Gazebo Transport

API Reference

14.0.0
List of all members | Static Public Member Functions | Static Public Attributes
TopicUtils Class Reference

This class provides different utilities related with topics. More...

#include <gz/transport/TopicUtils.hh>

Static Public Member Functions

static std::string AsValidTopic (const std::string &_topic)
 Convert a topic name to a valid topic. The input topic is modified by:
 
static bool DecomposeFullyQualifiedTopic (const std::string &_fullyQualifiedName, std::string &_partition, std::string &_namespaceAndTopic)
 Decompose a fully qualified topic name into its partition and topic strings. Note that if the topic is preceded by a namespace, then the namespace and topic name will remain together as one string.
 
static bool FullyQualifiedName (const std::string &_partition, const std::string &_ns, const std::string &_topic, std::string &_name)
 Get the full topic path given a namespace and a topic name. A fully qualified topic name's length must not exceed kMaxNameLength. The fully qualified name follows the next syntax: @<PARTITION>@<NAMESPACE>/<TOPIC> where: <PARTITION>: The name of the partition or empty string. A "/" will be prefixed to the partition name unless is empty or it already starts with slash. A trailing slash will always be removed. <NAMESPACE>: The namespace or empty string. A namespace is a prefix applied to the topic name. If not empty, it will always start with a "/". A trailing slash will always be removed <TOPIC>: The topic name. A trailing slash will always be removed.
 
static bool IsValidNamespace (const std::string &_ns)
 Determines if a namespace is valid. A namespace's length must not exceed kMaxNameLength. The following symbols are not allowed as part of the namespace: '@', ':=', '~'.
 
static bool IsValidPartition (const std::string &_partition)
 Determines if a partition is valid. The same rules to validate a topic name applies to a partition with the addition of the empty string, which is a valid partition (meaning no partition is used). A partition name's length must not exceed kMaxNameLength.
 
static bool IsValidTopic (const std::string &_topic)
 Determines if a topic name is valid. A topic name is any non-empty alphanumeric string. The symbol '/' is also allowed as part of a topic name. The following symbols are not allowed as part of the topic name: '@', ':=', '~'. A topic name's length must not exceed kMaxNameLength. Examples of valid topics: abc, /abc, /abc/de, /abc/de/.
 

Static Public Attributes

static const uint16_t kMaxNameLength = 65535
 The kMaxNameLength specifies the maximum number of characters allowed in a namespace, a partition name, a topic name, and a fully qualified topic name.
 

Detailed Description

This class provides different utilities related with topics.

Member Function Documentation

◆ AsValidTopic()

static std::string AsValidTopic ( const std::string &  _topic)
static

Convert a topic name to a valid topic. The input topic is modified by:

  • turning white space into _.
  • removing special characters and combinations.
    Parameters
    [in]_topicInput topic, which may be invalid.
    Returns
    A valid topic, or empty string if not possible to convert.

◆ DecomposeFullyQualifiedTopic()

static bool DecomposeFullyQualifiedTopic ( const std::string &  _fullyQualifiedName,
std::string &  _partition,
std::string &  _namespaceAndTopic 
)
static

Decompose a fully qualified topic name into its partition and topic strings. Note that if the topic is preceded by a namespace, then the namespace and topic name will remain together as one string.

Given a fully qualified topic name with the following syntax:

@<PARTITION>@<NAMESPACE>/<TOPIC>

The _partition output argument will be set to <PARTITION>, and the _namespaceAndTopic output argument will be set to <NAMESPACE>/<TOPIC>.

Parameters
[in]_fullyQualifiedNameThe fully qualified topic name.
[out]_partitionThe partition component of the fully qualified topic name.
[out]_namespaceAndTopicThe namespace and topic name component. Note that there is no way to distinguish between where a namespace ends and a topic name begins, since topic names may contain slashes.
Returns
True if the topic and partition were set.
See also
FullyQualifiedName

◆ FullyQualifiedName()

static bool FullyQualifiedName ( const std::string &  _partition,
const std::string &  _ns,
const std::string &  _topic,
std::string &  _name 
)
static

Get the full topic path given a namespace and a topic name. A fully qualified topic name's length must not exceed kMaxNameLength. The fully qualified name follows the next syntax: @<PARTITION>@<NAMESPACE>/<TOPIC> where: <PARTITION>: The name of the partition or empty string. A "/" will be prefixed to the partition name unless is empty or it already starts with slash. A trailing slash will always be removed. <NAMESPACE>: The namespace or empty string. A namespace is a prefix applied to the topic name. If not empty, it will always start with a "/". A trailing slash will always be removed <TOPIC>: The topic name. A trailing slash will always be removed.

Note: Intuitively, you can imagine the fully qualified name as a UNIX absolute path, where the partition is always sorrounded by "@". A namespace, if present, corresponds with the directories of the path, and you can imagine the topic as the filename.

E.g.: Only topic: @/topic No partition: @/namespace/topic1 No namespace: @/partition@/topic1 Partition+namespace+topic: @/my_partition@/name/space/topic

Parameters
[in]_partitionPartition name.
[in]_nsNamespace.
[in]_topicTopic name.
[out]_nameFully qualified topic name.
Returns
True if the fully qualified name is valid (if partition, namespace and topic are correct).
See also
IsValidPartition
IsValidNamespace
IsValidTopic
DecomposeFullyQualifiedTopic

◆ IsValidNamespace()

static bool IsValidNamespace ( const std::string &  _ns)
static

Determines if a namespace is valid. A namespace's length must not exceed kMaxNameLength. The following symbols are not allowed as part of the namespace: '@', ':=', '~'.

Parameters
[in]_nsNamespace to be checked.
Returns
true if the namespace is valid.

◆ IsValidPartition()

static bool IsValidPartition ( const std::string &  _partition)
static

Determines if a partition is valid. The same rules to validate a topic name applies to a partition with the addition of the empty string, which is a valid partition (meaning no partition is used). A partition name's length must not exceed kMaxNameLength.

Parameters
[in]_partitionPartition to be checked.
Returns
true if the partition is valid.

◆ IsValidTopic()

static bool IsValidTopic ( const std::string &  _topic)
static

Determines if a topic name is valid. A topic name is any non-empty alphanumeric string. The symbol '/' is also allowed as part of a topic name. The following symbols are not allowed as part of the topic name: '@', ':=', '~'. A topic name's length must not exceed kMaxNameLength. Examples of valid topics: abc, /abc, /abc/de, /abc/de/.

Parameters
[in]_topicTopic name to be checked.
Returns
true if the topic name is valid.

Member Data Documentation

◆ kMaxNameLength

const uint16_t kMaxNameLength = 65535
static

The kMaxNameLength specifies the maximum number of characters allowed in a namespace, a partition name, a topic name, and a fully qualified topic name.

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