Cut serial_diff and cumulative_sum to registerPipelineAggregation

and remove their PROTOTYPEs.

Relates to #17085

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

@@ -212,8 +212,8 @@ import org.elasticsearch.search.aggregations.pipeline.bucketscript.BucketScriptP
 import org.elasticsearch.search.aggregations.pipeline.bucketscript.BucketScriptPipelineAggregator;
 import org.elasticsearch.search.aggregations.pipeline.bucketselector.BucketSelectorParser;
 import org.elasticsearch.search.aggregations.pipeline.bucketselector.BucketSelectorPipelineAggregator;
-import org.elasticsearch.search.aggregations.pipeline.cumulativesum.CumulativeSumParser;
 import org.elasticsearch.search.aggregations.pipeline.cumulativesum.CumulativeSumPipelineAggregator;
+import org.elasticsearch.search.aggregations.pipeline.cumulativesum.CumulativeSumPipelineAggregatorBuilder;
 import org.elasticsearch.search.aggregations.pipeline.derivative.DerivativePipelineAggregator;
 import org.elasticsearch.search.aggregations.pipeline.derivative.DerivativePipelineAggregatorBuilder;
 import org.elasticsearch.search.aggregations.pipeline.derivative.InternalDerivative;
@@ -221,8 +221,8 @@ import org.elasticsearch.search.aggregations.pipeline.movavg.MovAvgParser;
 import org.elasticsearch.search.aggregations.pipeline.movavg.MovAvgPipelineAggregator;
 import org.elasticsearch.search.aggregations.pipeline.movavg.models.MovAvgModel;
 import org.elasticsearch.search.aggregations.pipeline.movavg.models.MovAvgModelParserMapper;
-import org.elasticsearch.search.aggregations.pipeline.serialdiff.SerialDiffParser;
 import org.elasticsearch.search.aggregations.pipeline.serialdiff.SerialDiffPipelineAggregator;
+import org.elasticsearch.search.aggregations.pipeline.serialdiff.SerialDiffPipelineAggregatorBuilder;
 import org.elasticsearch.search.controller.SearchPhaseController;
 import org.elasticsearch.search.dfs.DfsPhase;
 import org.elasticsearch.search.fetch.FetchPhase;
@@ -512,10 +512,12 @@ public class SearchModule extends AbstractModule {
                 ExtendedStatsBucketPipelineAggregatorBuilder.AGGREGATION_NAME_FIELD);
         registerPipelineParser(new PercentilesBucketParser());
         registerPipelineParser(new MovAvgParser(movAvgModelParserMapper));
-        registerPipelineParser(new CumulativeSumParser());
+        registerPipelineAggregation(CumulativeSumPipelineAggregatorBuilder::new, CumulativeSumPipelineAggregatorBuilder::parse,
+                CumulativeSumPipelineAggregatorBuilder.AGGREGATION_NAME_FIELD);
         registerPipelineParser(new BucketScriptParser());
         registerPipelineParser(new BucketSelectorParser());
-        registerPipelineParser(new SerialDiffParser());
+        registerPipelineAggregation(SerialDiffPipelineAggregatorBuilder::new, SerialDiffPipelineAggregatorBuilder::parse,
+                SerialDiffPipelineAggregatorBuilder.AGGREGATION_NAME_FIELD);
 
         AggregationParseElement aggParseElement = new AggregationParseElement(aggregatorParsers, queryParserRegistry);
         AggregationBinaryParseElement aggBinaryParseElement = new AggregationBinaryParseElement(aggregatorParsers, queryParserRegistry);

core/src/main/java/org/elasticsearch/search/aggregations/pipeline/cumulativesum/CumulativeSumParser.java

