Module: BitFields::InstanceMethods

Included in:
BitFields
Defined in:
lib/bit_fields.rb

Defined Under Namespace

Classes: ValueOverflow

Instance Attribute Summary collapse

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object 



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# File 'lib/bit_fields.rb', line 251

def method_missing name, *args
  if @raw.respond_to? name
    @raw.send name, *args
  else
    super
  end
end

Instance Attribute Details

#attributes ⇒ Object (readonly)

caches the bit field values



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# File 'lib/bit_fields.rb', line 160

def attributes
  @attributes
end

#raw ⇒ Object (readonly)

Contains the raw string



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# File 'lib/bit_fields.rb', line 157

def raw
  @raw
end

#unpacked ⇒ Object (readonly)

caches the bin string unpacked values



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# File 'lib/bit_fields.rb', line 163

def unpacked
  @unpacked
end

Instance Method Details

#[](name) ⇒ Object

Makes defined fields accessible like a Hash



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# File 'lib/bit_fields.rb', line 179

def [](name) 
  self.attributes[name]
end

#initialize(bit_string_or_hash) ⇒ Object

Takes the raw binary string and parses it



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# File 'lib/bit_fields.rb', line 169

def initialize bit_string_or_hash
  if bit_string_or_hash.kind_of?(Hash)
    @attributes = bit_string_or_hash
    pack_bit_fields
  else
    parse_bit_fields(bit_string_or_hash) #.dup.freeze REMOVED: seems useless
  end
end

#pack_bit_fields ⇒ Object Also known as: pack

Parses the raw value extracting the defined bit fields



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# File 'lib/bit_fields.rb', line 215

def pack_bit_fields
  @unpacked = []
  
  self.class.fields.each_with_index do |name, position|
    
    if bit_fields = self.class.bit_fields[name]
    
      bit_value = 0
      bit_fields.each do |(bit_name, bits_number, bit_mask)|
        masked = @attributes[bit_name] & bit_mask
        
        raise ValueOverflow, 
              "the value #{@attributes[bit_name]} "+
              "is too big for #{bits_number} bits" if masked != @attributes[bit_name]
        
        bit_value = bit_value << bits_number
        bit_value |= masked
      end
      
      # Value of fields composed by binary fields is always overwritten
      # by the composition of the latter
      attributes[name] = bit_value
    end
    
    @unpacked[position] = @attributes[name] || 0
    
  end
  
  @raw = @unpacked.pack( self.class.unpack_recipe )
end

#to_s ⇒ Object 



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# File 'lib/bit_fields.rb', line 247

def to_s
  raw.to_s
end