Module: NATS

Defined in:
lib/nats/client.rb

Defined Under Namespace

Classes: AuthError, ClientError, ConnectError, Error, ServerError

Constant Summary collapse

VERSION =
"0.5.0".freeze
DEFAULT_PORT =
4222
DEFAULT_URI =
"nats://localhost:#{DEFAULT_PORT}".freeze
MAX_RECONNECT_ATTEMPTS =
10
RECONNECT_TIME_WAIT =
2
MAX_PENDING_SIZE =
32768
FAST_PRODUCER_THRESHOLD =

Maximum outbound size per client to trigger FP, 20MB

(10*1024*1024)
DEFAULT_PING_INTERVAL =

Ping intervals

120
DEFAULT_PING_MAX =
2
MSG =

Protocol

/\AMSG\s+([^\s]+)\s+([^\s]+)\s+(([^\s]+)[^\S\r\n]+)?(\d+)\r\n/i
OK =

:nodoc:

/\A\+OK\s*\r\n/i
ERR =

:nodoc:

/\A-ERR\s+('.+')?\r\n/i
PING =

:nodoc:

/\APING\s*\r\n/i
PONG =

:nodoc:

/\APONG\s*\r\n/i
INFO =

:nodoc:

/\AINFO\s+([^\r\n]+)\r\n/i
UNKNOWN =

:nodoc:

/\A(.*)\r\n/
CR_LF =

Responses

("\r\n".freeze)
CR_LF_SIZE =

:nodoc:

(CR_LF.bytesize)
PING_REQUEST =

:nodoc:

("PING#{CR_LF}".freeze)
PONG_RESPONSE =

:nodoc:

("PONG#{CR_LF}".freeze)
EMPTY_MSG =

:nodoc:

(''.freeze)
SUB =

Used for future pedantic Mode

/^([^\.\*>\s]+|>$|\*)(\.([^\.\*>\s]+|>$|\*))*$/
SUB_NO_WC =

:nodoc:

/^([^\.\*>\s]+)(\.([^\.\*>\s]+))*$/
AWAITING_CONTROL_LINE =

Parser

1
AWAITING_MSG_PAYLOAD =

:nodoc:

2
AUTOSTART_PID_FILE =

Autostart properties

'/tmp/nats-server.pid'
AUTOSTART_LOG_FILE =
'/tmp/nats-server.log'
@@tried_autostart =

Duplicate autostart protection

{}

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Class Attribute Details

.clientObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 78

def client
  @client
end

.err_cbObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 78

def err_cb
  @err_cb
end

.err_cb_overriddenObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 78

def err_cb_overridden
  @err_cb_overridden
end

.reactor_was_runningObject (readonly) Also known as: reactor_was_running?

:nodoc:


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# File 'lib/nats/client.rb', line 78

def reactor_was_running
  @reactor_was_running
end

.reconnect_cbObject (readonly)

:nodoc


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# File 'lib/nats/client.rb', line 79

def reconnect_cb
  @reconnect_cb
end

.timeout_cbObject

:nodoc


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# File 'lib/nats/client.rb', line 80

def timeout_cb
  @timeout_cb
end

Instance Attribute Details

#bytes_receivedObject (readonly)

Returns the value of attribute bytes_received


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# File 'lib/nats/client.rb', line 308

def bytes_received
  @bytes_received
end

#bytes_sentObject (readonly)

Returns the value of attribute bytes_sent


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# File 'lib/nats/client.rb', line 308

def bytes_sent
  @bytes_sent
end

#closingObject (readonly) Also known as: closing?

:nodoc


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# File 'lib/nats/client.rb', line 307

def closing
  @closing
end

#connect_cbObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 306

def connect_cb
  @connect_cb
end

#connectedObject (readonly) Also known as: connected?

