Aggregations: Added pre and post offset to histogram aggregation

Added preOffset and postOffset parameters to the API for the histogram aggregation which work in the same way as in the date histogram

Closes #6605

src/main/java/org/elasticsearch/common/rounding/Rounding.java

@@ -128,6 +128,108 @@ public abstract class Rounding implements Streamable {
         }
     }
 
+    public static class FactorRounding extends Rounding {
+
+        final static byte ID = 7;
+
+        private Rounding rounding;
+
+        private float factor;
+
+        FactorRounding() { // for serialization
+        }
+
+        FactorRounding(Rounding rounding, float factor) {
+            this.rounding = rounding;
+            this.factor = factor;
+        }
+
+        @Override
+        public byte id() {
+            return ID;
+        }
+
+        @Override
+        public long roundKey(long utcMillis) {
+            return rounding.roundKey((long) (factor * utcMillis));
+        }
+
+        @Override
+        public long valueForKey(long key) {
+            return rounding.valueForKey(key);
+        }
+
+        @Override
+        public long nextRoundingValue(long value) {
+            return rounding.nextRoundingValue(value);
+        }
+
+        @Override
+        public void readFrom(StreamInput in) throws IOException {
+            rounding = (TimeZoneRounding) Rounding.Streams.read(in);
+            factor = in.readFloat();
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            Rounding.Streams.write(rounding, out);
+            out.writeFloat(factor);
+        }
+    }
+    
+    public static class PrePostRounding extends Rounding {
+
+        final static byte ID = 8;
+
+        private Rounding rounding;
+
+        private long preOffset;
+        private long postOffset;
+
+        PrePostRounding() { // for serialization
+        }
+
+        public PrePostRounding(Rounding intervalRounding, long preOffset, long postOffset) {
+            this.rounding = intervalRounding;
+            this.preOffset = preOffset;
+            this.postOffset = postOffset;
+        }
+
+        @Override
+        public byte id() {
+            return ID;
+        }
+
+        @Override
+        public long roundKey(long value) {
+            return rounding.roundKey(value + preOffset);
+        }
+
+        @Override
+        public long valueForKey(long key) {
+            return postOffset + rounding.valueForKey(key);
+        }
+
+        @Override
+        public long nextRoundingValue(long value) {
+            return postOffset + rounding.nextRoundingValue(value - postOffset);
+        }
+
+        @Override
+        public void readFrom(StreamInput in) throws IOException {
+            rounding = Rounding.Streams.read(in);
+            preOffset = in.readVLong();
+            postOffset = in.readVLong();
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            Rounding.Streams.write(rounding, out);
+            out.writeVLong(preOffset);
+            out.writeVLong(postOffset);
+        }
+    }
+
     public static class Streams {
 
         public static void write(Rounding rounding, StreamOutput out) throws IOException {
@@ -146,8 +248,8 @@ public abstract class Rounding implements Streamable {
                 case TimeZoneRounding.UTCIntervalTimeZoneRounding.ID: rounding = new TimeZoneRounding.UTCIntervalTimeZoneRounding(); break;
                 case TimeZoneRounding.TimeIntervalTimeZoneRounding.ID: rounding = new TimeZoneRounding.TimeIntervalTimeZoneRounding(); break;
                 case TimeZoneRounding.DayIntervalTimeZoneRounding.ID: rounding = new TimeZoneRounding.DayIntervalTimeZoneRounding(); break;
-                case TimeZoneRounding.FactorTimeZoneRounding.ID: rounding = new TimeZoneRounding.FactorTimeZoneRounding(); break;
-                case TimeZoneRounding.PrePostTimeZoneRounding.ID: rounding = new TimeZoneRounding.PrePostTimeZoneRounding(); break;
+                case TimeZoneRounding.FactorRounding.ID: rounding = new FactorRounding(); break;
+                case PrePostRounding.ID: rounding = new PrePostRounding(); break;
                 default: throw new ElasticsearchException("unknown rounding id [" + id + "]");
             }
             rounding.readFrom(in);

src/main/java/org/elasticsearch/common/rounding/TimeZoneRounding.java

@@ -94,8 +94,8 @@ public abstract class TimeZoneRounding extends Rounding {
             return this;
         }
 
