#include <rmw/names_and_types.h>
#include <rmw/get_topic_names_and_types.h>
#include "rcutils/types.h"
#include "rosidl_generator_c/service_type_support.h"
#include "rcl/macros.h"
#include "rcl/client.h"
#include "rcl/node.h"
#include "rcl/visibility_control.h"

Macros
#define	rcl_get_zero_initialized_names_and_types rmw_get_zero_initialized_names_and_types

Typedefs
typedef rmw_names_and_types_t	rcl_names_and_types_t

Functions
rcl_ret_t	rcl_get_topic_names_and_types (const rcl_node_t node, rcl_allocator_t allocator, bool no_demangle, rcl_names_and_types_t *topic_names_and_types)
	Return a list of topic names and their types. More...

rcl_ret_t	rcl_get_service_names_and_types (const rcl_node_t node, rcl_allocator_t allocator, rcl_names_and_types_t *service_names_and_types)
	Return a list of service names and their types. More...

rcl_ret_t	rcl_names_and_types_fini (rcl_names_and_types_t *names_and_types)
	Finalize a rcl_names_and_types_t object. More...

rcl_ret_t	rcl_get_node_names (const rcl_node_t node, rcl_allocator_t allocator, rcutils_string_array_t node_names)
	Return a list of available nodes in the ROS graph. More...

rcl_ret_t	rcl_count_publishers (const rcl_node_t node, const char topic_name, size_t *count)
	Return the number of publishers on a given topic. More...

rcl_ret_t	rcl_count_subscribers (const rcl_node_t node, const char topic_name, size_t *count)
	Return the number of subscriptions on a given topic. More...

rcl_ret_t	rcl_service_server_is_available (const rcl_node_t node, const rcl_client_t client, bool *is_available)
	Check if a service server is available for the given service client. More...

Macro Definition Documentation

◆ rcl_get_zero_initialized_names_and_types

#define rcl_get_zero_initialized_names_and_types rmw_get_zero_initialized_names_and_types

Typedef Documentation

◆ rcl_names_and_types_t

typedef rmw_names_and_types_t rcl_names_and_types_t

Function Documentation

◆ rcl_get_topic_names_and_types()

rcl_ret_t rcl_get_topic_names_and_types	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		bool	no_demangle,
		rcl_names_and_types_t *	topic_names_and_types
	)

Return a list of topic names and their types.

This function returns a list of topic names in the ROS graph and their types.

The node parameter must not be NULL, and must point to a valid node.

The topic_names_and_types parameter must be allocated and zero initialized. The topic_names_and_types is the output for this function, and contains allocated memory. Therefore, it should be passed to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

There may be some demangling that occurs when listing the topics from the middleware implementation. If the no_demangle argument is true, then this will be avoided and the topics will be returned as they appear to the middleware.

See also: rmw_get_topic_names_and_types for more details on no_demangle

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Maybe [1]

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[in]	no_demangle	if true, list all topics without any demangling
[out]	topic_names_and_types	list of topic names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_service_names_and_types()

rcl_ret_t rcl_get_service_names_and_types	(	const rcl_node_t *	node,
		rcl_allocator_t *	allocator,
		rcl_names_and_types_t *	service_names_and_types
	)

Return a list of service names and their types.

This function returns a list of service names in the ROS graph and their types.

The node parameter must not be NULL, and must point to a valid node.

The service_names_and_types parameter must be allocated and zero initialized. The service_names_and_types is the output for this function, and contains allocated memory. Therefore, it should be passed to rcl_names_and_types_fini() when it is no longer needed. Failing to do so will result in leaked memory.

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Maybe [1]

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	allocator to be used when allocating space for strings
[out]	service_names_and_types	list of service names and their types

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_names_and_types_fini()

rcl_ret_t rcl_names_and_types_fini ( rcl_names_and_types_t * names_and_types )

Finalize a rcl_names_and_types_t object.

The object is populated when given to one of the rcl_get_*_names_and_types() functions. This function reclaims any resources allocated during population.

The names_and_types parameter must not be NULL, and must point to an already allocated rcl_names_and_types_t struct that was previously passed to a successful rcl_get_*_names_and_types() function call.

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Yes

Parameters

[in,out] names_and_types struct to be finalized

Returns: RCL_RET_OK if successful, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_get_node_names()

rcl_ret_t rcl_get_node_names	(	const rcl_node_t *	node,
		rcl_allocator_t	allocator,
		rcutils_string_array_t *	node_names
	)

Return a list of available nodes in the ROS graph.

