Function convert_prep_stmt_params

contrib/postgres_fdw/postgres_fdw.c:4263–4333

* convert_prep_stmt_params * Create array of text strings representing parameter values * * tupleid is ctid to send, or NULL if none * slot is slot to get remaining parameters from, or NULL if none * * Data is constructed in temp_cxt; caller should reset that after use. */

 * Data is constructed in temp_cxt; caller should reset that after use.
 */
static const char **
convert_prep_stmt_params(PgFdwModifyState *fmstate,
						 ItemPointer tupleid,
						 TupleTableSlot **slots,
						 int numSlots)
{
	const char **p_values;
	int			i;
	int			j;
	int			pindex = 0;
	MemoryContext oldcontext;

	oldcontext = MemoryContextSwitchTo(fmstate->temp_cxt);

	p_values = (const char **) palloc(sizeof(char *) * fmstate->p_nums * numSlots);

	/* ctid is provided only for UPDATE/DELETE, which don't allow batching */
	Assert(!(tupleid != NULL && numSlots > 1));

	/* 1st parameter should be ctid, if it's in use */
	if (tupleid != NULL)
	{
		Assert(numSlots == 1);
		/* don't need set_transmission_modes for TID output */
		p_values[pindex] = OutputFunctionCall(&fmstate->p_flinfo[pindex],
											  PointerGetDatum(tupleid));
		pindex++;
	}

	/* get following parameters from slots */
	if (slots != NULL && fmstate->target_attrs != NIL)
	{
		TupleDesc	tupdesc = RelationGetDescr(fmstate->rel);
		int			nestlevel;
		ListCell   *lc;

		nestlevel = set_transmission_modes();

		for (i = 0; i < numSlots; i++)
		{
			j = (tupleid != NULL) ? 1 : 0;
			foreach(lc, fmstate->target_attrs)
			{
				int			attnum = lfirst_int(lc);
				Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
				Datum		value;
				bool		isnull;

				/* Ignore generated columns; they are set to DEFAULT */
				if (attr->attgenerated)
					continue;
				value = slot_getattr(slots[i], attnum, &isnull);
				if (isnull)
					p_values[pindex] = NULL;
				else
					p_values[pindex] = OutputFunctionCall(&fmstate->p_flinfo[j],
														  value);
				pindex++;