Function CacheFileSize

be/src/kudu/util/pb_util.cc:245–255

// If 'cached_file_size' already has a value, this is a no-op.
template<typename ReadableFileType>
Status CacheFileSize(ReadableFileType* reader,
                     optional<uint64_t>* cached_file_size) {
  if (cached_file_size->has_value()) {
    return Status::OK();
  }

  uint64_t file_size;
  RETURN_NOT_OK(reader->Size(&file_size));
  *cached_file_size = file_size;
  return Status::OK();
}

template<typename ReadableFileType>
Status RestOfFileIsAllZeros(ReadableFileType* reader,