node.h File Reference

Common CRTP base for every VLink communication primitive. More...

#include <atomic>
#include <memory>
#include <mutex>
#include <optional>
#include <string>
#include "./extension/security.h"
#include "./impl/node_impl.h"
#include "./internal/node-inl.h"

Include dependency graph for node.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
class	vlink::Node< ImplT, SecT >
	Transport-agnostic CRTP base for all VLink communication primitives. More...

Namespaces
	vlink

Detailed Description

Common CRTP base for every VLink communication primitive.

Node<ImplT, SecT> is the polymorphic base class shared by all six VLink communication primitives. It owns the transport-specific implementation pointer (impl_), drives the node lifecycle, and exposes the cross-cutting services that every primitive needs: zero-copy loans, peer-discovery toggling, message-loop attachment, recording, security installation, profiling, and SSL/TLS configuration.

Class Hierarchy

*   +--------------------------------------------------------------+
*   |                  User-facing primitives                      |
*   |  Publisher<T>   Subscriber<T>   Setter<T>    Getter<T>       |
*   |  Client<Req,Resp>               Server<Req,Resp>             |
*   +-----------------------------+--------------------------------+
*                                 | inherits
*   +-----------------------------v--------------------------------+
*   |                  Node<ImplT, SecT>                           |
*   |  lifecycle | loans | properties | profiler | ssl | security  |
*   +-----------------------------+--------------------------------+
*                                 | owns std::unique_ptr<ImplT>
*   +-----------------------------v--------------------------------+
*   |     ImplT  (PublisherImpl, SubscriberImpl, SetterImpl, ...)  |
*   +-----------------------------+--------------------------------+
*                                 | dispatches to transport
*   +-----------------------------v--------------------------------+
*   |    Transport back-ends                                       |
*   |    intra | shm | shm2 | dds | ddsc | zenoh | someip | ...    |
*   +--------------------------------------------------------------+
* 

Lifecycle State Diagram

*      +------------+    constructor    +------------+    init()    +------------+
*      | (uninited) |------------------>|  parsed    |------------->|   active   |
*      |            |  parse URL / Conf |  (impl_)   |  init_ext    | (using API)|
*      +------------+                   +------------+              +------------+
*                                              ^                          |
*                                              |  init()                  | interrupt()
*                                              |                          v
*                                       +------+------+            +-------------+
*                                       |  deinited   |<-----------|  blocking   |
*                                       |             |  deinit()  |  wait aborts|
*                                       +-------------+            +-------------+
*                                              |
*                                              | destructor (calls deinit if active)
*                                              v
*                                         destroyed
* 

Step	Method	Notes
Construction	constructor	Parses URL, creates impl via Conf factory.
Initialisation	init()	Runs impl init + init_ext, samples loans.
Active	publish / listen / ...	Normal operation.
Interrupt	interrupt()	Aborts blocking waits immediately.
Deinitialisation	deinit()	interrupt() then impl deinit + deinit_ext.
Destruction	destructor	Auto-deinits if still active.

ImplType Roles

ImplType	Primitive that uses it	Direction
kPublisher	Publisher<T>	Event write
kSubscriber	Subscriber<T>	Event read
kClient	Client<Req,Resp>	RPC caller
kServer	Server<Req,Resp>	RPC handler
kSetter	Setter<T>	Field write
kGetter	Getter<T>	Field read

Deferred Initialisation

vlink::Publisher<MyMsg> pub("dds://topic", vlink::InitType::kWithoutInit);
pub.set_ser_type("my.custom.Type");
pub.set_discovery_enabled(false);
pub.init();

Security

Use the Security* primitive aliases to enable per-message encryption. The Security::Config aggregate is passed as the second constructor argument; omitting it (or passing an empty aggregate) uses the built-in default symmetric slot:

vlink::Security::Config cfg;
cfg.key = "my-secret";
vlink::SecurityPublisher<MyMsg> pub("shm://topic", cfg);

Note

intra:// and dds:// CDR payloads do not support per-message security; constructing a Security* primitive there is a fatal.

Zero-copy Loans

On loan-capable transports the loan API avoids extra copies:

vlink::Publisher<vlink::Bytes> pub("shm://topic");
if (pub.is_support_loan()) {
  vlink::Bytes buf = pub.loan(payload_size);
  write_into(buf);
  pub.publish(buf);  // loan is returned automatically
}

Template Parameters

ImplT	Concrete transport implementation derived from NodeImpl.
SecT	Security mode: kWithoutSecurity (default) or kWithSecurity.

See also

publisher.h, subscriber.h, client.h, server.h, getter.h, setter.h, extension/security.h, extension/ssl_options.h