Cut avg aggregation to registerAggregation

and remove its PROTOTYPE

Relates to #17085

core/src/main/java/org/elasticsearch/search/SearchModule.java

@@ -148,6 +148,7 @@ import org.elasticsearch.search.aggregations.bucket.terms.LongTerms;
 import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsParser;
 import org.elasticsearch.search.aggregations.bucket.terms.UnmappedTerms;
+import org.elasticsearch.search.aggregations.metrics.avg.AvgAggregatorBuilder;
 import org.elasticsearch.search.aggregations.metrics.avg.AvgParser;
 import org.elasticsearch.search.aggregations.metrics.avg.InternalAvg;
 import org.elasticsearch.search.aggregations.metrics.cardinality.CardinalityParser;
@@ -442,7 +443,7 @@ public class SearchModule extends AbstractModule {
 
         SignificanceHeuristicParserMapper significanceHeuristicParserMapper = new SignificanceHeuristicParserMapper(heuristicParsers);
 
-        registerAggregatorParser(new AvgParser());
+        registerAggregation(AvgAggregatorBuilder::new, new AvgParser(), AvgAggregatorBuilder.AGGREGATION_NAME_FIELD);
         registerAggregatorParser(new SumParser());
         registerAggregatorParser(new MinParser());
         registerAggregatorParser(new MaxParser());

core/src/main/java/org/elasticsearch/search/aggregations/AggregatorBuilder.java

@@ -191,6 +191,7 @@ public abstract class AggregatorBuilder<AB extends AggregatorBuilder<AB>> extend
     @Override
     public String getWriteableName() {
         // NORELEASE remove this before 5.0.0GA - all builders will implement this method on their own.
+        assert usesNewStyleSerialization() == false: "migrated aggregations should just return their NAME";
         return type.stream().toUtf8();
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/metrics/avg/AvgAggregatorBuilder.java

@@ -19,47 +19,53 @@
 
 package org.elasticsearch.search.aggregations.metrics.avg;
 
+import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.common.xcontent.ToXContent.Params;
-import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
+import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
+import org.elasticsearch.search.aggregations.support.ValuesSource.Numeric;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorBuilder;
 import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.ValuesSourceType;
-import org.elasticsearch.search.aggregations.support.ValuesSource.Numeric;
 
 import java.io.IOException;
 
 public class AvgAggregatorBuilder extends ValuesSourceAggregatorBuilder.LeafOnly<ValuesSource.Numeric, AvgAggregatorBuilder> {
-
-    static final AvgAggregatorBuilder PROTOTYPE = new AvgAggregatorBuilder("");
+    public static final String NAME = InternalAvg.TYPE.name();
+    public static final ParseField AGGREGATION_NAME_FIELD = new ParseField(NAME);
 
     public AvgAggregatorBuilder(String name) {
         super(name, InternalAvg.TYPE, ValuesSourceType.NUMERIC, ValueType.NUMERIC);
     }
 
+    /**
+     * Read from a stream.
+     */
+    public AvgAggregatorBuilder(StreamInput in) throws IOException {
+        super(in, InternalAvg.TYPE, ValuesSourceType.NUMERIC, ValueType.NUMERIC);
+    }
+
+    @Override
+    protected void innerWriteTo(StreamOutput out) {
+        // Do nothing, no extra state to write to stream
+    }
+
+    @Override
+    protected boolean usesNewStyleSerialization() {
+        return true;
+    }
+
     @Override
     protected AvgAggregatorFactory innerBuild(AggregationContext context, ValuesSourceConfig<Numeric> config,
             AggregatorFactory<?> parent, Builder subFactoriesBuilder) throws IOException {
         return new AvgAggregatorFactory(name, type, config, context, parent, subFactoriesBuilder, metaData);
     }
 
-    @Override
-    protected AvgAggregatorBuilder innerReadFrom(String name, ValuesSourceType valuesSourceType,
-            ValueType targetValueType, StreamInput in) {
-        return new AvgAggregatorBuilder(name);
-    }
-
-    @Override
-    protected void innerWriteTo(StreamOutput out) {
-        // Do nothing, no extra state to write to stream
-    }
-
     @Override
     public XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
         return builder;
@@ -74,4 +80,9 @@ public class AvgAggregatorBuilder extends ValuesSourceAggregatorBuilder.LeafOnly
     protected boolean innerEquals(Object obj) {
         return true;
     }
+
+    @Override
+    public String getWriteableName() {
+        return NAME;
+    }
 }

core/src/main/java/org/elasticsearch/search/aggregations/metrics/avg/AvgParser.java

@@ -37,11 +37,6 @@ public class AvgParser extends NumericValuesSourceParser {
         super(true, true, false);
     }
 
-    @Override
-    public String type() {
-        return InternalAvg.TYPE.name();
-    }
-
     @Override
     protected boolean token(String aggregationName, String currentFieldName, XContentParser.Token token, XContentParser parser,
             ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
@@ -53,10 +48,4 @@ public class AvgParser extends NumericValuesSourceParser {
             ValueType targetValueType, Map<ParseField, Object> otherOptions) {
         return new AvgAggregatorBuilder(aggregationName);
     }
-
-    @Override
-    public AvgAggregatorBuilder getFactoryPrototypes() {
-        return AvgAggregatorBuilder.PROTOTYPE;
-    }
-
 }

core/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceAggregatorBuilder.java

@@ -21,7 +21,6 @@ package org.elasticsearch.search.aggregations.support;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
-import org.elasticsearch.common.joda.FormatDateTimeFormatter;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.fielddata.IndexFieldData;
 import org.elasticsearch.index.fielddata.IndexGeoPointFieldData;
@@ -32,9 +31,9 @@ import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.SearchScript;
 import org.elasticsearch.search.DocValueFormat;
 import org.elasticsearch.search.aggregations.AggregationInitializationException;
-import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
 import org.elasticsearch.search.aggregations.AggregatorBuilder;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
+import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.InternalAggregation.Type;
 import org.elasticsearch.search.internal.SearchContext;
@@ -57,6 +56,13 @@ public abstract class ValuesSourceAggregatorBuilder<VS extends ValuesSource, AB
             super(name, type, valuesSourceType, targetValueType);
         }
 
+        /**
+         * Read from a stream.
+         */
+        protected LeafOnly(StreamInput in, Type type, ValuesSourceType valuesSourceType, ValueType targetValueType) throws IOException {
+            super(in, type, valuesSourceType, targetValueType);
+        }
+
         @Override
         public AB subAggregations(Builder subFactories) {
             throw new AggregationInitializationException("Aggregator [" + name + "] of type [" + type + "] cannot accept sub-aggregations");
@@ -138,6 +144,9 @@ public abstract class ValuesSourceAggregatorBuilder<VS extends ValuesSource, AB
         }
     }
 
+    /**
+     * Write subclass's state to the stream.
+     */
     protected abstract void innerWriteTo(StreamOutput out) throws IOException;
 
     @SuppressWarnings("unchecked")