详细描述

Transport configuration for the dds:// Fast-DDS RTPS backend.

DdsConf configures the eProsima Fast-DDS (Fast-RTPS) transport, which provides standards-compliant DDS pub/sub and RPC over Ethernet. It is the primary cross-machine transport in VLink and is suitable for both LAN and WAN deployments.

Supported Node Types: dds:// supports all six node types: kPublisher, kSubscriber, kServer, kClient, kSetter, and kGetter.

URL Format: dds://<topic>[?domain=<N>&depth=<N>&qos=<name>]

dds://<topic>[?domain=<N>&part=<v>&topic=<v>&pub=<v>&sub=<v>&writer=<v>&reader=<v>]

Component	Description
`topic`	DDS topic name; formed from `host` + `"/"` + `path`
`domain`	DDS Domain ID (?domain=, default from `VLINK_DDS_DOMAIN` env var)
`depth`	History depth for the DDS endpoint (?depth=, default 0)
`qos`	Named QoS profile registered via `register_qos()` (?qos=)
`qos_ext`	Extended QoS map: `part`, `topic`, `pub`, `sub`, `writer`, `reader`

QoS Registration: Named QoS profiles must be registered before creating any dds:// nodes:
vlink::Qos my_qos;

my_qos.reliability = vlink::Reliability::kReliable;

my_qos.durability = vlink::Durability::kTransientLocal;

vlink::DdsConf::register_qos("my_profile", my_qos);

vlink::Subscriber<MyMsg> sub("dds://my_topic?qos=my_profile");

vlink::Subscriber
Type-safe subscriber for the VLink event communication model.
定义 subscriber.h:110

vlink::Qos
Aggregate Quality of Service policy for a VLink communication endpoint.
定义 qos.h:86

vlink::Qos::durability
Durability durability
Sample persistence policy.
定义 qos.h:308

vlink::Qos::reliability
Reliability reliability
Delivery guarantee policy.
定义 qos.h:306

Type Support Registration: For CDR-serialised types the DDS type support factory must be registered before any publisher or subscriber is created on that topic:
// Register request type only (for pub/sub):

vlink::DdsConf::register_topic<MyMsgPubSubType>("my_topic");

// Register request + response types (for RPC):

vlink::DdsConf::register_topic<MyReqPubSubType, MyRespPubSubType>("my_rpc_topic");

// Register from a full URL:

vlink::DdsConf::register_url<MyMsgPubSubType>("dds://my_topic?domain=1");

Global QoS File: An XML QoS profile file can be loaded at startup so that DDS participants and endpoints inherit profiles by name:
vlink::DdsConf::load_global_qos_file("/etc/vlink/dds_profile.xml");

注解: This header is compiled only when VLINK_SUPPORT_DDS is defined.; qos and qos_ext are mutually exclusive; setting both causes is_valid() to return false.; Response topics are automatically registered with a "___resp" suffix.