Upgrade to a Lucene 7 snapshot (#24089)

We want to upgrade to Lucene 7 ahead of time in order to be able to check whether it causes any trouble to Elasticsearch before Lucene 7.0 gets released. From a user perspective, the main benefit of this upgrade is the enhanced support for sparse fields, whose resource consumption is now function of the number of docs that have a value rather than the total number of docs in the index.

Some notes about the change:
 - it includes the deprecation of the `disable_coord` parameter of the `bool` and `common_terms` queries: Lucene has removed support for coord factors
 - it includes the deprecation of the `index.similarity.base` expert setting, since it was only useful to configure coords and query norms, which have both been removed
 - two tests have been marked with `@AwaitsFix` because of #23966, which we intend to address after the merge

1 files changed, 14 insertions, 9 deletions

diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoGridAggregationBuilder.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoGridAggregationBuilder.java
index 602c3a81c6..1c60247446 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoGridAggregationBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoGridAggregationBuilder.java
@@ -28,10 +28,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.index.fielddata.AbstractSortingNumericDocValues;
 import org.elasticsearch.index.fielddata.MultiGeoPointValues;
 import org.elasticsearch.index.fielddata.SortedBinaryDocValues;
 import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
-import org.elasticsearch.index.fielddata.SortingNumericDocValues;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
@@ -187,7 +187,7 @@ public class GeoGridAggregationBuilder extends ValuesSourceAggregationBuilder<Va
         return NAME;
     }
 
-    private static class CellValues extends SortingNumericDocValues {
+    private static class CellValues extends AbstractSortingNumericDocValues {
         private MultiGeoPointValues geoValues;
         private int precision;
 
@@ -197,14 +197,19 @@ public class GeoGridAggregationBuilder extends ValuesSourceAggregationBuilder<Va
         }
 
         @Override
-        public void setDocument(int docId) {
-            geoValues.setDocument(docId);
-            resize(geoValues.count());
-            for (int i = 0; i < count(); ++i) {
-                GeoPoint target = geoValues.valueAt(i);
-                values[i] = GeoHashUtils.longEncode(target.getLon(), target.getLat(), precision);
+        public boolean advanceExact(int docId) throws IOException {
+            if (geoValues.advanceExact(docId)) {
+                resize(geoValues.docValueCount());
+                for (int i = 0; i < docValueCount(); ++i) {
+                    GeoPoint target = geoValues.nextValue();
+                    values[i] = GeoHashUtils.longEncode(target.getLon(), target.getLat(),
+                            precision);
+                }
+                sort();
+                return true;
+            } else {
+                return false;
             }
-            sort();
         }
     }