Add hits length in SearchRequestContext

server/src/main/java/org/opensearch/action/search/AbstractSearchAsyncAction.java

@@ -792,6 +792,7 @@ public void sendSearchResponse(InternalSearchResponse internalSearchResponse, At
                 }
             }
             searchRequestContext.setTotalHits(internalSearchResponse.hits().getTotalHits());
+            searchRequestContext.setHitsLength(internalSearchResponse.hits().getHits().length);
             searchRequestContext.setShardStats(results.getNumShards(), successfulOps.get(), skippedOps.get(), failures.length);
             searchRequestContext.setSuccessfulSearchShardIndices(
                 results.getSuccessfulResults()

server/src/main/java/org/opensearch/action/search/SearchRequestContext.java

@@ -37,6 +37,7 @@ public class SearchRequestContext {
     private long absoluteStartNanos;
     private final Map<String, Long> phaseTookMap;
     private TotalHits totalHits;
+    private int hitsLength;
     private final EnumMap<ShardStatsFieldNames, Integer> shardStats;
     private Set<Index> successfulSearchShardIndices;
 
@@ -102,6 +103,14 @@ public TotalHits totalHits() {
         return totalHits;
     }
 
+    void setHitsLength(int hitsLength) {
+        this.hitsLength = hitsLength;
+    }
+
+    public int getHitsLength() {
+        return hitsLength;
+    }
+
     void setShardStats(int total, int successful, int skipped, int failed) {
         this.shardStats.put(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_TOTAL, total);
         this.shardStats.put(ShardStatsFieldNames.SEARCH_REQUEST_SLOWLOG_SHARD_SUCCESSFUL, successful);