Use Double.NEGATIVE_INFINITY and Double.POSITIVE_INFINITY (#4496)

* Use Double.NEGATIVE_INFINITY and Double.POSITIVE_INFINITY instead of Double.MIN_VALUE and Double.MAX_VALUE, same for Float

* Replace usages in comments

* Fix RTree

* Remove commented code

* Add tests

api/src/test/java/io/druid/jackson/JacksonExtremeDoubleValuesSerdeTest.java

@@ -0,0 +1,41 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets 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 io.druid.jackson;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+
+public class JacksonExtremeDoubleValuesSerdeTest
+{
+  @Test
+  public void testExtremeDoubleValuesSerde() throws IOException
+  {
+    ObjectMapper objectMapper = new ObjectMapper();
+    for (double value : new double[] {Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY}) {
+      String serialized = objectMapper.writeValueAsString(value);
+      Assert.assertEquals(new Double(value), objectMapper.readValue(serialized, Double.class));
+    }
+    String negativeInfinityString = objectMapper.writeValueAsString(Double.NaN);
+    Assert.assertTrue(objectMapper.readValue(negativeInfinityString, Double.class).isNaN());
+  }
+}

bytebuffer-collections/src/main/java/io/druid/collections/spatial/Node.java

@@ -151,9 +151,9 @@ public class Node
   {
     boolean retVal = false;
     float[] minCoords = new float[getNumDims()];
-    Arrays.fill(minCoords, Float.MAX_VALUE);
+    Arrays.fill(minCoords, Float.POSITIVE_INFINITY);
     float[] maxCoords = new float[getNumDims()];
-    Arrays.fill(maxCoords, -Float.MAX_VALUE);
+    Arrays.fill(maxCoords, Float.NEGATIVE_INFINITY);
 
     for (Node child : getChildren()) {
       for (int i = 0; i < getNumDims(); i++) {

bytebuffer-collections/src/main/java/io/druid/collections/spatial/RTree.java

@@ -128,8 +128,8 @@ public class RTree
   {
     float[] initMinCoords = new float[numDims];
     float[] initMaxCoords = new float[numDims];
-    Arrays.fill(initMinCoords, -Float.MAX_VALUE);
-    Arrays.fill(initMaxCoords, Float.MAX_VALUE);
+    Arrays.fill(initMinCoords, Float.NEGATIVE_INFINITY);
+    Arrays.fill(initMaxCoords, Float.POSITIVE_INFINITY);
 
     return new Node(initMinCoords, initMaxCoords, isLeaf, bitmapFactory);
   }
@@ -178,7 +178,7 @@ public class RTree
       return node;
     }
 
-    double minCost = Double.MAX_VALUE;
+    double minCost = Double.POSITIVE_INFINITY;
     Node optimal = node.getChildren().get(0);
     for (Node child : node.getChildren()) {
       double cost = RTreeUtils.getExpansionCost(child, point);

bytebuffer-collections/src/main/java/io/druid/collections/spatial/split/LinearGutmanSplitStrategy.java

@@ -58,10 +58,10 @@ public class LinearGutmanSplitStrategy extends GutmanSplitStrategy
 
     double bestNormalized = 0.0;
     for (int i = 0; i < numDims; i++) {
-      float minCoord = Float.MAX_VALUE;
-      float maxCoord = -Float.MAX_VALUE;
-      float highestLowSide = -Float.MAX_VALUE;
-      float lowestHighside = Float.MAX_VALUE;
+      float minCoord = Float.POSITIVE_INFINITY;
+      float maxCoord = Float.NEGATIVE_INFINITY;
+      float lowestHighside = Float.POSITIVE_INFINITY;
+      float highestLowSide = Float.NEGATIVE_INFINITY;
       int highestLowSideIndex = 0;
       int lowestHighSideIndex = 0;
 

bytebuffer-collections/src/main/java/io/druid/collections/spatial/split/QuadraticGutmanSplitStrategy.java