This function returns a list of nodes in the ROS graph.

The node parameter must not be NULL, and must point to a valid node.

The node_names parameter must be allocated and zero initialized. The node_names is the output for this function, and contains allocated memory. Use rcutils_get_zero_initialized_string_array() for initializing an empty rcutils_string_array_t struct. This node_names struct should therefore be passed to rcutils_string_array_fini() when it is no longer needed. Failing to do so will result in leaked memory.

Example:

rcutils_string_array_t node_names =
  rcutils_get_zero_initialized_string_array();
rcl_ret_t ret = rcl_get_node_names(node, &node_names);
if (ret != RCL_RET_OK) {
  // ... error handling
}
// ... use the node_names struct, and when done:
rcutils_ret_t rcutils_ret = rcutils_string_array_fini(&node_names);
if (rcutils_ret != RCUTILS_RET_OK) {
  // ... error handling
}

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Maybe [1]

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	allocator	used to control allocation and deallocation of names
[out]	node_names	struct storing discovered node names.

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_count_publishers()

rcl_ret_t rcl_count_publishers	(	const rcl_node_t *	node,
		const char *	topic_name,
		size_t *	count
	)

Return the number of publishers on a given topic.

This function returns the number of publishers on a given topic.

The node parameter must not be NULL, and must point to a valid node.

The topic_name parameter must not be NULL, and must not be an empty string. It should also follow the topic name rules.

Todo:: TODO(wjwwood): link to the topic name rules.

The count parameter must not be NULL, and must point to a valid bool. The count parameter is the output for this function and will be set.

In the event that error handling needs to allocate memory, this function will try to use the node's allocator.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	No
Uses Atomics	No
Lock-Free	Maybe [1]

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	topic_name	the name of the topic in question
[out]	count	number of publishers on the given topic

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_count_subscribers()

rcl_ret_t rcl_count_subscribers	(	const rcl_node_t *	node,
		const char *	topic_name,
		size_t *	count
	)

Return the number of subscriptions on a given topic.

This function returns the number of subscriptions on a given topic.

The node parameter must not be NULL, and must point to a valid node.

The topic_name parameter must not be NULL, and must not be an empty string. It should also follow the topic name rules.

Todo:: TODO(wjwwood): link to the topic name rules.

The count parameter must not be NULL, and must point to a valid bool. The count parameter is the output for this function and will be set.

In the event that error handling needs to allocate memory, this function will try to use the node's allocator.

Attribute	Adherence
Allocates Memory	No
Thread-Safe	No
Uses Atomics	No
Lock-Free	Maybe [1]

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	topic_name	the name of the topic in question
[out]	count	number of subscriptions on the given topic

Returns: RCL_RET_OK if the query was successful, or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

◆ rcl_service_server_is_available()

rcl_ret_t rcl_service_server_is_available	(	const rcl_node_t *	node,
		const rcl_client_t *	client,
		bool *	is_available
	)

Check if a service server is available for the given service client.

This function will return true for is_available if there is a service server available for the given client.

The node parameter must not be NULL, and must point to a valid node.

The client parameter must not be NULL, and must point to a valid client.

The given client and node must match, i.e. the client must have been created using the given node.

The is_available parameter must not be NULL, and must point a bool variable. The result of the check will be stored in the is_available parameter.

In the event that error handling needs to allocate memory, this function will try to use the node's allocator.

Attribute	Adherence
Allocates Memory	Yes
Thread-Safe	No
Uses Atomics	No
Lock-Free	Maybe [1]

[1] implementation may need to protect the data structure with a lock

Parameters

[in]	node	the handle to the node being used to query the ROS graph
[in]	client	the handle to the service client being queried
[out]	is_available	set to true if there is a service server available, else false

Returns: RCL_RET_OK if the check was made successfully (regardless of the service readiness), or; RCL_RET_NODE_INVALID if the node is invalid, or; RCL_RET_INVALID_ARGUMENT if any arguments are invalid, or; RCL_RET_ERROR if an unspecified error occurs.

Macros

Typedefs

Functions

Macro Definition Documentation

◆ rcl_get_zero_initialized_names_and_types

Typedef Documentation

◆ rcl_names_and_types_t

Function Documentation

◆ rcl_get_topic_names_and_types()

◆ rcl_get_service_names_and_types()

◆ rcl_names_and_types_fini()

◆ rcl_get_node_names()

◆ rcl_count_publishers()

◆ rcl_count_subscribers()

◆ rcl_service_server_is_available()