Verify that the sort field is specifically the TS timestamp

Only activate the time-series optimizations if the aggregation is both: * Within a time-series aggregation (ie. tsid and @timestamp ordered) * The geo_line sort field is @timestamp

Author: craigtaverner

x-pack/plugin/spatial/src/main/java/org/elasticsearch/xpack/spatial/search/aggregations/GeoLineAggregatorFactory.java

@@ -20,6 +20,9 @@
 import java.io.IOException;
 import java.util.Map;
 
+import static org.elasticsearch.cluster.metadata.DataStream.TIMESTAMP_FIELD;
+import static org.elasticsearch.xpack.spatial.search.aggregations.GeoLineAggregationBuilder.SORT_FIELD;
+
 final class GeoLineAggregatorFactory extends MultiValuesSourceAggregatorFactory {
 
  private final boolean includeSort;
@@ -58,13 +61,20 @@ protected Aggregator doCreateInternal(
  Map<String, Object> metaData
  ) throws IOException {
  GeoLineMultiValuesSource valuesSources = new GeoLineMultiValuesSource(configs);
- if (context.isInSortOrderExecutionRequired()) {
+ if (context.isInSortOrderExecutionRequired() && isSortByTimestamp(configs)) {
+ // We require both that this aggregation is a sub-aggregation of time-series, and that the sort field is '@timestamp'
  return new GeoLineAggregator.TimeSeries(name, valuesSources, context, parent, metaData, includeSort, sortOrder, size);
  } else {
  return new GeoLineAggregator.Normal(name, valuesSources, context, parent, metaData, includeSort, sortOrder, size);
  }
  }
 
+ private boolean isSortByTimestamp(Map<String, ValuesSourceConfig> configs) {
+ ValuesSourceConfig sortConfig = configs.get(SORT_FIELD.getPreferredName());
+ // TODO: for 'position' metric no sort field is required
+ return sortConfig.fieldContext().field().equals(TIMESTAMP_FIELD.getName());
+ }
+
  @Override
  public String getStatsSubtype() {
  return configs.get(GeoLineAggregationBuilder.POINT_FIELD.getPreferredName()).valueSourceType().typeName();