LUCENE-7889: Allow grouping on Double/LongValuesSource (#1484)

The grouping module currently allows grouping on a SortedDocValues field, or on
a ValueSource. The latter groups only on exact values, and so will not perform well
on numeric-valued fields. This commit adds the ability to group by defined ranges
from a Long or DoubleValuesSource.

lucene/CHANGES.txt

@@ -159,7 +159,9 @@ API Changes
 
 New Features
 ---------------------
-(No changes)
+
+* LUCENE-7889: Grouping by range based on values from DoubleValuesSource and LongValuesSource
+  (Alan Woodward)
 
 Improvements
 ---------------------

lucene/grouping/src/java/org/apache/lucene/search/grouping/DoubleRange.java

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import java.util.Objects;
+
+/**
+ * Represents a contiguous range of double values, with an inclusive minimum and
+ * exclusive maximum
+ */
+public class DoubleRange {
+
+  /** The inclusive minimum value of this range */
+  public double min;
+  /** The exclusive maximum value of this range */
+  public double max;
+
+  /**
+   * Creates a new double range, running from {@code min} inclusive to {@code max} exclusive
+   */
+  public DoubleRange(double min, double max) {
+    this.min = min;
+    this.max = max;
+  }
+
+  @Override
+  public String toString() {
+    return "DoubleRange(" + min + ", " + max + ")";
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    DoubleRange that = (DoubleRange) o;
+    return Double.compare(that.min, min) == 0 &&
+        Double.compare(that.max, max) == 0;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(min, max);
+  }
+}

lucene/grouping/src/java/org/apache/lucene/search/grouping/DoubleRangeFactory.java

@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+/**
+ * Groups double values into ranges
+ */
+public class DoubleRangeFactory {
+
+  private final double min;
+  private final double width;
+  private final double max;
+
+  /**
+   * Creates a new DoubleRangeFactory
+   * @param min     a minimum value; all doubles below this value are grouped into a single range
+   * @param width   a standard width; all ranges between {@code min} and {@code max} are this wide,
+   *                with the exception of the final range which may be up to this width.  Ranges
+   *                are inclusive at the lower end, and exclusive at the upper end.
+   * @param max     a maximum value; all doubles above this value are grouped into a single range
+   */
+  public DoubleRangeFactory(double min, double width, double max) {
+    this.min = min;
+    this.width = width;
+    this.max = max;
+  }
+
+  /**
+   * Finds the DoubleRange that a value should be grouped into
+   * @param value the value to group
+   * @param reuse an existing DoubleRange object to reuse
+   */
+  public DoubleRange getRange(double value, DoubleRange reuse) {
+    if (reuse == null)
+      reuse = new DoubleRange(Double.MIN_VALUE, Double.MAX_VALUE);
+    if (value < min) {
+      reuse.max = min;
+      reuse.min = Double.MIN_VALUE;
+      return reuse;
+    }
+    if (value >= max) {
+      reuse.min = max;
+      reuse.max = Double.MAX_VALUE;
+      return reuse;
+    }
+    double bucket = Math.floor((value - min) / width);
+    reuse.min = min + (bucket * width);
+    reuse.max = reuse.min + width;
+    return reuse;
+  }
+
+}

lucene/grouping/src/java/org/apache/lucene/search/grouping/DoubleRangeGroupSelector.java

@@ -0,0 +1,100 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.search.DoubleValues;
+import org.apache.lucene.search.DoubleValuesSource;
+import org.apache.lucene.search.Scorable;
+
+/**
+ * A GroupSelector implementation that groups documents by double values
+ */
+public class DoubleRangeGroupSelector extends GroupSelector<DoubleRange> {
+
+  private final DoubleValuesSource source;
+  private final DoubleRangeFactory rangeFactory;
+
+  private Set<DoubleRange> inSecondPass;
+  private boolean includeEmpty = true;
+  private boolean positioned;
+  private DoubleRange current;
+
+  private LeafReaderContext context;
+  private DoubleValues values;
+
+  /**
+   * Creates a new DoubleRangeGroupSelector
+   * @param source        a DoubleValuesSource to retrieve double values per document
+   * @param rangeFactory  a DoubleRangeFactory that defines how to group the double values into range buckets
+   */
+  public DoubleRangeGroupSelector(DoubleValuesSource source, DoubleRangeFactory rangeFactory) {
+    this.source = source;
+    this.rangeFactory = rangeFactory;
+  }
+
+  @Override
+  public void setNextReader(LeafReaderContext readerContext) throws IOException {
+    this.context = readerContext;
+  }
+
+  @Override
+  public void setScorer(Scorable scorer) throws IOException {
+    this.values = source.getValues(context, DoubleValuesSource.fromScorer(scorer));
+  }
+
+  @Override
+  public State advanceTo(int doc) throws IOException {
+    positioned = values.advanceExact(doc);
+    if (positioned == false) {
+      return includeEmpty ? State.ACCEPT : State.SKIP;
+    }
+    this.current = rangeFactory.getRange(values.doubleValue(), this.current);
+    if (inSecondPass == null) {
+      return State.ACCEPT;
+    }
+    return inSecondPass.contains(this.current) ? State.ACCEPT : State.SKIP;
+  }
+
+  @Override
+  public DoubleRange currentValue() throws IOException {
+    return positioned ? this.current : null;
+  }
+
+  @Override
+  public DoubleRange copyValue() throws IOException {
+    return positioned ? new DoubleRange(this.current.min, this.current.max) : null;
+  }
+
+  @Override
+  public void setGroups(Collection<SearchGroup<DoubleRange>> searchGroups) {
+    inSecondPass = new HashSet<>();
+    includeEmpty = false;
+    for (SearchGroup<DoubleRange> group : searchGroups) {
+      if (group.groupValue == null)
+        includeEmpty = true;
+      else
+        inSecondPass.add(group.groupValue);
+    }
+  }
+}