:nodoc:


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# File 'lib/nats/client.rb', line 306

def connected
  @connected
end

#err_cbObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 306

def err_cb
  @err_cb
end

#err_cb_overriddenObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 306

def err_cb_overridden
  @err_cb_overridden
end

#msgs_receivedObject (readonly)

Returns the value of attribute msgs_received


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# File 'lib/nats/client.rb', line 308

def msgs_received
  @msgs_received
end

#msgs_sentObject (readonly)

Returns the value of attribute msgs_sent


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# File 'lib/nats/client.rb', line 308

def msgs_sent
  @msgs_sent
end

#optionsObject (readonly)

:nodoc


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# File 'lib/nats/client.rb', line 307

def options
  @options
end

#pingsObject (readonly)

Returns the value of attribute pings


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# File 'lib/nats/client.rb', line 308

def pings
  @pings
end

#pongs_receivedObject (readonly)

:nodoc:


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# File 'lib/nats/client.rb', line 306

def pongs_received
  @pongs_received
end

#reconnectingObject (readonly) Also known as: reconnecting?

:nodoc


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# File 'lib/nats/client.rb', line 307

def reconnecting
  @reconnecting
end

#server_infoObject (readonly)

:nodoc


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# File 'lib/nats/client.rb', line 307

def server_info
  @server_info
end

#server_poolObject (readonly)

:nodoc


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# File 'lib/nats/client.rb', line 307

def server_pool
  @server_pool
end

Class Method Details

.clear_clientObject

:nodoc:


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# File 'lib/nats/client.rb', line 275

def clear_client # :nodoc:
  @client = nil
end

.connect(opts = {}, &blk) ⇒ NATS

Create and return a connection to the server with the given options. The server will be autostarted if requested and the uri is determined to be local. The optional block will be called when the connection has been completed.

Options Hash (opts):

  • :uri (String|URI)

    The URI to connect to, example nats://localhost:4222

  • :autostart (Boolean)

    Boolean that can be used to engage server autostart functionality.

  • :reconnect (Boolean)

    Boolean that can be used to suppress reconnect functionality.

  • :debug (Boolean)

    Boolean that can be used to output additional debug information.

  • :verbose (Boolean)

    Boolean that is sent to server for setting verbose protocol mode.

  • :pedantic (Boolean)

    Boolean that is sent to server for setting pedantic mode.

  • :ssl (Boolean)

    Boolean that is sent to server for setting TLS/SSL mode.

  • :max_reconnect_attempts (Integer)

    Integer that can be used to set the max number of reconnect tries

  • :reconnect_time_wait (Integer)

    Integer that can be used to set the number of seconds to wait between reconnect tries

  • :ping_interval (Integer)

    Integer that can be used to set the ping interval in seconds.

  • :max_outstanding_pings (Integer)

    Integer that can be used to set the max number of outstanding pings before declaring a connection closed.


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# File 'lib/nats/client.rb', line 102

def connect(opts={}, &blk)
  # Defaults
  opts[:verbose] = false if opts[:verbose].nil?
  opts[:pedantic] = false if opts[:pedantic].nil?
  opts[:reconnect] = true if opts[:reconnect].nil?
  opts[:ssl] = false if opts[:ssl].nil?
  opts[:max_reconnect_attempts] = MAX_RECONNECT_ATTEMPTS if opts[:max_reconnect_attempts].nil?
  opts[:reconnect_time_wait] = RECONNECT_TIME_WAIT if opts[:reconnect_time_wait].nil?
  opts[:ping_interval] = DEFAULT_PING_INTERVAL if opts[:ping_interval].nil?
  opts[:max_outstanding_pings] = DEFAULT_PING_MAX if opts[:max_outstanding_pings].nil?

  # Override with ENV
  opts[:uri] ||= ENV['NATS_URI'] || DEFAULT_URI
  opts[:verbose] = ENV['NATS_VERBOSE'].downcase == 'true' unless ENV['NATS_VERBOSE'].nil?
  opts[:pedantic] = ENV['NATS_PEDANTIC'].downcase == 'true' unless ENV['NATS_PEDANTIC'].nil?
  opts[:debug] = ENV['NATS_DEBUG'].downcase == 'true' unless ENV['NATS_DEBUG'].nil?
  opts[:reconnect] = ENV['NATS_RECONNECT'].downcase == 'true' unless ENV['NATS_RECONNECT'].nil?
  opts[:fast_producer_error] = ENV['NATS_FAST_PRODUCER'].downcase == 'true' unless ENV['NATS_FAST_PRODUCER'].nil?
  opts[:ssl] = ENV['NATS_SSL'].downcase == 'true' unless ENV['NATS_SSL'].nil?
  opts[:max_reconnect_attempts] = ENV['NATS_MAX_RECONNECT_ATTEMPTS'].to_i unless ENV['NATS_MAX_RECONNECT_ATTEMPTS'].nil?
  opts[:reconnect_time_wait] = ENV['NATS_RECONNECT_TIME_WAIT'].to_i unless ENV['NATS_RECONNECT_TIME_WAIT'].nil?