@@ -1,99 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.search.aggregations.pipeline.cumulativesum;
-
-import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParsingException;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.index.query.QueryParseContext;
-import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-
-public class CumulativeSumParser implements PipelineAggregator.Parser {
-
-    public static final ParseField FORMAT = new ParseField("format");
-    public static final ParseField GAP_POLICY = new ParseField("gap_policy");
-    public static final ParseField UNIT = new ParseField("unit");
-
-    @Override
-    public String type() {
-        return CumulativeSumPipelineAggregator.TYPE.name();
-    }
-
-    @Override
-    public CumulativeSumPipelineAggregatorBuilder parse(String pipelineAggregatorName, QueryParseContext context) throws IOException {
-        XContentParser parser = context.parser();
-        XContentParser.Token token;
-        String currentFieldName = null;
-        String[] bucketsPaths = null;
-        String format = null;
-
-        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
-            if (token == XContentParser.Token.FIELD_NAME) {
-                currentFieldName = parser.currentName();
-            } else if (token == XContentParser.Token.VALUE_STRING) {
-                if (context.getParseFieldMatcher().match(currentFieldName, FORMAT)) {
-                    format = parser.text();
-                } else if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
-                    bucketsPaths = new String[] { parser.text() };
-                } else {
-                    throw new ParsingException(parser.getTokenLocation(),
-                            "Unknown key for a " + token + " in [" + pipelineAggregatorName + "]: [" + currentFieldName + "].");
-                }
-            } else if (token == XContentParser.Token.START_ARRAY) {
-                if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
-                    List<String> paths = new ArrayList<>();
-                    while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
-                        String path = parser.text();
-                        paths.add(path);
-                    }
-                    bucketsPaths = paths.toArray(new String[paths.size()]);
-                } else {
-                    throw new ParsingException(parser.getTokenLocation(),
-                            "Unknown key for a " + token + " in [" + pipelineAggregatorName + "]: [" + currentFieldName + "].");
-                }
-            } else {
-                throw new ParsingException(parser.getTokenLocation(),
-                        "Unexpected token " + token + " in [" + pipelineAggregatorName + "].");
-            }
-        }
-
-        if (bucketsPaths == null) {
-            throw new ParsingException(parser.getTokenLocation(), "Missing required field [" + BUCKETS_PATH.getPreferredName()
-                    + "] for derivative aggregation [" + pipelineAggregatorName + "]");
-        }
-
-        CumulativeSumPipelineAggregatorBuilder factory =
-                new CumulativeSumPipelineAggregatorBuilder(pipelineAggregatorName, bucketsPaths[0]);
-        if (format != null) {
-            factory.format(format);
-        }
-        return factory;
-    }
-
-    @Override
-    public CumulativeSumPipelineAggregatorBuilder getFactoryPrototype() {
-        return CumulativeSumPipelineAggregatorBuilder.PROTOTYPE;
-    }
-
-}

core/src/main/java/org/elasticsearch/search/aggregations/pipeline/cumulativesum/CumulativeSumPipelineAggregatorBuilder.java

@@ -19,9 +19,13 @@
 
 package org.elasticsearch.search.aggregations.pipeline.cumulativesum;
 
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParsingException;
 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.XContentParser;
+import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.search.DocValueFormat;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.bucket.histogram.AbstractHistogramAggregatorFactory;
@@ -30,22 +34,40 @@ import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorBuilder;
 import org.elasticsearch.search.aggregations.pipeline.bucketmetrics.BucketMetricsParser;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 
-public class CumulativeSumPipelineAggregatorBuilder extends PipelineAggregatorBuilder<CumulativeSumPipelineAggregatorBuilder> {
+import static org.elasticsearch.search.aggregations.pipeline.PipelineAggregator.Parser.BUCKETS_PATH;
+import static org.elasticsearch.search.aggregations.pipeline.PipelineAggregator.Parser.FORMAT;
 
-    static final CumulativeSumPipelineAggregatorBuilder PROTOTYPE = new CumulativeSumPipelineAggregatorBuilder("", "");
+public class CumulativeSumPipelineAggregatorBuilder extends PipelineAggregatorBuilder<CumulativeSumPipelineAggregatorBuilder> {
+    public static final String NAME = CumulativeSumPipelineAggregator.TYPE.name();
+    public static final ParseField AGGREGATION_NAME_FIELD = new ParseField(NAME);
 
     private String format;
 
     public CumulativeSumPipelineAggregatorBuilder(String name, String bucketsPath) {
-        this(name, new String[] { bucketsPath });
+        super(name, CumulativeSumPipelineAggregator.TYPE.name(), new String[] { bucketsPath });
     }
 
