Method sleuth

src/dsql/BoolNodes.cpp:1066–1137

Execute SLEUTH operator.

// Execute SLEUTH operator.
bool ComparativeBoolNode::sleuth(thread_db* tdbb, Request* request, const dsc* desc1,
	const dsc* desc2) const
{
	SET_TDBB(tdbb);

	// Choose interpretation for the operation

 	USHORT ttype;
	if (desc1->isBlob())
	{
		if (desc1->dsc_sub_type == isc_blob_text)
			ttype = desc1->dsc_blob_ttype();	// Load blob character set and collation
		else
			ttype = INTL_TTYPE(desc2);
	}
	else
		ttype = INTL_TTYPE(desc1);

	Collation* obj = INTL_texttype_lookup(tdbb, ttype);

	// Get operator definition string (control string)

	dsc* desc3 = EVL_expr(tdbb, request, arg3);

	UCHAR* p1;
	MoveBuffer sleuth_str;
	USHORT l1 = MOV_make_string2(tdbb, desc3, ttype, &p1, sleuth_str);
	// Get address and length of search string
	UCHAR* p2;
	MoveBuffer match_str;
	USHORT l2 = MOV_make_string2(tdbb, desc2, ttype, &p2, match_str);

	// Merge search and control strings
	UCHAR control[BUFFER_SMALL];
	const SLONG control_length = obj->sleuthMerge(*tdbb->getDefaultPool(), p2, l2, p1, l1, control); //, BUFFER_SMALL);

	// Note: resulting string from sleuthMerge is either USHORT or UCHAR
	// and never Multibyte (see note in EVL_mb_sleuthCheck)
	bool ret_val;
	MoveBuffer data_str;
	if (!desc1->isBlob())
	{
		// Source is not a blob, do a simple search

		l1 = MOV_make_string2(tdbb, desc1, ttype, &p1, data_str);
		ret_val = obj->sleuthCheck(*tdbb->getDefaultPool(), 0, p1, l1, control, control_length);
	}
	else
	{
		// Source string is a blob, things get interesting

		blb* blob = blb::open(tdbb, request->req_transaction,
			reinterpret_cast<bid*>(desc1->dsc_address));

		UCHAR buffer[BUFFER_LARGE];
		ret_val = false;

		while (!(blob->blb_flags & BLB_eof))