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



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# File 'lib/message_bus.rb', line 34

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.



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# File 'lib/message_bus.rb', line 557

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)



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# File 'lib/message_bus.rb', line 274

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.



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# File 'lib/message_bus.rb', line 280

def allow_broadcast?
  @config[:allow_broadcast] ||=
    if defined? ::Rails.env
      ::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



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# File 'lib/message_bus.rb', line 325

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



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# File 'lib/message_bus.rb', line 495

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.



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# File 'lib/message_bus.rb', line 170

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.



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

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:



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# File 'lib/message_bus.rb', line 415

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



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# File 'lib/message_bus.rb', line 57

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



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# File 'lib/message_bus.rb', line 52

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



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# File 'lib/message_bus.rb', line 91

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.



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# File 'lib/message_bus.rb', line 85

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



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# File 'lib/message_bus.rb', line 617

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



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

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 destroy entire bus.



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

def destroy
  return if @destroyed

  reliable_pub_sub.global_unsubscribe
  reliable_pub_sub.destroy

  @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



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# File 'lib/message_bus.rb', line 331

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



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# File 'lib/message_bus.rb', line 257

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



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

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



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# File 'lib/message_bus.rb', line 229

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

#initialize ⇒ Object 



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# File 'lib/message_bus.rb', line 41

def initialize
  @config = {}
  @mutex = Synchronizer.new
  @off = false
  @destroyed = false
  @timer_thread = nil
  @subscriber_thread = nil
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



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# File 'lib/message_bus.rb', line 238

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`.



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# File 'lib/message_bus.rb', line 598

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.



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# File 'lib/message_bus.rb', line 592

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



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# File 'lib/message_bus.rb', line 515

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:



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# File 'lib/message_bus.rb', line 524

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



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

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



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# File 'lib/message_bus.rb', line 452

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.



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# File 'lib/message_bus.rb', line 474

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.



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# File 'lib/message_bus.rb', line 73

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



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# File 'lib/message_bus.rb', line 67

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



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

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.



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# File 'lib/message_bus.rb', line 97

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.



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# File 'lib/message_bus.rb', line 157

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



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# File 'lib/message_bus.rb', line 151

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

#max_active_clients ⇒ Integer

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



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# File 'lib/message_bus.rb', line 117

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 simultaneous clients we can service; will revert to polling if we are out of slots



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

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

#off ⇒ void

This method returns an undefined value.

Disables publication to the bus



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# File 'lib/message_bus.rb', line 181

def off
  @off = true
end

#off? ⇒ Boolean

Returns whether the bus is disabled or not.

Returns:

  • (Boolean) —

    whether the bus is disabled or not



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# File 'lib/message_bus.rb', line 175

def off?
  @off
end

#on ⇒ void

This method returns an undefined value.

Enables publication to the bus



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

def on
  @destroyed = @off = false
end

#on_connect(&blk) ⇒ Object 



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# File 'lib/message_bus.rb', line 262

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

#on_disconnect(&blk) ⇒ Object 



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

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



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# File 'lib/message_bus.rb', line 248

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 being 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:



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# File 'lib/message_bus.rb', line 353

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

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

  if (user_ids == []) || (group_ids == []) || (client_ids == [])
    raise ::MessageBus::InvalidMessageTarget
  end

  encoded_data = transport_codec.encode({
    "data" => data,
    "user_ids" => user_ids,
    "group_ids" => group_ids,
    "client_ids" => client_ids
  })

  channel_opts = {}

  if opts
    if ((age = opts[:max_backlog_age]) || (size = opts[:max_backlog_size]))
      channel_opts[:max_backlog_size] = size
      channel_opts[:max_backlog_age] = age
    end

    if opts.has_key?(:queue_in_memory)
      channel_opts[:queue_in_memory] = opts[:queue_in_memory]
    end
  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



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# File 'lib/message_bus.rb', line 145

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.



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# File 'lib/message_bus.rb', line 124

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



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# File 'lib/message_bus.rb', line 201

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



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# File 'lib/message_bus.rb', line 609

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.



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# File 'lib/message_bus.rb', line 308

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



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# File 'lib/message_bus.rb', line 302

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

#reset! ⇒ Object 



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# File 'lib/message_bus.rb', line 571

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



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# File 'lib/message_bus.rb', line 211

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



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# File 'lib/message_bus.rb', line 435

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.



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# File 'lib/message_bus.rb', line 577

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

#transport_codec ⇒ MessageBus::Codec::Base

Returns codec used to encode and decode Message payloads.

Returns:



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# File 'lib/message_bus.rb', line 296

def transport_codec
  @config[:transport_codec] ||= MessageBus::Codec::Json.new
end

#transport_codec=(codec) ⇒ void

This method returns an undefined value.

Parameters:



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# File 'lib/message_bus.rb', line 291

def transport_codec=(codec)
  configure(transport_codec: codec)
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.



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# File 'lib/message_bus.rb', line 463

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



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# File 'lib/message_bus.rb', line 220

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