applied feedback 1

docs/reference/search/field-stats.asciidoc

@@ -3,9 +3,9 @@
 
 experimental[]
 
-The field stats api allows to easily figure certain statistical properties without a field without executing a search, but
-looking up measurements that are natively available in the Lucene index. This can be useful to explore a data set,
-that you don't know much about in order to for example create histogram aggregation with a meaningful interval.
+The field stats api allows one to find statistical properties of a field without executing a search, but
+looking up measurements that are natively available in the Lucene index. This can be useful to explore a dataset which
+you don't know much about. For example, this allows creating a histogram aggregation with meaningful intervals.
 
 The field stats api by defaults executes on all indices, but can execute on specific indices too.
 
@@ -32,7 +32,7 @@ The field stats api is supported on string based, number based and date based fi
 
 * `max_doc`             - The total number of documents.
 * `doc_count`           - The number of documents that have at least one term for this field, or -1 if this measurement isn't available on one or more shards.
-* `density`             - A ratio as a percentage between all the documents that have at least one value for this field and all documents.
+* `density`             - The percentage of documents that have at least one value for this field. This is a derived statistic and is based on the `max_doc` and `doc_count`.
 * `sum_doc_freq`        - The sum of each term's document frequency in this field, or -1 if this measurement isn't available on one or more shards.
                           Document frequency is the number of documents containing a particular term.
 * `sum_total_term_freq` - The sum of the term frequencies of all terms in this field across all documents, or -1 if this measurement isn't available on one or more shards.

src/main/java/org/elasticsearch/action/fieldstats/FieldStats.java

@@ -31,8 +31,6 @@
 
 import java.io.IOException;
 
-/**
- */
 public abstract class FieldStats<T> implements Streamable, ToXContent {
 
     private byte type;
@@ -73,7 +71,9 @@ public long getDocCount() {
     }
 
     /**
-     * @return A ratio as percentage of between all the documents that have at least one value for this field and all documents. (doc_count / max_doc)
+     * @return The percentage of documents that have at least one value for this field.
+     *
+     * This is a derived statistic and is based on: 'doc_count / max_doc'
      */
     public int getDensity() {
         if (docCount < 0 || maxDoc <= 0) {

src/main/java/org/elasticsearch/action/fieldstats/FieldStatsRequest.java

@@ -31,30 +31,23 @@ public class FieldStatsRequest extends BroadcastOperationRequest<FieldStatsReque
 
     private String[] fields;
 
-    public String[] fields() {
+    public String[] getFields() {
         return fields;
     }
 
-    public void fields(String[] fields) {
+    public void setFields(String[] fields) {
         this.fields = fields;
     }
 
     @Override
     public void readFrom(StreamInput in) throws IOException {
         super.readFrom(in);
-        if (in.readBoolean()) {
-            fields = in.readStringArray();
-        }
+        fields = in.readStringArray();
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
-        if (fields != null) {
-            out.writeBoolean(true);
-            out.writeStringArray(fields);
-        } else {
-            out.writeBoolean(false);
-        }
+        out.writeStringArrayNullable(fields);
     }
 }

src/main/java/org/elasticsearch/action/fieldstats/FieldStatsRequestBuilder.java

@@ -32,7 +32,7 @@ public FieldStatsRequestBuilder(Client client) {
     }
 
     public FieldStatsRequestBuilder fields(String... fields) {
-        request().fields(fields);
+        request().setFields(fields);
         return this;
     }
 

src/main/java/org/elasticsearch/action/fieldstats/FieldStatsShardRequest.java

@@ -37,34 +37,23 @@ public FieldStatsShardRequest() {
 
     public FieldStatsShardRequest(ShardId shardId, FieldStatsRequest request) {
         super(shardId, request);
-        this.fields = request.fields();
+        this.fields = request.getFields();
     }
 
-    public String[] fields() {
+    public String[] getFields() {
         return fields;
     }
 
-    public void fields(String[] fields) {
-        this.fields = fields;
-    }
-
     @Override
     public void readFrom(StreamInput in) throws IOException {
         super.readFrom(in);
-        if (in.readBoolean()) {
-            fields = in.readStringArray();
-        }
+        fields = in.readStringArray();
     }
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
-        if (fields != null) {
-            out.writeBoolean(true);
-            out.writeStringArray(fields);
-        } else {
-            out.writeBoolean(false);
-        }
+        out.writeStringArrayNullable(fields);
     }
 
 }

src/main/java/org/elasticsearch/action/fieldstats/TransportFieldStatsTransportAction.java

@@ -81,16 +81,13 @@ protected FieldStatsResponse newResponse(FieldStatsRequest request, AtomicRefere
         int successfulShards = 0;
         int failedShards = 0;
         Map<String, FieldStats> mergedFieldStats = new HashMap<>();
-        List<ShardOperationFailedException> shardFailures = null;
+        List<ShardOperationFailedException> shardFailures = new ArrayList<>();
         for (int i = 0; i < shardsResponses.length(); i++) {
             Object shardResponse = shardsResponses.get(i);
             if (shardResponse == null) {
                 // simply ignore non active shards
             } else if (shardResponse instanceof BroadcastShardOperationFailedException) {
                 failedShards++;
-                if (shardFailures == null) {
-                    shardFailures = new ArrayList<>();
-                }
                 shardFailures.add(new DefaultShardOperationFailedException((BroadcastShardOperationFailedException) shardResponse));
             } else {
                 successfulShards++;
@@ -132,7 +129,7 @@ protected FieldStatsShardResponse shardOperation(FieldStatsShardRequest request)
         IndexShard shard = indexServices.shardSafe(shardId.id());
         shard.readAllowed();
         try (Engine.Searcher searcher = shard.acquireSearcher("fieldstats")) {
-            for (String field : request.fields()) {
+            for (String field : request.getFields()) {
                 FieldMappers fieldMappers = mapperService.fullName(field);
                 if (fieldMappers != null) {
                     IndexReader reader = searcher.reader();

src/main/java/org/elasticsearch/rest/action/fieldstats/RestFieldStatsAction.java

@@ -55,7 +55,7 @@ public void handleRequest(final RestRequest request, final RestChannel channel,
         final FieldStatsRequest fieldStatsRequest = new FieldStatsRequest();
         fieldStatsRequest.indices(Strings.splitStringByCommaToArray(request.param("index")));
         fieldStatsRequest.indicesOptions(IndicesOptions.fromRequest(request, fieldStatsRequest.indicesOptions()));
-        fieldStatsRequest.fields(Strings.splitStringByCommaToArray(request.param("fields")));
+        fieldStatsRequest.setFields(Strings.splitStringByCommaToArray(request.param("fields")));
         fieldStatsRequest.indicesOptions(IndicesOptions.fromRequest(request, fieldStatsRequest.indicesOptions()));
         fieldStatsRequest.listenerThreaded(false);
 

src/test/java/org/elasticsearch/fieldstats/FieldStatsTests.java → src/test/java/org/elasticsearch/fieldstats/FieldStatsIntegrationTests.java

@@ -34,7 +34,7 @@
 
 /**
  */
-public class FieldStatsTests extends ElasticsearchIntegrationTest {
+public class FieldStatsIntegrationTests extends ElasticsearchIntegrationTest {
 
     @Test
     public void testRandom() throws Exception {