Class: Pokan::RequestHandler

Inherits:
EM::Connection
  • Object
show all
Includes:
CollectivePeerOperations
Defined in:
lib/pokan/request_handler.rb

Overview

Gossiper module is the implementation of the push-pull-gossip protocol.

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from CollectivePeerOperations

#merge, #newer, #older, #retrieve

Class Attribute Details

.address ⇒ Object

Returns the value of attribute address.



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# File 'lib/pokan/request_handler.rb', line 12

def address
  @address
end

.port ⇒ Object

Returns the value of attribute port.



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# File 'lib/pokan/request_handler.rb', line 12

def port
  @port
end

Instance Attribute Details

#address ⇒ Object

Returns the value of attribute address.



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# File 'lib/pokan/request_handler.rb', line 25

def address
  @address
end

#port ⇒ Object

Returns the value of attribute port.



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# File 'lib/pokan/request_handler.rb', line 25

def port
  @port
end

Class Method Details

.new(sig, *args) ⇒ Object 



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# File 'lib/pokan/request_handler.rb', line 16

def new(sig, *args)
  rh = old_new(sig, *args)
  rh.address = address
  rh.port    = port

  rh
end

.old_new ⇒ Object 



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# File 'lib/pokan/request_handler.rb', line 14

alias_method :old_new, :new

Instance Method Details

#pull_message(keys) ⇒ Object

Get a push message containing all status and keys based on the given keys following the structure: Given structure: {key: timestamp, … …}



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# File 'lib/pokan/request_handler.rb', line 74

def pull_message(keys)
  { action: 'pull',
    data: {
      newer: newer(keys),
      older: older(keys)
    },
    origin:"#{address}:#{port}" 
  }.to_json
end

#push_message(keys) ⇒ Object

Get a pull message containing all status and keys based on the given keys following the structure: Given structure: [:key1, :key2, …]



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# File 'lib/pokan/request_handler.rb', line 67

def push_message(keys)
  { action: 'push', data: retrieve(keys), origin:"#{address}:#{port}" }.to_json
end

#receive_data(json_data) ⇒ Object

Receives the gossip message and returns the apropriate message

  • digest message -> pull message

  • pull message -> push message and newer keys stored

  • push message -> newer keys stored

  • hello message -> peer created locally

  • goodbye message -> peer killed locally



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# File 'lib/pokan/request_handler.rb', line 34

def receive_data(json_data)
  message = JSON.parse(json_data)
  data = message['data']

  case message['action']
  when 'digest'
    pull = pull_message(data)
    send_datagram(pull, *message['origin'].split(':'))

    pull
  when 'pull'
    response = push_message(data['older'])
    merge(data['newer'])
    send_datagram(response, *message['origin'].split(':'))

    response
  when 'push'
    merge(data)
  when 'hello'
    peer = Peer.new
    peer.id = message['origin']
    # peer.store(:role, message['role'])
    peer.save
  when 'goodbye'
    peer = Query.new(Peer).where(id: message['origin'])[0]
    peer.store(:status, 'dead', message['timestamp'])
    peer.save
  end
end