persistable sclass SynchronizedLongBufferStoredAsLinearInts is ILongBuffer {

  int[] data;

  int size;

  // affine conversion to long (long = int*factor+base)

  long base, factor;

  *(long *base, long *factor) {}

  *(long *base, long *factor, int size) { if (size != 0) data = new int[size]; }

  *(long *base, long *factor, Iterable<Long> l) {

    if (l cast Cl) allocate(l.size());

    addAll(l);

  }

  public synchronized void addRaw(int i) {

    if (size >= lIntArray(data)) {

      data = resizeIntArray(data, Math.max(1, toInt(Math.min(maximumSafeArraySize(), lIntArray(data)*2L))));

      if (size >= data.length) fail(shortClassName(this) + " too large: " + size);

    }

    data[size++] = i;

  }

  public synchronized void add(long i) {

    addRaw(compress(i));

  }

  synchronized void allocate(int n) {

    data = resizeIntArray(data, max(n, size()));

  }

  public synchronized void addAll(Iterable<Long> l) {

    if (l != null) for (long i : l) add(i);

  }

  public synchronized long[] toArray() {

    if (size == 0) null;

    long[] out = new[size];

    for i to size:

      out[i] = expand(data[i]);

    ret out;

  }

  /*synchronized L<Long> toList() {

    ret longArrayToList(data, 0, size);

  }*/

  public synchronized L<Long> asVirtualList() {

    ret listFromFunction get(size);

  }

  synchronized void reset { size = 0; }

  void clear { reset(); }

  synchronized public int size() { ret size; }

  public synchronized bool isEmpty() { ret size == 0; }

  public synchronized int getRaw(int idx) {

    if (idx >= size) fail("Index out of range: " + idx + "/" + size);

    ret data[idx];

  }

  public synchronized long get(int idx) {

    if (idx >= size) fail("Index out of range: " + idx + "/" + size);

    ret expand(data[idx]);

  }

  synchronized void set(int idx, long value) {

    if (idx >= size) fail("Index out of range: " + idx + "/" + size);

    data[idx] = compress(value);

  }

  public synchronized long popLast() {

    if (size == 0) fail("empty buffer");

    ret expand(data[--size]);

  }

  public synchronized long last() { ret expand(data[size-1]); }

  synchronized long nextToLast() { ret expand(data[size-2]); }

  toString { ret squareBracket(joinWithSpace(asVirtualList())); }

  public synchronized Iterator<Long> iterator() {

    ret new ItIt<Long> {

      int i = 0;

      public bool hasNext() { ret i < size(); }

      public Long next() {

        synchronized(SynchronizedLongBufferStoredAsLinearInts.this) {

          if (!hasNext()) fail("Index out of bounds: " + i);

          ret expand(data[i++]);

        }

      }

    };

  }

  public synchronized void trimToSize {

    data = resizeIntArray(data, size);

  }

  synchronized void remove(int idx) {

    arraycopy(data, idx+1, data, idx, size-1-idx);

    --size;

  }

  // don't rely on return value if buffer is empty

  public synchronized long poll() { 

    ret size == 0 ? -1 : expand(data[--size]);

  }

  long expand(int value) { ret base+value*factor; }

  int compress(long value) { ret toInt(ldiv_round(value-base, factor); }

  public synchronized void insertAt(int idx, long[] l) {

    int n = l(l);

    if (n == 0) ret;

    int[] newData = new[size+n];

    arraycopy(data, 0, newData, 0, idx);

    for i to n:

      newData[idx+i] = compress(l[i]);

    arraycopy(data, idx, newData, idx+n, size-idx);

    data = newData;

    size = newData.length;

  }

  public void integrityCheck {

    assertTrue("Size positive", size >= 0);

    assertTrue("Data length", l(data) >= size);

  }

}