std::size_t IOBuf::computeChainCapacity() const {
  std::size_t fullCapacity = capacity_;
  for (IOBuf* current = next_; current != this; current = current->next_) {
    fullCapacity += current->capacity_;
  }
  return fullCapacity;
}
std::size_t IOBuf::computeChainCapacity() const {
  std::size_t fullCapacity = capacity_;
  for (IOBuf* current = next_; current != this; current = current->next_) {
    fullCapacity += current->capacity_;
  }
  return fullCapacity;
}