public long getDataCacheUsedMemorySizeInBytes() {
    return dataCacheMemoryBlock == null ? 0 : dataCacheMemoryBlock.getMemoryUsageInBytes();
  }
Resize the memory block to the new size.

@throws LoadRuntimeOutOfMemoryException if failed to allocate enough memory
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/load/memory/LoadTsFileMemoryManager.java