public static KNNQueryBuilder fromXContent()

in src/main/java/org/opensearch/knn/index/KNNQueryBuilder.java [107:154]
47 lines of code
12 McCabe index (conditional complexity)

    public static KNNQueryBuilder fromXContent(XContentParser parser) throws IOException {
        String fieldName = null;
        List<Object> vector = null;
        float boost = AbstractQueryBuilder.DEFAULT_BOOST;
        int k = 0;
        String queryName = null;
        String currentFieldName = null;
        XContentParser.Token token;
        KNNCounter.KNN_QUERY_REQUESTS.increment();
        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
            if (token == XContentParser.Token.FIELD_NAME) {
                currentFieldName = parser.currentName();
            } else if (token == XContentParser.Token.START_OBJECT) {
                throwParsingExceptionOnMultipleFields(NAME, parser.getTokenLocation(), fieldName, currentFieldName);
                fieldName = currentFieldName;
                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                    if (token == XContentParser.Token.FIELD_NAME) {
                        currentFieldName = parser.currentName();
                    } else if (token.isValue() || token == XContentParser.Token.START_ARRAY) {
                        if (VECTOR_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
                            vector = parser.list();
                        } else if (AbstractQueryBuilder.BOOST_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
                            boost = parser.floatValue();
                        } else if (K_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
                            k = (Integer) NumberFieldMapper.NumberType.INTEGER.parse(parser.objectBytes(), false);
                        } else if (AbstractQueryBuilder.NAME_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
                            queryName = parser.text();
                        } else {
                            throw new ParsingException(parser.getTokenLocation(),
                                    "[" + NAME + "] query does not support [" + currentFieldName + "]");
                        }
                    } else {
                        throw new ParsingException(parser.getTokenLocation(),
                                "[" + NAME + "] unknown token [" + token + "] after [" + currentFieldName + "]");
                    }
                }
            } else {
                throwParsingExceptionOnMultipleFields(NAME, parser.getTokenLocation(), fieldName, parser.currentName());
                fieldName = parser.currentName();
                vector = parser.list();
            }
        }

        KNNQueryBuilder knnQuery = new KNNQueryBuilder(fieldName, ObjectsToFloats(vector), k);
        knnQuery.queryName(queryName);
        knnQuery.boost(boost);
        return knnQuery;
    }