Fix calculations in bloom filter implementation.

atomix · Feb 26, 2015 · ace4fb8 · ace4fb8
1 parent 8a2ec36
commit ace4fb8
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Showing 3 changed files with 6 additions and 7 deletions.
diff --git a/util/src/main/java/net/kuujo/copycat/util/concurrent/NamedThreadFactory.java b/util/src/main/java/net/kuujo/copycat/util/concurrent/NamedThreadFactory.java
@@ -20,6 +20,8 @@
 /**
  * Named thread factory.
  *
+ * TODO: This can be replaced with OpenHFT's NamedThreadFactory
+ *
  * @author <a href="http://github.com/kuujo">Jordan Halterman</a>
  */
 public class NamedThreadFactory implements ThreadFactory {

diff --git a/...jo/copycat/util/internal/BloomFilter.java → .../kuujo/copycat/util/hash/BloomFilter.java b/...jo/copycat/util/internal/BloomFilter.java → .../kuujo/copycat/util/hash/BloomFilter.java
@@ -13,11 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package net.kuujo.copycat.util.internal;
+package net.kuujo.copycat.util.hash;
 
-import net.kuujo.copycat.util.hash.CityHashFunction;
-import net.kuujo.copycat.util.hash.HashFunction;
-import net.kuujo.copycat.util.hash.Murmur3HashFunction;
+import net.openhft.lang.Maths;
 import net.openhft.lang.collection.DirectBitSet;
 import net.openhft.lang.collection.DirectBitSetBuilder;
 
@@ -46,7 +44,7 @@ public class BloomFilter<T> {
    *                     with the desired false positive probability to calculate the number of bits and hashes to use.
    */
   public BloomFilter(double falsePositiveProbability, int expectedSize) {
-    numBits = (long) Math.pow(2, (long) Math.log(((-expectedSize * Math.log(falsePositiveProbability == 0 ? Double.MIN_VALUE : falsePositiveProbability) / (Math.log(2) * Math.log(2))) - 1) / Math.log(2)) + 1);
+    numBits = Maths.nextPower2((long) (-expectedSize * Math.log(falsePositiveProbability == 0 ? Double.MIN_VALUE : falsePositiveProbability) / (Math.log(2) * Math.log(2))), 128);
     numHashes = Math.max(1, (int) Math.round((double) numBits / expectedSize * Math.log(2)));
     bits = new DirectBitSetBuilder().threadSafe(false).create(numBits);
     function1 = new CityHashFunction();

diff --git a/util/src/test/java/net/kuujo/copycat/util/BloomFilterTest.java b/util/src/test/java/net/kuujo/copycat/util/BloomFilterTest.java
@@ -15,7 +15,7 @@
  */
 package net.kuujo.copycat.util;
 
-import net.kuujo.copycat.util.internal.BloomFilter;
+import net.kuujo.copycat.util.hash.BloomFilter;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
@@ -35,7 +35,6 @@ public void testAddContains() {
     filter.add("Hello world!");
     Assert.assertTrue(filter.contains("Hello world!"));
     Assert.assertFalse(filter.contains("Hello world again!"));
-    System.out.println(filter.toString());for (;;);
   }
 
 }