Function PopulateRegexState

pg_documentdb/src/query/bson_dollar_operators.c:3513–3538

* Given a top level function arguments for regex and a traverse state for * regex, populates the data inside the validation state. */

 * regex, populates the data inside the validation state.
 */
static pgbsonelement
PopulateRegexState(PG_FUNCTION_ARGS, TraverseRegexValidateState *state)
{
	pgbson *filter = PG_GETARG_PGBSON(1);
	const RegexData *regexState;
	pgbsonelement filterElement;

	/* collation does not take effect on $regex  */
	PgbsonToSinglePgbsonElement(filter, &filterElement);

	/* State populated if and only if cached state is unusable */
	SetCachedFunctionState(regexState, RegexData, 1, PopulateRegexFromQuery,
						   &filterElement);
	if (regexState == NULL)
	{
		/* Cache not available */
		PopulateRegexFromQuery(&state->regexData, &filterElement);
	}
	else
	{
		state->regexData = *regexState;
	}

	state->traverseState.matchFunc = CompareRegexMatch;
	return filterElement;
}


/*