Add hasValue() aggregation inspection helpers

modules/aggs-matrix-stats/src/main/java/org/elasticsearch/search/aggregations/matrix/stats/MatrixAggregationInspectionHelper.java

@@ -0,0 +1,29 @@
+/*
+ * 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.matrix.stats;
+
+/**
+ * Counterpart to {@link org.elasticsearch.search.aggregations.support.AggregationInspectionHelper}, providing
+ * helpers for some aggs in the MatrixStats package
+ */
+public class MatrixAggregationInspectionHelper {
+    public static boolean hasValue(InternalMatrixStats agg) {
+        return agg.getResults() != null;
+    }
+}

modules/aggs-matrix-stats/src/test/java/org/elasticsearch/search/aggregations/matrix/stats/MatrixStatsAggregatorTests.java

@@ -53,10 +53,12 @@ public void testNoData() throws Exception {
                     .fields(Collections.singletonList("field"));
                 InternalMatrixStats stats = search(searcher, new MatchAllDocsQuery(), aggBuilder, ft);
                 assertNull(stats.getStats());
+                assertFalse(MatrixAggregationInspectionHelper.hasValue(stats));
             }
         }
     }
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/37587")
     public void testTwoFields() throws Exception {
         String fieldA = "a";
         MappedFieldType ftA = new NumberFieldMapper.NumberFieldType(NumberFieldMapper.NumberType.DOUBLE);
@@ -87,8 +89,9 @@ public void testTwoFields() throws Exception {
                 IndexSearcher searcher = new IndexSearcher(reader);
                 MatrixStatsAggregationBuilder aggBuilder = new MatrixStatsAggregationBuilder("my_agg")
                     .fields(Arrays.asList(fieldA, fieldB));
-                InternalMatrixStats stats = search(searcher, new MatchAllDocsQuery(), aggBuilder, ftA, ftB);
+                InternalMatrixStats stats = searchAndReduce(searcher, new MatchAllDocsQuery(), aggBuilder, ftA, ftB);
                 multiPassStats.assertNearlyEqual(new MatrixStatsResults(stats.getStats()));
+                assertTrue(MatrixAggregationInspectionHelper.hasValue(stats));
             }
         }
     }

modules/parent-join/src/main/java/org/elasticsearch/join/aggregations/JoinAggregationInspectionHelper.java

@@ -0,0 +1,34 @@
+/*
+ * 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.join.aggregations;
+
+/**
+ * Counterpart to {@link org.elasticsearch.search.aggregations.support.AggregationInspectionHelper}, providing
+ * helpers for some aggs in the Join package
+ */
+public class JoinAggregationInspectionHelper {
+
+    public static boolean hasValue(InternalParent agg) {
+        return agg.getDocCount() > 0;
+    }
+
+    public static boolean hasValue(InternalChildren agg) {
+        return agg.getDocCount() > 0;
+    }
+}

modules/parent-join/src/test/java/org/elasticsearch/join/aggregations/ChildrenToParentAggregatorTests.java

@@ -90,6 +90,7 @@ public void testNoDocs() throws IOException {
             assertEquals(0, childrenToParent.getDocCount());
             assertNotNull("Aggregations: " + childrenToParent.getAggregations().asMap(), parentAggregation);
             assertEquals(Double.POSITIVE_INFINITY, ((InternalMin) parentAggregation).getValue(), Double.MIN_VALUE);
+            assertFalse(JoinAggregationInspectionHelper.hasValue(childrenToParent));
         });
         indexReader.close();
         directory.close();
@@ -119,6 +120,7 @@ public void testParentChild() throws IOException {
                     parent.getAggregations().asMap(),
                 expectedTotalParents, parent.getDocCount());
             assertEquals(expectedMinValue, ((InternalMin) parent.getAggregations().get("in_parent")).getValue(), Double.MIN_VALUE);
+            assertTrue(JoinAggregationInspectionHelper.hasValue(parent));
         });
 
         // verify for each children
@@ -170,6 +172,7 @@ public void testParentChildTerms() throws IOException {
         // verify a terms-aggregation inside the parent-aggregation
         testCaseTerms(new MatchAllDocsQuery(), indexSearcher, parent -> {
             assertNotNull(parent);
+            assertTrue(JoinAggregationInspectionHelper.hasValue(parent));
             LongTerms valueTerms = parent.getAggregations().get("value_terms");
             assertNotNull(valueTerms);
 

modules/parent-join/src/test/java/org/elasticsearch/join/aggregations/ParentToChildrenAggregatorTests.java

@@ -105,6 +105,7 @@ public void testParentChild() throws IOException {
                 expectedMinValue = Math.min(expectedMinValue, expectedValues.v2());
             }
             assertEquals(expectedTotalChildren, child.getDocCount());
+            assertTrue(JoinAggregationInspectionHelper.hasValue(child));
             assertEquals(expectedMinValue, ((InternalMin) child.getAggregations().get("in_child")).getValue(), Double.MIN_VALUE);
         });
 

server/src/main/java/org/elasticsearch/search/aggregations/bucket/composite/InternalComposite.java

