Class: NL::KndClient::SimpleKndClient

Inherits:
Object
  • Object
show all
Defined in:
lib/nl/knd_client/simple_knd_client.rb

Overview

A simple KND client that uses a background thread for I/O and works without EventMachine. This client does not (yet) support all of KND’s features.

Instance Method Summary collapse

Constructor Details

#initialize(host: 'localhost', port: 14308) ⇒ SimpleKndClient

Returns a new instance of SimpleKndClient.



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 9

def initialize(host: 'localhost', port: 14308)
  @host = host
  @port = 14308

  @callbacks = {}
  @zones = {}
end

Instance Method Details

#close ⇒ Object

Close the connection to KND and stop the background thread.



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 40

def close
  @run = false
  @t&.wakeup
  @t&.kill
  @socket&.close
  @t = nil
  @socket = nil
end

#get_depth ⇒ Object

Waits for and then returns depth data.



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 63

def get_depth
  data = nil
  t = Thread.current

  cb = ->(d) { data = d; t.wakeup }
  on_zone('! DEPTH', &cb)

  request_depth
  sleep(1)

  raise "Data wasn't set within 1 second" if data.nil?

  data
ensure
  remove_callback('! DEPTH', &cb)
end

#on_zone(name, &block) ⇒ Object

Calls the given block with the current full state of a zone, the type of command received for a zone, and the updates for the zone. ‘! DEPTH’ is a special zone name for depth images [HACK].



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 20

def on_zone(name, &block)
  @callbacks[name] ||= []
  @callbacks[name] << block
end

#open ⇒ Object

Connect to KND.



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 32

def open
  @socket = TCPSocket.new(@host, @port)
  @run = true
  @t = Thread.new do read_loop end
  @socket.puts('sub')
end

#remove_callback(name, &block) ⇒ Object

Removes the given callback from the given zone name. ‘! DEPTH’ is a special zone name for depth images [HACK].



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 27

def remove_callback(name, &block)
  @callbacks[name]&.delete(block)
end

#request_depth ⇒ Object

Sends the getdepth command to KND to request async delivery of a single depth frame.



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 51

def request_depth
  @socket.puts('getdepth')
end

#subscribe_depth(count = nil) ⇒ Object

Sends the subdepth command to KND to request continuous async delivery of depth frames. The optional count will cause only that number of frames to be delivered.



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# File 'lib/nl/knd_client/simple_knd_client.rb', line 58

def subscribe_depth(count = nil)
  @socket.puts("subdepth#{count && " #{count}"}")
end