lucene/grouping/src/java/org/apache/lucene/search/grouping/FirstPassGroupingCollector.java

@@ -151,6 +151,7 @@ public class FirstPassGroupingCollector<T> extends SimpleCollector {
 
   @Override
   public void setScorer(Scorable scorer) throws IOException {
+    groupSelector.setScorer(scorer);
     for (LeafFieldComparator comparator : leafComparators) {
       comparator.setScorer(scorer);
     }

lucene/grouping/src/java/org/apache/lucene/search/grouping/GroupSelector.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.util.Collection;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.search.Scorable;
 
 /**
  * Defines a group, for use by grouping collectors
@@ -43,6 +44,11 @@ public abstract class GroupSelector<T> {
    */
   public abstract void setNextReader(LeafReaderContext readerContext) throws IOException;
 
+  /**
+   * Set the current Scorer
+   */
+  public abstract void setScorer(Scorable scorer) throws IOException;
+
   /**
    * Advance the GroupSelector's iterator to the given document
    */
@@ -53,12 +59,12 @@ public abstract class GroupSelector<T> {
    *
    * N.B. this object may be reused, for a persistent version use {@link #copyValue()}
    */
-  public abstract T currentValue();
+  public abstract T currentValue() throws IOException;
 
   /**
    * @return a copy of the group value of the current document
    */
-  public abstract T copyValue();
+  public abstract T copyValue() throws IOException;
 
   /**
    * Set a restriction on the group values returned by this selector

lucene/grouping/src/java/org/apache/lucene/search/grouping/GroupingSearch.java

@@ -71,6 +71,10 @@ public class GroupingSearch {
     this(new TermGroupSelector(groupField), null);
   }
 
+  /**
+   * Constructs a <code>GroupingSearch</code> instance that groups documents using a {@link GroupSelector}
+   * @param groupSelector a {@link GroupSelector} that defines groups for this GroupingSearch
+   */
   public GroupingSearch(GroupSelector<?> groupSelector) {
     this(groupSelector, null);
   }

lucene/grouping/src/java/org/apache/lucene/search/grouping/LongRange.java

@@ -0,0 +1,58 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import java.util.Objects;
+
+/**
+ * Represents a contiguous range of long values, with an inclusive minimum and
+ * exclusive maximum
+ */
+public class LongRange {
+
+  /** The inclusive minimum value of this range */
+  public long min;
+  /** The exclusive maximum value of this range */
+  public long max;
+
+  /**
+   * Creates a new double range, running from {@code min} inclusive to {@code max} exclusive
+   */
+  public LongRange(long min, long max) {
+    this.min = min;
+    this.max = max;
+  }
+
+  @Override
+  public String toString() {
+    return "LongRange(" + min + ", " + max + ")";
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    LongRange that = (LongRange) o;
+    return that.min == min && that.max == max;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(min, max);
+  }
+}