@@ -226,7 +226,7 @@ InternalBucket next() {
         }
     }
 
-    static class InternalBucket extends InternalMultiBucketAggregation.InternalBucket
+    public static class InternalBucket extends InternalMultiBucketAggregation.InternalBucket
         implements CompositeAggregation.Bucket, KeyComparable<InternalBucket> {
 
         private final CompositeKey key;

server/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/InternalFilter.java

@@ -50,4 +50,4 @@ public String getWriteableName() {
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
         return new InternalFilter(name, docCount, subAggregations, pipelineAggregators(), getMetaData());
     }
-}
+}

server/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoGridBucket.java

@@ -34,7 +34,7 @@
 import java.util.List;
 import java.util.Objects;
 
-class GeoGridBucket extends InternalMultiBucketAggregation.InternalBucket implements GeoHashGrid.Bucket, Comparable<GeoGridBucket> {
+public class GeoGridBucket extends InternalMultiBucketAggregation.InternalBucket implements GeoHashGrid.Bucket, Comparable<GeoGridBucket> {
 
     protected long geohashAsLong;
     protected long docCount;

server/src/main/java/org/elasticsearch/search/aggregations/bucket/sampler/InternalSampler.java

@@ -59,4 +59,4 @@ protected InternalSingleBucketAggregation newAggregation(String name, long docCo
             InternalAggregations subAggregations) {
         return new InternalSampler(name, docCount, subAggregations, pipelineAggregators(), metaData);
     }
-}
+}

server/src/main/java/org/elasticsearch/search/aggregations/metrics/AbstractInternalHDRPercentiles.java

@@ -98,6 +98,10 @@ public long getEstimatedMemoryFootprint() {
         return state.getEstimatedFootprintInBytes();
     }
 
+    DoubleHistogram getState() {
+        return state;
+    }
+
     @Override
     public AbstractInternalHDRPercentiles doReduce(List<InternalAggregation> aggregations, ReduceContext reduceContext) {
         DoubleHistogram merged = null;

server/src/main/java/org/elasticsearch/search/aggregations/metrics/AbstractInternalTDigestPercentiles.java

@@ -82,6 +82,10 @@ public long getEstimatedMemoryFootprint() {
         return state.byteSize();
     }
 
+    TDigestState getState() {
+        return state;
+    }
+
     @Override
     public AbstractInternalTDigestPercentiles doReduce(List<InternalAggregation> aggregations, ReduceContext reduceContext) {
         TDigestState merged = null;

server/src/main/java/org/elasticsearch/search/aggregations/metrics/InternalCardinality.java

@@ -79,6 +79,10 @@ public long getValue() {
         return counts == null ? 0 : counts.cardinality(0);
     }
 
+    HyperLogLogPlusPlus getCounts() {
+        return counts;
+    }
+
     @Override
     public InternalAggregation doReduce(List<InternalAggregation> aggregations, ReduceContext reduceContext) {
         InternalCardinality reduced = null;

server/src/main/java/org/elasticsearch/search/aggregations/metrics/InternalMedianAbsoluteDeviation.java

@@ -121,7 +121,7 @@ public String getWriteableName() {
         return MedianAbsoluteDeviationAggregationBuilder.NAME;
     }
 
-    public TDigestState getValuesSketch() {
+    TDigestState getValuesSketch() {
         return valuesSketch;
     }
 

server/src/main/java/org/elasticsearch/search/aggregations/metrics/InternalScriptedMetric.java

@@ -80,6 +80,10 @@ public Object aggregation() {
         return aggregation.get(0);
     }
 
+    List<Object> getAggregation() {
+        return aggregation;
+    }
+
     @Override
     public InternalAggregation doReduce(List<InternalAggregation> aggregations, ReduceContext reduceContext) {
         List<Object> aggregationObjects = new ArrayList<>();

server/src/main/java/org/elasticsearch/search/aggregations/metrics/MetricInspectionHelper.java

@@ -0,0 +1,78 @@
+/*
+ * 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;
+
+import org.elasticsearch.search.aggregations.pipeline.InternalDerivative;
+
+/**
+ * Counterpart to {@link org.elasticsearch.search.aggregations.support.AggregationInspectionHelper}, providing
+ * helpers for some aggs that have package-private getters.  AggregationInspectionHelper delegates to these
+ * helpers when needed, and consumers should prefer to use AggregationInspectionHelper instead of these
+ * helpers.
+ */
+public class MetricInspectionHelper {
+
+    public static boolean hasValue(InternalAvg agg) {
+        return agg.getCount() > 0;
+    }
+
+    public static boolean hasValue(InternalCardinality agg) {
+        return agg.getCounts() != null;
+    }
+
+    public static boolean hasValue(InternalHDRPercentileRanks agg) {
+        return agg.getState().getTotalCount() > 0;
+    }
+
+    public static boolean hasValue(InternalHDRPercentiles agg) {
+        return agg.getState().getTotalCount() > 0;
+    }
+
+    public static boolean hasValue(InternalMedianAbsoluteDeviation agg) {
+        return agg.getValuesSketch().size() > 0;
+    }
+
+    public static boolean hasValue(InternalScriptedMetric agg) {
+        // TODO better way to know if the scripted metric received documents?
+        // Could check for null too, but a script might return null on purpose...
+        return agg.getAggregation().size() > 0 ;
+    }
+
+    public static boolean hasValue(InternalTDigestPercentileRanks agg) {
+        return agg.getState().size() > 0;
+    }
+
+    public static boolean hasValue(InternalTDigestPercentiles agg) {
+        return agg.getState().size() > 0;
+    }
+
+    public static boolean hasValue(InternalTopHits agg) {
+        return (agg.getHits().getTotalHits().value == 0
+            && Double.isNaN(agg.getHits().getMaxScore())
+            && Double.isNaN(agg.getTopDocs().maxScore)) == false;
+    }
+
+    public static boolean hasValue(InternalWeightedAvg agg) {
+        return (agg.getSum() == 0.0 && agg.getWeight() == 0L) == false;
+    }
+
+    public static boolean hasValue(InternalDerivative agg) {
+        return true;
+    }
+}