@@ -37,7 +37,7 @@ public class QuadraticGutmanSplitStrategy extends GutmanSplitStrategy
   @Override
   public Node[] pickSeeds(List<Node> nodes)
   {
-    double highestCost = Double.MIN_VALUE;
+    double highestCost = Double.NEGATIVE_INFINITY;
     int[] highestCostIndices = new int[2];
 
     for (int i = 0; i < nodes.size() - 1; i++) {
@@ -58,7 +58,7 @@ public class QuadraticGutmanSplitStrategy extends GutmanSplitStrategy
   @Override
   public Node pickNext(List<Node> nodes, Node[] groups)
   {
-    double highestCost = Double.MIN_VALUE;
+    double highestCost = Double.NEGATIVE_INFINITY;
     Node costlyNode = null;
     int counter = 0;
     int index = -1;

codestyle/checkstyle.xml

@@ -71,10 +71,31 @@
       <property name="illegalPattern" value="true"/>
       <property name="message" value="Use Comparators.naturalNullsFirst() instead of Ordering.natural().nullsFirst()"/>
     </module>
+
     <module name="Regexp">
       <property name="format" value="(Byte|Character|Short|Integer|Long|Float|Double)\.TYPE"/>
       <property name="illegalPattern" value="true"/>
       <property name="message" value="Use primitive.class instead. But check twice that you don't actually need BoxedPrimitive.class instead of BoxedPrimitive.TYPE"/>
     </module>
+    <module name="Regexp">
+      <property name="format" value="Float\.MAX_VALUE"/>
+      <property name="illegalPattern" value="true"/>
+      <property name="message" value="Use Float.POSITIVE_INFINITY"/>
+    </module>
+    <module name="Regexp">
+      <property name="format" value="Float\.MIN_VALUE"/>
+      <property name="illegalPattern" value="true"/>
+      <property name="message" value="Use Float.NEGATIVE_INFINITY"/>
+    </module>
+    <module name="Regexp">
+      <property name="format" value="Double\.MAX_VALUE"/>
+      <property name="illegalPattern" value="true"/>
+      <property name="message" value="Use Double.POSITIVE_INFINITY"/>
+    </module>
+    <module name="Regexp">
+      <property name="format" value="Double\.MIN_VALUE"/>
+      <property name="illegalPattern" value="true"/>
+      <property name="message" value="Use Double.NEGATIVE_INFINITY"/>
+    </module>
   </module>
 </module>

extensions-core/histogram/src/main/java/io/druid/query/aggregation/histogram/ApproximateHistogram.java

@@ -335,11 +335,11 @@ public class ApproximateHistogram
     // or merge existing bins before inserting the new one
 
     int minPos = minDeltaIndex();
-    float minDelta = minPos >= 0 ? positions[minPos + 1] - positions[minPos] : Float.MAX_VALUE;
+    float minDelta = minPos >= 0 ? positions[minPos + 1] - positions[minPos] : Float.POSITIVE_INFINITY;
 
     // determine the distance of new value to the nearest bins
-    final float deltaRight = insertAt < binCount ? positions[insertAt] - value : Float.MAX_VALUE;
-    final float deltaLeft = insertAt > 0 ? value - positions[insertAt - 1] : Float.MAX_VALUE;
+    final float deltaRight = insertAt < binCount ? positions[insertAt] - value : Float.POSITIVE_INFINITY;
+    final float deltaLeft = insertAt > 0 ? value - positions[insertAt - 1] : Float.POSITIVE_INFINITY;
 
     boolean mergeValue = false;
     if (deltaRight < minDelta) {
@@ -368,7 +368,7 @@ public class ApproximateHistogram
   protected int minDeltaIndex()
   {
     // determine minimum distance between existing bins
-    float minDelta = Float.MAX_VALUE;
+    float minDelta = Float.POSITIVE_INFINITY;
     int minPos = -1;
     for (int i = 0; i < binCount - 1; ++i) {
       float delta = (positions[i + 1] - positions[i]);
@@ -886,9 +886,6 @@ public class ApproximateHistogram
       while (i < numMerge) {
         // find the smallest delta within the range used for bins
 
-        // pick minimum delta by scanning array
-        //int currentIndex = minIndex(deltas, lastValidIndex);
-
         // pick minimum delta index using min-heap
         int currentIndex = heap[0];
 
@@ -908,17 +905,13 @@ public class ApproximateHistogram
         final float mm0 = (m0 - m1) * w + m1;
 
         mergedPositions[currentIndex] = mm0;
-        //mergedPositions[nextIndex] = Float.MAX_VALUE; // for debugging
 
         mergedBins[currentIndex] = sum | APPROX_FLAG_BIT;
-        //mergedBins[nextIndex] = -1; // for debugging
 
