Method: Moped::Protocol::Message::ClassMethods#flags

Defined in:
lib/moped/protocol/message.rb

#flags(name, flag_map = {}) ⇒ Object

Declare a flag field (32 bit signed integer)

Examples:

class Update < Message
  flags :flags, upsert: 2 ** 0,
                multi:  2 ** 1
end

Parameters:

  • name (String) —

    the name of this field

  • flags (Hash{Symbol => Number}) —

    the flags for this flag field



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# File 'lib/moped/protocol/message.rb', line 154

def flags(name, flag_map = {})
  class_eval <<-RUBY, __FILE__, __LINE__ + 1
    def #{name}
      @#{name} ||= []
    end

    def #{name}=(flags)
      if flags.is_a? Numeric
        @#{name} = #{name}_from_int(flags)
      else
        @#{name} = flags
      end
    end

    def #{name}_as_int
      bits = 0
      flags = self.#{name}
      #{flag_map.map { |flag, value| "bits |= #{value} if flags.include? #{flag.inspect}" }.join "\n"}
      bits
    end

    def #{name}_from_int(bits)
      flags = []
      #{flag_map.map { |flag, value| "flags << #{flag.inspect} if #{value} & bits == #{value}" }.join "\n"}
      flags
    end

    def serialize_#{name}(buffer)
      buffer << [#{name}_as_int].pack('l<')
    end

    def deserialize_#{name}(buffer)
      bits, = buffer.read(4).unpack('l<')

      self.#{name} = bits
    end
  RUBY

  fields << name
end