Module: MessageBus::Implementation

Included in:
MessageBus, Instance
Defined in:
lib/message_bus.rb

Overview

The main server-side interface to a message bus for the purposes of configuration, publishing and subscribing

Defined Under Namespace

Classes: Synchronizer

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#config ⇒ Hash<Symbol => Object> (readonly) Also known as: redis_config

Returns Configuration options hash.

Returns:

  • (Hash<Symbol => Object>) —

    Configuration options hash



29
30
31
 
# File 'lib/message_bus.rb', line 29

def config
  @config
end

Instance Method Details

#after_fork ⇒ void

This method returns an undefined value.

Performs routines that are necessary after a process fork, typically

triggered by a forking webserver. Performs whatever the backend requires
and ensures the server is listening for publications and running
scheduled tasks.



525
526
527
528
529
530
 
# File 'lib/message_bus.rb', line 525

def after_fork
  reliable_pub_sub.after_fork
  ensure_subscriber_thread
  # will ensure timer is running
  timer.queue {}
end

#allow_broadcast=(val) ⇒ void

This method returns an undefined value.

Parameters:

  • val (Boolean) —

    whether or not to allow broadcasting (debugging)



265
266
267
 
# File 'lib/message_bus.rb', line 265

def allow_broadcast=(val)
  configure(allow_broadcast: val)
end

#allow_broadcast? ⇒ Boolean

Returns whether or not broadcasting is allowed. If not explicitly set, defaults to false unless we’re in Rails test or development mode.

Returns:

  • (Boolean) —

    whether or not broadcasting is allowed. If not explicitly set, defaults to false unless we’re in Rails test or development mode.



271
272
273
274
275
276
277
278
 
# File 'lib/message_bus.rb', line 271

def allow_broadcast?
  @config[:allow_broadcast] ||=
    if defined? ::Rails
      ::Rails.env.test? || ::Rails.env.development?
    else
      false
    end
end

#backend ⇒ Symbol

Returns the name of the backend implementation configured.

Returns:

  • (Symbol) —

    the name of the backend implementation configured



305
306
307
 
# File 'lib/message_bus.rb', line 305

def backend
  @config[:backend] || :redis
end

#backlog(channel = nil, last_id = nil, site_id = nil) ⇒ Array<MessageBus::Message>

Get messages from a channel backlog since the last ID specified, filtered by site

Parameters:

  • channel (String) (defaults to: nil) —

    the name of the channel in question

  • last_id (#to_i) (defaults to: nil) —

    the channel-specific ID of the last message that the caller received on the specified channel

  • site_id (String) (defaults to: nil) —

    the ID of the site by which to filter

Returns:

  • (Array<MessageBus::Message>) —

    all messages published to the specified channel since the specified last ID



464
465
466
467
468
469
470
471
472
473
474
475
476
 
# File 'lib/message_bus.rb', line 464

def backlog(channel = nil, last_id = nil, site_id = nil)
  old =
    if channel
      reliable_pub_sub.backlog(encode_channel_name(channel, site_id), last_id)
    else
      reliable_pub_sub.global_backlog(last_id)
    end

  old.each do |m|
    decode_message!(m)
  end
  old
end

#base_route ⇒ String

Returns the route that message bus will respond to. If not explicitly set, defaults to “/”. Requests to “##base_routemessage-bus/*” will be handled by the message bus server.

Returns:

  • (String) —

    the route that message bus will respond to. If not explicitly set, defaults to “/”. Requests to “##base_routemessage-bus/*” will be handled by the message bus server.



161
162
163
 
# File 'lib/message_bus.rb', line 161

def base_route
  @config[:base_route] || "/"
end

#base_route=(route) ⇒ void

This method returns an undefined value.

Parameters:

  • route (String) —

    Message bus will listen to requests on this route.