-        public TimeZoneRounding build() {
-            TimeZoneRounding timeZoneRounding;
+        public Rounding build() {
+            Rounding timeZoneRounding;
             if (unit != null) {
                 if (preTz.equals(DateTimeZone.UTC) && postTz.equals(DateTimeZone.UTC)) {
                     timeZoneRounding = new UTCTimeZoneRoundingFloor(unit);
@@ -114,10 +114,10 @@ public abstract class TimeZoneRounding extends Rounding {
                 }
             }
             if (preOffset != 0 || postOffset != 0) {
-                timeZoneRounding = new PrePostTimeZoneRounding(timeZoneRounding, preOffset, postOffset);
+                timeZoneRounding = new PrePostRounding(timeZoneRounding, preOffset, postOffset);
             }
             if (factor != 1.0f) {
-                timeZoneRounding = new FactorTimeZoneRounding(timeZoneRounding, factor);
+                timeZoneRounding = new FactorRounding(timeZoneRounding, factor);
             }
             return timeZoneRounding;
         }
@@ -439,106 +439,4 @@ public abstract class TimeZoneRounding extends Rounding {
             out.writeSharedString(postTz.getID());
         }
     }
-
-    static class FactorTimeZoneRounding extends TimeZoneRounding {
-
-        final static byte ID = 7;
-
-        private TimeZoneRounding timeZoneRounding;
-
-        private float factor;
-
-        FactorTimeZoneRounding() { // for serialization
-        }
-
-        FactorTimeZoneRounding(TimeZoneRounding timeZoneRounding, float factor) {
-            this.timeZoneRounding = timeZoneRounding;
-            this.factor = factor;
-        }
-
-        @Override
-        public byte id() {
-            return ID;
-        }
-
-        @Override
-        public long roundKey(long utcMillis) {
-            return timeZoneRounding.roundKey((long) (factor * utcMillis));
-        }
-
-        @Override
-        public long valueForKey(long key) {
-            return timeZoneRounding.valueForKey(key);
-        }
-
-        @Override
-        public long nextRoundingValue(long value) {
-            return timeZoneRounding.nextRoundingValue(value);
-        }
-
-        @Override
-        public void readFrom(StreamInput in) throws IOException {
-            timeZoneRounding = (TimeZoneRounding) Rounding.Streams.read(in);
-            factor = in.readFloat();
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            Rounding.Streams.write(timeZoneRounding, out);
-            out.writeFloat(factor);
-        }
-    }
-
-    static class PrePostTimeZoneRounding extends TimeZoneRounding {
-
-        final static byte ID = 8;
-
-        private TimeZoneRounding timeZoneRounding;
-
-        private long preOffset;
-        private long postOffset;
-
-        PrePostTimeZoneRounding() { // for serialization
-        }
-
-        PrePostTimeZoneRounding(TimeZoneRounding timeZoneRounding, long preOffset, long postOffset) {
-            this.timeZoneRounding = timeZoneRounding;
-            this.preOffset = preOffset;
-            this.postOffset = postOffset;
-        }
-
-        @Override
-        public byte id() {
-            return ID;
-        }
-
-        @Override
-        public long roundKey(long utcMillis) {
-            return timeZoneRounding.roundKey(utcMillis + preOffset);
-        }
-
-        @Override
-        public long valueForKey(long key) {
-            return postOffset + timeZoneRounding.valueForKey(key);
-        }
-
-        @Override
-        public long nextRoundingValue(long value) {
-            return postOffset + timeZoneRounding.nextRoundingValue(value - postOffset);
-        }
-
-        @Override
-        public void readFrom(StreamInput in) throws IOException {
-            timeZoneRounding = (TimeZoneRounding) Rounding.Streams.read(in);
-            preOffset = in.readVLong();
-            postOffset = in.readVLong();
-        }
-
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            Rounding.Streams.write(timeZoneRounding, out);
-            out.writeVLong(preOffset);
-            out.writeVLong(postOffset);
-        }
-    }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/DateHistogramParser.java