-    private CumulativeSumPipelineAggregatorBuilder(String name, String[] bucketsPaths) {
+    /**
-        super(name, CumulativeSumPipelineAggregator.TYPE.name(), bucketsPaths);
+     * Read from a stream.
+     */
+    public CumulativeSumPipelineAggregatorBuilder(StreamInput in) throws IOException {
+        super(in, CumulativeSumPipelineAggregator.TYPE.name());
+        format = in.readOptionalString();
+    }
+
+    @Override
+    protected final void doWriteTo(StreamOutput out) throws IOException {
+        out.writeOptionalString(format);
+    }
+
+    @Override
+    protected boolean usesNewStyleSerialization() {
+        return true;
     }
 
     /**
@@ -83,7 +105,7 @@ public class CumulativeSumPipelineAggregatorBuilder extends PipelineAggregatorBu
     public void doValidate(AggregatorFactory<?> parent, AggregatorFactory<?>[] aggFactories,
             List<PipelineAggregatorBuilder<?>> pipelineAggregatorFactories) {
         if (bucketsPaths.length != 1) {
-            throw new IllegalStateException(PipelineAggregator.Parser.BUCKETS_PATH.getPreferredName()
+            throw new IllegalStateException(BUCKETS_PATH.getPreferredName()
                     + " must contain a single entry for aggregation [" + name + "]");
         }
         if (!(parent instanceof AbstractHistogramAggregatorFactory<?>)) {
@@ -106,17 +128,55 @@ public class CumulativeSumPipelineAggregatorBuilder extends PipelineAggregatorBu
         return builder;
     }
 
-    @Override
+    public static CumulativeSumPipelineAggregatorBuilder parse(String pipelineAggregatorName, QueryParseContext context)
-    protected final CumulativeSumPipelineAggregatorBuilder doReadFrom(String name, String[] bucketsPaths, StreamInput in)
             throws IOException {
-        CumulativeSumPipelineAggregatorBuilder factory = new CumulativeSumPipelineAggregatorBuilder(name, bucketsPaths);
+        XContentParser parser = context.parser();
-        factory.format = in.readOptionalString();
+        XContentParser.Token token;
-        return factory;
+        String currentFieldName = null;
+        String[] bucketsPaths = null;
+        String format = null;
+
+        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                currentFieldName = parser.currentName();
+            } else if (token == XContentParser.Token.VALUE_STRING) {
+                if (context.getParseFieldMatcher().match(currentFieldName, FORMAT)) {
+                    format = parser.text();
+                } else if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
+                    bucketsPaths = new String[] { parser.text() };
+                } else {
+                    throw new ParsingException(parser.getTokenLocation(),
+                            "Unknown key for a " + token + " in [" + pipelineAggregatorName + "]: [" + currentFieldName + "].");
+                }
+            } else if (token == XContentParser.Token.START_ARRAY) {
+                if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
+                    List<String> paths = new ArrayList<>();
+                    while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
+                        String path = parser.text();
+                        paths.add(path);
+                    }
+                    bucketsPaths = paths.toArray(new String[paths.size()]);
+                } else {
+                    throw new ParsingException(parser.getTokenLocation(),
+                            "Unknown key for a " + token + " in [" + pipelineAggregatorName + "]: [" + currentFieldName + "].");
+                }
+            } else {
+                throw new ParsingException(parser.getTokenLocation(),
+                        "Unexpected token " + token + " in [" + pipelineAggregatorName + "].");
+            }
         }
 
