Class MCAPSink

Inheritance Relationships

Base Type

Class Documentation

class MCAPSink : public DataTamer::DataSinkBase

The MCAPSink is an implementation of DataSinkBase that will save the data as MCAP file (https://mcap.dev/)

Public Functions

explicit MCAPSink(std::string const &filepath, bool do_compression = false)

MCAPSink. IMPORTANT: if you want the recorder to be more robust to crash/segfault, set do_compression to false. Compression is safe if your application is closing cleanly.

Parameters:

  • filepath – path of the file to be saved. Should have extension “.mcap”

  • do_compression – if true, compress the data on the fly.

~MCAPSink() override
virtual void addChannel(std::string const &channel_name, Schema const &schema) override

addChannel will register a schema into the sink. That schema will be recognized by its hash.

Parameters:
virtual bool storeSnapshot(const Snapshot &snapshot) override

storeSnapshot contains the code to execute when popping a snapshot from the queue.

Parameters:

snapshot – data to be pushed into the sink.

Returns:

true if processed successfully

void setMaxTimeBeforeReset(std::chrono::seconds reset_time)

After a certain amount of time, the MCAP file will be reset and overwritten. Default value is 600 seconds (10 minutes) To disable this feature, use a time of 0 seconds. WARNING: this can consume a large amount of disk space very quickly.

void setCreateNewFileOnReset(bool create_new_file)

When resetting the MCAP recording (see setMaxTimeBeforeReset), if create_new_file is true then the filename will be incremented and then saved instead of overwriting the previous file.

void stopRecording()

Stop recording and save the file.

void finishQueueAndStop()

Stop taking snapshots, finish the existing queue, then stopRecording will block for at least 250 us to ensure the queue is empty

void restartRecording(std::string const &filepath, bool do_compression = false)

restartRecording saves the current file (unless we did it already, calling stopRecording) and start recording into a new one. Note that all the registered channels and their schemas will be copied into the new file.

Parameters:

  • filepath – file path of the new file (should be “.mcap” extension)

  • do_compression – if true, compress the data on the fly. WARNING: if this is called with the same filename as previously, the file counter will be reset, too.