Class: Cotcube::Helpers::JoSchClient

Inherits:
Object
  • Object
show all
Defined in:
lib/cotcube-helpers/josch_client.rb

Constant Summary collapse

SECRETS_DEFAULT = 
{
  'josch_mq_proto' => 'http',
  'josch_mq_user' => 'guest',
  'josch_mq_password' => 'guest',
  'josch_mq_host' => 'localhost',
  'josch_mq_port' => '15672',
  'josch_mq_vhost' => '%2F'
}.freeze
SECRETS = 
SECRETS_DEFAULT.merge(
  lambda {
    begin
      YAML.safe_load(File.read(Cotcube::Helpers.init[:secrets_file]))
    rescue StandardError
      {}
    end
  }.call
)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ JoSchClient

Returns a new instance of JoSchClient.



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# File 'lib/cotcube-helpers/josch_client.rb', line 29

def initialize
  @connection = Bunny.new(user:     SECRETS['josch_mq_user'],
                          password: SECRETS['josch_mq_password'],
                          vhost:    SECRETS['josch_mq_vhost'])
  @connection.start

  @commands  = connection.create_channel
  @exchange  = commands.direct('josch_commands')
  @requests  = {}
  @debug     = false
  setup_reply_queue
end

Instance Attribute Details

#condition ⇒ Object (readonly)

Returns the value of attribute condition.



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# File 'lib/cotcube-helpers/josch_client.rb', line 77

def condition
  @condition
end

#lock ⇒ Object (readonly)

Returns the value of attribute lock.



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# File 'lib/cotcube-helpers/josch_client.rb', line 77

def lock
  @lock
end

#response ⇒ Object

Returns the value of attribute response.



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# File 'lib/cotcube-helpers/josch_client.rb', line 76

def response
  @response
end

Instance Method Details

#command(command, timeout: 10) ⇒ Object Also known as: send_command

command acts a synchronizer: it sends the command and waits for the response

otherwise times out --- the counterpart here is the subscription within 
setup_reply_queue



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# File 'lib/cotcube-helpers/josch_client.rb', line 46

def command(command, timeout: 10)
  command = { command: command.to_s } unless command.is_a? Hash
  command[:timestamp] ||= (Time.now.to_f * 1000).to_i
  request_id = Digest::SHA256.hexdigest(command.to_json)[..6]
  requests[request_id] = {
    request: command,
    id: request_id,
    lock: Mutex.new,
    condition: ConditionVariable.new
  }

  exchange.publish(command.to_json,
                   routing_key: 'josch_commands',
                   correlation_id: request_id,
                   reply_to: reply_queue.name)

  # wait for the signal to continue the execution
  #
  requests[request_id][:lock].synchronize do
    requests[request_id][:condition].wait(requests[request_id][:lock], timeout)
  end

  # if we reached timeout, we will return nil, just for explicity
  response = requests[request_id][:response].dup
  requests.delete(request_id)
  response
end