@@ -22,6 +22,7 @@ import com.google.common.collect.ImmutableMap;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.rounding.DateTimeUnit;
+import org.elasticsearch.common.rounding.Rounding;
 import org.elasticsearch.common.rounding.TimeZoneRounding;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentParser;
@@ -192,7 +193,7 @@ public class DateHistogramParser implements Aggregator.Parser {
             tzRoundingBuilder = TimeZoneRounding.builder(TimeValue.parseTimeValue(interval, null));
         }
 
-        TimeZoneRounding rounding = tzRoundingBuilder
+        Rounding rounding = tzRoundingBuilder
                 .preZone(preZone).postZone(postZone)
                 .preZoneAdjustLargeInterval(preZoneAdjustLargeInterval)
                 .preOffset(preOffset).postOffset(postOffset)

src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/HistogramBuilder.java

@@ -35,6 +35,8 @@ public class HistogramBuilder extends ValuesSourceAggregationBuilder<HistogramBu
     private Long minDocCount;
     private Long extendedBoundsMin;
     private Long extendedBoundsMax;
+    private Long preOffset;
+    private Long postOffset;
 
     /**
      * Constructs a new histogram aggregation builder.
@@ -83,6 +85,16 @@ public class HistogramBuilder extends ValuesSourceAggregationBuilder<HistogramBu
         extendedBoundsMax = max;
         return this;
     }
+    
+    public HistogramBuilder preOffset(long preOffset) {
+        this.preOffset = preOffset;
+        return this;
+    }
+    
+    public HistogramBuilder postOffset(long postOffset) {
+        this.postOffset = postOffset;
+        return this;
+    }
 
     @Override
     protected XContentBuilder doInternalXContent(XContentBuilder builder, Params params) throws IOException {
@@ -96,6 +108,15 @@ public class HistogramBuilder extends ValuesSourceAggregationBuilder<HistogramBu
             order.toXContent(builder, params);
         }
 
+        if (preOffset != null) {
+            builder.field("pre_offset", preOffset);
+        }
+
+        if (postOffset != null) {
+            builder.field("post_offset", postOffset);
+        }
+
+
         if (minDocCount != null) {
             builder.field("min_doc_count", minDocCount);
         }

src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/HistogramParser.java

@@ -57,6 +57,8 @@ public class HistogramParser implements Aggregator.Parser {
         InternalOrder order = (InternalOrder) InternalOrder.KEY_ASC;
         long interval = -1;
         ExtendedBounds extendedBounds = null;
+        long preOffset = 0;
+        long postOffset = 0;
 
         XContentParser.Token token;
         String currentFieldName = null;
@@ -72,6 +74,10 @@ public class HistogramParser implements Aggregator.Parser {
                     minDocCount = parser.longValue();
                 } else if ("keyed".equals(currentFieldName)) {
                     keyed = parser.booleanValue();
+                } else if ("pre_offset".equals(currentFieldName) || "preOffset".equals(currentFieldName)) {
+                    preOffset = parser.longValue();
+                } else if ("post_offset".equals(currentFieldName) || "postOffset".equals(currentFieldName)) {
+                    postOffset = parser.longValue();
                 } else {
                     throw new SearchParseException(context, "Unknown key for a " + token + " in aggregation [" + aggregationName + "]: [" + currentFieldName + "].");
                 }
@@ -116,7 +122,11 @@ public class HistogramParser implements Aggregator.Parser {
         if (interval < 0) {
             throw new SearchParseException(context, "Missing required field [interval] for histogram aggregation [" + aggregationName + "]");
         }
+        
         Rounding rounding = new Rounding.Interval(interval);
+        if (preOffset != 0 || postOffset != 0) {
+            rounding = new Rounding.PrePostRounding((Rounding.Interval) rounding, preOffset, postOffset);
+        }
 
         if (extendedBounds != null) {
             // with numeric histogram, we can process here and fail fast if the bounds are invalid

src/main/java/org/elasticsearch/search/facet/datehistogram/CountDateHistogramFacetExecutor.java

@@ -24,7 +24,7 @@ import org.apache.lucene.index.AtomicReaderContext;
 import org.apache.lucene.index.SortedNumericDocValues;
 import org.elasticsearch.cache.recycler.CacheRecycler;
 import org.elasticsearch.common.recycler.Recycler;
-import org.elasticsearch.common.rounding.TimeZoneRounding;
+import org.elasticsearch.common.rounding.Rounding;
 import org.elasticsearch.index.fielddata.IndexNumericFieldData;
 import org.elasticsearch.search.facet.FacetExecutor;
 import org.elasticsearch.search.facet.InternalFacet;
@@ -38,13 +38,13 @@ import java.io.IOException;
  */
 public class CountDateHistogramFacetExecutor extends FacetExecutor {
 