-    @Override
+        if (bucketsPaths == null) {
-    protected final void doWriteTo(StreamOutput out) throws IOException {
+            throw new ParsingException(parser.getTokenLocation(), "Missing required field [" + BUCKETS_PATH.getPreferredName()
-        out.writeOptionalString(format);
+                    + "] for derivative aggregation [" + pipelineAggregatorName + "]");
+        }
+
+        CumulativeSumPipelineAggregatorBuilder factory =
+                new CumulativeSumPipelineAggregatorBuilder(pipelineAggregatorName, bucketsPaths[0]);
+        if (format != null) {
+            factory.format(format);
+        }
+        return factory;
     }
 
     @Override
@@ -129,4 +189,9 @@ public class CumulativeSumPipelineAggregatorBuilder extends PipelineAggregatorBu
         CumulativeSumPipelineAggregatorBuilder other = (CumulativeSumPipelineAggregatorBuilder) obj;
         return Objects.equals(format, other.format);
     }
+
+    @Override
+    public String getWriteableName() {
+        return NAME;
+    }
 }

core/src/main/java/org/elasticsearch/search/aggregations/pipeline/serialdiff/SerialDiffParser.java

@@ -1,123 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.search.aggregations.pipeline.serialdiff;
-
-import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.ParsingException;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.index.query.QueryParseContext;
-import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
-import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-
-public class SerialDiffParser implements PipelineAggregator.Parser {
-
-    public static final ParseField FORMAT = new ParseField("format");
-    public static final ParseField GAP_POLICY = new ParseField("gap_policy");
-    public static final ParseField LAG = new ParseField("lag");
-
-    @Override
-    public String type() {
-        return SerialDiffPipelineAggregator.TYPE.name();
-    }
-
-    @Override
-    public SerialDiffPipelineAggregatorBuilder parse(String reducerName, QueryParseContext context) throws IOException {
-        XContentParser parser = context.parser();
-        XContentParser.Token token;
-        String currentFieldName = null;
-        String[] bucketsPaths = null;
-        String format = null;
-        GapPolicy gapPolicy = null;
-        Integer lag = null;
-
-        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
-            if (token == XContentParser.Token.FIELD_NAME) {
-                currentFieldName = parser.currentName();
-            } else if (token == XContentParser.Token.VALUE_STRING) {
-                if (context.getParseFieldMatcher().match(currentFieldName, FORMAT)) {
-                    format = parser.text();
-                } else if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
-                    bucketsPaths = new String[] { parser.text() };
-                } else if (context.getParseFieldMatcher().match(currentFieldName, GAP_POLICY)) {
-                    gapPolicy = GapPolicy.parse(context, parser.text(), parser.getTokenLocation());
-                } else {
-                    throw new ParsingException(parser.getTokenLocation(),
-                            "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
-                }
-            } else if (token == XContentParser.Token.VALUE_NUMBER) {
-                if (context.getParseFieldMatcher().match(currentFieldName, LAG)) {
-                    lag = parser.intValue(true);
-                    if (lag <= 0) {
-                        throw new ParsingException(parser.getTokenLocation(),
-                                "Lag must be a positive, non-zero integer.  Value supplied was" +
-                                lag + " in [" + reducerName + "]: ["
-                                        + currentFieldName + "].");
-                    }
-                }  else {
-                    throw new ParsingException(parser.getTokenLocation(),
-                            "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
-                }
-            } else if (token == XContentParser.Token.START_ARRAY) {
-                if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
-                    List<String> paths = new ArrayList<>();
-                    while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
-                        String path = parser.text();
-                        paths.add(path);
-                    }
-                    bucketsPaths = paths.toArray(new String[paths.size()]);
-                } else {
-                    throw new ParsingException(parser.getTokenLocation(),
-                            "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
-                }
-            } else {
-                throw new ParsingException(parser.getTokenLocation(), "Unexpected token " + token + " in [" + reducerName + "].",
-                        parser.getTokenLocation());
-            }
-        }
-
-        if (bucketsPaths == null) {
-            throw new ParsingException(parser.getTokenLocation(),
-                    "Missing required field [" + BUCKETS_PATH.getPreferredName() + "] for derivative aggregation [" + reducerName + "]");
-        }
-
-        SerialDiffPipelineAggregatorBuilder factory =
-                new SerialDiffPipelineAggregatorBuilder(reducerName, bucketsPaths[0]);
-        if (lag != null) {
-            factory.lag(lag);
-        }
-        if (format != null) {
-            factory.format(format);
-        }
-        if (gapPolicy != null) {
-            factory.gapPolicy(gapPolicy);
-        }
-        return factory;
-    }
-
-    @Override
-    public SerialDiffPipelineAggregatorBuilder getFactoryPrototype() {
-        return SerialDiffPipelineAggregatorBuilder.PROTOTYPE;
-    }
-
-}

