Function TupleDescGetAttInMetadata

src/backend/executor/execTuples.c:2102–2144

* TupleDescGetAttInMetadata - Build an AttInMetadata structure based on the * supplied TupleDesc. AttInMetadata can be used in conjunction with C strings * to produce a properly formed tuple. */

 * to produce a properly formed tuple.
 */
AttInMetadata *
TupleDescGetAttInMetadata(TupleDesc tupdesc)
{
	int			natts = tupdesc->natts;
	int			i;
	Oid			atttypeid;
	Oid			attinfuncid;
	FmgrInfo   *attinfuncinfo;
	Oid		   *attioparams;
	int32	   *atttypmods;
	AttInMetadata *attinmeta;

	attinmeta = (AttInMetadata *) palloc(sizeof(AttInMetadata));

	/* "Bless" the tupledesc so that we can make rowtype datums with it */
	attinmeta->tupdesc = BlessTupleDesc(tupdesc);

	/*
	 * Gather info needed later to call the "in" function for each attribute
	 */
	attinfuncinfo = (FmgrInfo *) palloc0(natts * sizeof(FmgrInfo));
	attioparams = (Oid *) palloc0(natts * sizeof(Oid));
	atttypmods = (int32 *) palloc0(natts * sizeof(int32));

	for (i = 0; i < natts; i++)
	{
		Form_pg_attribute att = TupleDescAttr(tupdesc, i);

		/* Ignore dropped attributes */
		if (!att->attisdropped)
		{
			atttypeid = att->atttypid;
			getTypeInputInfo(atttypeid, &attinfuncid, &attioparams[i]);
			fmgr_info(attinfuncid, &attinfuncinfo[i]);
			atttypmods[i] = att->atttypmod;
		}
	}
	attinmeta->attinfuncs = attinfuncinfo;
	attinmeta->attioparams = attioparams;
	attinmeta->atttypmods = atttypmods;

	return attinmeta;
}

/*
 * BuildTupleFromCStrings - build a HeapTuple given user data in C string form.