Add interval response parameter to AutoDateInterval histogram

docs/reference/aggregations/bucket/autodatehistogram-aggregation.asciidoc

@@ -81,7 +81,8 @@ Response:
                     "key": 1425168000000,
                     "doc_count": 2
                 }
-            ]
+            ],
+            "interval": "1M"
         }
     }
 }
@@ -174,7 +175,8 @@ starting at midnight UTC on 1 October 2015:
           "key": 1443664800000,
           "doc_count": 1
         }
-      ]
+      ],
+      "interval": "1h"
     }
   }
 }
@@ -229,7 +231,8 @@ the specified time zone.
           "key": 1443664800000,
           "doc_count": 1
         }
-      ]
+      ],
+      "interval": "1h"
     }
   }
 }

server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregationBuilder.java

@@ -73,17 +73,17 @@ public class AutoDateHistogramAggregationBuilder
     static RoundingInfo[] buildRoundings(DateTimeZone timeZone) {
         RoundingInfo[] roundings = new RoundingInfo[6];
         roundings[0] = new RoundingInfo(createRounding(DateTimeUnit.SECOND_OF_MINUTE, timeZone),
-            1000L, 1, 5, 10, 30);
+            1000L, "s" , 1, 5, 10, 30);
         roundings[1] = new RoundingInfo(createRounding(DateTimeUnit.MINUTES_OF_HOUR, timeZone),
-            60 * 1000L, 1, 5, 10, 30);
+            60 * 1000L, "m", 1, 5, 10, 30);
         roundings[2] = new RoundingInfo(createRounding(DateTimeUnit.HOUR_OF_DAY, timeZone),
-            60 * 60 * 1000L, 1, 3, 12);
+            60 * 60 * 1000L, "h", 1, 3, 12);
         roundings[3] = new RoundingInfo(createRounding(DateTimeUnit.DAY_OF_MONTH, timeZone),
-            24 * 60 * 60 * 1000L, 1, 7);
+            24 * 60 * 60 * 1000L, "d", 1, 7);
         roundings[4] = new RoundingInfo(createRounding(DateTimeUnit.MONTH_OF_YEAR, timeZone),
-            30 * 24 * 60 * 60 * 1000L, 1, 3);
+            30 * 24 * 60 * 60 * 1000L, "M", 1, 3);
         roundings[5] = new RoundingInfo(createRounding(DateTimeUnit.YEAR_OF_CENTURY, timeZone),
-            365 * 24 * 60 * 60 * 1000L, 1, 5, 10, 20, 50, 100);
+            365 * 24 * 60 * 60 * 1000L, "y", 1, 5, 10, 20, 50, 100);
         return roundings;
     }
 
@@ -186,24 +186,28 @@ public static class RoundingInfo implements Writeable {
         final Rounding rounding;
         final int[] innerIntervals;
         final long roughEstimateDurationMillis;
+        final String unitAbbreviation;
 
-        public RoundingInfo(Rounding rounding, long roughEstimateDurationMillis, int... innerIntervals) {
+        public RoundingInfo(Rounding rounding, long roughEstimateDurationMillis, String unitAbbreviation, int... innerIntervals) {
             this.rounding = rounding;
             this.roughEstimateDurationMillis = roughEstimateDurationMillis;
+            this.unitAbbreviation = unitAbbreviation;
             this.innerIntervals = innerIntervals;
         }
 
         public RoundingInfo(StreamInput in) throws IOException {
             rounding = Rounding.Streams.read(in);
             roughEstimateDurationMillis = in.readVLong();
             innerIntervals = in.readIntArray();
+            unitAbbreviation = in.readString();
         }
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             Rounding.Streams.write(rounding, out);
             out.writeVLong(roughEstimateDurationMillis);
             out.writeIntArray(innerIntervals);
+            out.writeString(unitAbbreviation);
         }
 
         public int getMaximumInnerInterval() {

server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/AutoDateHistogramAggregator.java

@@ -181,15 +181,16 @@ public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOE
         InternalAutoDateHistogram.BucketInfo emptyBucketInfo = new InternalAutoDateHistogram.BucketInfo(roundingInfos, roundingIdx,
                 buildEmptySubAggregations());
 
-        return new InternalAutoDateHistogram(name, buckets, targetBuckets, emptyBucketInfo, formatter, pipelineAggregators(), metaData());
+        return new InternalAutoDateHistogram(name, buckets, targetBuckets, emptyBucketInfo,
+            formatter, pipelineAggregators(), metaData(), 1);
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
         InternalAutoDateHistogram.BucketInfo emptyBucketInfo = new InternalAutoDateHistogram.BucketInfo(roundingInfos, roundingIdx,
                 buildEmptySubAggregations());
         return new InternalAutoDateHistogram(name, Collections.emptyList(), targetBuckets, emptyBucketInfo, formatter,
-                pipelineAggregators(), metaData());
+                pipelineAggregators(), metaData(), 1);
     }
 
     @Override

server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogram.java

@@ -208,15 +208,16 @@ public int hashCode() {
     private final DocValueFormat format;
     private final BucketInfo bucketInfo;
     private final int targetBuckets;
-
+    private long bucketInnerInterval;
 