         // update deltas and min-heap
         if (nextIndex == lastValidIndex) {
           // merged bin is the last => remove the current bin delta from the heap
           heapSize = heapDelete(heap, reverseIndex, heapSize, reverseIndex[currentIndex], deltas);
-
-          //deltas[currentIndex] = Float.MAX_VALUE; // for debugging
         } else {
           // merged bin is not the last => remove the merged bin delta from the heap
           heapSize = heapDelete(heap, reverseIndex, heapSize, reverseIndex[nextIndex], deltas);
@@ -938,9 +931,6 @@ public class ApproximateHistogram
           siftDown(heap, reverseIndex, reverseIndex[prevIndex], heapSize - 1, deltas);
         }
 
-        // mark the merged bin as invalid
-        // deltas[nextIndex] = Float.MAX_VALUE; // for debugging
-
         // update last valid index if we merged the last bin
         if (nextIndex == lastValidIndex) {
           lastValidIndex = currentIndex;
@@ -1037,7 +1027,7 @@ public class ApproximateHistogram
   private static int minIndex(float[] deltas, int lastValidIndex)
   {
     int minIndex = -1;
-    float min = Float.MAX_VALUE;
+    float min = Float.POSITIVE_INFINITY;
     for (int k = 0; k < lastValidIndex; ++k) {
       float value = deltas[k];
       if (value < min) {

hll/src/main/java/io/druid/hll/HyperLogLogCollector.java

@@ -146,7 +146,7 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
       final double ratio = e / TWO_TO_THE_SIXTY_FOUR;
       if (ratio >= 1) {
         // handle very unlikely case that value is > 2^64
-        return Double.MAX_VALUE;
+        return Double.POSITIVE_INFINITY;
       } else {
         return -TWO_TO_THE_SIXTY_FOUR * Math.log(1 - ratio);
       }

hll/src/test/java/io/druid/hll/HyperLogLogCollectorTest.java

@@ -698,7 +698,7 @@ public class HyperLogLogCollectorTest
     fillBuckets(collector, (byte) 0, (byte) 63);
     collector.add(new byte[]{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0});
 
-    Assert.assertEquals(Double.MAX_VALUE, collector.estimateCardinality(), 1000);
+    Assert.assertEquals(Double.POSITIVE_INFINITY, collector.estimateCardinality(), 1000);
   }
 
   @Test

processing/src/main/java/io/druid/query/aggregation/DoubleMaxAggregatorFactory.java

@@ -86,7 +86,13 @@ public class DoubleMaxAggregatorFactory extends AggregatorFactory
 
   private FloatColumnSelector getFloatColumnSelector(ColumnSelectorFactory metricFactory)
   {
-    return AggregatorUtil.getFloatColumnSelector(metricFactory, macroTable, fieldName, expression, Float.MIN_VALUE);
+    return AggregatorUtil.getFloatColumnSelector(
+        metricFactory,
+        macroTable,
+        fieldName,
+        expression,
+        Float.NEGATIVE_INFINITY
+    );
   }
 
   @Override

processing/src/main/java/io/druid/query/aggregation/DoubleMinAggregatorFactory.java

@@ -87,7 +87,13 @@ public class DoubleMinAggregatorFactory extends AggregatorFactory
 
   private FloatColumnSelector getFloatColumnSelector(ColumnSelectorFactory metricFactory)
   {
-    return AggregatorUtil.getFloatColumnSelector(metricFactory, macroTable, fieldName, expression, Float.MAX_VALUE);
+    return AggregatorUtil.getFloatColumnSelector(
+        metricFactory,
+        macroTable,
+        fieldName,
+        expression,
+        Float.POSITIVE_INFINITY
+    );
   }
 
   @Override

processing/src/main/java/io/druid/query/aggregation/Histogram.java

@@ -42,8 +42,8 @@ public class Histogram
     this.breaks = breaks;
     this.bins   = new long[this.breaks.length + 1];
     this.count  = 0;
-    this.min = Float.MAX_VALUE;
-    this.max = Float.MIN_VALUE;
+    this.min = Float.POSITIVE_INFINITY;
+    this.max = Float.NEGATIVE_INFINITY;
   }
 
   public Histogram(float[] breaks, long[] bins, float min, float max) {

processing/src/main/java/io/druid/query/aggregation/HistogramBufferAggregator.java

