ruby/lib/codec/mapping.rb

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#
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module Qpid::Proton
  module Codec

    # Maps between Proton types and their Ruby native language counterparts.
    #
    # @private
    class Mapping

      attr_reader :code
      attr_reader :put_method
      attr_reader :get_method

      @@by_code = {}
      @@by_class = {}

      # Creates a new mapping.
      #
      # ==== Arguments
      #
      # * code    - the AMQP code for this type
      # * name    - the AMQP name for this type
      # * klasses - native Ruby classes that are mapped to this AMQP type
      # * getter  - overrides the get method for the type
      def initialize(code, name, klasses = nil, getter = nil)

        @code = code
        @name = name

        @@by_code[code] = self

        unless klasses.nil?
          klasses.each do |klass|
            raise "entry exists for #{klass}" if @@by_class.keys.include? klass
            @@by_class[klass] = self unless klass.nil?
          end
        end

        @put_method = (name + "=").intern

        if getter.nil?
          @get_method = name.intern
        else
          @get_method = getter.intern
        end
      end

      def to_s; @name; end

      def put(data, value)
        data.__send__(@put_method, value)
      end

      def get(data)
        data.__send__(@get_method)
      end

      def self.for_class(klass)
        c = klass
        c = c.superclass while c && (x = @@by_class[c]).nil?
        raise TypeError, "#{klass} cannot be converted to AMQP" unless x
        x
      end

      def self.for_code(code)
        @@by_code[code]
      end

      # Convert x to a Mapping
      def self.[](x)
        case x
        when Mapping then x
        when Integer then @@by_code[x]
        when Types::Type then @@by_code[x.code]
        end
      end

    end

    NULL       = Mapping.new(Cproton::PN_NULL, "null", [NilClass])
    BOOL       = Mapping.new(Cproton::PN_BOOL, "bool", [TrueClass, FalseClass])
    UBYTE      = Mapping.new(Cproton::PN_UBYTE, "ubyte")
    BYTE       = Mapping.new(Cproton::PN_BYTE, "byte")
    USHORT     = Mapping.new(Cproton::PN_USHORT, "ushort")
    SHORT      = Mapping.new(Cproton::PN_SHORT, "short")
    UINT       = Mapping.new(Cproton::PN_UINT, "uint")
    INT        = Mapping.new(Cproton::PN_INT, "int")
    CHAR       = Mapping.new(Cproton::PN_CHAR, "char")
    ULONG      = Mapping.new(Cproton::PN_ULONG, "ulong")
    LONG       = Mapping.new(Cproton::PN_LONG, "long", [Integer])
    TIMESTAMP  = Mapping.new(Cproton::PN_TIMESTAMP, "timestamp", [Date, Time])
    FLOAT      = Mapping.new(Cproton::PN_FLOAT, "float")
    DOUBLE     = Mapping.new(Cproton::PN_DOUBLE, "double", [Float])
    DECIMAL32  = Mapping.new(Cproton::PN_DECIMAL32, "decimal32")
    DECIMAL64  = Mapping.new(Cproton::PN_DECIMAL64, "decimal64")
    DECIMAL128 = Mapping.new(Cproton::PN_DECIMAL128, "decimal128")
    UUID       = Mapping.new(Cproton::PN_UUID, "uuid")
    BINARY     = Mapping.new(Cproton::PN_BINARY, "binary")
    STRING     = Mapping.new(Cproton::PN_STRING, "string", [::String,
                                                            Types::UTFString,
                                                            Types::BinaryString])
    SYMBOL     = Mapping.new(Cproton::PN_SYMBOL, "symbol", [::Symbol])
    DESCRIBED  = Mapping.new(Cproton::PN_DESCRIBED, "described", [Types::Described])
    ARRAY      = Mapping.new(Cproton::PN_ARRAY, "array", [Types::UniformArray])
    LIST       = Mapping.new(Cproton::PN_LIST, "list", [::Array])
    MAP        = Mapping.new(Cproton::PN_MAP, "map", [::Hash])

    private

    class << STRING
      def put(data, value)
        # if we have a symbol then convert it to a string
        value = value.to_s if value.is_a?(Symbol)

        isutf = false

        if value.is_a?(Types::UTFString)
          isutf = true
        else
          # For Ruby 1.8 we will just treat all strings as binary.
          # For Ruby 1.9+ we can check the encoding first to see what it is
          if RUBY_VERSION >= "1.9"
            # If the string is ASCII-8BIT then treat is as binary. Otherwise,
            # try to convert it to UTF-8 and, if successful, send as that.
            if value.encoding != Encoding::ASCII_8BIT &&
                value.encode(Encoding::UTF_8).valid_encoding?
              isutf = true
            end
          end
        end

        data.string = value if isutf
        data.binary = value if !isutf
      end
    end

    class << MAP
      def put(data, map, options = {})
        data.put_map
        data.enter
        map.each_pair do |key, value|
          if options[:keys] == :SYMBOL
            SYMBOL.put(data, key)
          else
            data.object = key
          end

          if value.nil?
            data.null
          else
            data.object = value
          end
        end
        data.exit
      end
    end

    class << DESCRIBED
      def put(data, described)
        data.put_described
        data.enter
        data.object = described.descriptor
        data.object = described.value
        data.exit
      end
    end
  end
end