DDSI-RTPS 2.3 RTF Avatar
  1. OMG Issue

DDSIRTP23 — Key attributes and Regular attributes of a topic should be individually de-serializable

  • Key: DDSIRTP23-24
  • Legacy Issue Number: 16558
  • Status: open  
  • Source: PrismTech ( Angelo Corsaro)
  • Summary:

    Key attributes and Regular attributes of a topic should be individually de-serializable (or at least make the keyhash compulsory)

    [Nature] Architectural
    [Severity] Major

    [Description]
    The "DDS Interoperability Wire Protocol v2.1" defines a a serialization format for topic types in which
    it is not easy, nor efficient, to simply get access to the key of a given topic. This has to do with how CDR
    serializes structs but could be worked around with the new X-Types specification.
    In essence the problem is that some applications such as DDS routers (such as the PrismTech BlendBox)
    require to perform some operations that while requiring a knowledge of the instance do not require the deserialization
    of the data payload.

    [Resolution]
    For DDS implementation compatible with the X-Types ensure that the regular data attributes and the key attributes are serialized
    in different chunks and thus individually accessible in an efficient manner – meaning to access the key I would prefer not to scan all
    the regular attributes.

    For non X-Types compatible DDS implementations make the KeyHash compulsory, meaning require DDS compliant implementation to
    always send a key-hash along with a Data submessage.

  • Reported: DDSI-RTPS 2.0b1 — Mon, 19 Sep 2011 04:00 GMT
  • Updated: Tue, 22 Sep 2015 17:43 GMT