lucene/grouping/src/java/org/apache/lucene/search/grouping/LongRangeFactory.java

@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+/**
+ * Groups double values into ranges
+ */
+public class LongRangeFactory {
+
+  private final long min;
+  private final long width;
+  private final long max;
+
+  /**
+   * Creates a new LongRangeFactory
+   * @param min     a minimum value; all longs below this value are grouped into a single range
+   * @param width   a standard width; all ranges between {@code min} and {@code max} are this wide,
+   *                with the exception of the final range which may be up to this width.  Ranges
+   *                are inclusive at the lower end, and exclusive at the upper end.
+   * @param max     a maximum value; all longs above this value are grouped into a single range
+   */
+  public LongRangeFactory(long min, long width, long max) {
+    this.min = min;
+    this.width = width;
+    this.max = max;
+  }
+
+  /**
+   * Finds the LongRange that a value should be grouped into
+   * @param value the value to group
+   * @param reuse an existing LongRange object to reuse
+   */
+  public LongRange getRange(long value, LongRange reuse) {
+    if (reuse == null)
+      reuse = new LongRange(Long.MIN_VALUE, Long.MAX_VALUE);
+    if (value < min) {
+      reuse.max = min;
+      reuse.min = Long.MIN_VALUE;
+      return reuse;
+    }
+    if (value >= max) {
+      reuse.min = max;
+      reuse.max = Long.MAX_VALUE;
+      return reuse;
+    }
+    long bucket = (value - min) / width;
+    reuse.min = min + (bucket * width);
+    reuse.max = reuse.min + width;
+    return reuse;
+  }
+
+}

lucene/grouping/src/java/org/apache/lucene/search/grouping/LongRangeGroupSelector.java

@@ -0,0 +1,101 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.search.DoubleValuesSource;
+import org.apache.lucene.search.LongValues;
+import org.apache.lucene.search.LongValuesSource;
+import org.apache.lucene.search.Scorable;
+
+/**
+ * A GroupSelector implementation that groups documents by long values
+ */
+public class LongRangeGroupSelector extends GroupSelector<LongRange> {
+
+  private final LongValuesSource source;
+  private final LongRangeFactory rangeFactory;
+
+  private Set<LongRange> inSecondPass;
+  private boolean includeEmpty = true;
+  private boolean positioned;
+  private LongRange current;
+
+  private LeafReaderContext context;
+  private LongValues values;
+
+  /**
+   * Creates a new LongRangeGroupSelector
+   * @param source        a LongValuesSource to retrieve long values per document
+   * @param rangeFactory  a LongRangeFactory that defines how to group the long values into range buckets
+   */
+  public LongRangeGroupSelector(LongValuesSource source, LongRangeFactory rangeFactory) {
+    this.source = source;
+    this.rangeFactory = rangeFactory;
+  }
+
+  @Override
+  public void setNextReader(LeafReaderContext readerContext) throws IOException {
+    this.context = readerContext;
+  }
+
+  @Override
+  public void setScorer(Scorable scorer) throws IOException {
+    this.values = source.getValues(context, DoubleValuesSource.fromScorer(scorer));
+  }
+
+  @Override
+  public State advanceTo(int doc) throws IOException {
+    positioned = values.advanceExact(doc);
+    if (positioned == false) {
+      return includeEmpty ? State.ACCEPT : State.SKIP;
+    }
+    this.current = rangeFactory.getRange(values.longValue(), this.current);
+    if (inSecondPass == null) {
+      return State.ACCEPT;
+    }
+    return inSecondPass.contains(this.current) ? State.ACCEPT : State.SKIP;
+  }
+
+  @Override
+  public LongRange currentValue() throws IOException {
+    return positioned ? this.current : null;
+  }
+
+  @Override
+  public LongRange copyValue() throws IOException {
+    return positioned ? new LongRange(this.current.min, this.current.max) : null;
+  }
+
+  @Override
+  public void setGroups(Collection<SearchGroup<LongRange>> searchGroups) {
+    inSecondPass = new HashSet<>();
+    includeEmpty = false;
+    for (SearchGroup<LongRange> group : searchGroups) {
+      if (group.groupValue == null)
+        includeEmpty = true;
+      else
+        inSecondPass.add(group.groupValue);
+    }
+  }
+}

lucene/grouping/src/java/org/apache/lucene/search/grouping/SecondPassGroupingCollector.java

@@ -78,6 +78,7 @@ public class SecondPassGroupingCollector<T> extends SimpleCollector {
 
   @Override
   public void setScorer(Scorable scorer) throws IOException {
+    groupSelector.setScorer(scorer);
     groupReducer.setScorer(scorer);
   }
 

lucene/grouping/src/java/org/apache/lucene/search/grouping/TermGroupSelector.java

@@ -25,6 +25,7 @@ import java.util.Map;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.SortedDocValues;
+import org.apache.lucene.search.Scorable;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.BytesRefHash;
 
@@ -64,6 +65,9 @@ public class TermGroupSelector extends GroupSelector<BytesRef> {
     }
   }
 