  opts[:ping_interval] = ENV['NATS_PING_INTERVAL'].to_i unless ENV['NATS_PING_INTERVAL'].nil?
  opts[:max_outstanding_pings] = ENV['NATS_MAX_OUTSTANDING_PINGS'].to_i unless ENV['NATS_MAX_OUTSTANDING_PINGS'].nil?

  uri = opts[:uris] || opts[:servers] || opts[:uri]

  # If they pass an array here just pass along to the real connection, and use first as the first attempt..
  # Real connection will do proper walk throughs etc..
  unless uri.nil?
    uris = uri.kind_of?(Array) ? uri : [uri]
    uris.shuffle! unless opts[:dont_randomize_servers]
    u = uris.first
    @uri = u.is_a?(URI) ? u.dup : URI.parse(u)
  end

  @err_cb = proc { |e| raise e } unless err_cb
  check_autostart(@uri) if opts[:autostart] == true

  client = EM.connect(@uri.host, @uri.port, self, opts)
  client.on_connect(&blk) if blk
  return client
end

.connected?Boolean


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# File 'lib/nats/client.rb', line 174

def connected?
  return false unless client
  client.connected?
end

.connected_serverURI


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# File 'lib/nats/client.rb', line 168

def connected_server
  return nil unless client
  client.connected_server
end

.create_inboxString

Returns a subject that can be used for “directed” communications.


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# File 'lib/nats/client.rb', line 242

def create_inbox
  "_INBOX.#{SecureRandom.hex(13)}"
end

.flush(*args, &blk) ⇒ Object

Flushes all messages and subscriptions in the default connection

See Also:


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# File 'lib/nats/client.rb', line 248

def flush(*args, &blk)
  (@client ||= connect).flush(*args, &blk)
end

.on_error(&callback) ⇒ Object

Set the default on_error callback.


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# File 'lib/nats/client.rb', line 199

def on_error(&callback)
  @err_cb, @err_cb_overridden = callback, true
end

.on_reconnect(&callback) ⇒ Object

Set the default on_reconnect callback.


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# File 'lib/nats/client.rb', line 205

def on_reconnect(&callback)
  @reconnect_cb = callback
  @client.on_reconnect(&callback) unless @client.nil?
end

.optionsHash


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# File 'lib/nats/client.rb', line 186

def options
  return {} unless client
  client.options
end

.pending_data_size(*args) ⇒ Object

Return bytes outstanding for the default client connection.

See Also:


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# File 'lib/nats/client.rb', line 254

def pending_data_size(*args)
  (@client ||= connect).pending_data_size(*args)
end

.publish(*args, &blk) ⇒ Object

Publish a message using the default client connection.

See Also:


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# File 'lib/nats/client.rb', line 212

def publish(*args, &blk)
  (@client ||= connect).publish(*args, &blk)
end

.reconnecting?Boolean


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# File 'lib/nats/client.rb', line 180

def reconnecting?
  return false unless client
  client.reconnecting?
end

.request(*args, &blk) ⇒ Object

Publish a message and wait for a response on the default client connection.

See Also:


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# File 'lib/nats/client.rb', line 236

def request(*args, &blk)
  (@client ||= connect).request(*args, &blk)
end

.server_infoHash


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# File 'lib/nats/client.rb', line 192

def server_info
  return nil unless client
  client.server_info
end

.server_running?(uri) ⇒ Boolean

:nodoc:


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# File 'lib/nats/client.rb', line 266

def server_running?(uri) # :nodoc:
  require 'socket'
  s = TCPSocket.new(uri.host, uri.port)
  s.close
  return true
rescue
  return false
end

.start(*args, &blk) ⇒ Object

Create a default client connection to the server.