154
155
156
 
# File 'lib/message_bus.rb', line 154

def base_route=(route)
  configure(base_route: route.gsub(Regexp.new('\A(?!/)|(?<!/)\Z|//+'), "/"))
end

#blocking_subscribe(channel = nil) {|message| ... } ⇒ void

This method returns an undefined value.

Subscribe to messages. Each message will be delivered by yielding to the passed block as soon as it is available. This will block until subscription is terminated.

Parameters:

  • channel (String, nil) (defaults to: nil) —

    the name of the channel to which we should subscribe. If ‘nil`, messages on every channel will be provided.

Yields:

  • (message) —

    a message-handler block

Yield Parameters:



384
385
386
387
388
389
390
 
# File 'lib/message_bus.rb', line 384

def blocking_subscribe(channel = nil, &blk)
  if channel
    reliable_pub_sub.subscribe(encode_channel_name(channel), &blk)
  else
    reliable_pub_sub.global_subscribe(&blk)
  end
end

#cache_assets ⇒ Boolean

Returns whether or not to cache static assets for the diagnostics pages.

Returns:

  • (Boolean) —

    whether or not to cache static assets for the diagnostics pages



48
49
50
51
52
53
54
 
# File 'lib/message_bus.rb', line 48

def cache_assets
  if defined? @config[:cache_assets]
    @config[:cache_assets]
  else
    true
  end
end

#cache_assets=(val) ⇒ void

This method returns an undefined value.

Parameters:

  • val (Boolean) —

    whether or not to cache static assets for the diagnostics pages



43
44
45
 
# File 'lib/message_bus.rb', line 43

def cache_assets=(val)
  configure(cache_assets: val)
end

#chunked_encoding_enabled=(val) ⇒ void

This method returns an undefined value.

Parameters:

  • val (Boolean) —

    whether or not to enable chunked encoding



82
83
84
 
# File 'lib/message_bus.rb', line 82

def chunked_encoding_enabled=(val)
  configure(chunked_encoding_enabled: val)
end

#chunked_encoding_enabled? ⇒ Boolean

Returns whether or not chunked encoding is enabled. If not explicitly set, defaults to true.

Returns:

  • (Boolean) —

    whether or not chunked encoding is enabled. If not explicitly set, defaults to true.



76
77
78
 
# File 'lib/message_bus.rb', line 76

def chunked_encoding_enabled?
  @config[:chunked_encoding_enabled] == false ? false : true
end

#client_message_filters ⇒ Array

Returns a hash of message filters that have been registered

Returns:

  • (Array) —

    returns a hash of message filters that have been registered



585
586
587
588
 
# File 'lib/message_bus.rb', line 585

def client_message_filters
  configure(client_message_filters: []) if !@config[:client_message_filters]
  @config[:client_message_filters]
end

#configure(config) ⇒ void

This method returns an undefined value.

Overrides existing configuration

Parameters:

  • config (Hash<Symbol => Object>) —

    values to merge into existing config



185
186
187
 
# File 'lib/message_bus.rb', line 185

def configure(config)
  @config.merge!(config)
end

#destroy ⇒ void

This method returns an undefined value.

Stops listening for publications and stops executing scheduled tasks. Mostly used in tests to detroy entire bus.



505
506
507
508
509
510
511
512
513
514
515
516
517
518
 
# File 'lib/message_bus.rb', line 505

def destroy
  return if @destroyed

  reliable_pub_sub.global_unsubscribe

  @mutex.synchronize do
    return if @destroyed

    @subscriptions ||= {}
    @destroyed = true
  end
  @subscriber_thread.join if @subscriber_thread
  timer.stop
end

#enable_diagnostics ⇒ void

This method returns an undefined value.

Enables diagnostics tracking



311
312
313
 
# File 'lib/message_bus.rb', line 311

def enable_diagnostics
  MessageBus::Diagnostics.enable(self)
end

#extra_response_headers_lookup {|env| ... } ⇒ void

This method returns an undefined value.

