@Override
  public void debugDumpShort(StringBuilder sb) {
    sb.append("\nORC cache state ");
    int allLocked = 0, allUnlocked = 0, allEvicted = 0, allMoving = 0, allMarked = 0;
    long totalUsedSpace = 0;
    for (Map.Entry<Object, FileCache<ConcurrentSkipListMap<Long, LlapDataBuffer>>> e :
      cache.entrySet()) {
      if (!e.getValue().incRef()) continue;
      try {
        int fileLocked = 0, fileUnlocked = 0, fileEvicted = 0, fileMoving = 0, fileMarked = 0;
        long fileMemoryUsage = 0;
        if (e.getValue().getCache().isEmpty()) continue;
        List<LlapDataBuffer> lockedBufs = null;
        if (LlapIoImpl.LOCKING_LOGGER.isTraceEnabled()) {
          lockedBufs = new ArrayList<>();
        }
        for (Map.Entry<Long, LlapDataBuffer> e2 : e.getValue().getCache().entrySet()) {
          int newRc = e2.getValue().tryIncRef();
          if (newRc < 0) {
            if (newRc == LlapAllocatorBuffer.INCREF_EVICTED) {
              ++fileEvicted;
            } else if (newRc == LlapAllocatorBuffer.INCREF_FAILED) {
              ++fileMoving;
            }
            continue;
          }
          if (e2.getValue().isMarkedForEviction()) {
            ++fileMarked;
          }
          try {
            if (newRc > 1) { // We hold one refcount.
              ++fileLocked;
              if (lockedBufs != null) {
                lockedBufs.add(e2.getValue());
              }
            } else {
              ++fileUnlocked;
            }
          } finally {
            fileMemoryUsage += e2.getValue().allocSize;
            e2.getValue().decRef();
          }
        }
        allLocked += fileLocked;
        allUnlocked += fileUnlocked;
        allEvicted += fileEvicted;
        allMoving += fileMoving;
        allMarked += fileMarked;
        totalUsedSpace += fileMemoryUsage;

        sb.append("\n  file "
            + e.getKey()
            + ": "
            + fileLocked
            + " locked, "
            + fileUnlocked
            + " unlocked, "
            + fileEvicted
            + " evicted, "
            + fileMoving
            + " being moved, "
            + fileMarked
            + " marked for eviction, "
            + fileMemoryUsage
            + " total used byte");
        if (fileLocked > 0 && LlapIoImpl.LOCKING_LOGGER.isTraceEnabled()) {
          LlapIoImpl.LOCKING_LOGGER.trace("locked-buffers: {}", lockedBufs);
        }
      } finally {
        e.getValue().decRef();
      }
    }
    sb.append("\nORC cache summary: "
        + allLocked
        + " locked, "
        + allUnlocked
        + " unlocked, "
        + allEvicted
        + " evicted, "
        + allMoving
        + " being moved, "
        + allMarked
        + " marked for eviction, "
        + totalUsedSpace
        + " total used space");
  }
Adds cached buffer to buffer list.
@param currentNotCached Pointer to the list node where we are inserting.
@param currentCached The cached buffer found for this node, to insert.
@return The new currentNotCached pointer, following the cached buffer insertion.
llap-server/src/java/org/apache/hadoop/hive/llap/cache/LowLevelCacheImpl.java