See Also:

  • connect

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# File 'lib/nats/client.rb', line 148

def start(*args, &blk)
  @reactor_was_running = EM.reactor_running?
  unless (@reactor_was_running || blk)
    raise(Error, "EM needs to be running when NATS.start is called without a run block")
  end
  # Setup optimized select versions
  EM.epoll; EM.kqueue
  EM.run { @client = connect(*args, &blk) }
end

.stop(&blk) ⇒ Object

Close the default client connection and optionally call the associated block.


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# File 'lib/nats/client.rb', line 160

def stop(&blk)
  client.close if (client and (client.connected? || client.reconnecting?))
  blk.call if blk
  @@tried_autostart = {}
  @err_cb = nil
end

.subscribe(*args, &blk) ⇒ Object

Subscribe using the default client connection.

See Also:


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# File 'lib/nats/client.rb', line 218

def subscribe(*args, &blk)
  (@client ||= connect).subscribe(*args, &blk)
end

.timeout(*args, &blk) ⇒ Object

Set a timeout for receiving messages for the subscription.

See Also:


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# File 'lib/nats/client.rb', line 230

def timeout(*args, &blk)
  (@client ||= connect).timeout(*args, &blk)
end

.unsubscribe(*args) ⇒ Object

Cancel a subscription on the default client connection.

See Also:


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# File 'lib/nats/client.rb', line 224

def unsubscribe(*args)
  (@client ||= connect).unsubscribe(*args)
end

.wait_for_server(uri, max_wait = 5) ⇒ Object

:nodoc:


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# File 'lib/nats/client.rb', line 258

def wait_for_server(uri, max_wait = 5) # :nodoc:
  start = Time.now
  while (Time.now - start < max_wait) # Wait max_wait seconds max
    break if server_running?(uri)
    sleep(0.1)
  end
end

Instance Method Details

#attempt_reconnectObject

:nodoc:


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# File 'lib/nats/client.rb', line 739

def attempt_reconnect #:nodoc:
  @reconnect_timer = nil
  current = server_pool.first
  current[:reconnect_attempts] += 1 if current[:reconnect_attempts]
  send_connect_command
  begin
    EM.reconnect(@uri.host, @uri.port, self)
  rescue
    current[:error_received] = true
    @uri = nil
    @connected = false
  end
end

#auth_connection?Boolean


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# File 'lib/nats/client.rb', line 465

def auth_connection?
  !@uri.user.nil?
end

#bind_primaryObject

:nodoc:


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# File 'lib/nats/client.rb', line 781

def bind_primary #:nodoc:
  first = server_pool.first
  @uri = first[:uri]
  @uri.user = options[:user] if options[:user]
  @uri.password = options[:pass] if options[:pass]
  first
end

#can_reuse_server?(server) ⇒ Boolean

:nodoc:


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# File 'lib/nats/client.rb', line 735

def can_reuse_server?(server) #:nodoc:
  reconnecting? && server[:was_connected] && server[:reconnect_attempts] <= @options[:max_reconnect_attempts]
end

#cancel_ping_timerObject


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# File 'lib/nats/client.rb', line 611

def cancel_ping_timer
  if @ping_timer
    EM.cancel_timer(@ping_timer)
    @ping_timer = nil
  end
end

#cancel_reconnect_timerObject


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# File 'lib/nats/client.rb', line 710

def cancel_reconnect_timer
  if @reconnect_timer
    EM.cancel_timer(@reconnect_timer)
    @reconnect_timer = nil
  end
end

#closeObject

Close the connection to the server.