Yields:

  • (env) —

    a routine to determine extra headers to be set on a subscriber response

Yield Parameters:

  • env (Rack::Request::Env) —

    the subscriber request environment

Yield Returns:

  • (Hash<String => String>) —

    the extra headers to set on the response



248
249
250
251
 
# File 'lib/message_bus.rb', line 248

def extra_response_headers_lookup(&blk)
  configure(extra_response_headers_lookup: blk) if blk
  @config[:extra_response_headers_lookup]
end

#global_backlog(last_id = nil) ⇒ Array<MessageBus::Message>

Get messages from the global backlog since the last ID specified

Parameters:

  • last_id (#to_i) (defaults to: nil) —

    the global ID of the last message that the caller received

Returns:

  • (Array<MessageBus::Message>) —

    all messages published on any channel since the specified last ID



453
454
455
 
# File 'lib/message_bus.rb', line 453

def global_backlog(last_id = nil)
  backlog(nil, last_id)
end

#group_ids_lookup {|env| ... } ⇒ void

This method returns an undefined value.

Yields:

  • (env) —

    a routine to determine the group IDs for a subscriber

Yield Parameters:

  • env (optional, Rack::Request::Env) —

    the subscriber request environment

Yield Returns:

  • (optional, Array<String,Integer>) —

    the group IDs for the subscriber



220
221
222
223
 
# File 'lib/message_bus.rb', line 220

def group_ids_lookup(&blk)
  configure(group_ids_lookup: blk) if blk
  @config[:group_ids_lookup]
end

#initialize ⇒ Object 



36
37
38
39
 
# File 'lib/message_bus.rb', line 36

def initialize
  @config = {}
  @mutex = Synchronizer.new
end

#is_admin_lookup {|env| ... } ⇒ void

This method returns an undefined value.

Yields:

  • (env) —

    a routine to determine if a request comes from an admin user

Yield Parameters:

  • env (Rack::Request::Env) —

    the subscriber request environment

Yield Returns:

  • (Boolean) —

    whether or not the request is from an admin user



229
230
231
232
 
# File 'lib/message_bus.rb', line 229

def is_admin_lookup(&blk)
  configure(is_admin_lookup: blk) if blk
  @config[:is_admin_lookup]
end

#keepalive_interval ⇒ Integer

Returns the keepalive interval in seconds. If not explicitly set, defaults to ‘60`.

Returns:

  • (Integer) —

    the keepalive interval in seconds. If not explicitly set, defaults to ‘60`.



566
567
568
 
# File 'lib/message_bus.rb', line 566

def keepalive_interval
  @config[:keepalive_interval] || 60
end

#keepalive_interval=(interval) ⇒ Object

Parameters:

  • interval (Integer) —

    the keepalive interval in seconds. Set to 0 to disable; anything higher and a keepalive will run every N seconds. If it fails, the process is killed.



560
561
562
 
# File 'lib/message_bus.rb', line 560

def keepalive_interval=(interval)
  configure(keepalive_interval: interval)
end

#last_id(channel, site_id = nil) ⇒ Integer

Get the ID of the last message published on a channel, filtered by site

Parameters:

  • channel (String) —

    the name of the channel in question

  • site_id (String) (defaults to: nil) —

    the ID of the site by which to filter

Returns:

  • (Integer) —

    the channel-specific ID of the last message published to the given channel



484
485
486
 
# File 'lib/message_bus.rb', line 484

def last_id(channel, site_id = nil)
  reliable_pub_sub.last_id(encode_channel_name(channel, site_id))
end

#last_message(channel) ⇒ MessageBus::Message

Get the last message published on a channel

Parameters:

  • channel (String) —

    the name of the channel in question

Returns:



493
494
495
496
497
498
499
500
 
# File 'lib/message_bus.rb', line 493

def last_message(channel)
  if last_id = last_id(channel)
    messages = backlog(channel, last_id - 1)
    if messages
      messages[0]
    end
  end
end

#listening? ⇒ Boolean

Returns whether or not the server is actively listening for publications on the bus.

