Function BTR_make_key

src/jrd/btr.cpp:1854–2030

idx_e BTR_make_key(thread_db* tdbb,
				   USHORT count,
				   const ValueExprNode* const* exprs,
				   const SSHORT* scale,
				   const index_desc* idx,
				   temporary_key* key,
				   USHORT keyType,
				   bool* forceInclude)
{
/**************************************
 *
 *	B T R _ m a k e _ k e y
 *
 **************************************
 *
 * Functional description
 *	Construct a (possibly) compound search key given a key count,
 *	a vector of value expressions, and a place to put the key.
 *
 **************************************/
	const auto dbb = tdbb->getDatabase();
	const auto request = tdbb->getRequest();

	temporary_key temp;
	temp.key_flags = 0;
	temp.key_length = 0;

	fb_assert(count > 0);
	fb_assert(idx != NULL);
	fb_assert(exprs != NULL);
	fb_assert(key != NULL);

	key->key_flags = 0;
	key->key_nulls = 0;

	const bool fuzzy = (keyType == INTL_KEY_PARTIAL || keyType == INTL_KEY_MULTI_STARTING);
	const bool descending = (idx->idx_flags & idx_descending);

	const index_desc::idx_repeat* tail = idx->idx_rpt;

	const USHORT maxKeyLength = dbb->getMaxIndexKeyLength();

	// If the index is a single segment index, don't sweat the compound stuff
	if (idx->idx_count == 1)
	{
		const auto desc = EVL_expr(tdbb, request, *exprs);

		if (!desc)
			key->key_nulls = 1;

		key->key_flags |= key_empty;

		compress(tdbb, desc, scale ? *scale : 0, key, tail->idx_itype, descending, keyType, forceInclude);

		if (fuzzy && (key->key_flags & key_empty))
		{
			key->key_length = 0;
			key->key_next.reset();