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# File 'lib/nats/client.rb', line 448

def close
  @closing = true
  cancel_ping_timer
  cancel_reconnect_timer
  close_connection_after_writing if connected?
  process_disconnect if reconnecting?
end

#connect_commandObject

:nodoc:


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# File 'lib/nats/client.rb', line 469

def connect_command #:nodoc:
  cs = {
    :verbose => @options[:verbose],
    :pedantic => @options[:pedantic],
    :lang => "ruby",
    :version => VERSION
  }
  if auth_connection?
    cs[:user] = @uri.user
    cs[:pass] = @uri.password
  end
  cs[:ssl_required] = @ssl if @ssl
  "CONNECT #{cs.to_json}#{CR_LF}"
end

#connected_serverURI


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# File 'lib/nats/client.rb', line 777

def connected_server
  connected? ? @uri : nil
end

#connection_completedObject

:nodoc:


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# File 'lib/nats/client.rb', line 618

def connection_completed #:nodoc:
  @connected = true unless @ssl

  current = server_pool.first
  current[:was_connected] = true
  current[:reconnect_attempts] = 0

  if reconnecting?
    cancel_reconnect_timer
    @subs.each_pair { |k, v| send_command("SUB #{v[:subject]} #{v[:queue]} #{k}#{CR_LF}") }
  end

  unless user_err_cb? or reconnecting?
    @err_cb = proc { |e| raise e }
  end

  flush_pending unless @ssl

  if (connect_cb and not @conn_cb_called)
    # We will round trip the server here to make sure all state from any pending commands
    # has been processed before calling the connect callback.
    queue_server_rt do
      connect_cb.call(self)
      @conn_cb_called = true
    end
  end

  if reconnecting?
    @reconnecting = false
    @reconnect_cb.call unless @reconnect_cb.nil?
  end

  @parse_state = AWAITING_CONTROL_LINE

  # Initialize ping timer and processing
  @pings_outstanding = 0
  @pongs_received = 0
  @ping_timer = EM.add_periodic_timer(@options[:ping_interval]) { send_ping }
end

#disconnect_error_stringObject


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# File 'lib/nats/client.rb', line 717

def disconnect_error_string
  return "Client disconnected from server on #{@uri}." if @connected
  return "Could not connect to server on #{@uri}"
end

#flush(&blk) ⇒ Object

Flushes all messages and subscriptions for the connection. All messages and subscriptions have been processed by the server when the optional callback is called.


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# File 'lib/nats/client.rb', line 425

def flush(&blk)
  queue_server_rt(&blk) if blk
end

#flush_pendingObject

:nodoc:


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# File 'lib/nats/client.rb', line 527

def flush_pending #:nodoc:
  return unless @pending
  send_data(@pending.join)
  @pending, @pending_size = nil, 0
end

#had_error?Boolean


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# File 'lib/nats/client.rb', line 702

def had_error?
  server_pool.first && server_pool.first[:error_received]
end

#initialize(options) ⇒ Object


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# File 'lib/nats/client.rb', line 314

def initialize(options)
  @options = options
  process_uri_options
  @ssl = options[:ssl] if options[:ssl]
  @ssid, @subs = 1, {}
  @err_cb = NATS.err_cb
  @reconnect_timer, @needed = nil, nil
  @reconnect_cb = NATS.reconnect_cb
  @connected, @closing, @reconnecting, @conn_cb_called = false, false, false, false
  @msgs_received = @msgs_sent = @bytes_received = @bytes_sent = @pings = 0
  @pending_size = 0
  send_connect_command
end

#inspectObject

:nodoc:


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# File 'lib/nats/client.rb', line 809

def inspect #:nodoc:
  "<nats client v#{NATS::VERSION}>"
end

#multiple_servers_available?Boolean


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# File 'lib/nats/client.rb', line 698

def multiple_servers_available?
  server_pool && server_pool.size > 1
end

#on_connect(&callback) ⇒ Object

Define a callback to be called when the client connection has been established.


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# File 'lib/nats/client.rb', line 431

def on_connect(&callback)
  @connect_cb = callback
end

#on_error(&callback) ⇒ Object

Define a callback to be called when errors occur on the client connection.


