From 7f9fbc3d35cccd3b81b5285344575b6448e974c5 Mon Sep 17 00:00:00 2001
From: Sebastian Jambor <seb.jambor@gmail.com>
Date: Tue, 29 Oct 2019 15:26:45 +0100
Subject: [PATCH] Change type of TDigest.Group.id from int to long

The assumption is that the id is unique. If the id value overflows, it
can lead to NullPointerExceptions. Changing the type to long doesn't
make overflows impossible, but highly unlikely.
---
 .../analytics/stream/quantile/TDigest.java       | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/main/java/com/clearspring/analytics/stream/quantile/TDigest.java b/src/main/java/com/clearspring/analytics/stream/quantile/TDigest.java
index c0aa150a5..23fdc86c2 100644
--- a/src/main/java/com/clearspring/analytics/stream/quantile/TDigest.java
+++ b/src/main/java/com/clearspring/analytics/stream/quantile/TDigest.java
@@ -21,7 +21,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Random;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
 
 import java.nio.ByteBuffer;
 
@@ -476,11 +476,11 @@ private double interpolate(double x, double x0, double x1) {
 
     public static class Group implements Comparable<Group> {
 
-        private static final AtomicInteger uniqueCount = new AtomicInteger(1);
+        private static final AtomicLong uniqueCount = new AtomicLong(1);
 
         private double centroid = 0;
         private int count = 0;
-        private int id;
+        private long id;
 
         private List<Double> actualData = null;
 
@@ -493,7 +493,7 @@ private Group(boolean record) {
 
         public Group(double x) {
             this(false);
-            start(x, uniqueCount.getAndIncrement());
+            start(x, uniqueCount.incrementAndGet());
         }
 
         public Group(double x, int id) {
@@ -506,7 +506,7 @@ public Group(double x, int id, boolean record) {
             start(x, id);
         }
 
-        private void start(double x, int id) {
+        private void start(double x, long id) {
             this.id = id;
             add(x, 1);
         }
@@ -527,7 +527,7 @@ public int count() {
             return count;
         }
 
-        public int id() {
+        public long id() {
             return id;
         }
 
@@ -541,14 +541,14 @@ public String toString() {
 
         @Override
         public int hashCode() {
-            return id;
+            return Long.hashCode(id);
         }
 
         @Override
         public int compareTo(Group o) {
             int r = Double.compare(centroid, o.centroid);
             if (r == 0) {
-                r = id - o.id;
+                r = Long.compare(id, o.id);
             }
             return r;
         }