Adding ParsedCardinality

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

@@ -38,14 +38,18 @@ protected static void declareCommonFields(ObjectParser<? extends ParsedAggregati
                 (parser, context) -> parser.map(), InternalAggregation.CommonFields.META);
     }
 
-    String name;
+    private String name;
     Map<String, Object> metadata;
 
     @Override
     public final String getName() {
         return name;
     }
 
+    protected void setName(String name) {
+        this.name = name;
+    }
+
     @Override
     public final Map<String, Object> getMetaData() {
         return metadata;
@@ -59,6 +63,7 @@ public final Map<String, Object> getMetaData() {
     //TODO it may make sense to move getType to the Aggregation interface given that we are duplicating it in both implementations
     protected abstract String getType();
 
+    @Override
     public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params params) throws IOException {
         // Concatenates the type and the name of the aggregation (ex: top_hits#foo)
         builder.startObject(String.join(InternalAggregation.TYPED_KEYS_DELIMITER, getType(), name));
@@ -72,4 +77,4 @@ public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params par
     }
 
     protected abstract XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException;
-}
+}

core/src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/InternalCardinality.java

@@ -128,3 +128,4 @@ HyperLogLogPlusPlus getState() {
         return counts;
     }
 }
+

core/src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/ParsedCardinality.java

@@ -0,0 +1,80 @@
+/*
+ * 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.metrics.cardinality;
+
+import org.elasticsearch.common.xcontent.ObjectParser;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.search.DocValueFormat;
+import org.elasticsearch.search.aggregations.ParsedAggregation;
+
+import java.io.IOException;
+
+public class ParsedCardinality extends ParsedAggregation implements Cardinality {
+
+    private long cardinalityValue;
+
+    @Override
+    public String getValueAsString() {
+        // InternalCardinality doesn't print "value_as_string", but you can get a formated value using
+        // getValueAsString(). That method uses the raw formatter so we also use it here.
+        return DocValueFormat.RAW.format((double) cardinalityValue);
+    }
+
+    @Override
+    public double value() {
+        return getValue();
+    }
+
+    @Override
+    public long getValue() {
+        return cardinalityValue;
+    }
+
+    private void setValue(long cardinalityValue) {
+        this.cardinalityValue = cardinalityValue;
+    }
+
+    @Override
+    protected String getType() {
+        return CardinalityAggregationBuilder.NAME;
+    }
+
+    private static final ObjectParser<ParsedCardinality, Void> PARSER = new ObjectParser<>(
+            CardinalityAggregationBuilder.NAME, true, ParsedCardinality::new);
+
+    static {
+        declareCommonFields(PARSER);
+        PARSER.declareLong(ParsedCardinality::setValue, CommonFields.VALUE);
+    }
+
+    public static ParsedCardinality fromXContent(XContentParser parser, final String name) {
+        ParsedCardinality cardinality = PARSER.apply(parser, null);
+        cardinality.setName(name);
+        return cardinality;
+    }
+
+    @Override
+    protected XContentBuilder doXContentBody(XContentBuilder builder, Params params)
+            throws IOException {
+        builder.field(CommonFields.VALUE.getPreferredName(), cardinalityValue);
+        return builder;
+    }
+}

core/src/test/java/org/elasticsearch/search/aggregations/InternalAggregationTestCase.java

@@ -98,10 +98,13 @@ protected final T createTestInstance() {
     private T createTestInstance(String name) {
         List<PipelineAggregator> pipelineAggregators = new ArrayList<>();
         // TODO populate pipelineAggregators
-        Map<String, Object> metaData = new HashMap<>();
-        int metaDataCount = randomBoolean() ? 0 : between(1, 10);
-        while (metaData.size() < metaDataCount) {
-            metaData.put(randomAlphaOfLength(5), randomAlphaOfLength(5));
+        Map<String, Object> metaData = null;
+        if (randomBoolean()) {
+            metaData = new HashMap<>();
+            int metaDataCount = between(0, 10);
+            while (metaData.size() < metaDataCount) {
+                metaData.put(randomAlphaOfLength(5), randomAlphaOfLength(5));
+            }
         }
         return createTestInstance(name, pipelineAggregators, metaData);
     }

core/src/test/java/org/elasticsearch/search/aggregations/ParsedAggregationTests.java