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# File 'lib/nats/client.rb', line 437

def on_error(&callback)
  @err_cb, @err_cb_overridden = callback, true
end

#on_msg(subject, sid, reply, msg) ⇒ Object

:nodoc:


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# File 'lib/nats/client.rb', line 494

def on_msg(subject, sid, reply, msg) #:nodoc:

  # Accounting - We should account for inbound even if they are not processed.
  @msgs_received += 1
  @bytes_received += msg.bytesize if msg

  return unless sub = @subs[sid]

  # Check for auto_unsubscribe
  sub[:received] += 1
  if sub[:max]
    # Client side support in case server did not receive unsubscribe
    return unsubscribe(sid) if (sub[:received] > sub[:max])
    # cleanup here if we have hit the max..
    @subs.delete(sid) if (sub[:received] == sub[:max])
  end

  if cb = sub[:callback]
    case cb.arity
      when 0 then cb.call
      when 1 then cb.call(msg)
      when 2 then cb.call(msg, reply)
      else cb.call(msg, reply, subject)
    end
  end

  # Check for a timeout, and cancel if received >= expected
  if (sub[:timeout] && sub[:received] >= sub[:expected])
    EM.cancel_timer(sub[:timeout])
    sub[:timeout] = nil
  end
end

#on_reconnect(&callback) ⇒ Object

Define a callback to be called when a reconnect attempt is made.


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# File 'lib/nats/client.rb', line 443

def on_reconnect(&callback)
  @reconnect_cb = callback
end

#pending_data_sizeObject

Return bytes outstanding waiting to be sent to server.


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# File 'lib/nats/client.rb', line 457

def pending_data_size
  get_outbound_data_size + @pending_size
end

#process_disconnectObject

:nodoc:


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# File 'lib/nats/client.rb', line 722

def process_disconnect #:nodoc:
  err_cb.call(NATS::ConnectError.new(disconnect_error_string)) if not closing? and @err_cb
  true # Chaining
ensure
  cancel_ping_timer
  cancel_reconnect_timer
  if (NATS.client == self)
    NATS.clear_client
    EM.stop if ((connected? || reconnecting?) and closing? and not NATS.reactor_was_running?)
  end
  @connected = @reconnecting = false
end

#process_info(info) ⇒ Object

:nodoc:


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# File 'lib/nats/client.rb', line 586

def process_info(info) #:nodoc:
  @server_info = JSON.parse(info, :symbolize_keys => true, :symbolize_names => true)
  if @server_info[:ssl_required] && @ssl
    start_tls
  else
    if @server_info[:ssl_required]
      err_cb.call(NATS::ClientError.new('TLS/SSL required by server'))
    elsif @ssl
      err_cb.call(NATS::ClientError.new('TLS/SSL not supported by server'))
    end
  end
  if @server_info[:auth_required]
    current = server_pool.first
    current[:auth_required] = true
    queue_server_rt { current[:auth_ok] = true }
    flush_pending
  end
  @server_info
end

#process_pongObject


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# File 'lib/nats/client.rb', line 670

def process_pong
  @pongs_received += 1
  @pings_outstanding -= 1
end

#process_uri_optionsObject

Parse out URIs which can now be an array of server choices The server pool will contain both explicit and implicit members.


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# File 'lib/nats/client.rb', line 768

def process_uri_options #:nodoc
  @server_pool = []
  uri = options[:uris] || options[:servers] || options[:uri]
  uri = uri.kind_of?(Array) ? uri : [uri]
  uri.each { |u| server_pool << { :uri => u.is_a?(URI) ? u.dup : URI.parse(u) } }
  bind_primary
end

#publish(subject, msg = EMPTY_MSG, opt_reply = nil, &blk) ⇒ Object

Publish a message to a given subject, with optional reply subject and completion block


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# File 'lib/nats/client.rb', line 333

def publish(subject, msg=EMPTY_MSG, opt_reply=nil, &blk)
  return unless subject
  msg = msg.to_s

  # Accounting
  @msgs_sent += 1
  @bytes_sent += msg.bytesize if msg

  send_command("PUB #{subject} #{opt_reply} #{msg.bytesize}#{CR_LF}#{msg}#{CR_LF}")
  queue_server_rt(&blk) if blk
end

#queue_server_rt(&cb) ⇒ Object

:nodoc:


