected_method, err_msg, err_class = Bunny::ProtocolError) click to toggle source

DESCRIPTION:

Checks response from AMQP methods and takes appropriate action

# File lib/bunny/client08.rb, line 65
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() click to toggle source
# File lib/bunny/client08.rb, line 87
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() click to toggle source
# File lib/bunny/client08.rb, line 98
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 = {}) click to toggle source

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

# File lib/bunny/client08.rb, line 132
def exchange(name, opts = {})
  exchanges[name] || Bunny::Exchange.new(self, name, opts)
end
init_connection() click to toggle source
# File lib/bunny/client08.rb, line 136
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 = {}) click to toggle source
# File lib/bunny/client08.rb, line 146
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() click to toggle source
# File lib/bunny/client08.rb, line 180
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 = {}) click to toggle source

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.

# File lib/bunny/client08.rb, line 241
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 = {}) click to toggle source

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

# File lib/bunny/client08.rb, line 286
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 = {}) click to toggle source

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.

# File lib/bunny/client08.rb, line 311
def recover(opts = {})
  send_frame(Qrack::Protocol::Basic::Recover.new({ :requeue => false }.merge(opts)))
end
request_access() click to toggle source
# File lib/bunny/client08.rb, line 315
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) click to toggle source
# File lib/bunny/client08.rb, line 325
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() click to toggle source
# File lib/bunny/client08.rb, line 341
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() click to toggle source
Alias for: start_session
start_session() click to toggle source

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.

# File lib/bunny/client08.rb, line 363
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
Also aliased as: start
tx_commit() click to toggle source

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.

# File lib/bunny/client08.rb, line 405
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() click to toggle source

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.

# File lib/bunny/client08.rb, line 429
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() click to toggle source

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.

# File lib/bunny/client08.rb, line 453
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