Remove PROTOTYPE from RescorerBuilders

This changes the serialization order for QueryRescorerBuilder's but
that is ok because 5.0.0 doesn't need to be wire compatible with anything.

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

@@ -286,6 +286,7 @@ public class SearchModule extends AbstractModule {
 
         registerBuiltinFunctionScoreParsers();
         registerBuiltinQueryParsers();
+        registerBuiltinRescorers();
     }
 
     public void registerHighlighter(String key, Class<? extends Highlighter> clazz) {
@@ -350,7 +351,6 @@ public class SearchModule extends AbstractModule {
         configureSuggesters();
         configureFetchSubPhase();
         configureShapes();
-        configureRescorers();
         configureSorts();
     }
 
@@ -491,8 +491,8 @@ public class SearchModule extends AbstractModule {
         }
     }
 
-    private void configureRescorers() {
+    private void registerBuiltinRescorers() {
-        namedWriteableRegistry.registerPrototype(RescoreBuilder.class, QueryRescorerBuilder.PROTOTYPE);
+        namedWriteableRegistry.register(RescoreBuilder.class, QueryRescorerBuilder.NAME, QueryRescorerBuilder::new);
     }
 
     private void configureSorts() {

core/src/main/java/org/elasticsearch/search/rescore/QueryRescoreMode.java

@@ -85,10 +85,7 @@ public enum QueryRescoreMode implements Writeable<QueryRescoreMode> {
 
     public abstract float combine(float primary, float secondary);
 
-    static QueryRescoreMode PROTOTYPE = Total;
+    public static QueryRescoreMode readFromStream(StreamInput in) throws IOException {
-
-    @Override
-    public QueryRescoreMode readFrom(StreamInput in) throws IOException {
         int ordinal = in.readVInt();
         if (ordinal < 0 || ordinal >= values().length) {
             throw new IOException("Unknown ScoreMode ordinal [" + ordinal + "]");

core/src/main/java/org/elasticsearch/search/rescore/QueryRescorerBuilder.java

@@ -25,7 +25,6 @@ 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.query.MatchAllQueryBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.query.QueryShardContext;
@@ -39,8 +38,6 @@ public class QueryRescorerBuilder extends RescoreBuilder<QueryRescorerBuilder> {
 
     public static final String NAME = "query";
 
-    public static final QueryRescorerBuilder PROTOTYPE = new QueryRescorerBuilder(new MatchAllQueryBuilder());
-
     public static final float DEFAULT_RESCORE_QUERYWEIGHT = 1.0f;
     public static final float DEFAULT_QUERYWEIGHT = 1.0f;
     public static final QueryRescoreMode DEFAULT_SCORE_MODE = QueryRescoreMode.Total;
@@ -77,6 +74,25 @@ public class QueryRescorerBuilder extends RescoreBuilder<QueryRescorerBuilder> {
         this.queryBuilder = builder;
     }
 
+    /**
+     * Read from a stream.
+     */
+    public QueryRescorerBuilder(StreamInput in) throws IOException {
+        super(in);
+        queryBuilder = in.readQuery();
+        scoreMode = QueryRescoreMode.readFromStream(in);
+        rescoreQueryWeight = in.readFloat();
+        queryWeight = in.readFloat();
+    }
+
+    @Override
+    public void doWriteTo(StreamOutput out) throws IOException {
+        out.writeQuery(queryBuilder);
+        scoreMode.writeTo(out);
+        out.writeFloat(rescoreQueryWeight);
+        out.writeFloat(queryWeight);
+    }
+
     /**
      * @return the query used for this rescore query
      */
@@ -140,9 +156,9 @@ public class QueryRescorerBuilder extends RescoreBuilder<QueryRescorerBuilder> {
         builder.endObject();
     }
 
-    public QueryRescorerBuilder fromXContent(QueryParseContext parseContext) throws IOException {
+    public static QueryRescorerBuilder fromXContent(QueryParseContext parseContext) throws IOException {
-            InnerBuilder innerBuilder = QUERY_RESCORE_PARSER.parse(parseContext.parser(), new InnerBuilder(), parseContext);
+        InnerBuilder innerBuilder = QUERY_RESCORE_PARSER.parse(parseContext.parser(), new InnerBuilder(), parseContext);
-            return innerBuilder.build();
+        return innerBuilder.build();
     }
 