Returns:

  • (Boolean) —

    whether or not the server is actively listening for publications on the bus



534
535
536
 
# File 'lib/message_bus.rb', line 534

def listening?
  @subscriber_thread && @subscriber_thread.alive?
end

#local_subscribe(channel = nil, last_id = -1,) {|message| ... } ⇒ Proc

Subscribe to messages on a particular channel, filtered by the current site (@see #site_id_lookup). Each message since the last ID specified will be delivered by yielding to the passed block as soon as it is available. This will not block, but instead the callbacks will be executed asynchronously in a dedicated subscriber thread.

Parameters:

  • channel (String) (defaults to: nil) —

    the name of the channel to which we should subscribe

  • last_id (#to_i) (defaults to: -1,) —

    the channel-specific ID of the last message that the caller received on the specified channel

Yields:

  • (message) —

    a message-handler block

Yield Parameters:

Returns:

  • (Proc) —

    the callback block that will be executed



421
422
423
424
 
# File 'lib/message_bus.rb', line 421

def local_subscribe(channel = nil, last_id = -1, &blk)
  site_id = site_id_lookup.call if site_id_lookup && !global?(channel)
  subscribe_impl(channel, site_id, last_id, &blk)
end

#local_unsubscribe(channel = nil, &blk) ⇒ void

This method returns an undefined value.

Removes a subscription to a particular channel, filtered by the current site (@see #site_id_lookup).

Parameters:

  • channel (String) (defaults to: nil) —

    the name of the channel from which we should unsubscribe

  • blk (Proc, nil) —

    the callback which should be removed. If ‘nil`, removes all.



443
444
445
446
 
# File 'lib/message_bus.rb', line 443

def local_unsubscribe(channel = nil, &blk)
  site_id = site_id_lookup.call if site_id_lookup
  unsubscribe_impl(channel, site_id, &blk)
end

#logger ⇒ Logger

Returns the logger used by the bus. If not explicitly set, is configured to log to STDOUT at INFO level.

Returns:

  • (Logger) —

    the logger used by the bus. If not explicitly set, is configured to log to STDOUT at INFO level.



64
65
66
67
68
69
70
71
72
 
# File 'lib/message_bus.rb', line 64

def logger
  return @config[:logger] if @config[:logger]

  require 'logger'
  logger = Logger.new(STDOUT)
  logger.level = Logger::INFO
  configure(logger: logger)
  logger
end

#logger=(logger) ⇒ void

This method returns an undefined value.

Parameters:

  • logger (Logger) —

    a logger object to be used by the bus



58
59
60
 
# File 'lib/message_bus.rb', line 58

def logger=(logger)
  configure(logger: logger)
end

#long_polling_enabled=(val) ⇒ void

This method returns an undefined value.

Parameters:

  • val (Boolean) —

    whether or not to enable long polling



94
95
96
 
# File 'lib/message_bus.rb', line 94

def long_polling_enabled=(val)
  configure(long_polling_enabled: val)
end

#long_polling_enabled? ⇒ Boolean

Returns whether or not long polling is enabled. If not explicitly set, defaults to true.

Returns:

  • (Boolean) —

    whether or not long polling is enabled. If not explicitly set, defaults to true.



88
89
90
 
# File 'lib/message_bus.rb', line 88

def long_polling_enabled?
  @config[:long_polling_enabled] == false ? false : true
end

#long_polling_interval ⇒ Integer

Returns the long-polling interval in milliseconds. If not explicitly set, defaults to 25,000.

Returns:

  • (Integer) —

    the long-polling interval in milliseconds. If not explicitly set, defaults to 25,000.



148
149
150
 
# File 'lib/message_bus.rb', line 148

def long_polling_interval
  @config[:long_polling_interval] || 25 * 1000
end

#long_polling_interval=(millisecs) ⇒ void

This method returns an undefined value.

