Class: Cosmos::SerialStream

Inherits:
Stream show all
Defined in:
lib/cosmos/streams/serial_stream.rb

Overview

Stream that reads and writes to serial ports by using SerialDriver.

Instance Method Summary collapse

Constructor Details

#initialize(write_port_name, read_port_name, baud_rate, parity, stop_bits, write_timeout, read_timeout, flow_control = :NONE, data_bits = 8) ⇒ SerialStream 



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# File 'lib/cosmos/streams/serial_stream.rb', line 49

def initialize(write_port_name,
               read_port_name,
               baud_rate,
               parity,
               stop_bits,
               write_timeout,
               read_timeout,
               flow_control = :NONE,
               data_bits = 8)
  super()

  # The SerialDriver class will validate the parameters
  @write_port_name = ConfigParser.handle_nil(write_port_name)
  @read_port_name  = ConfigParser.handle_nil(read_port_name)
  @baud_rate       = Integer(baud_rate)
  @parity          = parity
  @stop_bits       = stop_bits.to_i
  @write_timeout   = ConfigParser.handle_nil(write_timeout)
  @write_timeout   = @write_timeout.to_f if @write_timeout
  @read_timeout    = ConfigParser.handle_nil(read_timeout)
  @read_timeout    = @read_timeout.to_f if @read_timeout
  @flow_control    = flow_control.to_s.intern
  @data_bits       = data_bits.to_i

  if @write_port_name
    @write_serial_port = SerialDriver.new(@write_port_name,
                                          @baud_rate,
                                          @parity,
                                          @stop_bits,
                                          @write_timeout,
                                          @read_timeout,
                                          @flow_control,
                                          @data_bits)
  else
    @write_serial_port = nil
  end
  if @read_port_name
    if @read_port_name == @write_port_name
      @read_serial_port = @write_serial_port
    else
      @read_serial_port = SerialDriver.new(@read_port_name,
                                           @baud_rate,
                                           @parity,
                                           @stop_bits,
                                           @write_timeout,
                                           @read_timeout,
                                           @flow_control,
                                           @data_bits)
    end
  else
    @read_serial_port = nil
  end
  if @read_serial_port.nil? && @write_serial_port.nil?
    raise "Either a write port or read port must be given"
  end

  # We 'connect' when we create the stream
  @connected = true

  # Mutex on write is needed to protect from commands coming in from more
  # than one tool
  @write_mutex = Mutex.new
end

Instance Method Details

#connect ⇒ Object

Connect the stream



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# File 'lib/cosmos/streams/serial_stream.rb', line 139

def connect
  # N/A - Serial streams 'connect' on creation
end

#connected? ⇒ Boolean 



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# File 'lib/cosmos/streams/serial_stream.rb', line 145

def connected?
  @connected
end

#disconnect ⇒ Object

Disconnect by closing the serial ports



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# File 'lib/cosmos/streams/serial_stream.rb', line 150

def disconnect
  if @connected
    begin
      @write_serial_port.close if @write_serial_port && !@write_serial_port.closed?
    rescue IOError
      # Ignore
    end

    begin
      @read_serial_port.close if @read_serial_port && !@read_serial_port.closed?
    rescue IOError
      # Ignore
    end
    @connected = false
  end
end

#read ⇒ String 



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# File 'lib/cosmos/streams/serial_stream.rb', line 114

def read
  raise "Attempt to read from write only stream" unless @read_serial_port

  # No read mutex is needed because reads happen serially
  @read_serial_port.read
end

#read_nonblock ⇒ String 



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# File 'lib/cosmos/streams/serial_stream.rb', line 122

def read_nonblock
  raise "Attempt to read from write only stream" unless @read_serial_port

  # No read mutex is needed because reads happen serially
  @read_serial_port.read_nonblock
end

#write(data) ⇒ Object 



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# File 'lib/cosmos/streams/serial_stream.rb', line 130

def write(data)
  raise "Attempt to write to read only stream" unless @write_serial_port

  @write_mutex.synchronize do
    @write_serial_port.write(data)
  end
end