core/src/main/java/org/elasticsearch/search/aggregations/pipeline/serialdiff/SerialDiffPipelineAggregatorBuilder.java

@@ -19,32 +19,62 @@
 
 package org.elasticsearch.search.aggregations.pipeline.serialdiff;
 
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
+import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorBuilder;
+import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.search.DocValueFormat;
 import org.elasticsearch.search.aggregations.pipeline.BucketHelpers.GapPolicy;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
+import org.elasticsearch.search.aggregations.pipeline.PipelineAggregatorBuilder;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 
-public class SerialDiffPipelineAggregatorBuilder extends PipelineAggregatorBuilder<SerialDiffPipelineAggregatorBuilder> {
+import static org.elasticsearch.search.aggregations.pipeline.PipelineAggregator.Parser.BUCKETS_PATH;
+import static org.elasticsearch.search.aggregations.pipeline.PipelineAggregator.Parser.FORMAT;
 
-    static final SerialDiffPipelineAggregatorBuilder PROTOTYPE = new SerialDiffPipelineAggregatorBuilder("", "");
+public class SerialDiffPipelineAggregatorBuilder extends PipelineAggregatorBuilder<SerialDiffPipelineAggregatorBuilder> {
+    public static final String NAME = SerialDiffPipelineAggregator.TYPE.name();
+    public static final ParseField AGGREGATION_NAME_FIELD = new ParseField(NAME);
+
+    private static final ParseField GAP_POLICY = new ParseField("gap_policy");
+    private static final ParseField LAG = new ParseField("lag");
 
     private String format;
     private GapPolicy gapPolicy = GapPolicy.SKIP;
     private int lag = 1;
 
     public SerialDiffPipelineAggregatorBuilder(String name, String bucketsPath) {
-        this(name, new String[] { bucketsPath });
+        super(name, SerialDiffPipelineAggregator.TYPE.name(), new String[] { bucketsPath });
     }
 
-    private SerialDiffPipelineAggregatorBuilder(String name, String[] bucketsPaths) {
+    /**
-        super(name, SerialDiffPipelineAggregator.TYPE.name(), bucketsPaths);
+     * Read from a stream.
+     */
+    public SerialDiffPipelineAggregatorBuilder(StreamInput in) throws IOException {
+        super(in, SerialDiffPipelineAggregator.TYPE.name());
+        format = in.readOptionalString();
+        gapPolicy = GapPolicy.readFrom(in);
+        lag = in.readVInt();
+    }
+
+    @Override
+    protected void doWriteTo(StreamOutput out) throws IOException {
+        out.writeOptionalString(format);
+        gapPolicy.writeTo(out);
+        out.writeVInt(lag);
+    }
+
+    @Override
+    protected boolean usesNewStyleSerialization() {
+        return true;
     }
 
     /**
@@ -117,27 +147,84 @@ public class SerialDiffPipelineAggregatorBuilder extends PipelineAggregatorBuild
     @Override
     protected XContentBuilder internalXContent(XContentBuilder builder, Params params) throws IOException {
         if (format != null) {
-            builder.field(SerialDiffParser.FORMAT.getPreferredName(), format);
+            builder.field(FORMAT.getPreferredName(), format);
         }
-        builder.field(SerialDiffParser.GAP_POLICY.getPreferredName(), gapPolicy.getName());
+        builder.field(GAP_POLICY.getPreferredName(), gapPolicy.getName());
-        builder.field(SerialDiffParser.LAG.getPreferredName(), lag);
+        builder.field(LAG.getPreferredName(), lag);
         return builder;
     }
 