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# File 'lib/nats/client.rb', line 488

def queue_server_rt(&cb) #:nodoc:
  return unless cb
  (@pongs ||= []) << cb
  send_command(PING_REQUEST)
end

#receive_data(data) ⇒ Object

:nodoc:


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# File 'lib/nats/client.rb', line 533

def receive_data(data) #:nodoc:
  @buf = @buf ? @buf << data : data
  while (@buf)
    case @parse_state
    when AWAITING_CONTROL_LINE
      case @buf
      when MSG
        @buf = $'
        @sub, @sid, @reply, @needed = $1, $2.to_i, $4, $5.to_i
        @parse_state = AWAITING_MSG_PAYLOAD
      when OK # No-op right now
        @buf = $'
      when ERR
        @buf = $'
        current = server_pool.first
        current[:error_received] = true
        if current[:auth_required] && !current[:auth_ok]
          err_cb.call(NATS::AuthError.new($1))
        else
          err_cb.call(NATS::ServerError.new($1))
        end
      when PING
        @pings += 1
        @buf = $'
        send_command(PONG_RESPONSE)
      when PONG
        @buf = $'
        cb = @pongs.shift
        cb.call if cb
      when INFO
        @buf = $'
        process_info($1)
      when UNKNOWN
        @buf = $'
        err_cb.call(NATS::ServerError.new("Unknown protocol: #{$1}"))
      else
        # If we are here we do not have a complete line yet that we understand.
        return
      end
      @buf = nil if (@buf && @buf.empty?)

    when AWAITING_MSG_PAYLOAD
      return unless (@needed && @buf.bytesize >= (@needed + CR_LF_SIZE))
      on_msg(@sub, @sid, @reply, @buf.slice(0, @needed))
      @buf = @buf.slice((@needed + CR_LF_SIZE), @buf.bytesize)
      @sub = @sid = @reply = @needed = nil
      @parse_state = AWAITING_CONTROL_LINE
      @buf = nil if (@buf && @buf.empty?)
    end

  end
end

#request(subject, data = nil, opts = {}, &cb) ⇒ Object

Send a request and have the response delivered to the supplied callback.


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# File 'lib/nats/client.rb', line 408

def request(subject, data=nil, opts={}, &cb)
  return unless subject
  inbox = NATS.create_inbox
  s = subscribe(inbox, opts) { |msg, reply|
    case cb.arity
      when 0 then cb.call
      when 1 then cb.call(msg)
      else cb.call(msg, reply)
    end
  }
  publish(subject, data, inbox)
  return s
end

#schedule_primary_and_connectObject

We have failed on an attempt at the primary (first) server, rotate and try again


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# File 'lib/nats/client.rb', line 790

def schedule_primary_and_connect #:nodoc:
  # Dump the one we were trying if it wasn't connected
  current = server_pool.shift
  # FIXME(dlc) - Should we remove from the list on error?
  server_pool << current if (current && can_reuse_server?(current) && !current[:error_received])
  # If we are out of options, go ahead and disconnect.
  process_disconnect and return if server_pool.empty?
  # bind new one
  next_server = bind_primary
  # If the next one was connected and we are trying to reconnect
  # set up timer if we tried once already.
  if should_delay_connect?(next_server)
    schedule_reconnect
  else
    attempt_reconnect
    schedule_primary_and_connect if had_error?
  end
end

#schedule_reconnectObject

:nodoc:


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# File 'lib/nats/client.rb', line 679

def schedule_reconnect #:nodoc:
  @reconnecting = true
  @connected = false
  @reconnect_timer = EM.add_timer(@options[:reconnect_time_wait]) { attempt_reconnect }
end

#send_command(command, priority = false) ⇒ Object

:nodoc:


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# File 'lib/nats/client.rb', line 753

def send_command(command, priority = false) #:nodoc:
  EM.next_tick { flush_pending } if (connected? && @pending.nil?)
  @pending ||= []
  @pending << command unless priority
  @pending.unshift(command) if priority
  @pending_size += command.bytesize
  flush_pending if (connected? && @pending_size > MAX_PENDING_SIZE)
  if (@options[:fast_producer_error] && pending_data_size > FAST_PRODUCER_THRESHOLD)
    err_cb.call(NATS::ClientError.new("Fast Producer: #{pending_data_size} bytes outstanding"))
  end
  true
end

