private IdHolderList queryByUserprop()

in hugegraph-core/src/main/java/org/apache/hugegraph/backend/tx/GraphIndexTransaction.java [448:505]
40 lines of code
12 McCabe index (conditional complexity)

    private IdHolderList queryByUserprop(ConditionQuery query) {
        // Get user applied label or collect all qualified labels with
        // related index labels
        if (!this.graph().readMode().showOlap()) {
            for (Id pkId : query.userpropKeys()) {
                PropertyKey propertyKey = this.graph().propertyKey(pkId);
                if (propertyKey.olap()) {
                    throw new NotAllowException(
                              "Not allowed to query by olap property key '%s'" +
                              " when graph-read-mode is '%s'",
                              propertyKey, this.graph().readMode());
                }
            }
        }
        Set<MatchedIndex> indexes = this.collectMatchedIndexes(query);
        if (indexes.isEmpty()) {
            Id label = query.condition(HugeKeys.LABEL);
            throw noIndexException(this.graph(), query, label);
        }

        // Value type of Condition not matched
        boolean paging = query.paging();
        if (!validQueryConditionValues(this.graph(), query)) {
            return IdHolderList.empty(paging);
        }

        // Do index query
        IdHolderList holders = new IdHolderList(paging);
        for (MatchedIndex index : indexes) {
            for (IndexLabel il : index.indexLabels()) {
                validateIndexLabel(il);
            }
            if (paging && index.indexLabels().size() > 1) {
                throw new NotSupportException("joint index query in paging");
            }

            if (index.containsSearchIndex()) {
                // Do search-index query
                holders.addAll(this.doSearchIndex(query, index));
            } else {
                // Do secondary-index, range-index or shard-index query
                IndexQueries queries = index.constructIndexQueries(query);
                assert !paging || queries.size() <= 1;
                IdHolder holder = this.doSingleOrJointIndex(queries);
                holders.add(holder);
            }

            /*
             * NOTE: need to skip the offset if offset > 0, but can't handle
             * it here because the query may a sub-query after flatten,
             * so the offset will be handle in QueryList.IndexQuery
             *
             * TODO: finish early here if records exceeds required limit with
             *       FixedIdHolder.
             */
        }
        return holders;
    }