@Test
  public void ortest4() {
    final MutableRoaringBitmap rb = new MutableRoaringBitmap();
    final MutableRoaringBitmap rb2 = new MutableRoaringBitmap();

    for (int i = 0; i < 200000; i += 4) rb2.add(i);
    for (int i = 200000; i < 400000; i += 14) rb2.add(i);
    final int rb2card = rb2.getCardinality();

    // check or against an empty bitmap
    final MutableRoaringBitmap orresult = MutableRoaringBitmap.or(rb, rb2);
    final MutableRoaringBitmap off = MutableRoaringBitmap.or(rb2, rb);
    Assert.assertTrue(orresult.equals(off));

    Assert.assertEquals(rb2card, orresult.getCardinality());

    for (int i = 500000; i < 600000; i += 14) rb.add(i);
    for (int i = 200000; i < 400000; i += 3) rb2.add(i);
    // check or against an empty bitmap
    final MutableRoaringBitmap orresult2 = MutableRoaringBitmap.or(rb, rb2);
    Assert.assertEquals(rb2card, orresult.getCardinality());

    Assert.assertEquals(rb2.getCardinality() + rb.getCardinality(), orresult2.getCardinality());
    rb.or(rb2);
    Assert.assertTrue(rb.equals(orresult2));
  }
  @Test
  public void andtest4() {
    final MutableRoaringBitmap rb = new MutableRoaringBitmap();
    final MutableRoaringBitmap rb2 = new MutableRoaringBitmap();

    for (int i = 0; i < 200000; i += 4) rb2.add(i);
    for (int i = 200000; i < 400000; i += 14) rb2.add(i);

    // check or against an empty bitmap
    final MutableRoaringBitmap andresult = MutableRoaringBitmap.and(rb, rb2);
    final MutableRoaringBitmap off = MutableRoaringBitmap.and(rb2, rb);
    Assert.assertTrue(andresult.equals(off));

    Assert.assertEquals(0, andresult.getCardinality());

    for (int i = 500000; i < 600000; i += 14) rb.add(i);
    for (int i = 200000; i < 400000; i += 3) rb2.add(i);
    // check or against an empty bitmap
    final MutableRoaringBitmap andresult2 = MutableRoaringBitmap.and(rb, rb2);
    Assert.assertEquals(0, andresult.getCardinality());

    Assert.assertEquals(0, andresult2.getCardinality());
    for (int i = 0; i < 200000; i += 4) rb.add(i);
    for (int i = 200000; i < 400000; i += 14) rb.add(i);
    Assert.assertEquals(0, andresult.getCardinality());
    final MutableRoaringBitmap rc = MutableRoaringBitmap.and(rb, rb2);
    rb.and(rb2);
    Assert.assertEquals(rc.getCardinality(), rb.getCardinality());
  }
  @Test
  public void ORtest() {
    final MutableRoaringBitmap rr = new MutableRoaringBitmap();
    for (int k = 4000; k < 4256; ++k) rr.add(k);
    for (int k = 65536; k < 65536 + 4000; ++k) rr.add(k);
    for (int k = 3 * 65536; k < 3 * 65536 + 9000; ++k) rr.add(k);
    for (int k = 4 * 65535; k < 4 * 65535 + 7000; ++k) rr.add(k);
    for (int k = 6 * 65535; k < 6 * 65535 + 10000; ++k) rr.add(k);
    for (int k = 8 * 65535; k < 8 * 65535 + 1000; ++k) rr.add(k);
    for (int k = 9 * 65535; k < 9 * 65535 + 30000; ++k) rr.add(k);

