Examples with ResultMergeQueryRunner io.druid.query.ResultMergeQueryRunner used on opensource projects

Example 1 with ResultMergeQueryRunner

use of io.druid.query.ResultMergeQueryRunner in project druid by druid-io.

the class GroupByStrategyV2 method mergeResults.

@Override
public Sequence<Row> mergeResults(final QueryRunner<Row> baseRunner, final GroupByQuery query, final Map<String, Object> responseContext) {
    // Merge streams using ResultMergeQueryRunner, then apply postaggregators, then apply limit (which may
    // involve materialization)
    final ResultMergeQueryRunner<Row> mergingQueryRunner = new ResultMergeQueryRunner<Row>(baseRunner) {

        @Override
        protected Ordering<Row> makeOrdering(Query<Row> queryParam) {
            return ((GroupByQuery) queryParam).getRowOrdering(true);
        }

        @Override
        protected BinaryFn<Row, Row, Row> createMergeFn(Query<Row> queryParam) {
            return new GroupByBinaryFnV2((GroupByQuery) queryParam);
        }
    };
    // Fudge timestamp, maybe.
    final DateTime fudgeTimestamp = getUniversalTimestamp(query);
    return query.applyLimit(Sequences.map(mergingQueryRunner.run(new GroupByQuery(query.getDataSource(), query.getQuerySegmentSpec(), query.getVirtualColumns(), query.getDimFilter(), query.getGranularity(), query.getDimensions(), query.getAggregatorSpecs(), // Don't do post aggs until the end of this method.
    ImmutableList.<PostAggregator>of(), // Don't do "having" clause until the end of this method.
    null, null, query.getContext()).withOverriddenContext(ImmutableMap.<String, Object>of("finalize", false, GroupByQueryConfig.CTX_KEY_STRATEGY, GroupByStrategySelector.STRATEGY_V2, CTX_KEY_FUDGE_TIMESTAMP, fudgeTimestamp == null ? "" : String.valueOf(fudgeTimestamp.getMillis()), CTX_KEY_OUTERMOST, false)), responseContext), new Function<Row, Row>() {

        @Override
        public Row apply(final Row row) {
            if (!query.getContextBoolean(CTX_KEY_OUTERMOST, true)) {
                return row;
            }
            if (query.getPostAggregatorSpecs().isEmpty() && fudgeTimestamp == null) {
                return row;
            }
            final Map<String, Object> newMap;
            if (query.getPostAggregatorSpecs().isEmpty()) {
                newMap = ((MapBasedRow) row).getEvent();
            } else {
                newMap = Maps.newLinkedHashMap(((MapBasedRow) row).getEvent());
                for (PostAggregator postAggregator : query.getPostAggregatorSpecs()) {
                    newMap.put(postAggregator.getName(), postAggregator.compute(newMap));
                }
            }
            return new MapBasedRow(fudgeTimestamp != null ? fudgeTimestamp : row.getTimestamp(), newMap);
        }
    }));
}