Aggregations Refactor: Refactor Nested and Reverse Nested Aggregations

core/src/main/java/org/elasticsearch/search/aggregations/bucket/nested/NestedAggregator.java

@@ -27,7 +27,11 @@ import org.apache.lucene.search.Query;
 import org.apache.lucene.search.Weight;
 import org.apache.lucene.search.join.BitSetProducer;
 import org.apache.lucene.util.BitSet;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.lucene.search.Queries;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.mapper.object.ObjectMapper;
 import org.elasticsearch.search.aggregations.AggregationExecutionException;
 import org.elasticsearch.search.aggregations.Aggregator;
@@ -44,12 +48,15 @@ import org.elasticsearch.search.aggregations.support.AggregationContext;
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  *
  */
 public class NestedAggregator extends SingleBucketAggregator {
 
+    static final ParseField PATH_FIELD = new ParseField("path");
+
     private BitSetProducer parentFilter;
     private final Query childFilter;
 
@@ -141,11 +148,25 @@ public class NestedAggregator extends SingleBucketAggregator {
 
         private final String path;
 
+        /**
+         * @param name
+         *            the name of this aggregation
+         * @param path
+         *            the path to use for this nested aggregation. The path must
+         *            match the path to a nested object in the mappings.
+         */
         public Factory(String name, String path) {
             super(name, InternalNested.TYPE);
             this.path = path;
         }
 
+        /**
+         * Get the path to use for this nested aggregation.
+         */
+        public String path() {
+            return path;
+        }
+
         @Override
         public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
                 List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
@@ -162,6 +183,37 @@ public class NestedAggregator extends SingleBucketAggregator {
             return new NestedAggregator(name, factories, objectMapper, context, parent, pipelineAggregators, metaData);
         }
 
+        @Override
+        protected XContentBuilder internalXContent(XContentBuilder builder, Params params) throws IOException {
+            builder.startObject();
+            builder.field(PATH_FIELD.getPreferredName(), path);
+            builder.endObject();
+            return builder;
+        }
+
+        @Override
+        protected AggregatorFactory doReadFrom(String name, StreamInput in) throws IOException {
+            String path = in.readString();
+            Factory factory = new Factory(name, path);
+            return factory;
+        }
+
+        @Override
+        protected void doWriteTo(StreamOutput out) throws IOException {
+            out.writeString(path);
+        }
+
+        @Override
+        protected int doHashCode() {
+            return Objects.hash(path);
+        }
+
+        @Override
+        protected boolean doEquals(Object obj) {
+            Factory other = (Factory) obj;
+            return Objects.equals(path, other.path);
+        }
+
         private final static class Unmapped extends NonCollectingAggregator {
 
             public Unmapped(String name, AggregationContext context, Aggregator parent, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData)

core/src/main/java/org/elasticsearch/search/aggregations/bucket/nested/NestedParser.java

@@ -46,7 +46,7 @@ public class NestedParser implements Aggregator.Parser {
             if (token == XContentParser.Token.FIELD_NAME) {
                 currentFieldName = parser.currentName();
             } else if (token == XContentParser.Token.VALUE_STRING) {
-                if ("path".equals(currentFieldName)) {
+                if (context.parseFieldMatcher().match(currentFieldName, NestedAggregator.PATH_FIELD)) {
                     path = parser.text();
                 } else {
                     throw new SearchParseException(context, "Unknown key for a " + token + " in [" + aggregationName + "]: ["
@@ -67,9 +67,8 @@ public class NestedParser implements Aggregator.Parser {
         return new NestedAggregator.Factory(aggregationName, path);
     }
 
-    // NORELEASE implement this method when refactoring this aggregation
     @Override
     public AggregatorFactory[] getFactoryPrototypes() {
-        return null;
+        return new AggregatorFactory[] { new NestedAggregator.Factory(null, null) };
     }
 }

core/src/main/java/org/elasticsearch/search/aggregations/bucket/nested/ReverseNestedAggregator.java

@@ -24,7 +24,11 @@ import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.join.BitSetProducer;
 import org.apache.lucene.util.BitSet;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.lucene.search.Queries;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.mapper.object.ObjectMapper;
 import org.elasticsearch.search.SearchParseException;
 import org.elasticsearch.search.aggregations.AggregationExecutionException;
@@ -42,12 +46,15 @@ import org.elasticsearch.search.aggregations.support.AggregationContext;
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  *
  */
 public class ReverseNestedAggregator extends SingleBucketAggregator {
 
+    static final ParseField PATH_FIELD = new ParseField("path");
+
     private final Query parentFilter;
     private final BitSetProducer parentBitsetProducer;
 
@@ -120,13 +127,28 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
 
     public static class Factory extends AggregatorFactory {
 
-        private final String path;
+        private String path;
 
