Module: Nutella::Net

Defined in:
lib/nutella_lib/net.rb

Overview

This module implements the pub/sub and request/response APIs at the run level

Class Method Summary collapse

Class Method Details

.async_request(channel, message = nil, callback) ⇒ Object

Performs an asynchronous request

Parameters:

  • channel (String) —

    we want to make the request to. CANNOT contain wildcard(s)!

  • message (Object) (defaults to: nil) —

    the body of request. This can be, nil/empty (default), a string, a hash and, in general, anything with a .to_json method.

  • callback (Proc) —

    the callback that is fired whenever a response is received. It takes one parameter (response).



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# File 'lib/nutella_lib/net.rb', line 64

def self.async_request( channel, message=nil, callback )
  async_request_to(channel, message, callback, Nutella.app_id, Nutella.run_id)
end

.callbacks ⇒ Object

Provides access to callbacks



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# File 'lib/nutella_lib/net.rb', line 14

def self.callbacks; @callbacks end

.handle_requests(channel, callback) ⇒ Object

Handles requests on a certain channel

Parameters:

  • channel (String) —

    we want to listen for requests on. Can contain wildcard(s).

  • callback (Proc) —

    a lambda expression that is fired whenever a message is received. The passed callback takes the following parameters:

    • String

      the received message (payload). Messages that are not JSON are discarded.

    • Hash

      the sender’s identifiers (run_id, app_id, component_id and optionally resource_id)

    • returns Hash

      The response sent back to the client that performed the request. Whatever is returned by the callback is marshaled into a JSON string and sent via MQTT.



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# File 'lib/nutella_lib/net.rb', line 78

def self.handle_requests( channel, callback )
  handle_requests_on(channel, callback, Nutella.app_id, Nutella.run_id)
end

.listen ⇒ Object

Listens for incoming messages. All this function does is to put the thread to sleep and wait for something to happen over the network to wake up.



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# File 'lib/nutella_lib/net.rb', line 99

def self.listen
  begin
    sleep
  rescue Interrupt
    # Simply returns once interrupted
  end
end

.publish(channel, message = nil) ⇒ Object

Publishes a message to a channel

Parameters:

  • channel (String) —

    we want to publish the message to. CANNOT contain wildcard(s)!

  • message (Object) (defaults to: nil) —

    the message we are publishing. This can be, nil/empty (default), a string, a hash and, in general, anything with a .to_json method.



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# File 'lib/nutella_lib/net.rb', line 43

def self.publish( channel, message=nil )
  publish_to( channel, message, Nutella.app_id, Nutella.run_id)
end

.start_pinging ⇒ Object

Sends a ping every 5 seconds to pings channel of the proper level



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# File 'lib/nutella_lib/net.rb', line 86

def self.start_pinging
  Nutella.ping_thread = Thread.new do
    loop do
      publish_to('pings', 'ping', Nutella.app_id, Nutella.run_id)
      sleep(5)
    end
  end
end

.subscribe(channel, callback) ⇒ Object

Subscribes to a channel or to a set of channels.

Parameters:

  • channel (String) —

    the channel or filter we are subscribing to. Can contain wildcard(s)

  • callback (Proc) —

    a lambda expression that is fired whenever a message is received. The passed callback takes the following parameters:

    • String

      message: the received message. Messages that are not JSON are discarded.

    • String

      channel: the channel the message was received on (optional, only for wildcard subscriptions)

    • Hash

      from: the sender’s identifiers (run_id, app_id, component_id and optionally resource_id)



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# File 'lib/nutella_lib/net.rb', line 25

def self.subscribe( channel, callback )
  subscribe_to( channel, callback, Nutella.app_id, Nutella.run_id)
end

.subscriptions ⇒ Object

Provides access to the subscriptions



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# File 'lib/nutella_lib/net.rb', line 11

def self.subscriptions; @subscriptions end

.sync_request(channel, message = nil) ⇒ Object

Performs a synchronous request.

Parameters:

  • channel (String) —

    we want to make the request to. CANNOT contain wildcard(s)!

  • message (Object) (defaults to: nil) —

    the body of request. This can be, nil/empty (default), a string, a hash and, in general, anything with a .to_json method.



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# File 'lib/nutella_lib/net.rb', line 53

def self.sync_request( channel, message=nil )
  sync_request_to(channel, message, Nutella.app_id, Nutella.run_id)
end

.unsubscribe(channel) ⇒ Object

Un-subscribes from a channel

Parameters:

  • channel (String) —

    we want to unsubscribe from. Can contain wildcard(s).



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# File 'lib/nutella_lib/net.rb', line 33

def self.unsubscribe( channel )
  unsubscribe_to( channel, Nutella.app_id, Nutella.run_id)
end