private Bson renderBinaryComparisonOperator()

in flink-connector-mongodb/src/main/java/org/apache/flink/connector/mongodb/table/MongoFilterPushDownVisitor.java [104:140]

31 lines of code
10 McCabe index (conditional complexity)


    private Bson renderBinaryComparisonOperator(
            String operator, List<ResolvedExpression> expressions) {
        Optional<FieldReferenceExpression> fieldReferenceExpr =
                extractExpression(expressions, FieldReferenceExpression.class);
        Optional<ValueLiteralExpression> fieldValueExpr =
                extractExpression(expressions, ValueLiteralExpression.class);

        // Nested complex expressions are not supported. e.g. f1 = (f2 > 2)
        if (!fieldReferenceExpr.isPresent() || !fieldValueExpr.isPresent()) {
            return Filters.empty();
        }

        String fieldName = visit(fieldReferenceExpr.get()).getValue();
        BsonValue fieldValue = visit(fieldValueExpr.get());

        // Unsupported values
        if (fieldValue.getBsonType() == BsonType.UNDEFINED) {
            return Filters.empty();
        }

        switch (operator) {
            case "$eq":
                return Filters.eq(fieldName, fieldValue);
            case "$lt":
                return Filters.lt(fieldName, fieldValue);
            case "$lte":
                return Filters.lte(fieldName, fieldValue);
            case "$gt":
                return Filters.gt(fieldName, fieldValue);
            case "$gte":
                return Filters.gte(fieldName, fieldValue);
            case "$ne":
                return Filters.ne(fieldName, fieldValue);
            default:
                return Filters.empty();
        }
    }