private static ConditionQuery constructQuery()

in hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphIndexTransaction.java [1193:1287]
79 lines of code
13 McCabe index (conditional complexity)

    private static ConditionQuery constructQuery(ConditionQuery query,
                                                 IndexLabel indexLabel) {
        IndexType indexType = indexLabel.indexType();
        boolean requireRange = query.hasRangeCondition();
        boolean supportRange = indexType.isNumeric();
        if (requireRange && !supportRange) {
            LOG.debug("There is range query condition in '{}', " +
                      "but the index label '{}' is unable to match",
                      query, indexLabel.name());
            return null;
        }

        Set<Id> queryKeys = query.userpropKeys();
        List<Id> indexFields = indexLabel.indexFields();
        if (!matchIndexFields(queryKeys, indexFields)) {
            return null;
        }
        LOG.debug("Matched index fields: {} of index '{}'",
                  indexFields, indexLabel);

        ConditionQuery indexQuery;

        switch (indexType) {
            case SEARCH:
                E.checkState(indexFields.size() == 1,
                             "Invalid index fields size for %s: %s",
                             indexType, indexFields);
                Object fieldValue = query.userpropValue(indexFields.get(0));
                assert fieldValue instanceof String;
                // Will escape special char inside concatValues()
                fieldValue = ConditionQuery.concatValues(fieldValue);

                indexQuery = new ConditionQuery(indexType.type(), query);
                indexQuery.eq(HugeKeys.INDEX_LABEL_ID, indexLabel.id());
                indexQuery.eq(HugeKeys.FIELD_VALUES, fieldValue);
                break;
            case SECONDARY:
                List<Id> joinedKeys = indexFields.subList(0, queryKeys.size());
                // Will escape special char inside userpropValuesString()
                String joinedValues = query.userpropValuesString(joinedKeys);

                indexQuery = new ConditionQuery(indexType.type(), query);
                indexQuery.eq(HugeKeys.INDEX_LABEL_ID, indexLabel.id());
                indexQuery.eq(HugeKeys.FIELD_VALUES, joinedValues);
                break;
            case RANGE_INT:
            case RANGE_FLOAT:
            case RANGE_LONG:
            case RANGE_DOUBLE:
                if (query.userpropConditions().size() > 2) {
                    throw new HugeException(
                              "Range query has two conditions at most, " +
                              "but got: %s", query.userpropConditions());
                }
                // Replace the query key with PROPERTY_VALUES, set number value
                indexQuery = new ConditionQuery(indexType.type(), query);
                indexQuery.eq(HugeKeys.INDEX_LABEL_ID, indexLabel.id());
                for (Condition condition : query.userpropConditions()) {
                    assert condition instanceof Relation;
                    Relation r = (Relation) condition;
                    Number value = NumericUtil.convertToNumber(r.value());
                    Relation sys = new Condition.SyspropRelation(
                                                 HugeKeys.FIELD_VALUES,
                                                 r.relation(), value);
                    condition = condition.replace(r, sys);
                    indexQuery.query(condition);
                }
                break;
            case SHARD:
                HugeType type = indexLabel.indexType().type();
                indexQuery = new ConditionQuery(type, query);
                indexQuery.eq(HugeKeys.INDEX_LABEL_ID, indexLabel.id());
                List<Condition> conditions = constructShardConditions(
                                             query, indexLabel.indexFields(),
                                             HugeKeys.FIELD_VALUES);
                indexQuery.query(conditions);
                break;
            default:
                throw new AssertionError(String.format(
                          "Unknown index type '%s'", indexType));
        }

        /*
         * Set limit for single index or composite index, also for joint index,
         * to avoid redundant element ids and out of capacity.
         * NOTE: not set offset because this query might be a sub-query,
         * see queryByUserprop()
         */
        indexQuery.page(query.page());
        indexQuery.limit(query.total());
        indexQuery.capacity(query.capacity());
        indexQuery.olap(indexLabel.olap());

        return indexQuery;
    }