Class: Arpie::PackBinaryType

Inherits:
BinaryType show all
Defined in:
lib/arpie/binary/pack_type.rb

Constant Summary

Constants included from Arpie

MTU, VERSION

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from BinaryType

#check_limit, #required_opts

Methods included from Arpie

#bogon!, #incomplete!

Constructor Details

#initialize(pack_string, force_opts = {}) ⇒ PackBinaryType

Returns a new instance of PackBinaryType.



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# File 'lib/arpie/binary/pack_type.rb', line 43

def initialize pack_string, force_opts = {}
  @pack_string = pack_string
  @force_opts = force_opts
end

Instance Attribute Details

#pack_string ⇒ Object (readonly)

Returns the value of attribute pack_string.



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# File 'lib/arpie/binary/pack_type.rb', line 3

def pack_string
  @pack_string
end

Class Method Details

.length_of(format) ⇒ Object 



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# File 'lib/arpie/binary/pack_type.rb', line 10

def self.length_of format
  length = 0
  format.scan(/(\S_?)\s*(\d*)/).each do |directive, count|
    count = count.to_i
    count = 1 if count == 0

    length += case directive
    when 'A', 'a', 'C', 'c', 'Z', 'x'
      count
    when 'B', 'b'
      (count / 8.0).ceil
    when 'D', 'd', 'E', 'G'
      count * 8
    when 'e', 'F', 'f', 'g'
      count * 4
    when 'H', 'h'
      (count / 2.0).ceil
    when 'I', 'i', 'L', 'l', 'N', 'V'
      count * 4
    when 'n', 'S', 's', 'v'
      count * 2
    when 'Q', 'q'
      count * 8
    when 'X'
      count * -1
    else
      raise ArgumentError, "#{directive} is not supported"
    end
  end

  length
end

Instance Method Details

#binary_size(opts) ⇒ Object 



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# File 'lib/arpie/binary/pack_type.rb', line 5

def binary_size opts
  opts = @force_opts.merge(opts || {})
  PackBinaryType.length_of(@pack_string + (opts[:length] || 1).to_s)
end

#from(binary, opts) ⇒ Object 



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# File 'lib/arpie/binary/pack_type.rb', line 48

def from binary, opts
  opts = @force_opts.merge(opts || {})
  binary && binary.size >= binary_size(opts) or incomplete!
  len = opts[:length] || 1
  pack_string = @pack_string + len.to_s
  value = binary.unpack(pack_string)[0]
  value += opts[:mod] if opts[:mod]
  check_limit value, opts[:limit]

  [value, binary_size(opts)]
end

#to(object, opts) ⇒ Object 



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# File 'lib/arpie/binary/pack_type.rb', line 60

def to object, opts
  opts = @force_opts.merge(opts || {})
  object.nil? and bogon! nil,"nil object given"
  object -= opts[:mod] if opts[:mod]
  len = opts[:length] || 1
  pack_string = @pack_string + len.to_s
  [object].pack(pack_string)
end