MessageLoop-based aggregator of live VLink endpoint announcements. More...

#include <discovery_viewer.h>

Inheritance diagram for vlink::DiscoveryViewer:

Collaboration diagram for vlink::DiscoveryViewer:

Classes
struct	Info
	One row of the discovery snapshot, describing a URL and its publishers/subscribers. More...

struct	Process
	Identity of a process that hosts at least one endpoint for a URL. More...

Public Types
enum	FilterType : uint8_t { kFilterNone = 0 , kFilterAvailable = 1 , kFilterNative = 2 }
	Selects which announcements contribute to the live snapshot. More...

using	Callback = Function< void(const std::vector< Info > &info_list)>
	Callback signature delivered whenever the snapshot changes. More...

Public Types inherited from vlink::MessageLoop
enum	Type : uint8_t { kNormalType = 0 , kLockfreeType = 1 , kPriorityType = 2 }
	Internal queue implementation type. More...

enum	Strategy : uint8_t { kOptimizationStrategy = 0 , kPopStrategy = 1 , kBlockStrategy = 2 }
	Back-pressure strategy applied when the bounded queue is at capacity. More...

enum	Priority : uint16_t { kNoPriority = 0 , kLowestPriority = 1 , kTimerPriority = 50 , kNormalPriority = 100 , kHighestPriority = std::numeric_limits<uint16_t>::max() }
	Built-in priority levels for `kPriorityType` loops; higher values dispatch first. More...

using	Callback = MoveFunction< void()>
	Callback type for tasks and event handlers. More...

Public Member Functions
	DiscoveryViewer (FilterType type=kFilterNone)
	Builds the viewer with the requested filter mode. More...

	~DiscoveryViewer () override
	Stops the viewer loop and releases resources. More...

void	register_callback (Callback &&callback)
	Registers the callback notified on every snapshot change. More...

std::vector< Info >	get_info_list ()
	Returns a copy of the live snapshot at the moment of the call. More...

std::string	get_ser_type (const std::string &url) const
	Resolves the announced serialisation type for `url`. More...

SchemaType	get_schema_type (const std::string &url) const
	Resolves the announced coarse schema family for `url`. More...

Public Member Functions inherited from vlink::MessageLoop
	MessageLoop ()
	Constructs a loop with the default `kNormalType` queue. More...

	MessageLoop (Type type)
	Constructs a loop with the given queue type. More...

virtual	~MessageLoop ()
	Destructor; requests quit and joins the dispatcher thread if needed. More...

void	set_name (const std::string &name)
	Sets a human-readable name visible to profiling tools. More...

const std::string &	get_name () const
	Returns the loop name set via `set_name`. More...

Type	get_type () const
	Returns the queue type this loop was constructed with. More...

Strategy	get_strategy () const
	Returns the active back-pressure strategy. More...

void	set_strategy (Strategy strategy)
	Replaces the back-pressure strategy. More...

void	register_begin_handler (Callback &&callback)
	Registers a callback fired once at loop thread startup. More...

void	register_end_handler (Callback &&callback)
	Registers a callback fired once when the loop thread exits. More...

void	register_idle_handler (Callback &&callback)
	Registers a callback fired every time the queue becomes empty. More...

bool	run ()
	Runs the loop on the calling thread until `quit` is requested. More...

bool	async_run ()
	Starts the loop on a new background thread. More...

bool	spin ()
	Alias of `run` blocking the calling thread. More...

bool	spin_once (bool block=true)
	Processes one batch of pending tasks and timers on the calling thread. More...

bool	quit (bool force=false)
	Requests the loop to exit. More...

bool	wait_for_quit (int ms=Timer::kInfinite, bool check=true)
	Waits until the loop has fully exited. More...

bool	post_task (Callback &&callback)
	Posts a task for execution on the loop thread. More...

TaskHandle	post_task_handle (Callback &&callback, const PostTaskOptions &options={})
	Tracked variant of `post_task` returning a `TaskHandle`. More...

bool	post_task_with_priority (Callback &&callback, uint16_t priority)
	Posts a task with an explicit priority on a `kPriorityType` loop. More...