Parameters:

  • millisecs (Integer) —

    the long-polling interval in milliseconds



142
143
144
 
# File 'lib/message_bus.rb', line 142

def long_polling_interval=(millisecs)
  configure(long_polling_interval: millisecs)
end

#max_active_clients ⇒ Integer

Returns The number of simultanuous clients we can service; will revert to polling if we are out of slots. Defaults to 1000 if not explicitly set.

Returns:

  • (Integer) —

    The number of simultanuous clients we can service; will revert to polling if we are out of slots. Defaults to 1000 if not explicitly set.



108
109
110
 
# File 'lib/message_bus.rb', line 108

def max_active_clients
  @config[:max_active_clients] || 1000
end

#max_active_clients=(val) ⇒ void

This method returns an undefined value.

Parameters:

  • val (Integer) —

    The number of simultanuous clients we can service; will revert to polling if we are out of slots



101
102
103
 
# File 'lib/message_bus.rb', line 101

def max_active_clients=(val)
  configure(max_active_clients: val)
end

#off ⇒ void

This method returns an undefined value.

Disables publication to the bus



172
173
174
 
# File 'lib/message_bus.rb', line 172

def off
  @off = true
end

#off? ⇒ Boolean

Returns whether the bus is disabled or not.

Returns:

  • (Boolean) —

    whether the bus is disabled or not



166
167
168
 
# File 'lib/message_bus.rb', line 166

def off?
  @off
end

#on ⇒ void

This method returns an undefined value.

Enables publication to the bus



178
179
180
 
# File 'lib/message_bus.rb', line 178

def on
  @destroyed = @off = false
end

#on_connect(&blk) ⇒ Object 



253
254
255
256
 
# File 'lib/message_bus.rb', line 253

def on_connect(&blk)
  configure(on_connect: blk) if blk
  @config[:on_connect]
end

#on_disconnect(&blk) ⇒ Object 



258
259
260
261
 
# File 'lib/message_bus.rb', line 258

def on_disconnect(&blk)
  configure(on_disconnect: blk) if blk
  @config[:on_disconnect]
end

#on_middleware_error {|env, e| ... } ⇒ void

This method returns an undefined value.

Yields:

  • (env, e) —

    a routine to handle exceptions raised when handling a subscriber request

Yield Parameters:

  • env (Rack::Request::Env) —

    the subscriber request environment

  • e (Exception) —

    the exception that was raised

Yield Returns:

  • (optional, Array<(Integer,Hash,Array)>) —

    a Rack response to be delivered



239
240
241
242
 
# File 'lib/message_bus.rb', line 239

def on_middleware_error(&blk)
  configure(on_middleware_error: blk) if blk
  @config[:on_middleware_error]
end

#publish(channel, data, opts = nil) ⇒ Integer

Publishes a message to a channel

Parameters:

  • channel (String) —

    the name of the channel to which the message should be published

  • data (JSON) —

    some data to publish to the channel. Must be an object that can be encoded as JSON

  • opts (Hash) (defaults to: nil)

Options Hash (opts):

  • :client_ids (Array<String>) — default: `nil` —

    the unique client IDs to which the message should be available. If nil, available to all.

  • :user_ids (Array<String,Integer>) — default: `nil` —

    the user IDs to which the message should be available. If nil, available to all.

  • :group_ids (Array<String,Integer>) — default: `nil` —

    the group IDs to which the message should be available. If nil, available to all.