-        public Factory(String name, String path) {
+        public Factory(String name) {
             super(name, InternalReverseNested.TYPE);
+        }
+
+        /**
+         * Set the path to use for this nested aggregation. The path must match
+         * the path to a nested object in the mappings. If it is not specified
+         * then this aggregation will go back to the root document.
+         */
+        public void path(String path) {
             this.path = path;
         }
 
+        /**
+         * Get the path to use for this nested aggregation.
+         */
+        public String path() {
+            return path;
+        }
+
         @Override
         public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
                 List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
@@ -152,6 +174,39 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
             return new ReverseNestedAggregator(name, factories, objectMapper, context, parent, pipelineAggregators, metaData);
         }
 
+        @Override
+        protected XContentBuilder internalXContent(XContentBuilder builder, Params params) throws IOException {
+            builder.startObject();
+            if (path != null) {
+                builder.field(PATH_FIELD.getPreferredName(), path);
+            }
+            builder.endObject();
+            return builder;
+        }
+
+        @Override
+        protected AggregatorFactory doReadFrom(String name, StreamInput in) throws IOException {
+            Factory factory = new Factory(name);
+            factory.path = in.readOptionalString();
+            return factory;
+        }
+
+        @Override
+        protected void doWriteTo(StreamOutput out) throws IOException {
+            out.writeOptionalString(path);
+        }
+
+        @Override
+        protected int doHashCode() {
+            return Objects.hash(path);
+        }
+
+        @Override
+        protected boolean doEquals(Object obj) {
+            Factory other = (Factory) obj;
+            return Objects.equals(path, other.path);
+        }
+
         private final static class Unmapped extends NonCollectingAggregator {
 
             public Unmapped(String name, AggregationContext context, Aggregator parent, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData)

core/src/main/java/org/elasticsearch/search/aggregations/bucket/nested/ReverseNestedParser.java

@@ -58,12 +58,15 @@ public class ReverseNestedParser implements Aggregator.Parser {
             }
         }
 
-        return new ReverseNestedAggregator.Factory(aggregationName, path);
+        ReverseNestedAggregator.Factory factory = new ReverseNestedAggregator.Factory(aggregationName);
+        if (path != null) {
+            factory.path(path);
+        }
+        return factory;
     }
 
-    // NORELEASE implement this method when refactoring this aggregation
     @Override
     public AggregatorFactory[] getFactoryPrototypes() {
-        return null;
+        return new AggregatorFactory[] { new ReverseNestedAggregator.Factory(null) };
     }
 }

core/src/test/java/org/elasticsearch/search/aggregations/bucket/nested/NestedAggregatorTests.java

@@ -119,7 +119,8 @@ public class NestedAggregatorTests extends ESSingleNodeTestCase {
         AggregationContext context = new AggregationContext(searchContext);
 
         AggregatorFactories.Builder builder = AggregatorFactories.builder();
-        builder.addAggregator(new NestedAggregator.Factory("test", "nested_field"));
+        NestedAggregator.Factory factory = new NestedAggregator.Factory("test", "nested_field");
+        builder.addAggregator(factory);
         AggregatorFactories factories = builder.build();
         searchContext.aggregations(new SearchContextAggregations(factories));
         factories.init(context);

core/src/test/java/org/elasticsearch/search/aggregations/bucket/nested/NestedTests.java

@@ -0,0 +1,32 @@
+/*
+ * 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.bucket.nested;
+
+import org.elasticsearch.search.aggregations.BaseAggregationTestCase;
+import org.elasticsearch.search.aggregations.bucket.nested.NestedAggregator.Factory;
+
+public class NestedTests extends BaseAggregationTestCase<NestedAggregator.Factory> {
+
+    @Override
+    protected Factory createTestAggregatorFactory() {
+        return new Factory(randomAsciiOfLengthBetween(1, 20), randomAsciiOfLengthBetween(3, 40));
+    }
+
+}

core/src/test/java/org/elasticsearch/search/aggregations/bucket/nested/ReverseNestedTests.java

@@ -0,0 +1,36 @@
+/*
+ * 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.bucket.nested;
+
+import org.elasticsearch.search.aggregations.BaseAggregationTestCase;
+import org.elasticsearch.search.aggregations.bucket.nested.ReverseNestedAggregator.Factory;
+
+public class ReverseNestedTests extends BaseAggregationTestCase<ReverseNestedAggregator.Factory> {
+
+    @Override
+    protected Factory createTestAggregatorFactory() {
+        Factory factory = new Factory(randomAsciiOfLengthBetween(1, 20));
+        if (randomBoolean()) {
+            factory.path(randomAsciiOfLengthBetween(3, 40));
+        }
+        return factory;
+    }
+
+}