Template Class ApproximateSync

• Defined in File approximate_sync.hpp

Class Documentation

template<typename ...MsgTypes>
class ApproximateSync

Public Types

using message_types = MsgPack<MsgTypes...>

Exposes the message types.

using Callback = std::function<void(const std::vector<std::shared_ptr<const MsgTypes>>&...)>

The type of callback to expect from this sync. A typical callback function signature would be

void foo(const std::vector<std::shared_ptr<const MsgType>> &vec1,
         const std::vector<std::shared_ptr<const MsgType>> &vec2)

Public Functions

inline ApproximateSync(const std::vector<std::vector<std::string>> &topics, Callback cb, size_t queue_size)

Creates an exact sync like the one in ROS1, but with flexible number of topics per type.

Parameters:

• topics – vector of vector of topics, corresponding to message type. The first vector has all topics for type 1, second for type 2 etc.

• cb – callback to invoke when sync is obtained. The callback signature looks different. For example for two message types, MsgType1 and MsgType2

  void callback(
         const std::vector<MsgType1::ConstPtr> &m1,
         const std::vector<MsgType2::ConstPtr> &m2);
  

• queue_size – depth of sync queue. A queue_size of 0 means unlimited queue.

inline size_t getNumberDropped() const

Query the number of messages dropped because they were not synced.

Returns:

total number of dropped messages since last call to clearNumberDropped()

inline void clearNumberDropped()

Clears number of dropped messages to zero. The number of dropped messages can be queried with getNumberDropped().

inline const std::vector<std::vector<std::string>> &getTopics() const

Get topics with which this sync was created.

Returns:

topics with which this sync was created.

inline size_t getQueueSize() const

Query the sync queue size.

Returns:

size of sync queue

template<typename MsgPtrT>
inline void process(const std::string &topic, const MsgPtrT &msg)

Call this method to feed data into the sync. Once a sync is obtained (all topics have messages for a given time), the sync will invoke the callback function.

Parameters:

• topic – topic of the message to be processed. Must be one of the topics provided when the sync was created.

• msg – shared pointer to message to be processed. Message type must match positionally to topic used when the sync was created.