qos_profile.h File Reference

Curated catalogue of pre-built Qos instances for common VLink workloads. More...

#include <string>
#include <unordered_map>
#include "../base/macros.h"
#include "./qos.h"

Include dependency graph for qos_profile.h:

Go to the source code of this file.

Namespaces
	vlink
	vlink::QosProfile
	Pre-built Qos constants for common autonomy and embedded workloads.

Functions
VLINK_EXPORT const std::unordered_map< std::string, Qos > &	vlink::QosProfile::get_available_qos_map () noexcept
	Returns the name-to-Qos lookup table containing every profile in this namespace. More...

Detailed Description

Curated catalogue of pre-built Qos instances for common VLink workloads.

Picking the right Qos for a topic involves balancing reliability, history depth, durability, publish mode and priority. This file declares sixteen ready-to-use constexpr profiles inside vlink::QosProfile, each tuned for a specific class of traffic encountered in autonomy and embedded stacks. Every profile is constructed with valid set to true and can be passed straight to any VLink endpoint or registered with a transport (DdsConf::register_qos) before being referenced from a URL.

Profile catalogue (use-case oriented):

Profile	Reliability	History	Durability	PublishMode	Priority
kEvent	Reliable	KeepLast(5)	Volatile	Sync	RealTime
kMethod	Reliable	KeepAll	Volatile	Sync	High
kField	Reliable	KeepLast(1)	TransientLocal	Sync	High
kSensor	BestEffort	KeepLast(10)	Volatile	ASync	Normal*
kParameter	Reliable	KeepLast(500)	TransientLocal	Sync	Normal
kService	Reliable	KeepLast(10)	TransientLocal	Sync	Normal
kClock	BestEffort	KeepLast(1)	Volatile	Sync	Low*
kStatic	Reliable	KeepAll	TransientLocal	Sync	Normal
kLight	Reliable	KeepLast(1)	Volatile	ASync	High
kPoor	BestEffort	KeepLast(5)	Volatile	ASync	Background
kBetter	BestEffort	KeepLast(50)	Volatile	Sync	RealTime
kBest	Reliable	KeepLast(200)	Volatile	Sync	RealTime
kLarge	Reliable (HB500)	KeepLast(500)	Volatile	Sync	Low
kAlarm	Reliable	KeepAll	TransientLocal	Sync	RealTime*
kCommand	Reliable	KeepLast(1)	Volatile	Sync	RealTime
kLog	Reliable	KeepLast(100)	Volatile	ASync	Background

Profiles marked * (kSensor, kClock, kAlarm) are dispatched as express (the is_express flag is set). Use-case mapping: kEvent = discrete control events, kMethod = RPC, kField = latest-value state sync, kSensor = high-rate sensors, kParameter = slow config, kService = discovery, kClock = time sync, kStatic = maps / calibration, kLight = small frequent traffic, kPoor = low-priority telemetry, kBetter = best-effort throughput, kBest = reliable throughput, kLarge = large payload (heartbeat 500 ms), kAlarm = safety-critical alarms, kCommand = actuator commands, kLog = log streams.

Looking profiles up by name

const auto& qos_map = vlink::QosProfile::get_available_qos_map();
 
if (auto it = qos_map.find("sensor"); it != qos_map.end()) {
  vlink::DdsConf::register_qos("my_sensor_qos", it->second);
}

Using a profile by URL

// Built-in names are recognised directly in URLs:
auto pub = vlink::Publisher<MyMsg>::create_unique("dds://sensor_data?qos=sensor");
 
// Or apply a profile programmatically:
vlink::Qos qos = vlink::QosProfile::kField;
qos.history.depth = 5;        // tweak the depth before use
vlink::DdsConf::register_qos("my_field_qos", qos);