Method call

src/core/TsdbQuery.java:991–1113

Creates the SpanGroups to form the final results of this query. @param spans The Spans found for this query (#findSpans). Can be null, in which case the array returned will be empty. @return A possibly empty array of SpanGroups built according to any 'GROUP BY

(final SortedMap<byte[], Span> spans)

    * any 'GROUP BY' formulated in this query.
    */
    @Override
    public DataPoints[] call(final SortedMap<byte[], Span> spans) throws Exception {
      if (query_stats != null) {
        query_stats.addStat(query_index, QueryStat.QUERY_SCAN_TIME, 
                (System.nanoTime() - TsdbQuery.this.scan_start_time));
      }
      
      if (spans == null || spans.size() <= 0) {
        if (query_stats != null) {
          query_stats.addStat(query_index, QueryStat.GROUP_BY_TIME, 0);
        }
        return NO_RESULT;
      }
      
      // The raw aggregator skips group bys and ignores downsampling
      if (aggregator == Aggregators.NONE) {
        final SpanGroup[] groups = new SpanGroup[spans.size()];
        int i = 0;
        for (final Span span : spans.values()) {
          final SpanGroup group = new SpanGroup(
              tsdb, 
              getScanStartTimeSeconds(),
              getScanEndTimeSeconds(),
              null, 
              rate, 
              rate_options,
              aggregator,
              downsampler,
              getStartTime(), 
              getEndTime(),
              query_index,
              rollup_query,
              null);
          group.add(span);
          groups[i++] = group;
        }
        return groups;
      }
      
      if (group_bys == null) {
        // We haven't been asked to find groups, so let's put all the spans
        // together in the same group.
        final SpanGroup group = new SpanGroup(tsdb,
                                              getScanStartTimeSeconds(),
                                              getScanEndTimeSeconds(),
                                              spans.values(),
                                              rate, rate_options,
                                              aggregator,
                                              downsampler,
                                              getStartTime(), 
                                              getEndTime(),
                                              query_index,
                                              rollup_query,
                                              new byte[0]);
        if (query_stats != null) {
          query_stats.addStat(query_index, QueryStat.GROUP_BY_TIME, 0);
        }
        return new SpanGroup[] { group };