void copyForwardForOverflowCompact(DiskEntry de, byte[] valueBytes, int length, byte userBits) {
    synchronized (overflowMap) {
      if (lastOverflowWrite != null) {
        if (lastOverflowWrite.copyForwardForOverflowCompact(de, valueBytes, length,
            userBits)) {
          return;
        }
      }
      OverflowOplog oo = createOverflowOplog(length);
      lastOverflowWrite = oo;
      addOverflow(oo);
      boolean didIt = oo.copyForwardForOverflowCompact(de, valueBytes, length, userBits);
      assert didIt;
    }
  }
@param minSize the minimum size this oplog can be
geode-core/src/main/java/org/apache/geode/internal/cache/OverflowOplogSet.java