18.2.7.4. ReaderHistory¶

class ReaderHistory : public eprosima::fastrtps::rtps::History ¶

Class ReaderHistory, container of the different CacheChanges of a reader

Public Functions

ReaderHistory(const HistoryAttributes &att)¶: Constructor of the ReaderHistory. It needs a HistoryAttributes.

virtual bool can_change_be_added_nts(const GUID_t &writer_guid, uint32_t total_payload_size, size_t unknown_missing_changes_up_to, bool &will_never_be_accepted) const¶

Check if a new change can be added to this history.

Parameters

writer_guid – [in] GUID of the writer where the change came from.
total_payload_size – [in] Total payload size of the incoming change.
unknown_missing_changes_up_to – [in] The number of changes from the same writer with a lower sequence number that could potentially be received in the future.
will_never_be_accepted – [out] When the method returns false, this parameter will inform whether the change could be accepted in the future or not.

Pre

change should not be present in the history

Returns

Whether a call to received_change will succeed when called with the same arguments.

virtual bool received_change(CacheChange_t *change, size_t unknown_missing_changes_up_to)¶

Virtual method that is called when a new change is received. In this implementation this method just calls add_change. The user can overload this method in case he needs to perform additional checks before adding the change.

Parameters

change – Pointer to the change
unknown_missing_changes_up_to – The number of changes from the same writer with a lower sequence number that could potentially be received in the future.

Returns

True if added.

inline virtual bool received_change(CacheChange_t *change, size_t unknown_missing_changes_up_to, fastdds::dds::SampleRejectedStatusKind &rejection_reason)¶

Virtual method that is called when a new change is received. In this implementation this method just calls add_change. The user can overload this method in case he needs to perform additional checks before adding the change.

Parameters

change – [in] Pointer to the change
unknown_missing_changes_up_to – [in] The number of changes from the same writer with a lower sequence number that could potentially be received in the future.
rejection_reason – [out] In case of been rejected the sample, it will contain the reason of the rejection.

Returns

True if added.

inline virtual bool completed_change(rtps::CacheChange_t *change)¶

Called when a fragmented change is received completely by the Subscriber. Will find its instance and store it.

Parameters: change – [in] The received change
Pre: Change should be already present in the history.
Returns

inline virtual bool completed_change(CacheChange_t *change, size_t unknown_missing_changes_up_to, fastdds::dds::SampleRejectedStatusKind &rejection_reason)¶

Called when a fragmented change is received completely by the Subscriber. Will find its instance and store it.

Parameters

change – [in] The received change
unknown_missing_changes_up_to – [in] Number of missing changes before this one
rejection_reason – [out] In case of been rejected the sample, it will contain the reason of the rejection.

Pre

Change should be already present in the history.

Returns

bool add_change(CacheChange_t *a_change)¶

Add a CacheChange_t to the ReaderHistory.

Parameters: a_change – Pointer to the CacheChange to add.
Returns: True if added.

virtual iterator remove_change_nts(const_iterator removal, bool release = true) override¶

Remove a specific change from the history. No Thread Safe

Parameters

removal – iterator to the change for removal
release – specifies if the change must be returned to the pool

Returns

iterator to the next change if any

virtual iterator remove_change_nts(const_iterator removal, const std::chrono::time_point<std::chrono::steady_clock> &max_blocking_time, bool release = true) override¶

Remove a specific change from the history. No Thread Safe

Parameters

removal – iterator to the change for removal
max_blocking_time – [in] Maximum time this method has to complete the task.
release – specifies if the change must be returned to the pool

Returns

iterator to the next change if any

virtual bool matches_change(const CacheChange_t *inner, CacheChange_t *outer) override¶

Criteria to search a specific CacheChange_t on history

Parameters

inner – change to compare
outer – change for comparison

Returns

true if inner matches outer criteria

bool remove_changes_with_guid(const GUID_t &a_guid)¶

Remove all changes from the History that have a certain guid.

Parameters: a_guid – Pointer to the target guid to search for.
Returns: True if successful, even if no changes have been removed.

bool remove_fragmented_changes_until(const SequenceNumber_t &seq_num, const GUID_t &writer_guid)¶

Remove all fragmented changes from certain writer up to certain sequence number.

Parameters

seq_num – First SequenceNumber_t not to be removed.
writer_guid – GUID of the writer for which changes should be looked for.

Returns

True if successful, even if no changes have been removed.

virtual void writer_unmatched(const GUID_t &writer_guid, const SequenceNumber_t &last_notified_seq)¶

Called when a writer is unmatched from the reader holding this history.

This method will remove all the changes on the history that came from the writer being unmatched and which have not yet been notified to the user.

Parameters

writer_guid – GUID of the writer being unmatched.
last_notified_seq – Last sequence number from the specified writer that was notified to the user.

inline virtual void writer_update_its_ownership_strength_nts(const GUID_t &writer_guid, const uint32_t ownership_strength)¶

This function should be called by reader if a writer updates its ownership strength.

Parameters

writer_guid – [in] Guid of the writer which changes its ownership strength.
ownership_strength – [out] New value of the writer’s Ownership strength.

bool remove_change(CacheChange_t *ch)¶: Introduce base class method into scope.

bool remove_change(CacheChange_t *ch, const std::chrono::time_point<std::chrono::steady_clock> &max_blocking_time)¶: Introduce base class method into scope.

inline iterator remove_change(const_iterator removal, bool release = true)¶: Introduce base class method into scope.