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/BucketScriptPipelineAggregator.java

@@ -114,7 +114,10 @@ public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext
                 } else {
                     final List<InternalAggregation> aggs = StreamSupport.stream(bucket.getAggregations().spliterator(), false).map(
                         (p) -> (InternalAggregation) p).collect(Collectors.toList());
-                    aggs.add(new InternalSimpleValue(name(), returned.doubleValue(), formatter, new ArrayList<>(), metaData()));
+
+                    InternalSimpleValue simpleValue = new InternalSimpleValue(name(), returned.doubleValue(),
+                        formatter, new ArrayList<>(), metaData());
+                    aggs.add(simpleValue);
                     InternalMultiBucketAggregation.InternalBucket newBucket = originalAgg.createBucket(new InternalAggregations(aggs),
                         bucket);
                     newBuckets.add(newBucket);

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/CumulativeSumPipelineAggregator.java

@@ -83,8 +83,7 @@ public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext
                 sum += thisBucketValue;
             }
 
-            List<InternalAggregation> aggs = StreamSupport
-                .stream(bucket.getAggregations().spliterator(), false)
+            List<InternalAggregation> aggs = StreamSupport.stream(bucket.getAggregations().spliterator(), false)
                 .map((p) -> (InternalAggregation) p)
                 .collect(Collectors.toList());
             aggs.add(new InternalSimpleValue(name(), sum, formatter, new ArrayList<>(), metaData()));

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/MovAvgPipelineAggregator.java

@@ -117,7 +117,7 @@ public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext
             // since we only change newBucket if we can add to it
             Bucket newBucket = bucket;
 
-            if (!(thisBucketValue == null || thisBucketValue.equals(Double.NaN))) {
+            if ((thisBucketValue == null || thisBucketValue.equals(Double.NaN)) == false) {
 
                 // Some models (e.g. HoltWinters) have certain preconditions that must be met
                 if (model.hasValue(values.size())) {
@@ -126,7 +126,7 @@ public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext
                     List<InternalAggregation> aggs = StreamSupport.stream(bucket.getAggregations().spliterator(), false)
                         .map((p) -> (InternalAggregation) p)
                         .collect(Collectors.toList());
-                    aggs.add(new InternalSimpleValue(name(), movavg, formatter, new ArrayList<PipelineAggregator>(), metaData()));
+                    aggs.add(new InternalSimpleValue(name(), movavg, formatter, new ArrayList<>(), metaData()));
                     newBucket = factory.createBucket(factory.getKey(bucket), bucket.getDocCount(), new InternalAggregations(aggs));
                 }
 
@@ -153,10 +153,10 @@ public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext
                     Bucket bucket = newBuckets.get(lastValidPosition + i + 1);
 
                     // Get the existing aggs in the bucket so we don't clobber data
-                    aggs = StreamSupport.stream(bucket.getAggregations().spliterator(), false).map((p) -> {
-                        return (InternalAggregation) p;
-                    }).collect(Collectors.toList());
-                    aggs.add(new InternalSimpleValue(name(), predictions[i], formatter, new ArrayList<PipelineAggregator>(), metaData()));
+                    aggs = StreamSupport.stream(bucket.getAggregations().spliterator(), false)
+                        .map((p) -> (InternalAggregation) p)
+                        .collect(Collectors.toList());
+                    aggs.add(new InternalSimpleValue(name(), predictions[i], formatter, new ArrayList<>(), metaData()));
 
                     Bucket newBucket = factory.createBucket(newKey, bucket.getDocCount(), new InternalAggregations(aggs));
 
@@ -166,7 +166,7 @@ public InternalAggregation reduce(InternalAggregation aggregation, ReduceContext
                 } else {
                     // Not seen before, create fresh
                     aggs = new ArrayList<>();
-                    aggs.add(new InternalSimpleValue(name(), predictions[i], formatter, new ArrayList<PipelineAggregator>(), metaData()));
+                    aggs.add(new InternalSimpleValue(name(), predictions[i], formatter, new ArrayList<>(), metaData()));
 
                     Bucket newBucket = factory.createBucket(newKey, 0, new InternalAggregations(aggs));