-    private final TimeZoneRounding tzRounding;
+    private final Rounding tzRounding;
     private final IndexNumericFieldData indexFieldData;
     final DateHistogramFacet.ComparatorType comparatorType;
 
     final Recycler.V<LongLongOpenHashMap> counts;
 
-    public CountDateHistogramFacetExecutor(IndexNumericFieldData indexFieldData, TimeZoneRounding tzRounding, DateHistogramFacet.ComparatorType comparatorType, CacheRecycler cacheRecycler) {
+    public CountDateHistogramFacetExecutor(IndexNumericFieldData indexFieldData, Rounding tzRounding, DateHistogramFacet.ComparatorType comparatorType, CacheRecycler cacheRecycler) {
         this.comparatorType = comparatorType;
         this.indexFieldData = indexFieldData;
         this.tzRounding = tzRounding;
@@ -101,9 +101,9 @@ public class CountDateHistogramFacetExecutor extends FacetExecutor {
     public static class DateHistogramProc extends LongFacetAggregatorBase {
 
         private final LongLongOpenHashMap counts;
-        private final TimeZoneRounding tzRounding;
+        private final Rounding tzRounding;
 
-        public DateHistogramProc(LongLongOpenHashMap counts, TimeZoneRounding tzRounding) {
+        public DateHistogramProc(LongLongOpenHashMap counts, Rounding tzRounding) {
             this.counts = counts;
             this.tzRounding = tzRounding;
         }

src/main/java/org/elasticsearch/search/facet/datehistogram/DateHistogramFacetParser.java

@@ -24,6 +24,7 @@ import org.elasticsearch.common.collect.MapBuilder;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.rounding.DateTimeUnit;
+import org.elasticsearch.common.rounding.Rounding;
 import org.elasticsearch.common.rounding.TimeZoneRounding;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
@@ -179,7 +180,7 @@ public class DateHistogramFacetParser extends AbstractComponent implements Facet
             tzRoundingBuilder = TimeZoneRounding.builder(TimeValue.parseTimeValue(interval, null));
         }
 
-        TimeZoneRounding tzRounding = tzRoundingBuilder
+        Rounding tzRounding = tzRoundingBuilder
                 .preZone(preZone).postZone(postZone)
                 .preZoneAdjustLargeInterval(preZoneAdjustLargeInterval)
                 .preOffset(preOffset).postOffset(postOffset)

src/main/java/org/elasticsearch/search/facet/datehistogram/ValueDateHistogramFacetExecutor.java

@@ -24,7 +24,7 @@ import org.apache.lucene.index.AtomicReaderContext;
 import org.apache.lucene.index.SortedNumericDocValues;
 import org.elasticsearch.cache.recycler.CacheRecycler;
 import org.elasticsearch.common.recycler.Recycler;
-import org.elasticsearch.common.rounding.TimeZoneRounding;
+import org.elasticsearch.common.rounding.Rounding;
 import org.elasticsearch.index.fielddata.IndexNumericFieldData;
 import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
 import org.elasticsearch.search.facet.DoubleFacetAggregatorBase;
@@ -43,11 +43,11 @@ public class ValueDateHistogramFacetExecutor extends FacetExecutor {
     private final IndexNumericFieldData keyIndexFieldData;
     private final IndexNumericFieldData valueIndexFieldData;
     private final DateHistogramFacet.ComparatorType comparatorType;
-    final TimeZoneRounding tzRounding;
+    final Rounding tzRounding;
 
     final Recycler.V<LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry>> entries;
 