  • :site_id (String) — default: `nil` —

    the site ID to scope the message to; used for hosting multiple applications or instances of an application against a single message_bus

  • :max_backlog_age (nil, Integer) —

    the longest amount of time a message may live in a backlog before beging removed, in seconds

  • :max_backlog_size (nil, Integer) —

    the largest permitted size (number of messages) for the channel backlog; beyond this capacity, old messages will be dropped

Returns:

  • (Integer) —

    the channel-specific ID the message was given

Raises:



332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
 
# File 'lib/message_bus.rb', line 332

def publish(channel, data, opts = nil)
  return if @off

  @mutex.synchronize do
    raise ::MessageBus::BusDestroyed if @destroyed
  end

  user_ids = nil
  group_ids = nil
  client_ids = nil

  site_id = nil
  if opts
    user_ids = opts[:user_ids]
    group_ids = opts[:group_ids]
    client_ids = opts[:client_ids]
    site_id = opts[:site_id]
  end

  raise ::MessageBus::InvalidMessage if (user_ids || group_ids) && global?(channel)

  encoded_data = JSON.dump(
    data: data,
    user_ids: user_ids,
    group_ids: group_ids,
    client_ids: client_ids
  )

  channel_opts = nil

  if opts && ((age = opts[:max_backlog_age]) || (size = opts[:max_backlog_size]))
    channel_opts = {
      max_backlog_size: size,
      max_backlog_age: age
    }
  end

  encoded_channel_name = encode_channel_name(channel, site_id)
  reliable_pub_sub.publish(encoded_channel_name, encoded_data, channel_opts)
end

#rack_hijack_enabled=(val) ⇒ void

This method returns an undefined value.

Parameters:

  • val (Boolean) —

    whether or not to enable Rack Hijack



136
137
138
 
# File 'lib/message_bus.rb', line 136

def rack_hijack_enabled=(val)
  configure(rack_hijack_enabled: val)
end

#rack_hijack_enabled? ⇒ Boolean

Returns whether or not Rack Hijack is enabled. If not explicitly set, will default to true, unless we’re on Passenger without the ability to set the advertised_concurrency_level to 0.

Returns:

  • (Boolean) —

    whether or not Rack Hijack is enabled. If not explicitly set, will default to true, unless we’re on Passenger without the ability to set the advertised_concurrency_level to 0.



115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
 
# File 'lib/message_bus.rb', line 115

def rack_hijack_enabled?
  if @config[:rack_hijack_enabled].nil?
    enable = true

    # without this switch passenger will explode
    # it will run out of connections after about 10
    if defined? PhusionPassenger
      enable = false
      if PhusionPassenger.respond_to? :advertised_concurrency_level
        PhusionPassenger.advertised_concurrency_level = 0
        enable = true
      end
    end
    configure(rack_hijack_enabled: enable)
  end

  @config[:rack_hijack_enabled]
end

#redis_config=(config) ⇒ void

This method returns an undefined value.

Overrides existing configuration, explicitly enabling the redis backend

Parameters:

  • config (Hash<Symbol => Object>) —

    values to merge into existing config



192
193
194
 
# File 'lib/message_bus.rb', line 192

def redis_config=(config)
  configure(config.merge(backend: :redis))
end

#register_client_message_filter(channel_prefix) {|message| ... } ⇒ void

This method returns an undefined value.

Registers a client message filter that allows messages to be filtered from the client.

Parameters:

  • channel_prefix (String, Regexp) —

    channel prefix to match against a message’s channel

Yield Parameters:

Yield Returns:

  • (Boolean) —

    whether the message should be published to the client



577
578
579
580
581
582
 
# File 'lib/message_bus.rb', line 577

def register_client_message_filter(channel_prefix, &blk)
  if blk
    configure(client_message_filters: []) if !@config[:client_message_filters]
    @config[:client_message_filters] << [channel_prefix, blk]
  end
end

#reliable_pub_sub ⇒ MessageBus::Backend::Base

Returns the configured backend. If not explicitly set, will be loaded based on the configuration provided.

Returns:

  • (MessageBus::Backend::Base) —

    the configured backend. If not explicitly set, will be loaded based on the configuration provided.