    final MutableRoaringBitmap rr2 = new MutableRoaringBitmap();
    for (int k = 4000; k < 4256; ++k) {
      rr2.add(k);
    }
    for (int k = 65536; k < 65536 + 4000; ++k) {
      rr2.add(k);
    }
    for (int k = 3 * 65536 + 2000; k < 3 * 65536 + 6000; ++k) {
      rr2.add(k);
    }
    for (int k = 6 * 65535; k < 6 * 65535 + 1000; ++k) {
      rr2.add(k);
    }
    for (int k = 7 * 65535; k < 7 * 65535 + 1000; ++k) {
      rr2.add(k);
    }
    for (int k = 10 * 65535; k < 10 * 65535 + 5000; ++k) {
      rr2.add(k);
    }
    final MutableRoaringBitmap correct = MutableRoaringBitmap.or(rr, rr2);
    rr.or(rr2);
    Assert.assertTrue(correct.equals(rr));
  }
 @Test
 public void testIterator() {
   MutableRoaringBitmap rb = new MutableRoaringBitmap();
   for (int k = 0; k < 4000; ++k) rb.add(k);
   for (int k = 0; k < 1000; ++k) rb.add(k * 100);
   MutableRoaringBitmap copy1 = new MutableRoaringBitmap();
   for (int x : rb) {
     copy1.add(x);
   }
   Assert.assertTrue(copy1.equals(rb));
   MutableRoaringBitmap copy2 = new MutableRoaringBitmap();
   IntIterator i = rb.getIntIterator();
   Iterator<Integer> is = rb.iterator();
   while (i.hasNext()) {
     if (!is.hasNext()) throw new RuntimeException("bug");
     int x = i.next();
     copy2.add(x);
     int xs = is.next();
     if (x != xs) throw new RuntimeException("values differ " + x + " " + xs);
   }
   if (is.hasNext()) throw new RuntimeException("bug: more data available");
   Assert.assertTrue(copy2.equals(rb));
 }
 @Test
 public void testSerialization2() throws IOException, ClassNotFoundException {
   final MutableRoaringBitmap rr = new MutableRoaringBitmap();
   for (int k = 200; k < 400; ++k) rr.add(k);
   final ByteArrayOutputStream bos = new ByteArrayOutputStream();
   // Note: you could use a file output steam instead of
   // ByteArrayOutputStream
   final ObjectOutputStream oo = new ObjectOutputStream(bos);
   rr.writeExternal(oo);
   oo.close();
   final MutableRoaringBitmap rrback = new MutableRoaringBitmap();
   final ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
   rrback.readExternal(new ObjectInputStream(bis));
   Assert.assertEquals(rr.getCardinality(), rrback.getCardinality());
   Assert.assertTrue(rr.equals(rrback));
 }
  /** Test massive and. */
  @Test
  public void testMassiveAnd() {
    System.out.println("testing massive logical and");
    MutableRoaringBitmap[] ewah = new MutableRoaringBitmap[1024];
    for (int k = 0; k < ewah.length; ++k) ewah[k] = new MutableRoaringBitmap();
    int howmany = 1000000;
    for (int k = 0; k < howmany; ++k) {
      ewah[Math.abs(k + 2 * k * k) % ewah.length].add(k);
    }
    for (int k = 3; k < ewah.length; k += 3) ewah[k].flip(13, howmany / 2);
    for (int N = 2; N < ewah.length; ++N) {
      MutableRoaringBitmap answer = ewah[0];
      for (int k = 1; k < N; ++k) answer = MutableRoaringBitmap.and(answer, ewah[k]);

      MutableRoaringBitmap answer2 = BufferFastAggregation.and(Arrays.copyOf(ewah, N));
      Assert.assertTrue(answer.equals(answer2));
    }
  }
 @Test
 public void testSerialization4() throws IOException, ClassNotFoundException {
   final MutableRoaringBitmap rr = new MutableRoaringBitmap();
   for (int k = 1; k <= 10000000; k += 10) rr.add(k);
   final ByteArrayOutputStream bos = new ByteArrayOutputStream();
   // Note: you could use a file output steam instead of
   // ByteArrayOutputStream
   int howmuch = rr.serializedSizeInBytes();
   final DataOutputStream oo = new DataOutputStream(bos);
   rr.serialize(oo);
   oo.close();
   Assert.assertEquals(howmuch, bos.toByteArray().length);
   final MutableRoaringBitmap rrback = new MutableRoaringBitmap();
   final ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
   rrback.deserialize(new DataInputStream(bis));
   Assert.assertEquals(rr.getCardinality(), rrback.getCardinality());
   Assert.assertTrue(rr.equals(rrback));
 }
 /** Test massive or. */
 @Test
 public void testMassiveOr() {
   System.out.println("testing massive logical or (can take a couple of minutes)");
   final int N = 128;
   for (int howmany = 512; howmany <= 1000000; howmany *= 2) {
     MutableRoaringBitmap[] ewah = new MutableRoaringBitmap[N];
     for (int k = 0; k < ewah.length; ++k) ewah[k] = new MutableRoaringBitmap();
     for (int k = 0; k < howmany; ++k) {
       ewah[Math.abs(k + 2 * k * k) % ewah.length].add(k);
     }
     for (int k = 3; k < ewah.length; k += 3) ewah[k].flip(13, howmany / 2);
     MutableRoaringBitmap answer = ewah[0];
     for (int k = 1; k < ewah.length; ++k) {
       answer = MutableRoaringBitmap.or(answer, ewah[k]);
     }
     MutableRoaringBitmap answer2 = BufferFastAggregation.or(ewah);
     MutableRoaringBitmap answer3 = BufferFastAggregation.horizontal_or(ewah);
     Assert.assertTrue(answer.equals(answer2));
     Assert.assertTrue(answer.equals(answer3));
   }
 }
  public void rTest(final int N) {
    System.out.println("rtest N=" + N);
    for (int gap = 1; gap <= 65536; gap *= 2) {
      final BitSet bs1 = new BitSet();
      final MutableRoaringBitmap rb1 = new MutableRoaringBitmap();
      for (int x = 0; x <= N; x += gap) {
        bs1.set(x);
        rb1.add(x);
      }
      if (bs1.cardinality() != rb1.getCardinality()) throw new RuntimeException("different card");
      if (!equals(bs1, rb1)) throw new RuntimeException("basic  bug");
      for (int offset = 1; offset <= gap; offset *= 2) {
        final BitSet bs2 = new BitSet();
        final MutableRoaringBitmap rb2 = new MutableRoaringBitmap();
        for (int x = 0; x <= N; x += gap) {
          bs2.set(x + offset);
          rb2.add(x + offset);
        }
        if (bs2.cardinality() != rb2.getCardinality()) throw new RuntimeException("different card");
        if (!equals(bs2, rb2)) throw new RuntimeException("basic  bug");

