Function EA_flatten_into

src/backend/utils/adt/array_expanded.c:292–338

* flatten_into method for expanded arrays */

 * flatten_into method for expanded arrays
 */
static void
EA_flatten_into(ExpandedObjectHeader *eohptr,
				void *result, Size allocated_size)
{
	ExpandedArrayHeader *eah = (ExpandedArrayHeader *) eohptr;
	ArrayType  *aresult = (ArrayType *) result;
	int			nelems;
	int			ndims;
	int32		dataoffset;

	Assert(eah->ea_magic == EA_MAGIC);

	/* Easy if we have a valid flattened value */
	if (eah->fvalue)
	{
		Assert(allocated_size == ARR_SIZE(eah->fvalue));
		memcpy(result, eah->fvalue, allocated_size);
		return;
	}

	/* Else allocation should match previous get_flat_size result */
	Assert(allocated_size == eah->flat_size);

	/* Fill result array from dvalues/dnulls */
	nelems = eah->nelems;
	ndims = eah->ndims;

	if (eah->dnulls)
		dataoffset = ARR_OVERHEAD_WITHNULLS(ndims, nelems);
	else
		dataoffset = 0;			/* marker for no null bitmap */

	/* We must ensure that any pad space is zero-filled */
	memset(aresult, 0, allocated_size);

	SET_VARSIZE(aresult, allocated_size);
	aresult->ndim = ndims;
	aresult->dataoffset = dataoffset;
	aresult->elemtype = eah->element_type;
	memcpy(ARR_DIMS(aresult), eah->dims, ndims * sizeof(int));
	memcpy(ARR_LBOUND(aresult), eah->lbound, ndims * sizeof(int));

	CopyArrayEls(aresult,
				 eah->dvalues, eah->dnulls, nelems,
				 eah->typlen, eah->typbyval, eah->typalign,
				 false);
}

/*
 * Argument fetching support code