-    public ValueDateHistogramFacetExecutor(IndexNumericFieldData keyIndexFieldData, IndexNumericFieldData valueIndexFieldData, TimeZoneRounding tzRounding, DateHistogramFacet.ComparatorType comparatorType, CacheRecycler cacheRecycler) {
+    public ValueDateHistogramFacetExecutor(IndexNumericFieldData keyIndexFieldData, IndexNumericFieldData valueIndexFieldData, Rounding tzRounding, DateHistogramFacet.ComparatorType comparatorType, CacheRecycler cacheRecycler) {
         this.comparatorType = comparatorType;
         this.keyIndexFieldData = keyIndexFieldData;
         this.valueIndexFieldData = valueIndexFieldData;
@@ -105,13 +105,13 @@ public class ValueDateHistogramFacetExecutor extends FacetExecutor {
     public static class DateHistogramProc extends LongFacetAggregatorBase {
 
         final LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry> entries;
-        private final TimeZoneRounding tzRounding;
+        private final Rounding tzRounding;
 
         SortedNumericDoubleValues valueValues;
 
         final ValueAggregator valueAggregator = new ValueAggregator();
 
-        public DateHistogramProc(TimeZoneRounding tzRounding, LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry> entries) {
+        public DateHistogramProc(Rounding tzRounding, LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry> entries) {
             this.tzRounding = tzRounding;
             this.entries = entries;
         }

src/main/java/org/elasticsearch/search/facet/datehistogram/ValueScriptDateHistogramFacetExecutor.java

@@ -25,7 +25,7 @@ import org.apache.lucene.index.SortedNumericDocValues;
 import org.apache.lucene.search.Scorer;
 import org.elasticsearch.cache.recycler.CacheRecycler;
 import org.elasticsearch.common.recycler.Recycler;
-import org.elasticsearch.common.rounding.TimeZoneRounding;
+import org.elasticsearch.common.rounding.Rounding;
 import org.elasticsearch.index.fielddata.IndexNumericFieldData;
 import org.elasticsearch.script.SearchScript;
 import org.elasticsearch.search.facet.FacetExecutor;
@@ -44,11 +44,11 @@ public class ValueScriptDateHistogramFacetExecutor extends FacetExecutor {
     private final IndexNumericFieldData keyIndexFieldData;
     private final DateHistogramFacet.ComparatorType comparatorType;
     final SearchScript valueScript;
-    final TimeZoneRounding tzRounding;
+    final Rounding tzRounding;
 
     final Recycler.V<LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry>> entries;
 
-    public ValueScriptDateHistogramFacetExecutor(IndexNumericFieldData keyIndexFieldData, SearchScript valueScript, TimeZoneRounding tzRounding, DateHistogramFacet.ComparatorType comparatorType, CacheRecycler cacheRecycler) {
+    public ValueScriptDateHistogramFacetExecutor(IndexNumericFieldData keyIndexFieldData, SearchScript valueScript, Rounding tzRounding, DateHistogramFacet.ComparatorType comparatorType, CacheRecycler cacheRecycler) {
         this.comparatorType = comparatorType;
         this.keyIndexFieldData = keyIndexFieldData;
         this.valueScript = valueScript;
@@ -110,12 +110,12 @@ public class ValueScriptDateHistogramFacetExecutor extends FacetExecutor {
 
     public static class DateHistogramProc extends LongFacetAggregatorBase {
 
-        private final TimeZoneRounding tzRounding;
+        private final Rounding tzRounding;
         protected final SearchScript valueScript;
 
         final LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry> entries;
 
-        public DateHistogramProc(TimeZoneRounding tzRounding, SearchScript valueScript, final LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry> entries) {
+        public DateHistogramProc(Rounding tzRounding, SearchScript valueScript, final LongObjectOpenHashMap<InternalFullDateHistogramFacet.FullEntry> entries) {
             this.tzRounding = tzRounding;
             this.valueScript = valueScript;
             this.entries = entries;

src/test/java/org/elasticsearch/common/rounding/TimeZoneRoundingTests.java

@@ -33,7 +33,7 @@ public class TimeZoneRoundingTests extends ElasticsearchTestCase {
 
     @Test
     public void testUTCMonthRounding() {
-        TimeZoneRounding tzRounding = TimeZoneRounding.builder(DateTimeUnit.MONTH_OF_YEAR).build();
+        Rounding tzRounding = TimeZoneRounding.builder(DateTimeUnit.MONTH_OF_YEAR).build();
         assertThat(tzRounding.round(utc("2009-02-03T01:01:01")), equalTo(utc("2009-02-01T00:00:00.000Z")));
         assertThat(tzRounding.nextRoundingValue(utc("2009-02-01T00:00:00.000Z")), equalTo(utc("2009-03-01T00:00:00.000Z")));
 
