Fixed a bug in Scaler

leventov · Nov 1, 2014 · 639b405 · 639b405
1 parent 736bd13
commit 639b405
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/lib/impl/src/main/java/net/openhft/koloboke/collect/impl/Scaler.java b/lib/impl/src/main/java/net/openhft/koloboke/collect/impl/Scaler.java
@@ -139,6 +139,7 @@ private static void check(long n) {
     }
 
     private static final BigDecimal LONG_MAX_VALUE = valueOf(Long.MAX_VALUE);
+    private static final BigDecimal INT_MAX_VALUE = valueOf(Integer.MAX_VALUE);
 
     final double scale;
     private BigDecimal scaleAsBD;
@@ -158,13 +159,19 @@ BigDecimal createBD() {
 
     public int scaleUpper(int n) {
         check(n);
-        int lower = (int) ((double) n * scale);
+        int lower = scaleLower(n);
         return lower < Integer.MAX_VALUE ? lower + 1 : Integer.MAX_VALUE;
     }
 
     public int scaleLower(int n) {
         check(n);
-        return (int) ((double) n * scale);
+        double d = ((double) n) * scale;
+        if (d != Math.rint(d)) {
+            return (int) d;
+        } else {
+            BigDecimal lower = valueOf(n).multiply(scaleAsBD());
+            return lower.compareTo(INT_MAX_VALUE) < 0 ? lower.intValue() : Integer.MAX_VALUE;
+        }
     }
 
     public long scaleUpper(long n) {

diff --git a/lib/impl/src/test/java/net/openhft/koloboke/collect/impl/ScalerTest.java b/lib/impl/src/test/java/net/openhft/koloboke/collect/impl/ScalerTest.java
@@ -54,6 +54,10 @@ public class ScalerTest {
     public static final Collection<Integer> ints = new ArrayList<Integer>();
     public static final Collection<Long> longs = new ArrayList<Long>();
     static {
+        // special property of this value: multiplied by Math.PI, it results to a double value
+        // which is actually an integer, i. e. d == Math.rint(d)
+        ints.add(415069444);
+
         for (int i = 1; i < 10000; i++) {
             ints.add(i);
             longs.add((long) i);