#send_connect_commandObject

:nodoc:


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# File 'lib/nats/client.rb', line 484

def send_connect_command #:nodoc:
  send_command(connect_command, true)
end

#send_pingObject

:nodoc:


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# File 'lib/nats/client.rb', line 658

def send_ping #:nodoc:
  return if @closing
  if @pings_outstanding > @options[:max_outstanding_pings]
    close_connection
    #close
    return
  end
  @pings_outstanding += 1
  queue_server_rt { process_pong }
  flush_pending
end

#should_delay_connect?(server) ⇒ Boolean


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# File 'lib/nats/client.rb', line 675

def should_delay_connect?(server)
  server[:was_connected] && server[:reconnect_attempts] >= 1
end

#should_not_reconnect?Boolean


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# File 'lib/nats/client.rb', line 706

def should_not_reconnect?
  !@options[:reconnect]
end

#ssl_handshake_completedObject


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# File 'lib/nats/client.rb', line 606

def ssl_handshake_completed
  @connected = true
  flush_pending
end

#subscribe(subject, opts = {}, &callback) ⇒ Object

Subscribe to a subject with optional wildcards. Messages will be delivered to the supplied callback. Callback can take any number of the supplied arguments as defined by the list: msg, reply, sub. Returns subscription id which can be passed to #unsubscribe.


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# File 'lib/nats/client.rb', line 353

def subscribe(subject, opts={}, &callback)
  return unless subject
  sid = (@ssid += 1)
  sub = @subs[sid] = { :subject => subject, :callback => callback, :received => 0 }
  sub[:queue] = opts[:queue] if opts[:queue]
  sub[:max] = opts[:max] if opts[:max]
  send_command("SUB #{subject} #{opts[:queue]} #{sid}#{CR_LF}")
  # Setup server support for auto-unsubscribe
  unsubscribe(sid, opts[:max]) if opts[:max]
  sid
end

#subscription_countNumber

Return the active subscription count.


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# File 'lib/nats/client.rb', line 378

def subscription_count
  @subs.size
end

#timeout(sid, timeout, opts = {}, &callback) ⇒ Object

Setup a timeout for receiving messages for the subscription.


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# File 'lib/nats/client.rb', line 386

def timeout(sid, timeout, opts={}, &callback)
  # Setup a timeout if requested
  return unless sub = @subs[sid]

  auto_unsubscribe, expected = true, 1
  auto_unsubscribe = opts[:auto_unsubscribe] if opts.key?(:auto_unsubscribe)
  expected = opts[:expected] if opts.key?(:expected)

  EM.cancel_timer(sub[:timeout]) if sub[:timeout]

  sub[:timeout] = EM.add_timer(timeout) do
    unsubscribe(sid) if auto_unsubscribe
    callback.call(sid) if callback
  end
  sub[:expected] = expected
end

#unbindObject

:nodoc:


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# File 'lib/nats/client.rb', line 685

def unbind #:nodoc:
  # If we are closing or shouldn't reconnect, go ahead and disconnect.
  process_disconnect and return if (closing? or should_not_reconnect?)

  @reconnecting = true if connected?
  @connected = false
  @pending = @pongs = nil
  @buf = nil
  cancel_ping_timer

  schedule_primary_and_connect
end

#unsubscribe(sid, opt_max = nil) ⇒ Object

Cancel a subscription.


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# File 'lib/nats/client.rb', line 368

def unsubscribe(sid, opt_max=nil)
  opt_max_str = " #{opt_max}" unless opt_max.nil?
  send_command("UNSUB #{sid}#{opt_max_str}#{CR_LF}")
  return unless sub = @subs[sid]
  sub[:max] = opt_max
  @subs.delete(sid) unless (sub[:max] && (sub[:received] < sub[:max]))
end

#user_err_cb?Boolean

:nodoc:


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# File 'lib/nats/client.rb', line 461

def user_err_cb? # :nodoc:
  err_cb_overridden || NATS.err_cb_overridden
end