Class: Pokan::Peer

Inherits:
Entity show all
Defined in:
lib/pokan/peer.rb

Overview

Peer is a Entity that takes care of the peer semantics. It controls the status, id and role attributes.

Direct Known Subclasses

Server

Instance Attribute Summary

Attributes inherited from Entity

#id

Instance Method Summary collapse

Methods inherited from Entity

#destroy, #digest, #keys, #match?, #merge, #newer, #older, #reload, #save, #timestamp, #value, #values

Constructor Details

#initialize ⇒ Peer 



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# File 'lib/pokan/peer.rb', line 9

def initialize
  super
  store(:role, 'peer', 0)
  store(:status, 'alive', 0)
end

Instance Method Details

#act_as_seed ⇒ Object

Turns the peer into a seed.



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# File 'lib/pokan/peer.rb', line 73

def act_as_seed
  store(:role, 'seed')
end

#address ⇒ Object 



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# File 'lib/pokan/peer.rb', line 20

def address
  @address = id.split(':').first
end

#address=(address) ⇒ Object 



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# File 'lib/pokan/peer.rb', line 15

def address=(address)
  @address = address
  self.id = "#{@address}:#{@udp_port}"  if defined?(@address) && defined?(@udp_port)
end

#alive? ⇒ Boolean 



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# File 'lib/pokan/peer.rb', line 109

def alive?
  status == 'alive'
end

#dead? ⇒ Boolean 



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# File 'lib/pokan/peer.rb', line 113

def dead?
  status == 'dead'
end

#kill ⇒ Object

Kills the peer



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# File 'lib/pokan/peer.rb', line 104

def kill
  store(:status, 'dead')
  self
end

#peer? ⇒ Boolean 



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# File 'lib/pokan/peer.rb', line 81

def peer?
  value(:role) == 'peer'
end

#revive ⇒ Object

Revives the peer



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# File 'lib/pokan/peer.rb', line 98

def revive
  store(:status, 'alive')
end

#role ⇒ Object 



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

def role
  value(:role)
end

#role=(role) ⇒ Object

Changes the role of the peer. The role must be peer or seed. Otherwise, the role will stay as it was and no exception will be thrown.



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# File 'lib/pokan/peer.rb', line 63

def role=(role)
  store(:role, role)
end

#seed? ⇒ Boolean 



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# File 'lib/pokan/peer.rb', line 77

def seed?
  value(:role) == 'seed'
end

#status ⇒ Object 



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# File 'lib/pokan/peer.rb', line 92

def status
  value(:status)
end

#status=(status) ⇒ Object

Changes the status of the peer. The status must be alive or dead. Otherwise, the role will stay as it was and no exception will be thrown.



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# File 'lib/pokan/peer.rb', line 88

def status=(status)
  store(:status, status)
end

#store(key, value, timestamp = Time.now) ⇒ Object

Stores the value and the timestamp for a given key. If the key, which must be a symbol, already exists, it will be updated if the timestamp is greater. The timestamp defaults to Time.now.

If the key is ‘:role’, the values have to be ‘peer’ or ‘seed’. In the same way, if the key is ‘:status’, the value have to be ‘alive’ or ‘dead’. Otherwise, the value will not be set.



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# File 'lib/pokan/peer.rb', line 50

def store(key, value, timestamp = Time.now)
  case key
  when :role
    super(:role, value, timestamp)  if ['peer', 'seed'].include?(value)
  when :status
    super(:status, value, timestamp)  if ['alive', 'dead'].include?(value)
  else
    super(key, value, timestamp)
  end
end

#sync_with(host, port) ⇒ Object

Gossips with the given seed and replicates its local storage.

If the host or port is invalid, the local storage will continue empty.

Usage

peer = Pokan::Peer.new
peer.address = '127.0.0.2'
peer.port = '1234'
peer.value(:key_not_present) # => nil
peer.gossip_with('127.0.0.2', '8888')
peer.value(:key_not_present) # => 'the value of the key'



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# File 'lib/pokan/peer.rb', line 128

def sync_with(host, port)
  db = Connection.redis
  db.slaveof(host, port)
  sleep(3) #while db.info['master_sync_in_progress'].to_i == 0
  @seed = host
  db.slaveof('no', 'one')
end

#tcp_port ⇒ Object 



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# File 'lib/pokan/peer.rb', line 37

def tcp_port
  value(:tcp_port)
end

#tcp_port=(port) ⇒ Object 



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# File 'lib/pokan/peer.rb', line 33

def tcp_port=(port)
  store(:tcp_port, port)
end

#udp_port ⇒ Object 



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# File 'lib/pokan/peer.rb', line 29

def udp_port
  @udp_port = id.split(':')[1]
end

#udp_port=(port) ⇒ Object 



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# File 'lib/pokan/peer.rb', line 24

def udp_port=(port)
  @udp_port = port
  self.id = "#{@address}:#{@udp_port}"  if defined?(@address) && defined?(@udp_port)
end