+  @Override
+  public void setScorer(Scorable scorer) throws IOException { }
+
   @Override
   public State advanceTo(int doc) throws IOException {
     if (this.docValues.advanceExact(doc) == false) {

lucene/grouping/src/java/org/apache/lucene/search/grouping/ValueSourceGroupSelector.java

@@ -26,6 +26,7 @@ import java.util.Set;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.queries.function.FunctionValues;
 import org.apache.lucene.queries.function.ValueSource;
+import org.apache.lucene.search.Scorable;
 import org.apache.lucene.util.mutable.MutableValue;
 
 /**
@@ -56,6 +57,9 @@ public class ValueSourceGroupSelector extends GroupSelector<MutableValue> {
     this.filler = values.getValueFiller();
   }
 
+  @Override
+  public void setScorer(Scorable scorer) throws IOException { }
+
   @Override
   public State advanceTo(int doc) throws IOException {
     this.filler.fillValue(doc);
@@ -67,7 +71,7 @@ public class ValueSourceGroupSelector extends GroupSelector<MutableValue> {
   }
 
   @Override
-  public MutableValue currentValue() {
+  public MutableValue currentValue() throws IOException {
     return filler.getValue();
   }
 

lucene/grouping/src/java/org/apache/lucene/search/grouping/package-info.java

@@ -28,11 +28,9 @@
  * <p>Grouping requires a number of inputs:</p>
  * 
  * <ul>
- *   <li><code>groupField</code>: this is the field used for grouping.
+ *   <li><code>groupSelector</code>: this defines how groups are created
- *       For example, if you use the <code>author</code> field then each
+ *       from values per-document.  The grouping module ships with
- *       group has all books by the same author.  Documents that don't
+ *       selectors for grouping by term, and by long and double ranges.
- *       have this field are grouped under a single group with
- *       a <code>null</code> group value.
  * 
  *   <li><code>groupSort</code>: how the groups are sorted.  For sorting
  *       purposes, each group is "represented" by the highest-sorted
@@ -80,6 +78,10 @@
  *     the value of a {@link org.apache.lucene.index.SortedDocValues} field</li>
  *     <li>{@link org.apache.lucene.search.grouping.ValueSourceGroupSelector} groups based on
  *     the value of a {@link org.apache.lucene.queries.function.ValueSource}</li>
+ *     <li>{@link org.apache.lucene.search.grouping.DoubleRangeGroupSelector} groups based on
+ *     the value of a {@link org.apache.lucene.search.DoubleValuesSource}</li>
+ *     <li>{@link org.apache.lucene.search.grouping.LongRangeGroupSelector} groups based on
+ *     the value of a {@link org.apache.lucene.search.LongValuesSource}</li>
  *   </ul>
  * 
  * <p>Known limitations:</p>
@@ -137,17 +139,10 @@
  *   writer.addDocuments(oneGroup);
  * </pre>
  * 
- * Then, at search time, do this up front:
+ * Then, at search time:
  * 
  * <pre class="prettyprint">
- *   // Set this once in your app &amp; save away for reusing across all queries:
+ *   Query groupEndDocs = new TermQuery(new Term("groupEnd", "x"));
- *   Filter groupEndDocs = new CachingWrapperFilter(new QueryWrapperFilter(new TermQuery(new Term("groupEnd", "x"))));
- * </pre>
- * 
- * Finally, do this per search:
- * 
- * <pre class="prettyprint">
- *   // Per search:
  *   BlockGroupingCollector c = new BlockGroupingCollector(groupSort, groupOffset+topNGroups, needsScores, groupEndDocs);
  *   s.search(new TermQuery(new Term("content", searchTerm)), c);
  *   TopGroups groupsResult = c.getTopGroups(withinGroupSort, groupOffset, docOffset, docOffset+docsPerGroup, fillFields);

lucene/grouping/src/test/org/apache/lucene/search/grouping/DoubleRangeGroupSelectorTest.java

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.DoublePoint;
+import org.apache.lucene.document.NumericDocValuesField;
+import org.apache.lucene.search.BooleanClause;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.DocValuesFieldExistsQuery;
+import org.apache.lucene.search.DoubleValuesSource;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.Query;
+
+public class DoubleRangeGroupSelectorTest extends BaseGroupSelectorTestCase<DoubleRange> {
+
+  @Override
+  protected void addGroupField(Document document, int id) {
+    if (rarely()) {
+      return;   // missing value
+    }
+    // numbers between 0 and 1000, groups are 100 wide from 100 to 900
+    double value = random().nextDouble() * 1000;
+    document.add(new DoublePoint("double", value));
+    document.add(new NumericDocValuesField("double", Double.doubleToLongBits(value)));
+  }
+
+  @Override
+  protected GroupSelector<DoubleRange> getGroupSelector() {
+    return new DoubleRangeGroupSelector(DoubleValuesSource.fromDoubleField("double"),
+        new DoubleRangeFactory(100, 100, 900));
+  }
+
+  @Override
+  protected Query filterQuery(DoubleRange groupValue) {
+    if (groupValue == null) {
+      return new BooleanQuery.Builder()
+          .add(new MatchAllDocsQuery(), BooleanClause.Occur.FILTER)
+          .add(new DocValuesFieldExistsQuery("double"), BooleanClause.Occur.MUST_NOT)
+          .build();
+    }
+    return DoublePoint.newRangeQuery("double", groupValue.min, Math.nextDown(groupValue.max));
+  }
+}

