Class: Vedeu::Distributed::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/vedeu/distributed/client.rb

Overview

A class for the client side of the DRb server/client relationship.

Examples:

client = Vedeu::Distributed::Client.
           connect("druby://localhost:21420")
client.input('a')
client.output # => 'some content...'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(uri) ⇒ Vedeu::Distributed::Client

Returns a new instance of Vedeu::Distributed::Client.

Parameters:



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# File 'lib/vedeu/distributed/client.rb', line 27

def initialize(uri)
  @uri = uri.to_s
end

Instance Attribute Details

#uri ⇒ String (readonly, protected)

Returns:

  • (String) 


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# File 'lib/vedeu/distributed/client.rb', line 98

def uri
  @uri
end

Class Method Details

.connect(uri) ⇒ Object

Parameters:



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# File 'lib/vedeu/distributed/client.rb', line 19

def self.connect(uri)
  new(uri).connect
end

Instance Method Details

#connect ⇒ Symbol

Simulate connecting to the DRb server by requesting its status.

Returns:

  • (Symbol) 


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# File 'lib/vedeu/distributed/client.rb', line 35

def connect
  server.status

rescue DRb::DRbConnError
  drb_connection_error

rescue DRb::DRbBadURI
  Vedeu.log_stdout(message: 'Could not connect to DRb server, URI may ' \
                            'be bad.'.freeze)

  :drb_bad_uri
end

#drb_connection_error ⇒ Symbol (private)

Returns:

  • (Symbol) 


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# File 'lib/vedeu/distributed/client.rb', line 108

def drb_connection_error
  Vedeu.log_stdout(message: 'Could not connect to DRb server.'.freeze)

  :drb_connection_error
end

#input(data) ⇒ void|Symbol Also known as: read

Send input to the DRb server.

Parameters:

  • data (String|Symbol)

Returns:

  • (void|Symbol) 


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# File 'lib/vedeu/distributed/client.rb', line 52

def input(data)
  server.input(data)

rescue DRb::DRbConnError
  drb_connection_error
end

#output ⇒ void|Symbol Also known as: write

Fetch output from the DRb server.

Returns:

  • (void|Symbol) 


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# File 'lib/vedeu/distributed/client.rb', line 63

def output
  server.output

rescue DRb::DRbConnError
  drb_connection_error
end

#server ⇒ void (private)

This method returns an undefined value.



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# File 'lib/vedeu/distributed/client.rb', line 103

def server
  @server ||= DRbObject.new_with_uri(uri)
end

#shutdown ⇒ void|Symbol

Note:

Runtime::Application will raise StopIteration when its ‘.stop` method is called. Here we rescue that to give a clean client exit.

Shutdown the DRb server and the client application.

Returns:

  • (void|Symbol) 


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# File 'lib/vedeu/distributed/client.rb', line 79

def shutdown
  server.shutdown

  Process.kill('KILL', server.pid)

rescue DRb::DRbConnError
  drb_connection_error

rescue Interrupt
  Vedeu.log_stdout(message: 'Client application exited.'.freeze)

ensure
  :shutdown
end