-    @Override
+    public static SerialDiffPipelineAggregatorBuilder parse(String reducerName, QueryParseContext context) throws IOException {
-    protected SerialDiffPipelineAggregatorBuilder doReadFrom(String name, String[] bucketsPaths, StreamInput in) throws IOException {
+        XContentParser parser = context.parser();
-        SerialDiffPipelineAggregatorBuilder factory = new SerialDiffPipelineAggregatorBuilder(name, bucketsPaths);
+        XContentParser.Token token;
-        factory.format = in.readOptionalString();
+        String currentFieldName = null;
-        factory.gapPolicy = GapPolicy.readFrom(in);
+        String[] bucketsPaths = null;
-        factory.lag = in.readVInt();
+        String format = null;
-        return factory;
+        GapPolicy gapPolicy = null;
+        Integer lag = null;
+
+        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                currentFieldName = parser.currentName();
+            } else if (token == XContentParser.Token.VALUE_STRING) {
+                if (context.getParseFieldMatcher().match(currentFieldName, FORMAT)) {
+                    format = parser.text();
+                } else if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
+                    bucketsPaths = new String[] { parser.text() };
+                } else if (context.getParseFieldMatcher().match(currentFieldName, GAP_POLICY)) {
+                    gapPolicy = GapPolicy.parse(context, parser.text(), parser.getTokenLocation());
+                } else {
+                    throw new ParsingException(parser.getTokenLocation(),
+                            "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
+                }
+            } else if (token == XContentParser.Token.VALUE_NUMBER) {
+                if (context.getParseFieldMatcher().match(currentFieldName, LAG)) {
+                    lag = parser.intValue(true);
+                    if (lag <= 0) {
+                        throw new ParsingException(parser.getTokenLocation(),
+                                "Lag must be a positive, non-zero integer.  Value supplied was" +
+                                lag + " in [" + reducerName + "]: ["
+                                        + currentFieldName + "].");
+                    }
+                }  else {
+                    throw new ParsingException(parser.getTokenLocation(),
+                            "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
+                }
+            } else if (token == XContentParser.Token.START_ARRAY) {
+                if (context.getParseFieldMatcher().match(currentFieldName, BUCKETS_PATH)) {
+                    List<String> paths = new ArrayList<>();
+                    while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
+                        String path = parser.text();
+                        paths.add(path);
+                    }
+                    bucketsPaths = paths.toArray(new String[paths.size()]);
+                } else {
+                    throw new ParsingException(parser.getTokenLocation(),
+                            "Unknown key for a " + token + " in [" + reducerName + "]: [" + currentFieldName + "].");
+                }
+            } else {
+                throw new ParsingException(parser.getTokenLocation(), "Unexpected token " + token + " in [" + reducerName + "].",
+                        parser.getTokenLocation());
+            }
         }
 
-    @Override
+        if (bucketsPaths == null) {
-    protected void doWriteTo(StreamOutput out) throws IOException {
+            throw new ParsingException(parser.getTokenLocation(),
-        out.writeOptionalString(format);
+                    "Missing required field [" + BUCKETS_PATH.getPreferredName() + "] for derivative aggregation [" + reducerName + "]");
-        gapPolicy.writeTo(out);
+        }
-        out.writeVInt(lag);
+
+        SerialDiffPipelineAggregatorBuilder factory =
+                new SerialDiffPipelineAggregatorBuilder(reducerName, bucketsPaths[0]);
+        if (lag != null) {
+            factory.lag(lag);
+        }
+        if (format != null) {
+            factory.format(format);
+        }
+        if (gapPolicy != null) {
+            factory.gapPolicy(gapPolicy);
+        }
+        return factory;
     }
 
     @Override
@@ -152,4 +239,8 @@ public class SerialDiffPipelineAggregatorBuilder extends PipelineAggregatorBuild
                 && Objects.equals(lag, other.lag);
     }
 
+    @Override
+    public String getWriteableName() {
+        return NAME;
+    }
 }