Class: Nitra::Channel

Inherits:
Object
  • Object
show all
Defined in:
lib/nitra/channel.rb

Constant Summary collapse

ProtocolInvalidError = 
Class.new(StandardError)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(rd, wr) ⇒ Channel

Returns a new instance of Channel.



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# File 'lib/nitra/channel.rb', line 10

def initialize(rd, wr)
  @rd = rd
  @wr = wr
end

Instance Attribute Details

#raise_epipe_on_write_error ⇒ Object

Returns the value of attribute raise_epipe_on_write_error.



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# File 'lib/nitra/channel.rb', line 8

def raise_epipe_on_write_error
  @raise_epipe_on_write_error
end

#rd ⇒ Object (readonly)

Returns the value of attribute rd.



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# File 'lib/nitra/channel.rb', line 7

def rd
  @rd
end

#wr ⇒ Object (readonly)

Returns the value of attribute wr.



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# File 'lib/nitra/channel.rb', line 7

def wr
  @wr
end

Class Method Details

.pipe ⇒ Object 



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# File 'lib/nitra/channel.rb', line 15

def self.pipe
  c_rd, s_wr = IO.pipe
  s_rd, c_wr = IO.pipe
  [new(c_rd, c_wr), new(s_rd, s_wr)]
end

.read_select(channels) ⇒ Object 



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# File 'lib/nitra/channel.rb', line 21

def self.read_select(channels)
  fds = IO.select(channels.collect(&:rd))
  fds.first.collect do |fd|
    channels.detect {|c| c.rd == fd}
  end
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/nitra/channel.rb', line 28

def close
  rd.close
  wr.close
end

#read ⇒ Object 



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# File 'lib/nitra/channel.rb', line 33

def read
  return unless line = rd.gets
  if result = line.strip.match(/\ANITRA,(\d+)\z/)
    data = rd.read(result[1].to_i)
    YAML.load(data)
  else
    raise ProtocolInvalidError, "Expected nitra length line, got #{line.inspect}"
  end
end

#write(data) ⇒ Object 



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# File 'lib/nitra/channel.rb', line 43

def write(data)
  encoded = YAML.dump(data)
  wr.write("NITRA,#{encoded.bytesize}\n#{encoded}")
  wr.flush
rescue Errno::EPIPE
  raise if raise_epipe_on_write_error
end