        BitSet clonebs1;
        // testing AND
        clonebs1 = (BitSet) bs1.clone();
        clonebs1.and(bs2);
        if (!equals(clonebs1, MutableRoaringBitmap.and(rb1, rb2)))
          throw new RuntimeException("bug and");
        {
          final MutableRoaringBitmap t = rb1.clone();
          t.and(rb2);
          if (!equals(clonebs1, t)) throw new RuntimeException("bug inplace and");
          if (!t.equals(MutableRoaringBitmap.and(rb1, rb2))) {
            System.out.println(
                t.highLowContainer.getContainerAtIndex(0).getClass().getCanonicalName());
            System.out.println(
                MutableRoaringBitmap.and(rb1, rb2)
                    .highLowContainer
                    .getContainerAtIndex(0)
                    .getClass()
                    .getCanonicalName());

            throw new RuntimeException("bug inplace and");
          }
        }

        // testing OR
        clonebs1 = (BitSet) bs1.clone();
        clonebs1.or(bs2);

        if (!equals(clonebs1, MutableRoaringBitmap.or(rb1, rb2)))
          throw new RuntimeException("bug or");
        {
          final MutableRoaringBitmap t = rb1.clone();
          t.or(rb2);
          if (!equals(clonebs1, t)) throw new RuntimeException("bug or");
          if (!t.equals(MutableRoaringBitmap.or(rb1, rb2))) throw new RuntimeException("bug or");
          if (!t.toString().equals(MutableRoaringBitmap.or(rb1, rb2).toString()))
            throw new RuntimeException("bug or");
        }
        // testing XOR
        clonebs1 = (BitSet) bs1.clone();
        clonebs1.xor(bs2);
        if (!equals(clonebs1, MutableRoaringBitmap.xor(rb1, rb2))) {
          throw new RuntimeException("bug xor");
        }
        {
          final MutableRoaringBitmap t = rb1.clone();
          t.xor(rb2);
          if (!equals(clonebs1, t)) throw new RuntimeException("bug xor");

          if (!t.equals(MutableRoaringBitmap.xor(rb1, rb2))) {
            System.out.println(t);
            System.out.println(MutableRoaringBitmap.xor(rb1, rb2));
            System.out.println(
                Arrays.equals(t.toArray(), MutableRoaringBitmap.xor(rb1, rb2).toArray()));
            throw new RuntimeException("bug xor");
          }
        }
        // testing NOTAND
        clonebs1 = (BitSet) bs1.clone();
        clonebs1.andNot(bs2);
        if (!equals(clonebs1, MutableRoaringBitmap.andNot(rb1, rb2))) {
          throw new RuntimeException("bug andnot");
        }
        clonebs1 = (BitSet) bs2.clone();
        clonebs1.andNot(bs1);
        if (!equals(clonebs1, MutableRoaringBitmap.andNot(rb2, rb1))) {
          throw new RuntimeException("bug andnot");
        }
        {
          final MutableRoaringBitmap t = rb2.clone();
          t.andNot(rb1);
          if (!equals(clonebs1, t)) {
            throw new RuntimeException("bug inplace andnot");
          }
          final MutableRoaringBitmap g = MutableRoaringBitmap.andNot(rb2, rb1);
          if (!equals(clonebs1, g)) {
            throw new RuntimeException("bug andnot");
          }
          if (!t.equals(g)) throw new RuntimeException("bug");
        }
        clonebs1 = (BitSet) bs1.clone();
        clonebs1.andNot(bs2);
        if (!equals(clonebs1, MutableRoaringBitmap.andNot(rb1, rb2))) {
          throw new RuntimeException("bug andnot");
        }
        {
          final MutableRoaringBitmap t = rb1.clone();
          t.andNot(rb2);
          if (!equals(clonebs1, t)) {
            throw new RuntimeException("bug andnot");
          }
          final MutableRoaringBitmap g = MutableRoaringBitmap.andNot(rb1, rb2);
          if (!equals(clonebs1, g)) {
            throw new RuntimeException("bug andnot");
          }
          if (!t.equals(g)) throw new RuntimeException("bug");
        }
      }
    }
  }