     @Override
@@ -181,23 +197,6 @@ public class QueryRescorerBuilder extends RescoreBuilder<QueryRescorerBuilder> {
                Objects.equals(queryBuilder, other.queryBuilder);
     }
 
-    @Override
-    public QueryRescorerBuilder doReadFrom(StreamInput in) throws IOException {
-        QueryRescorerBuilder rescorer = new QueryRescorerBuilder(in.readQuery());
-        rescorer.setScoreMode(QueryRescoreMode.PROTOTYPE.readFrom(in));
-        rescorer.setRescoreQueryWeight(in.readFloat());
-        rescorer.setQueryWeight(in.readFloat());
-        return rescorer;
-    }
-
-    @Override
-    public void doWriteTo(StreamOutput out) throws IOException {
-        out.writeQuery(queryBuilder);
-        scoreMode.writeTo(out);
-        out.writeFloat(rescoreQueryWeight);
-        out.writeFloat(queryWeight);
-    }
-
     @Override
     public String getWriteableName() {
         return NAME;
@@ -208,7 +207,7 @@ public class QueryRescorerBuilder extends RescoreBuilder<QueryRescorerBuilder> {
      * for the constructor of {@link QueryRescorerBuilder}, but {@link ObjectParser} only
      * allows filling properties of an already constructed value.
      */
-    private class InnerBuilder {
+    private static class InnerBuilder {
 
         private QueryBuilder<?> queryBuilder;
         private float rescoreQueryWeight = DEFAULT_RESCORE_QUERYWEIGHT;

core/src/main/java/org/elasticsearch/search/rescore/RescoreBuilder.java

@@ -46,6 +46,27 @@ public abstract class RescoreBuilder<RB extends RescoreBuilder<RB>> implements T
 
     private static ParseField WINDOW_SIZE_FIELD = new ParseField("window_size");
 
+    /**
+     * Construct an empty RescoreBuilder.
+     */
+    public RescoreBuilder() {
+    }
+
+    /**
+     * Read from a stream.
+     */
+    protected RescoreBuilder(StreamInput in) throws IOException {
+        windowSize = in.readOptionalVInt();
+    }
+
+    @Override
+    public final void writeTo(StreamOutput out) throws IOException {
+        out.writeOptionalVInt(this.windowSize);
+        doWriteTo(out);
+    }
+
+    protected abstract void doWriteTo(StreamOutput out) throws IOException;
+
     @SuppressWarnings("unchecked")
     public RB windowSize(int windowSize) {
         this.windowSize = windowSize;
@@ -74,7 +95,7 @@ public abstract class RescoreBuilder<RB extends RescoreBuilder<RB>> implements T
             } else if (token == XContentParser.Token.START_OBJECT) {
                 // we only have QueryRescorer at this point
                 if (QueryRescorerBuilder.NAME.equals(fieldName)) {
-                    rescorer = QueryRescorerBuilder.PROTOTYPE.fromXContent(parseContext);
+                    rescorer = QueryRescorerBuilder.fromXContent(parseContext);
                 } else {
                     throw new ParsingException(parser.getTokenLocation(), "rescore doesn't support rescorer with name [" + fieldName + "]");
                 }
@@ -128,23 +149,6 @@ public abstract class RescoreBuilder<RB extends RescoreBuilder<RB>> implements T
         return Objects.equals(windowSize, other.windowSize);
     }
 
-    @Override
-    public RB readFrom(StreamInput in) throws IOException {
-        RB builder = doReadFrom(in);
-        builder.windowSize = in.readOptionalVInt();
-        return builder;
-    }
-
-    protected abstract RB doReadFrom(StreamInput in) throws IOException;
-
-    @Override
-    public void writeTo(StreamOutput out) throws IOException {
-        doWriteTo(out);
-        out.writeOptionalVInt(this.windowSize);
-    }
-
-    protected abstract void doWriteTo(StreamOutput out) throws IOException;
-
     @Override
     public final String toString() {
         try {

core/src/test/java/org/elasticsearch/search/rescore/QueryRescoreBuilderTests.java

@@ -69,7 +69,6 @@ public class QueryRescoreBuilderTests extends ESTestCase {
     @BeforeClass
     public static void init() {
         namedWriteableRegistry = new NamedWriteableRegistry();
-        namedWriteableRegistry.registerPrototype(RescoreBuilder.class, QueryRescorerBuilder.PROTOTYPE);
         indicesQueriesRegistry = new SearchModule(Settings.EMPTY, namedWriteableRegistry).buildQueryParserRegistry();
     }