     InternalAutoDateHistogram(String name, List<Bucket> buckets, int targetBuckets, BucketInfo emptyBucketInfo, DocValueFormat formatter,
-            List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) {
+                              List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData, long bucketInnerInterval) {
         super(name, pipelineAggregators, metaData);
         this.buckets = buckets;
         this.bucketInfo = emptyBucketInfo;
         this.format = formatter;
         this.targetBuckets = targetBuckets;
+        this.bucketInnerInterval = bucketInnerInterval;
     }
 
     /**
@@ -238,6 +239,13 @@ protected void doWriteTo(StreamOutput out) throws IOException {
         out.writeVInt(targetBuckets);
     }
 
+    public DateHistogramInterval getInterval() {
+
+        RoundingInfo roundingInfo = this.bucketInfo.roundingInfos[this.bucketInfo.roundingIdx];
+        String unitAbbreviation = roundingInfo.unitAbbreviation;
+        return new DateHistogramInterval(Long.toString(bucketInnerInterval) + unitAbbreviation);
+    }
+
     @Override
     public String getWriteableName() {
         return AutoDateHistogramAggregationBuilder.NAME;
@@ -262,7 +270,7 @@ public BucketInfo getBucketInfo() {
 
     @Override
     public InternalAutoDateHistogram create(List<Bucket> buckets) {
-        return new InternalAutoDateHistogram(name, buckets, targetBuckets, bucketInfo, format, pipelineAggregators(), metaData);
+        return new InternalAutoDateHistogram(name, buckets, targetBuckets, bucketInfo, format, pipelineAggregators(), metaData, 1);
     }
 
     @Override
@@ -279,7 +287,6 @@ private static class IteratorAndCurrent {
             this.iterator = iterator;
             current = iterator.next();
         }
-
     }
 
     /**
@@ -365,7 +372,7 @@ private BucketReduceResult mergeBucketsIfNeeded(List<Bucket> reducedBuckets, int
             reduceRoundingInfo = bucketInfo.roundingInfos[reduceRoundingIdx];
             reducedBuckets = mergeBuckets(reducedBuckets, reduceRoundingInfo.rounding, reduceContext);
         }
-        return new BucketReduceResult(reducedBuckets, reduceRoundingInfo, reduceRoundingIdx);
+        return new BucketReduceResult(reducedBuckets, reduceRoundingInfo, reduceRoundingIdx, 1);
     }
 
     private List<Bucket> mergeBuckets(List<Bucket> reducedBuckets, Rounding reduceRounding, ReduceContext reduceContext) {
@@ -403,12 +410,13 @@ private static class BucketReduceResult {
         List<Bucket> buckets;
         RoundingInfo roundingInfo;
         int roundingIdx;
+        long innerInterval;
 
-        BucketReduceResult(List<Bucket> buckets, RoundingInfo roundingInfo, int roundingIdx) {
+        BucketReduceResult(List<Bucket> buckets, RoundingInfo roundingInfo, int roundingIdx, long innerInterval) {
             this.buckets = buckets;
             this.roundingInfo = roundingInfo;
             this.roundingIdx = roundingIdx;
-
+            this.innerInterval = innerInterval;
         }
     }
 
@@ -444,7 +452,7 @@ private BucketReduceResult addEmptyBuckets(BucketReduceResult currentResult, Red
             }
             lastBucket = iter.next();
         }
-        return new BucketReduceResult(list, roundingInfo, roundingIdx);
+        return new BucketReduceResult(list, roundingInfo, roundingIdx, currentResult.innerInterval);
     }
 
     static int getAppropriateRounding(long minKey, long maxKey, int roundingIdx,
@@ -507,7 +515,7 @@ public InternalAggregation doReduce(List<InternalAggregation> aggregations, Redu
                 this.bucketInfo.emptySubAggregations);
 
         return new InternalAutoDateHistogram(getName(), reducedBucketsResult.buckets, targetBuckets, bucketInfo, format,
-                pipelineAggregators(), getMetaData());
+                pipelineAggregators(), getMetaData(), reducedBucketsResult.innerInterval);
     }
 
     private BucketReduceResult maybeMergeConsecutiveBuckets(BucketReduceResult reducedBucketsResult,
@@ -547,7 +555,7 @@ private BucketReduceResult mergeConsecutiveBuckets(List<Bucket> reducedBuckets,
             reduceContext.consumeBucketsAndMaybeBreak(1);
             mergedBuckets.add(sameKeyedBuckets.get(0).reduce(sameKeyedBuckets, roundingInfo.rounding, reduceContext));
         }
-        return new BucketReduceResult(mergedBuckets, roundingInfo, roundingIdx);
+        return new BucketReduceResult(mergedBuckets, roundingInfo, roundingIdx, mergeInterval);
     }
 
     @Override
@@ -557,6 +565,7 @@ public XContentBuilder doXContentBody(XContentBuilder builder, Params params) th
             bucket.toXContent(builder, params);
         }
         builder.endArray();
+        builder.field("interval", getInterval().toString());
         return builder;
     }
 
