18.2.12.2. RTPSWriter

class RTPSWriter : public eprosima::fastrtps::rtps::Endpoint, public eprosima::fastdds::statistics::StatisticsWriterImpl

Class RTPSWriter, manages the sending of data to the readers. Is always associated with a HistoryCache.

Subclassed by eprosima::fastrtps::rtps::StatefulWriter, eprosima::fastrtps::rtps::StatelessWriter

Public Functions

template<typename T>
inline CacheChange_t *new_change(T &data, ChangeKind_t changeKind, InstanceHandle_t handle = c_InstanceHandle_Unknown)

Create a new change based with the provided changeKind.

Parameters
  • data – Data of the change.

  • changeKind – The type of change.

  • handle – InstanceHandle to assign.

Returns

Pointer to the CacheChange or nullptr if incorrect.

bool release_change(CacheChange_t *change)

Release a change when it is not being used anymore.

Parameters

change – Pointer to the cache change to be released.

Returns

whether the operation succeeded or not

Pre

  • change is not nullptr

  • change points to a cache change obtained from a call to this->new_change

Post

memory pointed to by change is not accessed

virtual bool matched_reader_add(const ReaderProxyData &data) = 0

Add a matched reader.

Parameters

data – Pointer to the ReaderProxyData object added.

Returns

True if added.

virtual bool matched_reader_remove(const GUID_t &reader_guid) = 0

Remove a matched reader.

Parameters

reader_guid – GUID of the reader to remove.

Returns

True if removed.

virtual bool matched_reader_is_matched(const GUID_t &reader_guid) = 0

Tells us if a specific Reader is matched against this writer.

Parameters

reader_guid – GUID of the reader to check.

Returns

True if it was matched.

virtual void reader_data_filter(fastdds::rtps::IReaderDataFilter *filter) = 0

Set a content filter to perform content filtering on this writer.

This method sets a content filter that will be used to check whether a cache change is relevant for a reader or not.

Parameters

filter – The content filter to use on this writer. May be nullptr to remove the content filter (i.e. treat all samples as relevant).

virtual const fastdds::rtps::IReaderDataFilter *reader_data_filter() const = 0

Get the content filter used to perform content filtering on this writer.

Returns

The content filter used on this writer.

inline virtual bool has_been_fully_delivered(const SequenceNumber_t &seq_num) const

Check if a specific change has been delivered to the transport layer of every matched remote RTPSReader at least once.

Parameters

seq_num – Sequence number of the change to check.

Returns

true if delivered. False otherwise.

inline virtual bool is_acked_by_all(const CacheChange_t*) const

Check if a specific change has been acknowledged by all Readers. Is only useful in reliable Writer. In BE Writers returns false when pending to be sent.

Returns

True if acknowledged by all.

inline virtual bool wait_for_all_acked(const Duration_t&)

Waits until all changes were acknowledged or max_wait.

Returns

True if all were acknowledged.

virtual void updateAttributes(const WriterAttributes &att) = 0

Update the Attributes of the Writer.

Parameters

att – New attributes

SequenceNumber_t get_seq_num_min()

Get Min Seq Num in History.

Returns

Minimum sequence number in history

SequenceNumber_t get_seq_num_max()

Get Max Seq Num in History.

Returns

Maximum sequence number in history

uint32_t getTypeMaxSerialized()

Get maximum size of the serialized type

Returns

Maximum size of the serialized type

uint32_t getMaxDataSize()

Get maximum size of the data.

uint32_t calculateMaxDataSize(uint32_t length)

Calculates the maximum size of the data.

inline WriterListener *getListener()

Get listener

Returns

Listener

inline bool isAsync() const

Get the publication mode

Returns

publication mode

bool remove_older_changes(unsigned int max = 0)

Remove an specified max number of changes

Parameters

max – Maximum number of changes to remove.

Returns

at least one change has been removed

inline virtual bool get_disable_positive_acks() const

Returns if disable positive ACKs QoS is enabled.

Returns

Best effort writers always return false. Reliable writers override this method.

virtual bool try_remove_change(const std::chrono::steady_clock::time_point &max_blocking_time_point, std::unique_lock<RecursiveTimedMutex> &lock) = 0

Tries to remove a change waiting a maximum of the provided microseconds.

Parameters
  • max_blocking_time_point – Maximum time to wait for.

  • lock – Lock of the Change list.

