Class: RServiceBus::MQ

Inherits:
Object
  • Object
show all
Defined in:
lib/rservicebus/MQ.rb

Overview

Wrapper base class for Queue implementations available to the applications, allowing rservicebus to instatiate and configure queue implementations at startup

  • dependency injection.

Direct Known Subclasses

MQ_Beanstalk, MQ_RabbitMq, MQ_Redis

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(uri) ⇒ MQ

Resources are attached resources, and can be specified using the URI syntax.

Parameters:

  • uri (URI) —

    the type and location of queue, eg beanstalk://127.0.0.1/foo

  • timeout (Integer) —

    the amount of time to wait for a msg to arrive



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# File 'lib/rservicebus/MQ.rb', line 47

def initialize( uri )
    
    if uri.is_a? URI then
        @uri = uri
        else
        puts 'uri must be a valid URI'
        abort()
    end

    if uri.path == '' || uri.path == '/' then
        @localQueueName = RServiceBus.getValue( 'APPNAME', 'RServiceBus')
        else
        @localQueueName = uri.path
        @localQueueName[0] = ''
    end

    if @localQueueName == '' then
        puts "@localQueueName: #{@localQueueName}"
        puts 'Queue name must be supplied '
        puts "*** uri, #{uri}, needs to contain a queue name"
        puts '*** the structure is scheme://host[:port]/queuename'
        abort()
    end
    
    @timeout = RServiceBus.getValue( 'QUEUE_TIMEOUT', '5').to_i
    self.connect(uri.host, uri.port)
    self.subscribe( @localQueueName )
end

Instance Attribute Details

#localQueueName ⇒ Object (readonly)

Returns the value of attribute localQueueName.



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# File 'lib/rservicebus/MQ.rb', line 14

def localQueueName
  @localQueueName
end

Class Method Details

.get ⇒ Object 



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# File 'lib/rservicebus/MQ.rb', line 19

def MQ.get
    mqString = RServiceBus.getValue( 'RSBMQ', 'beanstalk://localhost');
    uri = URI.parse( mqString )
    
    case uri.scheme
        when 'beanstalk'
        require 'rservicebus/MQ/Beanstalk'
        mq = MQ_Beanstalk.new( uri )
        
        when 'redis'
        require 'rservicebus/MQ/Redis'
        mq = MQ_Redis.new( uri )
        
        when 'rabbitmq'
        require 'rservicebus/MQ/RabbitMq'
        mq = MQ_RabbitMq.new( uri )

        else
        abort("Scheme, #{uri.scheme}, not recognised when configuring mq, #{string}");
    end
    
    return mq
end

Instance Method Details

#ack ⇒ Object

“Commit” the pop



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# File 'lib/rservicebus/MQ.rb', line 97

def ack
    raise 'Method, ack, needs to be implemented'
end

#connect(host, port) ⇒ Object

Connect to the broker

Parameters:

  • host (String) —

    machine runnig the mq

  • port (String) —

    port the mq is running on



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# File 'lib/rservicebus/MQ.rb', line 80

def connect( host, port )
    raise 'Method, connect, needs to be implemented'
end

#pop ⇒ Object

Get next msg from queue



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# File 'lib/rservicebus/MQ.rb', line 92

def pop
    raise 'Method, pop, needs to be implemented'
end

#send(queueName, msg) ⇒ Object

At least called in the Host rescue block, to ensure all network links are healthy

Parameters:

  • queueName (String) —

    name of the queue to which the m sg should be sent

  • msg (String) —

    msg to be sent



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# File 'lib/rservicebus/MQ.rb', line 105

def send( queueName, msg )
    begin
        @connection.close
        rescue
        puts 'AppResource. An error was raised while closing connection to, ' + @uri.to_s
    end
    
end

#subscribe(queuename) ⇒ Object

Connect to the receiving queue

Parameters:

  • queuename (String) —

    name of the receiving queue



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# File 'lib/rservicebus/MQ.rb', line 87

def subscribe( queuename )
    raise 'Method, subscribe, needs to be implemented'
end