discovery_viewer.h File Reference

Live aggregator of VLink endpoint announcements emitted by DiscoveryReporter. More...

#include <cstdint>
#include <memory>
#include <string>
#include <vector>
#include "../base/functional.h"
#include "../base/macros.h"
#include "../base/message_loop.h"
#include "../impl/types.h"

Include dependency graph for discovery_viewer.h:

Go to the source code of this file.

Classes
class	vlink::DiscoveryViewer
	MessageLoop-based aggregator of live VLink endpoint announcements. More...
struct	vlink::DiscoveryViewer::Process
	Identity of a process that hosts at least one endpoint for a URL. More...
struct	vlink::DiscoveryViewer::Info
	One row of the discovery snapshot, describing a URL and its publishers/subscribers. More...

Namespaces
	vlink

Detailed Description

Live aggregator of VLink endpoint announcements emitted by DiscoveryReporter.

DiscoveryViewer is the listening counterpart of DiscoveryReporter. It joins the discovery UDP multicast group, decodes incoming announcements, and maintains an in-memory snapshot of every URL/process currently advertised on the host or network. It powers vlink-cli, dashboards and any custom monitoring tool that needs a live topology view.

Filter modes select which announcements survive into the snapshot:

Value	Description
kFilterNone	Keep every announcement regardless of origin
kFilterAvailable	Drop remote announcements for local-only URL schemes (intra, shm, ...)
kFilterNative	Keep only announcements emitted by the same host as the viewer

Viewer interaction:

*   DiscoveryReporter --(UDP multicast)--> +----------------+    Callback(info_list)
*                                          |    Viewer      | ---------------------> user code
*   Heartbeat timeout         ----+--->    |  (MessageLoop) | <--- get_info_list()
*   process_offline()         ----+--->    +----------------+
* 

Example

vlink::DiscoveryViewer viewer(vlink::DiscoveryViewer::kFilterAvailable);
viewer.register_callback([](const std::vector<vlink::DiscoveryViewer::Info>& list) {
  for (const auto& entry : list) {
    VLOG_I("url=", entry.url, " ser=", entry.ser_type,
           " hosts=", entry.process_list.size());
  }
});
viewer.async_run();

Note

The callback runs on the viewer's MessageLoop thread; copy the snapshot if it needs to outlive the call. Endpoints whose heartbeat lapses are pruned automatically.