@@ -50,8 +50,8 @@ public class HistogramBufferAggregator implements BufferAggregator
 
     final long[] bins = new long[breaks.length + 1];
     mutationBuffer.asLongBuffer().put(bins);
-    mutationBuffer.putFloat(position + minOffset, Float.MAX_VALUE);
-    mutationBuffer.putFloat(position + maxOffset, Float.MIN_VALUE);
+    mutationBuffer.putFloat(position + minOffset, Float.POSITIVE_INFINITY);
+    mutationBuffer.putFloat(position + maxOffset, Float.NEGATIVE_INFINITY);
   }
 
   @Override

processing/src/main/java/io/druid/segment/FloatDimensionIndexer.java

@@ -69,13 +69,13 @@ public class FloatDimensionIndexer implements DimensionIndexer<Float, Float, Flo
   @Override
   public Float getMinValue()
   {
-    return Float.MIN_VALUE;
+    return Float.NEGATIVE_INFINITY;
   }
 
   @Override
   public Float getMaxValue()
   {
-    return Float.MAX_VALUE;
+    return Float.POSITIVE_INFINITY;
   }
 
   @Override

processing/src/test/java/io/druid/query/aggregation/HistogramTest.java

@@ -45,6 +45,25 @@ public class HistogramTest
     Assert.assertEquals("histogram matches expected histogram", hExpected, h);
   }
 
+  /**
+   * This test differs from {@link #testOffer()} only in that it offers only negative values into Histogram. It's to
+   * expose the issue of using Float's MIN_VALUE that is actually positive as initial value for {@link Histogram#max}.
+   */
+  @Test
+  public void testOfferOnlyNegative() {
+    final float[] values = {-0.3f, -.1f, -0.8f, -.7f, -.5f, -3f};
+    final float[] breaks = {-1f, -0.5f, 0.0f, 0.5f, 1f};
+
+    Histogram hExpected = new Histogram(breaks, new long[]{1,3,2,0,0,0}, -3f, -0.1f);
+
+    Histogram h = new Histogram(breaks);
+    for(float v : values) {
+      h.offer(v);
+    }
+
+    Assert.assertEquals("histogram matches expected histogram", hExpected, h);
+  }
+
   @Test
   public void testToFromBytes() {
     float[] breaks = {-1f, -0.5f, 0.0f, 0.5f, 1f};

processing/src/test/java/io/druid/segment/data/CompressedFloatsSerdeTest.java

@@ -70,8 +70,8 @@ public class CompressedFloatsSerdeTest
   private final float values5[] = {123.16f, 1.12f, 62.00f, 462.12f, 517.71f, 56.54f, 971.32f, 824.22f, 472.12f, 625.26f};
   private final float values6[] = {1000000f, 1000001f, 1000002f, 1000003f, 1000004f, 1000005f, 1000006f, 1000007f, 1000008f};
   private final float values7[] = {
-      Float.MAX_VALUE, Float.MIN_VALUE, 12378.5734f, -12718243.7496f, -93653653.1f, 12743153.385534f, 21431.414538f,
-      65487435436632.123f, -43734526234564.65f
+      Float.POSITIVE_INFINITY, Float.NEGATIVE_INFINITY, 12378.5734f, -12718243.7496f, -93653653.1f, 12743153.385534f,
+      21431.414538f, 65487435436632.123f, -43734526234564.65f
   };
 
   public CompressedFloatsSerdeTest(

processing/src/test/java/io/druid/segment/incremental/IncrementalIndexTest.java

@@ -214,7 +214,7 @@ public class IncrementalIndexTest
             Lists.newArrayList("string", "float", "long"),
             ImmutableMap.<String, Object>of(
                 "string", Arrays.asList("A", null, ""),
-                "float", Arrays.asList(Float.MAX_VALUE, null, ""),
+                "float", Arrays.asList(Float.POSITIVE_INFINITY, null, ""),
                 "long", Arrays.asList(Long.MIN_VALUE, null, "")
             )
         )
@@ -223,7 +223,7 @@ public class IncrementalIndexTest
     Row row = index.iterator().next();
 
     Assert.assertEquals(Arrays.asList(new String[]{"", "", "A"}), row.getRaw("string"));
-    Assert.assertEquals(Arrays.asList(new String[]{"", "", String.valueOf(Float.MAX_VALUE)}), row.getRaw("float"));
+    Assert.assertEquals(Arrays.asList(new String[]{"", "", String.valueOf(Float.POSITIVE_INFINITY)}), row.getRaw("float"));
     Assert.assertEquals(Arrays.asList(new String[]{"", "", String.valueOf(Long.MIN_VALUE)}), row.getRaw("long"));
   }