Fix BitBufferDirect

Author: thomasmueller

src/main/java/org/fastfilter/FilterType.java

@@ -9,6 +9,7 @@
 import org.fastfilter.cuckoo.CuckooPlus16;
 import org.fastfilter.cuckoo.CuckooPlus8;
 import org.fastfilter.gcs.GolombCompressedSet;
+import org.fastfilter.gcs.GolombCompressedSet2;
 import org.fastfilter.mphf.MPHFilter;
 import org.fastfilter.xor.Xor16;
 import org.fastfilter.xor.Xor8;
@@ -104,6 +105,12 @@ public Filter construct(long[] keys, int setting) {
             return GolombCompressedSet.construct(keys, setting);
         }
     },
+    GCS2 {
+        @Override
+        public Filter construct(long[] keys, int setting) {
+            return GolombCompressedSet2.construct(keys, setting);
+        }
+    },
     MPHF {
         @Override
         public Filter construct(long[] keys, int setting) {

src/main/java/org/fastfilter/gcs/BitBufferDirect.java

@@ -1,7 +1,6 @@
 package org.fastfilter.gcs;
 
 import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
 
 public class BitBufferDirect {
 
@@ -11,14 +10,14 @@ public class BitBufferDirect {
 
     public BitBufferDirect(long bits) {
         this.data = ByteBuffer.allocateDirect((int)((bits + 7) / 8));
-        this.data.order(ByteOrder.nativeOrder());
+        // this.data.order(ByteOrder.nativeOrder());
     }
 
     public BitBufferDirect(byte[] byteArray) {
         this.data = ByteBuffer.allocateDirect(byteArray.length);
         data.put(byteArray);
         data.flip();
-        this.data.order(ByteOrder.nativeOrder());
+        // this.data.order(ByteOrder.nativeOrder());
     }
 
     public int position() {
@@ -124,26 +123,6 @@ public int readUntilZero(int pos) {
         long current = data.getLong((int) (pos >>> 3));
         long x = ~current << ((pos & 7));
         return Long.numberOfLeadingZeros(x);
-    	
-//        int remainingBits = 64 - (pos & 63);
-//        int index = pos >>> 6;
-//        long x = data.getLong(index << 3) << (64 - remainingBits);
-//        int count = Long.numberOfLeadingZeros(~x);
-//        if (count < remainingBits) {
-//            return count;
-//        }
-//        return readUntilZeroMore(count, index);
-    }
-
-    private int readUntilZeroMore(int count, int index) {
-        while (true) {
-            long x = data.getLong(++index << 3);
-            if (x == -1L) {
-                count += 64;
-                continue;
-            }
-            return count + Long.numberOfLeadingZeros(~x);
-        }
     }
 
     public void write(BitBufferDirect bits) {

src/test/java/org/fastfilter/gcs/BitBufferTest.java

@@ -137,11 +137,13 @@ public void testEliasDeltaRoundtrip() {
 
     @Test
     public void testNumberRoundtrip() {
+        // with regular BitBuffer, the max bit count is 65 (that is, 0..64)
+        int maxBitCount = 58;
         Random r = new Random(1);
         BitBufferDirect buff = new BitBufferDirect(8 * 1024 * 1024);
         for (int i = 0; i < 1000; i++) {
             long val = r.nextLong();
-            int bitCount = r.nextInt(65);
+            int bitCount = r.nextInt(maxBitCount);
             if (bitCount < 64) {
                 val &= ((1L << bitCount) - 1);
             }
@@ -151,7 +153,7 @@ public void testNumberRoundtrip() {
         r = new Random(1);
         for (int i = 0; i < 1000; i++) {
             long val = r.nextLong();
-            int bitCount = r.nextInt(65);
+            int bitCount = r.nextInt(maxBitCount);
             if (bitCount < 64) {
                 val &= ((1L << bitCount) - 1);
             }
@@ -208,35 +210,6 @@ public void testWriteBuffer() {
         }
     }
 
-    @Test
-    public void testWriteBuffer2() {
-        BitBufferDirect buff = new BitBufferDirect(8000);
-        for (int i = 1; i < 100; i++) {
-            BitBufferDirect b = new BitBufferDirect(100);
-//            b.writeEliasDelta(i);
-//            assertEquals(b.position(), BitBufferDirect.getEliasDeltaSize(i));
-            for (int j = 0; j < i; j++) {
-                b.writeBit(1);
-            }
-            b.writeBit(0);
-            buff.write(b);
-        }
-        buff.seek(0);
-        for (int i = 1; i < 100; i++) {
-//            if (i != buff.readEliasDelta()) {
-//                System.out.println("??");
-//            }
-//            assertEquals(i, buff.readEliasDelta());
-            for (int j = 0; j < i; j++) {
-              if (1 != buff.readBit()) {
-              System.out.println("??");
-          }
-//                assertEquals(1, buff.readBit());
-            }
-            assertEquals(0, buff.readBit());
-        }
-    }
-
     @Test
     public void testSeek() {
         BitBufferDirect buff = new BitBufferDirect(8000);