@@ -580,7 +589,7 @@ public InternalAggregation createAggregation(List<MultiBucketsAggregation.Bucket
             buckets2.add((Bucket) b);
         }
         buckets2 = Collections.unmodifiableList(buckets2);
-        return new InternalAutoDateHistogram(name, buckets2, targetBuckets, bucketInfo, format, pipelineAggregators(), getMetaData());
+        return new InternalAutoDateHistogram(name, buckets2, targetBuckets, bucketInfo, format, pipelineAggregators(), getMetaData(), 1);
     }
 
     @Override

server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/ParsedAutoDateHistogram.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.search.aggregations.bucket.histogram;
 
+import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -36,6 +37,16 @@ public String getType() {
         return AutoDateHistogramAggregationBuilder.NAME;
     }
 
+    private String interval;
+
+    public String getInterval() {
+        return interval;
+    }
+
+    public void setInterval(String interval) {
+        this.interval = interval;
+    }
+
     @Override
     public List<? extends Histogram.Bucket> getBuckets() {
         return buckets;
@@ -47,6 +58,8 @@ public List<? extends Histogram.Bucket> getBuckets() {
         declareMultiBucketAggregationFields(PARSER,
                 parser -> ParsedBucket.fromXContent(parser, false),
                 parser -> ParsedBucket.fromXContent(parser, true));
+        PARSER.declareString((parsed, value) -> parsed.interval = value,
+            new ParseField("interval"));
     }
 
     public static ParsedAutoDateHistogram fromXContent(XContentParser parser, String name) throws IOException {
@@ -55,6 +68,14 @@ public static ParsedAutoDateHistogram fromXContent(XContentParser parser, String
         return aggregation;
     }
 
+    @Override
+    protected XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
+        builder = super.doXContentBody(builder, params);
+        builder.field("interval", getInterval());
+        return builder;
+    }
+
+
     public static class ParsedBucket extends ParsedMultiBucketAggregation.ParsedBucket implements Histogram.Bucket {
 
         private Long key;

server/src/test/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalAutoDateHistogramTests.java

@@ -80,7 +80,7 @@ protected InternalAutoDateHistogram createTestInstance(String name,
         }
         InternalAggregations subAggregations = new InternalAggregations(Collections.emptyList());
         BucketInfo bucketInfo = new BucketInfo(roundingInfos, randomIntBetween(0, roundingInfos.length - 1), subAggregations);
-        return new InternalAutoDateHistogram(name, buckets, targetBuckets, bucketInfo, format, pipelineAggregators, metaData);
+        return new InternalAutoDateHistogram(name, buckets, targetBuckets, bucketInfo, format, pipelineAggregators, metaData, 1);
     }
 
     /*
@@ -94,11 +94,11 @@ public void testGetAppropriateRoundingUsesCorrectIntervals() {
         // an innerInterval that is quite large, such that targetBuckets * roundings[i].getMaximumInnerInterval()
         // will be larger than the estimate.
         roundings[0] = new RoundingInfo(createRounding(DateTimeUnit.SECOND_OF_MINUTE, timeZone),
-            1000L, 1000);
+            1000L, "s", 1000);
         roundings[1] = new RoundingInfo(createRounding(DateTimeUnit.MINUTES_OF_HOUR, timeZone),
-            60 * 1000L, 1, 5, 10, 30);
+            60 * 1000L, "m", 1, 5, 10, 30);
         roundings[2] = new RoundingInfo(createRounding(DateTimeUnit.HOUR_OF_DAY, timeZone),
-            60 * 60 * 1000L, 1, 3, 12);
+            60 * 60 * 1000L, "h", 1, 3, 12);
 
         OffsetDateTime timestamp = Instant.parse("2018-01-01T00:00:01.000Z").atOffset(ZoneOffset.UTC);
         // We want to pass a roundingIdx of zero, because in order to reproduce this bug, we need the function
@@ -198,6 +198,14 @@ protected void assertReduced(InternalAutoDateHistogram reduced, List<InternalAut
                     (key, oldValue) -> (oldValue == null ? 0 : oldValue) + bucket.getDocCount());
         }
         assertEquals(expectedCounts, actualCounts);
+
+        DateHistogramInterval expectedInterval;
+        if (reduced.getBuckets().size() == 1) {
+            expectedInterval = reduced.getInterval();
+        } else {
+            expectedInterval = new DateHistogramInterval(innerIntervalToUse+roundingInfo.unitAbbreviation);
+        }
+        assertThat(reduced.getInterval(), equalTo(expectedInterval));
     }
 
     private int getBucketCount(long lowest, long highest, RoundingInfo roundingInfo, long intervalInMillis) {
@@ -252,6 +260,6 @@ protected InternalAutoDateHistogram mutateInstance(InternalAutoDateHistogram ins
         default:
             throw new AssertionError("Illegal randomisation branch");
         }
-        return new InternalAutoDateHistogram(name, buckets, targetBuckets, bucketInfo, format, pipelineAggregators, metaData);
+        return new InternalAutoDateHistogram(name, buckets, targetBuckets, bucketInfo, format, pipelineAggregators, metaData, 1);
     }
 }