Function dds_take_instance

Function Documentation

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

Access the collection of data values (of same type) and sample info from the data reader, readcondition or querycondition but scoped by the given instance handle.

This operation mplements the same functionality as dds_take, except that only data scoped to the provided instance handle is taken.

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.

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.