[Rollup] Move getMetadata() methods out of rollup config objects (#32579)

This committ removes the getMetadata() methods from the DateHistoGroupConfig
and HistoGroupConfig objects. This way the configuration objects do not rely
on RollupField.formatMetaField() anymore and do not expose a getMetadata()
method that is tighlty coupled to the rollup indexer.

Author: tlrx

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/rollup/job/DateHistogramGroupConfig.java

@@ -211,10 +211,6 @@ public Map<String, Object> toAggCap() {
         return map;
     }
 
-    public Map<String, Object> getMetadata() {
-        return Collections.singletonMap(RollupField.formatMetaField(RollupField.INTERVAL), interval.toString());
-    }
-
     public void validateMappings(Map<String, Map<String, FieldCapabilities>> fieldCapsResponse,
                                                              ActionRequestValidationException validationException) {
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/rollup/job/HistogramGroupConfig.java

@@ -28,6 +28,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
@@ -115,8 +116,8 @@ public Map<String, Object> toAggCap() {
         return map;
     }
 
-    public Map<String, Object> getMetadata() {
-        return Collections.singletonMap(RollupField.formatMetaField(RollupField.INTERVAL), interval);
+    public Set<String> getAllFields() {
+        return Arrays.stream(fields).collect(Collectors.toSet());
     }
 
     public void validateMappings(Map<String, Map<String, FieldCapabilities>> fieldCapsResponse,

x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/job/RollupIndexer.java

@@ -23,6 +23,7 @@
 import org.elasticsearch.xpack.core.rollup.RollupField;
 import org.elasticsearch.xpack.core.rollup.job.DateHistogramGroupConfig;
 import org.elasticsearch.xpack.core.rollup.job.GroupConfig;
+import org.elasticsearch.xpack.core.rollup.job.HistogramGroupConfig;
 import org.elasticsearch.xpack.core.rollup.job.IndexerState;
 import org.elasticsearch.xpack.core.rollup.job.RollupJob;
 import org.elasticsearch.xpack.core.rollup.job.RollupJobConfig;
@@ -392,15 +393,12 @@ private SearchRequest buildSearchRequest() {
     private CompositeAggregationBuilder createCompositeBuilder(RollupJobConfig config) {
         final GroupConfig groupConfig = config.getGroupConfig();
         List<CompositeValuesSourceBuilder<?>> builders = new ArrayList<>();
-        Map<String, Object> metadata = new HashMap<>();
 
         // Add all the agg builders to our request in order: date_histo -> histo -> terms
         if (groupConfig != null) {
             builders.addAll(groupConfig.getDateHistogram().toBuilders());
-            metadata.putAll(groupConfig.getDateHistogram().getMetadata());
             if (groupConfig.getHistogram() != null) {
                 builders.addAll(groupConfig.getHistogram().toBuilders());
-                metadata.putAll(groupConfig.getHistogram().getMetadata());
             }
             if (groupConfig.getTerms() != null) {
                 builders.addAll(groupConfig.getTerms().toBuilders());
@@ -409,6 +407,8 @@ private CompositeAggregationBuilder createCompositeBuilder(RollupJobConfig confi
 
         CompositeAggregationBuilder composite = new CompositeAggregationBuilder(AGGREGATION_NAME, builders);
         config.getMetricsConfig().forEach(m -> m.toBuilders().forEach(composite::subAggregation));
+
+        final Map<String, Object> metadata = createMetadata(groupConfig);
         if (metadata.isEmpty() == false) {
             composite.setMetaData(metadata);
         }
@@ -441,5 +441,20 @@ private QueryBuilder createBoundaryQuery(Map<String, Object> position) {
                 .format("epoch_millis");
         return query;
     }
+
+    static Map<String, Object> createMetadata(final GroupConfig groupConfig) {
+        final Map<String, Object> metadata = new HashMap<>();
+        if (groupConfig != null) {
+            // Add all the metadata in order: date_histo -> histo
+            final DateHistogramGroupConfig dateHistogram = groupConfig.getDateHistogram();
+            metadata.put(RollupField.formatMetaField(RollupField.INTERVAL), dateHistogram.getInterval().toString());
+
+            final HistogramGroupConfig histogram = groupConfig.getHistogram();
+            if (histogram != null) {
+                metadata.put(RollupField.formatMetaField(RollupField.INTERVAL), histogram.getInterval());
+            }
+        }
+        return metadata;
+    }
 }
 

x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/job/RollupIndexerTests.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.xpack.rollup.job;
+
+import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.xpack.core.rollup.ConfigTestHelpers;
+import org.elasticsearch.xpack.core.rollup.job.DateHistogramGroupConfig;
+import org.elasticsearch.xpack.core.rollup.job.GroupConfig;
+import org.elasticsearch.xpack.core.rollup.job.HistogramGroupConfig;
+
+import java.util.Map;
+
+import static org.hamcrest.Matchers.equalTo;
+
+public class RollupIndexerTests extends ESTestCase {
+
+    public void testCreateMetadataNoGroupConfig() {
+        final Map<String, Object> metadata = RollupIndexer.createMetadata(null);
+        assertNotNull(metadata);
+        assertTrue(metadata.isEmpty());
+    }
+
+    public void testCreateMetadataWithDateHistogramGroupConfigOnly() {
+        final DateHistogramGroupConfig dateHistogram = ConfigTestHelpers.randomDateHistogramGroupConfig(random());
+        final GroupConfig groupConfig = new GroupConfig(dateHistogram);
+
+        final Map<String, Object> metadata = RollupIndexer.createMetadata(groupConfig);
+        assertEquals(1, metadata.size());
+        assertTrue(metadata.containsKey("_rollup.interval"));
+        Object value = metadata.get("_rollup.interval");
+        assertThat(value, equalTo(dateHistogram.getInterval().toString()));
+    }
+
+    public void testCreateMetadata() {
+        final DateHistogramGroupConfig dateHistogram = ConfigTestHelpers.randomDateHistogramGroupConfig(random());
+        final HistogramGroupConfig histogram = ConfigTestHelpers.randomHistogramGroupConfig(random());
+        final GroupConfig groupConfig = new GroupConfig(dateHistogram, histogram, null);
+
+        final Map<String, Object> metadata = RollupIndexer.createMetadata(groupConfig);
+        assertEquals(1, metadata.size());
+        assertTrue(metadata.containsKey("_rollup.interval"));
+        Object value = metadata.get("_rollup.interval");
+        assertThat(value, equalTo(histogram.getInterval()));
+    }
+}
+