288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
 
# File 'lib/message_bus.rb', line 288

def reliable_pub_sub
  @mutex.synchronize do
    return nil if @destroyed

    # Make sure logger is loaded before config is
    # passed to backend.
    logger

    @config[:reliable_pub_sub] ||= begin
      @config[:backend_options] ||= {}
      require "message_bus/backends/#{backend}"
      MessageBus::BACKENDS[backend].new @config
    end
  end
end

#reliable_pub_sub=(pub_sub) ⇒ void

This method returns an undefined value.

Parameters:

  • pub_sub (MessageBus::Backend::Base) —

    a configured backend



282
283
284
 
# File 'lib/message_bus.rb', line 282

def reliable_pub_sub=(pub_sub)
  configure(reliable_pub_sub: pub_sub)
end

#reset! ⇒ Object 



539
540
541
 
# File 'lib/message_bus.rb', line 539

def reset!
  reliable_pub_sub.reset! if reliable_pub_sub
end

#site_id_lookup {|env| ... } ⇒ void

This method returns an undefined value.

Yields:

  • (env) —

    a routine to determine the site ID for a subscriber

Yield Parameters:

  • env (optional, Rack::Request::Env) —

    the subscriber request environment

Yield Returns:

  • (optional, String) —

    the site ID for the subscriber



202
203
204
205
 
# File 'lib/message_bus.rb', line 202

def site_id_lookup(&blk)
  configure(site_id_lookup: blk) if blk
  @config[:site_id_lookup]
end

#subscribe(channel = nil, last_id = -1,) {|message| ... } ⇒ Proc

Subscribe to messages on a particular channel. Each message since the last ID specified will be delivered by yielding to the passed block as soon as it is available. This will not block, but instead the callbacks will be executed asynchronously in a dedicated subscriber thread.

Parameters:

  • channel (String) (defaults to: nil) —

    the name of the channel to which we should subscribe

  • last_id (#to_i) (defaults to: -1,) —

    the channel-specific ID of the last message that the caller received on the specified channel

Yields:

  • (message) —

    a message-handler block

Yield Parameters:

Returns:

  • (Proc) —

    the callback block that will be executed



404
405
406
 
# File 'lib/message_bus.rb', line 404

def subscribe(channel = nil, last_id = -1, &blk)
  subscribe_impl(channel, nil, last_id, &blk)
end

#timer ⇒ MessageBus::TimerThread

Returns the timer thread used for triggering scheduled routines at specific times/intervals.

Returns:

  • (MessageBus::TimerThread) —

    the timer thread used for triggering scheduled routines at specific times/intervals.



545
546
547
548
549
550
551
552
553
554
555
 
# File 'lib/message_bus.rb', line 545

def timer
  return @timer_thread if @timer_thread

  @timer_thread ||= begin
    t = MessageBus::TimerThread.new
    t.on_error do |e|
      logger.warn "Failed to process job: #{e} #{e.backtrace}"
    end
    t
  end
end

#unsubscribe(channel = nil, &blk) ⇒ void

This method returns an undefined value.

Removes a subscription to a particular channel.

Parameters:

  • channel (String) (defaults to: nil) —

    the name of the channel from which we should unsubscribe

  • blk (Proc, nil) —

    the callback which should be removed. If ‘nil`, removes all.



432
433
434
 
# File 'lib/message_bus.rb', line 432

def unsubscribe(channel = nil, &blk)
  unsubscribe_impl(channel, nil, &blk)
end

#user_id_lookup {|env| ... } ⇒ void

This method returns an undefined value.

Yields:

  • (env) —

    a routine to determine the user ID for a subscriber (authenticate)

Yield Parameters:

  • env (optional, Rack::Request::Env) —

    the subscriber request environment

Yield Returns:

  • (optional, String, Integer) —

    the user ID for the subscriber



211
212
213
214
 
# File 'lib/message_bus.rb', line 211

def user_id_lookup(&blk)
  configure(user_id_lookup: blk) if blk
  @config[:user_id_lookup]
end