TaskHandle	post_task_with_priority_handle (Callback &&callback, uint16_t priority, const PostTaskOptions &options={})
	Tracked variant of `post_task_with_priority` returning a `TaskHandle`. More...

template<typename CallbackT , typename = std::enable_if_t<!std::is_convertible_v<CallbackT, Schedule::RetCallback>>>
Schedule::Status	exec_task (const Schedule::Config &config, CallbackT &&callback)
	Schedules a `void-returning` callable and returns a chainable `Schedule::Status`. More...

template<typename CallbackT , typename = std::enable_if_t<std::is_convertible_v<CallbackT, Schedule::RetCallback>>>
Schedule::RetStatus	exec_task (const Schedule::Config &config, CallbackT &&callback)
	Schedules a `bool-returning` callable and returns a chainable `Schedule::RetStatus`. More...

bool	wakeup ()
	Wakes the loop thread if it is suspended in its idle wait. More...

void	reset_lockfree_capacity ()
	Recreates the lock-free queue, clearing all queued tasks and counters. More...

bool	is_running () const
	Reports whether the loop is currently running. More...

bool	is_ready_to_quit () const
	Reports whether `quit` has been requested and the loop is winding down. More...

bool	is_busy () const
	Reports whether the loop is currently executing a task. More...

size_t	get_task_count () const
	Returns the current pending task count. More...

virtual bool	wait_for_idle (int ms=Timer::kInfinite, bool check=true)
	Waits until the loop has drained its queue and is not executing a task. More...

virtual size_t	get_max_timer_count () const
	Returns the maximum number of timers that can be attached. More...

virtual bool	is_in_same_thread () const
	Reports whether the calling thread is owned by this loop. More...

std::shared_ptr< AliveState >	get_alive_state () const
	Returns the shared lifetime flag used by cross-thread bridges. More...

template<class FunctionT , class... ArgsT, typename ResultT = std::invoke_result_t<FunctionT, ArgsT...>>
std::future< ResultT >	invoke_task (FunctionT &&function, ArgsT &&... args)
	Dispatches a callable to the loop thread and returns a `std::future` for the result. More...

template<class FunctionT , class... ArgsT, typename ResultT = std::invoke_result_t<FunctionT, ArgsT...>>
std::future< ResultT >	invoke_task_with_priority (FunctionT &&function, uint16_t priority, ArgsT &&... args)
	Priority variant of `invoke_task`; requires a `kPriorityType` loop. More...

Static Public Member Functions
static ImplType	convert_type (std::string_view str)
	Translates a discovery role token to the corresponding `ImplType` bit. More...

static std::string	convert_type_to_view (uint32_t type)
	Formats an `ImplType` bitmask as a human-readable label. More...

static std::string	convert_type_to_view (uint32_t type, const std::vector< Process > &process_list)
	Formats an `ImplType` bitmask together with its process list. More...

static std::string	get_listen_address ()
	Returns the UDP multicast/broadcast address used by the discovery subsystem. More...

Protected Member Functions
size_t	get_max_task_count () const override
	Returns the maximum queue depth. More...

uint32_t	get_max_elapsed_time () const override
	Returns the maximum allowed task execution time in milliseconds. More...

void	on_begin () override
	Hook invoked once on the loop thread before the first task runs. More...

void	on_end () override
	Hook invoked once on the loop thread after the last task runs. More...

Protected Member Functions inherited from vlink::MessageLoop
virtual void	on_idle ()
	Hook invoked on the loop thread each time the queue becomes empty. More...

virtual void	on_task_changed (Callback &&callback, uint32_t start_time)
	Dispatches a ready task on the loop thread. More...

virtual void	on_task_timeout (Callback &&callback, uint32_t elapsed_time)
	Hook invoked when a task exceeds `get_max_elapsed_time()`. More...

Detailed Description

MessageLoop-based aggregator of live VLink endpoint announcements.

Construct with the desired filter and start with async_run(). Each viewer is explicitly owned by the caller; no process-global viewer is exposed. The viewer continuously rebuilds an Info list and notifies the registered callback every time the topology changes.

Member Typedef Documentation

◆ Callback

using vlink::DiscoveryViewer::Callback = Function<void(const std::vector<Info>& info_list)>

Callback signature delivered whenever the snapshot changes.

Invoked on the viewer's MessageLoop thread with the freshly built list.

Member Enumeration Documentation

◆ FilterType

enum vlink::DiscoveryViewer::FilterType : uint8_t

Selects which announcements contribute to the live snapshot.

Value	Effect
kFilterNone	All announcements visible
kFilterAvailable	Drop remote announcements for local-only URL schemes
kFilterNative	Keep only announcements from the same host

Enumerator
kFilterNone	No filtering applied.
kFilterAvailable	Drop remote announcements for local-only URL schemes.
kFilterNative	Keep only same-host announcements.

