Objects and Data Structures

In order to make the most of eProsima Fast RTPS it is important to have a grasp of the objects and data structures that conform the library. eProsima Fast RTPS objects are classified by modules, which are briefly listed and described in this section. For full coverage take a look at the API Reference document that comes with the distribution.

Publisher Subscriber Module

This module composes the Publisher-Subscriber abstraction we saw in the Library Overview. The concepts here are higher level than the RTPS standard.

  • Domain Used to create, manage and destroy high-level Participants.

  • Participant Contains Publishers and Subscribers, and manages their configuration.

    • ParticipantAttributes Configuration parameters used in the creation of a Participant.
    • ParticipantListener Allows you to implement callbacks within scope of the Participant.
  • Publisher Sends (publishes) data in the form of topic changes.

    • PublisherAttributes Configuration parameters for the construction of a Publisher.
    • PublisherListener Allows you to implement callbacks within scope of the Publisher.
  • Subscriber Receives data for the topics it subscribes to.

    • SubscriberAttributes Configuration parameters for the construction of a Subscriber.
    • SubscriberListener Allows you to implement callbacks within scope of the Subscriber.

RTPS Module

This module directly maps to the ideas defined in the RTPS standard, and allows you to interact with RTPS entities directly. It consists of a few sub-modules:

RTPS Common

  • CacheChange_t Represents a change to a topic, to be stored in a history cache.
  • Data Payload associated to a cache change. May be empty depending on the message and change type.
  • Message Defines the organization of a RTPS Message.
  • Header Standard header that identifies a message as belonging to the RTPS protocol, and includes the vendor id.
  • Sub-Message Header Identifier for an RTPS sub-message. An RTPS Message can be composed of several sub-messages.
  • MessageReceiver Deserializes and processes received RTPS messages.
  • RTPSMessageCreator Composes RTPS messages.

RTPS Domain

  • RTPSDomain Use it to create, manage and destroy low-level RTPSParticipants.

  • RTPSParticipant Contains RTPS Writers and Readers, and manages their configuration.

    • RTPSParticipantAttributes Configuration parameters used in the creation of an RTPS Participant.
    • PDPSimple Allows the participant to become aware of the other participants within the Network, through the Participant Discovery Protocol.
    • EDPSimple Allows the Participant to become aware of the endpoints (RTPS Writers and Readers) present in the other Participants within the network, through the Endpoint Discovery Protocol.
    • EDPStatic Reads information about remote endpoints from a user file.
    • TimedEvent Base class for periodic or timed events.

RTPS Reader

  • RTPSReader Base class for the reader endpoint.

    • ReaderAttributes Configuration parameters used in the creation of an RTPS Reader.
    • ReaderHistory History data structure. Stores recent topic changes.
    • ReaderListener Use it to define callbacks in scope of the Reader.

RTPS Writer

  • RTPSWriter Base class for the writer endpoint.

    • WriterAttributes Configuration parameters used in the creation of an RTPS Writer.
    • WriterHistory History data structure. Stores outgoing topic changes and schedules them to be sent.