Serialization to string

patrickr — Thu, 31 May 2007 04:37:21 -0700

Since some time Eiffel supports a serialization method completely written in Eiffel. It directly supports serialization to a file or to memory. This example shows how to use this to serialize an arbitrary object structure to a string. The trick is to serialize to memory and look at the serialized byte buffer as a c string which then can be read into an Eiffel string. To deserialize we do the reverse.

serialize (a_object: ANY): STRING is

        -- Serialize `a_object'.

    require

        a_object_not_void: a_object /= Void

    local

        l_sed_rw: SED_MEMORY_READER_WRITER

        l_sed_ser: SED_INDEPENDENT_SERIALIZER

        l_cstring: C_STRING

        l_cnt: INTEGER

    do

        create l_sed_rw.make

        l_sed_rw.set_for_writing

        create l_sed_ser.make (l_sed_rw)

        l_sed_ser.set_root_object (a_object)

        l_sed_ser.encode

            -- the `count' gives us the number of bytes 

            -- we have to read and put into the string.

        l_cnt := l_sed_rw.count

        create l_cstring.make_by_pointer_and_count (l_sed_rw.buffer.item, l_cnt)

        Result := l_cstring.substring (1, l_cnt)

    ensure

        serialize_not_void: Result /= Void

    end

deserialize (a_string: STRING): ANY is

        -- Deserialize `a_string'.

    require

        a_string_not_void: a_string /= Void

    local

        l_sed_rw: SED_MEMORY_READER_WRITER

        l_sed_ser: SED_INDEPENDENT_DESERIALIZER

        l_cstring: C_STRING

    do

        create l_cstring.make (a_string)

        create l_sed_rw.make_with_buffer (l_cstring.managed_data)

        l_sed_rw.set_for_reading

        create l_sed_ser.make (l_sed_rw)

        l_sed_ser.decode (True)

        Result := l_sed_ser.last_decoded_object

    end

eiffelroom - Serialization to string - Comments

Serialization to string