Constructor & Destructor Documentation

◆ DiscoveryViewer()

vlink::DiscoveryViewer::DiscoveryViewer ( FilterType type = kFilterNone )

explicit

Builds the viewer with the requested filter mode.

Parameters

type	Filter selecting which announcements survive (default: `kFilterNone`).

◆ ~DiscoveryViewer()

vlink::DiscoveryViewer::~DiscoveryViewer ( )

override

Stops the viewer loop and releases resources.

Member Function Documentation

◆ convert_type()

static ImplType vlink::DiscoveryViewer::convert_type ( std::string_view str )

static

Translates a discovery role token to the corresponding ImplType bit.

Parameters

str	Role token: `"Ser"`, `"Cli"`, `"Pub"`, `"Sub"`, `"Set"` or `"Get"`.

Returns: Matching ImplType, or 0 when the token is not recognised.

◆ convert_type_to_view() [1/2]

static std::string vlink::DiscoveryViewer::convert_type_to_view ( uint32_t type )

static

Formats an ImplType bitmask as a human-readable label.

Parameters

type	ImplType bitmask.

Returns: Display string suitable for tooling output.

◆ convert_type_to_view() [2/2]

static std::string vlink::DiscoveryViewer::convert_type_to_view	(	uint32_t	type,
		const std::vector< Process > &	process_list
	)

static

Formats an ImplType bitmask together with its process list.

Parameters

type	ImplType bitmask.
process_list	Processes to include in the display.

Returns: Combined display string.

◆ get_info_list()

std::vector<Info> vlink::DiscoveryViewer::get_info_list ( )

Returns a copy of the live snapshot at the moment of the call.

Returns: Vector of Info rows.

◆ get_listen_address()

static std::string vlink::DiscoveryViewer::get_listen_address ( )

static

Returns the UDP multicast/broadcast address used by the discovery subsystem.

◆ get_max_elapsed_time()

uint32_t vlink::DiscoveryViewer::get_max_elapsed_time ( ) const

overrideprotectedvirtual

Returns the maximum allowed task execution time in milliseconds.

Tasks exceeding this duration trigger on_task_timeout. Zero disables the check.

Returns: Maximum execution time in milliseconds.

Reimplemented from vlink::MessageLoop.

◆ get_max_task_count()

size_t vlink::DiscoveryViewer::get_max_task_count ( ) const

overrideprotectedvirtual

Returns the maximum queue depth.

Returns: kMaxTaskSize (10000) by default.

Reimplemented from vlink::MessageLoop.

◆ get_schema_type()

SchemaType vlink::DiscoveryViewer::get_schema_type ( const std::string & url ) const

Resolves the announced coarse schema family for url.

Parameters

url	Topic URL.

Returns: SchemaType, or SchemaType::kUnknown when unavailable.

◆ get_ser_type()

std::string vlink::DiscoveryViewer::get_ser_type ( const std::string & url ) const

Resolves the announced serialisation type for url.

Parameters

url	Topic URL.

Returns: Announced serialisation type, or an empty string when unknown.

◆ on_begin()

void vlink::DiscoveryViewer::on_begin ( )

overrideprotectedvirtual

Hook invoked once on the loop thread before the first task runs.

Subclasses override to perform per-thread initialisation.

Reimplemented from vlink::MessageLoop.

◆ on_end()

void vlink::DiscoveryViewer::on_end ( )

overrideprotectedvirtual

Hook invoked once on the loop thread after the last task runs.

Subclasses override to perform per-thread cleanup.

Reimplemented from vlink::MessageLoop.

◆ register_callback()

void vlink::DiscoveryViewer::register_callback ( Callback && callback )

Registers the callback notified on every snapshot change.

Replaces any previously installed callback; only the most recent registration remains effective.

Parameters

callback Function invoked with the new Info list.

The documentation for this class was generated from the following file:

include/vlink/extension/discovery_viewer.h

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ Callback

Member Enumeration Documentation

◆ FilterType

Constructor & Destructor Documentation

◆ DiscoveryViewer()

◆ ~DiscoveryViewer()

Member Function Documentation

◆ convert_type()

◆ convert_type_to_view() [1/2]

◆ convert_type_to_view() [2/2]

◆ get_info_list()

◆ get_listen_address()

◆ get_max_elapsed_time()

◆ get_max_task_count()

◆ get_schema_type()

◆ get_ser_type()

◆ on_begin()

◆ on_end()

◆ register_callback()