Returns

at least one change has been removed

virtual bool wait_for_acknowledgement(const SequenceNumber_t &seq, const std::chrono::steady_clock::time_point &max_blocking_time_point, std::unique_lock<RecursiveTimedMutex> &lock) = 0

Waits till a change has been acknowledged.

Parameters
  • seq – Sequence number to wait for acknowledgement.

  • max_blocking_time_point – Maximum time to wait for.

  • lock – Lock of the Change list.

Returns

true when change was acknowledged, false when timeout is reached.

inline RTPSParticipantImpl *getRTPSParticipant() const

Get RTPS participant

Returns

RTPS participant

inline void set_separate_sending(bool enable)

Enable or disable sending data to readers separately NOTE: This will only work for synchronous writers

Parameters

enable – If separate sending should be enabled

inline bool get_separate_sending() const

Inform if data is sent to readers separately

Returns

true if separate sending is enabled

inline virtual bool process_acknack(const GUID_t &writer_guid, const GUID_t &reader_guid, uint32_t ack_count, const SequenceNumberSet_t &sn_set, bool final_flag, bool &result, fastdds::rtps::VendorId_t origin_vendor_id = c_VendorId_Unknown)

Process an incoming ACKNACK submessage.

Parameters
  • writer_guid[in] GUID of the writer the submessage is directed to.

  • reader_guid[in] GUID of the reader originating the submessage.

  • ack_count[in] Count field of the submessage.

  • sn_set[in] Sequence number bitmap field of the submessage.

  • final_flag[in] Final flag field of the submessage.

  • result[out] true if the writer could process the submessage. Only valid when returned value is true.

  • origin_vendor_id[in] VendorId of the source participant from which the message was received

Returns

true when the submessage was destinated to this writer, false otherwise.

inline virtual bool process_nack_frag(const GUID_t &writer_guid, const GUID_t &reader_guid, uint32_t ack_count, const SequenceNumber_t &seq_num, const FragmentNumberSet_t fragments_state, bool &result, fastdds::rtps::VendorId_t origin_vendor_id = c_VendorId_Unknown)

Process an incoming NACKFRAG submessage.

Parameters
  • writer_guid[in] GUID of the writer the submessage is directed to.

  • reader_guid[in] GUID of the reader originating the submessage.

  • ack_count[in] Count field of the submessage.

  • seq_num[in] Sequence number field of the submessage.

  • fragments_state[in] Fragment number bitmap field of the submessage.

  • result[out] true if the writer could process the submessage. Only valid when returned value is true.

  • origin_vendor_id[in] VendorId of the source participant from which the message was received

Returns

true when the submessage was destinated to this writer, false otherwise.

const LivelinessQosPolicyKind &get_liveliness_kind() const

A method to retrieve the liveliness kind.

Returns

Liveliness kind

const Duration_t &get_liveliness_lease_duration() const

A method to retrieve the liveliness lease duration.

Returns

Lease duration

const Duration_t &get_liveliness_announcement_period() const

A method to return the liveliness announcement period.

Returns

The announcement period

bool is_datasharing_compatible() const
Returns

Whether the writer is data sharing compatible or not

virtual DeliveryRetCode deliver_sample_nts(CacheChange_t *cache_change, RTPSMessageGroup &group, LocatorSelectorSender &locator_selector, const std::chrono::time_point<std::chrono::steady_clock> &max_blocking_time) = 0

Tells writer the sample can be sent to the network.

This function should be used by a fastdds::rtps::FlowController.

Note

Must be non-thread safe.

Parameters
  • cache_change – Pointer to the CacheChange_t that represents the sample which can be sent.

  • group – RTPSMessageGroup reference uses for generating the RTPS message.

  • locator_selector – RTPSMessageSenderInterface reference uses for selecting locators. The reference has to be a member of this RTPSWriter object.

  • max_blocking_time – Future timepoint where blocking send should end.

Returns

Return code.

virtual bool send_nts(CDRMessage_t *message, const LocatorSelectorSender &locator_selector, std::chrono::steady_clock::time_point &max_blocking_time_point) const

Send a message through this interface.

Parameters
  • message – Pointer to the buffer with the message already serialized.

  • locator_selector – RTPSMessageSenderInterface reference uses for selecting locators. The reference has to be a member of this RTPSWriter object.

  • max_blocking_time_point – Future timepoint where blocking send should end.

Public Members

LivelinessLostStatus liveliness_lost_status_

Liveliness lost status of this writer.