@@ -48,7 +48,7 @@ public class TimeZoneRoundingTests extends ElasticsearchTestCase {
 
     @Test
     public void testDayTimeZoneRounding() {
-        TimeZoneRounding tzRounding = TimeZoneRounding.builder(DateTimeUnit.DAY_OF_MONTH).preZone(DateTimeZone.forOffsetHours(-2)).build();
+        Rounding tzRounding = TimeZoneRounding.builder(DateTimeUnit.DAY_OF_MONTH).preZone(DateTimeZone.forOffsetHours(-2)).build();
         assertThat(tzRounding.round(0), equalTo(0l - TimeValue.timeValueHours(24).millis()));
         assertThat(tzRounding.nextRoundingValue(0l - TimeValue.timeValueHours(24).millis()), equalTo(0l));
 
@@ -67,7 +67,7 @@ public class TimeZoneRoundingTests extends ElasticsearchTestCase {
 
     @Test
     public void testTimeTimeZoneRounding() {
-        TimeZoneRounding tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forOffsetHours(-2)).build();
+        Rounding tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forOffsetHours(-2)).build();
         assertThat(tzRounding.round(0), equalTo(0l));
         assertThat(tzRounding.nextRoundingValue(0l), equalTo(TimeValue.timeValueHours(1l).getMillis()));
 

src/test/java/org/elasticsearch/search/aggregations/bucket/HistogramTests.java

@@ -129,6 +129,52 @@ public class HistogramTests extends ElasticsearchIntegrationTest {
         }
     }
 
+    @Test
+    public void singleValuedField_withPreOffset() throws Exception {
+        long preOffsetMultiplier = randomIntBetween(2, 10);
+        SearchResponse response = client().prepareSearch("idx")
+                .addAggregation(histogram("histo").field(SINGLE_VALUED_FIELD_NAME).interval(interval).preOffset(preOffsetMultiplier * interval))
+                .execute().actionGet();
+
+        assertSearchResponse(response);
+
+
+        Histogram histo = response.getAggregations().get("histo");
+        assertThat(histo, notNullValue());
+        assertThat(histo.getName(), equalTo("histo"));
+        assertThat(histo.getBuckets().size(), equalTo(numValueBuckets));
+
+        for (int i = 0; i < numValueBuckets; ++i) {
+            Histogram.Bucket bucket = histo.getBucketByKey((i + preOffsetMultiplier) * interval);
+            assertThat(bucket, notNullValue());
+            assertThat(bucket.getKeyAsNumber().longValue(), equalTo((long) (i + preOffsetMultiplier) * interval));
+            assertThat(bucket.getDocCount(), equalTo(valueCounts[i]));
+        }
+    }
+
+    @Test
+    public void singleValuedField_withPostOffset() throws Exception {
+        long postOffsetMultiplier = randomIntBetween(2, 10);
+        SearchResponse response = client().prepareSearch("idx")
+                .addAggregation(histogram("histo").field(SINGLE_VALUED_FIELD_NAME).interval(interval).postOffset(postOffsetMultiplier * interval))
+                .execute().actionGet();
+
+        assertSearchResponse(response);
+
+
+        Histogram histo = response.getAggregations().get("histo");
+        assertThat(histo, notNullValue());
+        assertThat(histo.getName(), equalTo("histo"));
+        assertThat(histo.getBuckets().size(), equalTo(numValueBuckets));
+
+        for (int i = 0; i < numValueBuckets; ++i) {
+            Histogram.Bucket bucket = histo.getBucketByKey((i + postOffsetMultiplier) * interval);
+            assertThat(bucket, notNullValue());
+            assertThat(bucket.getKeyAsNumber().longValue(), equalTo((long) (i + postOffsetMultiplier) * interval));
+            assertThat(bucket.getDocCount(), equalTo(valueCounts[i]));
+        }
+    }
+
     @Test
     public void singleValuedField_OrderedByKeyAsc() throws Exception {
         SearchResponse response = client().prepareSearch("idx")