lucene/grouping/src/test/org/apache/lucene/search/grouping/LongRangeGroupSelectorTest.java

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.LongPoint;
+import org.apache.lucene.document.NumericDocValuesField;
+import org.apache.lucene.search.BooleanClause;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.DocValuesFieldExistsQuery;
+import org.apache.lucene.search.LongValuesSource;
+import org.apache.lucene.search.MatchAllDocsQuery;
+import org.apache.lucene.search.Query;
+
+public class LongRangeGroupSelectorTest extends BaseGroupSelectorTestCase<LongRange> {
+
+  @Override
+  protected void addGroupField(Document document, int id) {
+    if (rarely()) {
+      return; // missing value
+    }
+    // numbers between 0 and 1000, groups are 100 wide from 100 to 900
+    long value = random().nextInt(1000);
+    document.add(new LongPoint("long", value));
+    document.add(new NumericDocValuesField("long", value));
+  }
+
+  @Override
+  protected GroupSelector<LongRange> getGroupSelector() {
+    return new LongRangeGroupSelector(LongValuesSource.fromLongField("long"),
+        new LongRangeFactory(100, 100, 900));
+  }
+
+  @Override
+  protected Query filterQuery(LongRange groupValue) {
+    if (groupValue == null) {
+      return new BooleanQuery.Builder()
+          .add(new MatchAllDocsQuery(), BooleanClause.Occur.FILTER)
+          .add(new DocValuesFieldExistsQuery("long"), BooleanClause.Occur.MUST_NOT)
+          .build();
+    }
+    return LongPoint.newRangeQuery("long", groupValue.min, groupValue.max - 1);
+  }
+}

lucene/grouping/src/test/org/apache/lucene/search/grouping/TestDoubleRangeFactory.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import org.apache.lucene.util.LuceneTestCase;
+
+public class TestDoubleRangeFactory extends LuceneTestCase {
+
+  public void test() {
+
+    DoubleRangeFactory factory = new DoubleRangeFactory(10, 10, 50);
+    DoubleRange scratch = new DoubleRange(0, 0);
+
+    assertEquals(new DoubleRange(Double.MIN_VALUE, 10), factory.getRange(4, scratch));
+    assertEquals(new DoubleRange(10, 20), factory.getRange(10, scratch));
+    assertEquals(new DoubleRange(20, 30), factory.getRange(20, scratch));
+    assertEquals(new DoubleRange(10, 20), factory.getRange(15, scratch));
+    assertEquals(new DoubleRange(30, 40), factory.getRange(35, scratch));
+    assertEquals(new DoubleRange(50, Double.MAX_VALUE), factory.getRange(50, scratch));
+    assertEquals(new DoubleRange(50, Double.MAX_VALUE), factory.getRange(500, scratch));
+
+  }
+
+}

lucene/grouping/src/test/org/apache/lucene/search/grouping/TestLongRangeFactory.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.search.grouping;
+
+import org.apache.lucene.util.LuceneTestCase;
+
+public class TestLongRangeFactory extends LuceneTestCase {
+
+  public void test() {
+
+    LongRangeFactory factory = new LongRangeFactory(10, 10, 50);
+    LongRange scratch = new LongRange(0, 0);
+
+    assertEquals(new LongRange(Long.MIN_VALUE, 10), factory.getRange(4, scratch));
+    assertEquals(new LongRange(10, 20), factory.getRange(10, scratch));
+    assertEquals(new LongRange(20, 30), factory.getRange(20, scratch));
+    assertEquals(new LongRange(10, 20), factory.getRange(15, scratch));
+    assertEquals(new LongRange(30, 40), factory.getRange(35, scratch));
+    assertEquals(new LongRange(50, Long.MAX_VALUE), factory.getRange(50, scratch));
+    assertEquals(new LongRange(50, Long.MAX_VALUE), factory.getRange(500, scratch));
+
+  }
+
+}