@@ -105,7 +105,7 @@ protected XContentBuilder doXContentBody(XContentBuilder builder, Params params)
 
         public static TestParsedAggregation fromXContent(XContentParser parser, String name) throws IOException {
             TestParsedAggregation parsedAgg = PARSER.parse(parser, null);
-            parsedAgg.name = name;
+            parsedAgg.setName(name);
             return parsedAgg;
         }
     }

core/src/test/java/org/elasticsearch/search/aggregations/metrics/cardinality/InternalCardinalityTests.java

@@ -19,20 +19,33 @@
 
 package org.elasticsearch.search.aggregations.metrics.cardinality;
 
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.stream.Writeable.Reader;
 import org.elasticsearch.common.lease.Releasables;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.MockBigArrays;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentHelper;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.indices.breaker.NoneCircuitBreakerService;
+import org.elasticsearch.rest.action.search.RestSearchAction;
+import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.InternalAggregationTestCase;
 import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 import org.junit.After;
 import org.junit.Before;
 
+import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
+import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertToXContentEquivalent;
+
 public class InternalCardinalityTests extends InternalAggregationTestCase<InternalCardinality> {
     private static List<HyperLogLogPlusPlus> algos;
     private static int p;
@@ -73,6 +86,41 @@ protected void assertReduced(InternalCardinality reduced, List<InternalCardinali
         }
     }
 
+    public void testFromXContent() throws IOException {
+        InternalCardinality cardinality = createTestInstance();
+        String type = cardinality.getWriteableName();
+        String name = cardinality.getName();
+        ToXContent.Params params = new ToXContent.MapParams(Collections.singletonMap(RestSearchAction.TYPED_KEYS_PARAM, "true"));
+        boolean humanReadable = randomBoolean();
+        XContentType xContentType = randomFrom(XContentType.values());
+        BytesReference originalBytes = toShuffledXContent(cardinality, xContentType, params, humanReadable);
+        ParsedCardinality parsed;
+        try (XContentParser parser = createParser(xContentType.xContent(), originalBytes)) {
+            assertEquals(XContentParser.Token.START_OBJECT, parser.nextToken());
+            assertEquals(XContentParser.Token.FIELD_NAME, parser.nextToken());
+            assertEquals(type + "#" + name, parser.currentName());
+            assertEquals(XContentParser.Token.START_OBJECT, parser.nextToken());
+            parsed = (ParsedCardinality)  parser.namedObject(Aggregation.class, type, name);
+            assertEquals(XContentParser.Token.END_OBJECT, parser.currentToken());
+            assertEquals(XContentParser.Token.END_OBJECT, parser.nextToken());
+            assertNull(parser.nextToken());
+        }
+        assertEquals(cardinality.getName(), parsed.getName());
+        assertEquals(cardinality.getValue(), parsed.getValue(), Double.MIN_VALUE);
+        assertEquals(cardinality.getValueAsString(), parsed.getValueAsString());
+        assertEquals(cardinality.getMetaData(), parsed.getMetaData());
+        BytesReference finalAgg = XContentHelper.toXContent(parsed, xContentType, params, humanReadable);
+        assertToXContentEquivalent(originalBytes, finalAgg, xContentType);
+    }
+
+    @Override
+    protected NamedXContentRegistry xContentRegistry() {
+        NamedXContentRegistry.Entry entry = new NamedXContentRegistry.Entry(Aggregation.class,
+                new ParseField(CardinalityAggregationBuilder.NAME),
+                (parser, name) -> ParsedCardinality.fromXContent(parser, (String) name));
+        return new NamedXContentRegistry(Collections.singletonList(entry));
+    }
+
     @After
     public void cleanup() {
         Releasables.close(algos);