Class: BinaryBlocker::BitFieldEncoder

Inherits:
Encoder
  • Object
show all
Defined in:
lib/blocker.rb

Instance Method Summary collapse

Methods inherited from Encoder

#block, #deblock, #key_value?, #me

Constructor Details

#initialize(type, bit_info, *opts) ⇒ BitFieldEncoder

Returns a new instance of BitFieldEncoder.



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# File 'lib/blocker.rb', line 1002

def initialize(type, bit_info, *opts)
  @type = BinaryBlocker.pack_symbols[type] || type
  @length = BinaryBlocker.sizeof_format(@type)
  @bit_info = {}
  pos = 0
  bit_info.each do |bi|
    case bi
    when Symbol
      @bit_info[bi.to_sym] = [pos,1]
      pos += 1
      
    when Fixnum
      pos += bi
      
    when Array
      @bit_info[bi.first.to_sym] = [pos, bi.last.to_i]
      pos += bi.last.to_i
    end
  end
  @value = 0
  initialize_options(*opts)
  initialize_data(*opts)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(sym, *args) ⇒ Object 



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# File 'lib/blocker.rb', line 1044

def method_missing(sym, *args)
  if (bi = @bit_info[sym])
    v = @value >> bi.first
    mask = (1 << bi.last) - 1
    v = v & mask
  else
    sym = sym.to_s
    if sym[-1] == ?=
      if bi = @bit_info[sym[0..-2].to_sym]
        @value &= ~(((1 << bi.last) - 1) << bi.first)
        @value |= args.first.to_i << bi.first 
        return @value
      end
    end
    raise NoMethodError.new("undefined method `#{sym}''")
    # I was using super, but it was throwing a different error
    # which seemed wrong, not sure why
  end
end

Instance Method Details

#internal_block(val) ⇒ Object 



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# File 'lib/blocker.rb', line 1026

def internal_block(val)
  [val.raw_value || 0].pack(@type)
end

#internal_deblock(io) ⇒ Object 



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# File 'lib/blocker.rb', line 1030

def internal_deblock(io)
  buffer = io.read(@length)
  result = buffer.unpack(@type)
  result.first
end

#raw_value ⇒ Object 



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# File 'lib/blocker.rb', line 1040

def raw_value
  @value
end

#value ⇒ Object 



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# File 'lib/blocker.rb', line 1036

def value
  self
end