Function dds_read_instance_mask

Function Documentation

dds_return_t dds_read_instance_mask(dds_entity_t reader_or_condition, void **buf, dds_sample_info_t *si, size_t bufsz, uint32_t maxs, dds_instance_handle_t handle, uint32_t mask)

Read the collection of data values and sample info from the data reader, readcondition or querycondition based on mask and scoped by the provided instance handle.

This operation implements the same functionality as dds_read_mask, except that only data scoped to the provided instance handle is read.

Parameters

  • reader_or_condition – [in] Reader, readcondition or querycondition entity.

  • buf – [out] An array of pointers to samples into which data is read (pointers can be NULL).

  • si – [out] Pointer to an array of dds_sample_info_t returned for each data value.

  • bufsz – [in] The size of buffer provided.

  • maxs – [in] Maximum number of samples to read.

  • handle – [in] Instance handle related to the samples to read.

  • mask – [in] Filter the data based on dds_sample_state_t|dds_view_state_t|dds_instance_state_t.

Return values

  • >=0 – Number of samples read.

  • DDS_RETCODE_ERROR – An internal error has occurred.

  • DDS_RETCODE_BAD_PARAMETER – One of the given arguments is not valid.

  • DDS_RETCODE_ILLEGAL_OPERATION – The operation is invoked on an inappropriate object.

  • DDS_RETCODE_ALREADY_DELETED – The entity has already been deleted.

  • DDS_RETCODE_PRECONDITION_NOT_MET – The instance handle has not been registered with this reader.

Returns

A dds_return_t with the number of samples read or an error code.