CustomBitSet.java

private class CustomBitSetList {

  final int bucket_size = 1024;
  int offset = -1;
  int currentBucketIdx = 0;

  ArrayList<FixedBitSet> buckets = new ArrayList<>(16);
  FixedBitSet currentBucket = new FixedBitSet(bucket_size);

  CustomBitSetList() {
    buckets.add(currentBucket);
  }

  void setNext(boolean bit) {
    offset++;
    if (offset == bucket_size) {
      currentBucket = new FixedBitSet(bucket_size);
      buckets.add(currentBucket);
      offset = 0;
    }
    if (bit) {
      currentBucket.set(offset);
    }
  }

  boolean getNext() {
    offset++;
    if (offset == bucket_size) {
      currentBucketIdx++;
      currentBucket = buckets.get(currentBucketIdx);
      offset = 0;
    }
    return currentBucket.get(offset);
  }

  void readMode() {
    offset = -1;
    currentBucket = buckets.get(0);
    currentBucketIdx = 0;
  }
}