Counting Bloom filters changes

Author: thomasmueller

src/main/java/org/fastfilter/bloom/CountingBloom.java

@@ -52,8 +52,8 @@ public void add(long key) {
         int a = (int) (hash >>> 32);
         int b = (int) hash;
         for (int i = 0; i < k; i++) {
-            int index = Hash.reduce(a, arraySize * 16);
-            counts[index / 16] += getBit(index);
+            int index = Hash.reduce(a, arraySize << 4);
+            counts[index >>> 4] += getBit(index);
             a += b;
         }
     }
@@ -69,14 +69,14 @@ public void remove(long key) {
         int a = (int) (hash >>> 32);
         int b = (int) hash;
         for (int i = 0; i < k; i++) {
-            int index = Hash.reduce(a, arraySize * 16);
-            counts[index / 16] -= getBit(index);
+            int index = Hash.reduce(a, arraySize << 4);
+            counts[index >>> 4] -= getBit(index);
             a += b;
         }
     }
 
     private static long getBit(int index) {
-        return 1L << (index * 4);
+        return 1L << (index << 2);
     }
 
     @Override
@@ -85,8 +85,8 @@ public boolean mayContain(long key) {
         int a = (int) (hash >>> 32);
         int b = (int) hash;
         for (int i = 0; i < k; i++) {
-            int index = Hash.reduce(a, arraySize * 16);
-            if ((counts[index / 16] & (0xf * getBit(index))) == 0) {
+            int index = Hash.reduce(a, arraySize << 4);
+            if (((counts[index >>> 4] >>> (index << 2)) & 0xf) == 0) {
                 return false;
             }
             a += b;

src/main/java/org/fastfilter/bloom/SuccinctCountingBloom.java

@@ -1,5 +1,7 @@
 package org.fastfilter.bloom;
 
+import java.math.BigInteger;
+
 import org.fastfilter.Filter;
 import org.fastfilter.utils.Hash;
 
@@ -73,7 +75,7 @@ public long getBitCount() {
         arraySize = (int) ((bits + 63) / 64);
         data = new BitField(64 * (arraySize + 10));
         counts = new BitField(64 * (arraySize + 10));
-        overflow = new long[100 + arraySize / 100 * 4];
+        overflow = new long[100 + arraySize / 100 * 12];
         for (int i = 0; i < overflow.length; i += 4) {
             overflow[i] = i + 4;
         }
@@ -91,7 +93,7 @@ public void add(long key) {
         int a = (int) (hash >>> 32);
         int b = (int) hash;
         for (int i = 0; i < k; i++) {
-            int index = Hash.reduce(a, arraySize) * 64 + (a & 63);
+            int index = (Hash.reduce(a, arraySize) << 6) + (a & 63);
             if (VERIFY_COUNTS) {
                 realCounts[index]++;
             }
@@ -111,7 +113,7 @@ public void remove(long key) {
         int a = (int) (hash >>> 32);
         int b = (int) hash;
         for (int i = 0; i < k; i++) {
-            int index = Hash.reduce(a, arraySize) * 64 + (a & 63);
+            int index = (Hash.reduce(a, arraySize) << 6) + (a & 63);
             if (VERIFY_COUNTS) {
                 realCounts[index]--;
             }