Interface: TupleIntf

TupleIntf allows interactions with Tuples, which are base data fetched from the Attr interface and stored in a packed array of fixed width fields.

Note that Tuple's should not be confused with QueryResults (or QueryResultTuples) which represent more complicated, arbitrary sized data structures consisting of an arbitrary number of records. Tuples are used internally to collect data about sensors -- QueryResults are sent to neighboring motes and stored in result buffers for external processing.

Components providing this interface:

tos.lib.TinyDB.Tuple

Components requiring this interface:

tos.lib.TinyDB.AggOperator
tos.lib.TinyDB.DBBufferC
tos.lib.TinyDB.ParsedQuery
tos.lib.TinyDB.QueryResult
tos.lib.TinyDB.SelOperator
tos.lib.TinyDB.TupleRouterM

Commands

• uint16_t tupleSize(ParsedQueryPtr q)

  Returns:

  The size (in bytes) of Tuples corresponding to the specified query

• uint16_t fieldSize(ParsedQueryPtr q, uint8_t fieldNo)

  Returns:

  The size (in bytes) of the specified field of the specified query, or 0 if the field is null or out of range

• result_t setField (ParsedQueryPtr q, TuplePtr t, uint8_t fieldIdx, CharPtr data) Set the speccified field in the specified tuple corresponding to the specified query to the specified data.

• CharPtr getFieldPtr(ParsedQueryPtr q, TuplePtr t, uint8_t fieldIdx) Return a pointer to the field data for the specified field of the specified query

  Parameters:	q - The query that t belongs to t - The Tuple to get the field from fieldIdx - The idx of the field to retrieve
  Returns:	A pointer to the requested field, or NULL if no such field exists (note that writing to this pointer will overwrite the tuple data!)

• result_t tupleInit(ParsedQueryPtr q, TuplePtr t) Set all the fields of the specified tuple to 0, and reset the bitmap that tracks which fields have been written

• bool isTupleComplete(ParsedQueryPtr q, TuplePtr t)

  Returns:

  TRUE iff all fields of the specified tuple have been set since it was last reset

• AttrDescPtr getNextQueryField (ParsedQueryPtr q, TuplePtr t)

• TinyDBError getNextEmptyFieldIdx(ParsedQueryPtr q, TuplePtr t, uint8_t *fieldIdx) Fetch the index of the next empty field in the tuple

  Parameters:	(on - return) fieldIdx The index of the next empty field in the query
  Returns:	err_NoMoreResults if there are no more empty fields

setField

getNextQueryField