Method ReadBuffer

cpp/src/arrow/ipc/reader.cc:193–221

        max_recursion_depth_(options.max_recursion_depth) {}

  Status ReadBuffer(int64_t offset, int64_t length, std::shared_ptr<Buffer>* out) {
    // This construct permits overriding GetBuffer at compile time
    if (skip_io_) {
      return Status::OK();
    }
    if (offset < 0) {
      return Status::Invalid("Negative offset for reading buffer ", buffer_index_);
    }
    if (length < 0) {
      return Status::Invalid("Negative length for reading buffer ", buffer_index_);
    }
    auto read_end = AddWithOverflow({offset, length});
    if (!read_end.has_value() || (file_length_.has_value() && read_end > file_length_)) {
      return Status::Invalid("Buffer ", buffer_index_, " exceeds IPC file area");
    }
    if (!bit_util::IsMultipleOf8(offset)) {
      return Status::Invalid("Buffer ", buffer_index_,
                             " did not start on 8-byte aligned offset: ", offset);
    }
    if (file_) {
      return file_->ReadAt(offset, length).Value(out);
    } else {
      if (!AddWithOverflow({read_end.value(), file_offset_}).has_value()) {
        return Status::Invalid("Buffer ", buffer_index_, " exceeds IPC file area");
      }
      read_request_.RequestRange(offset + file_offset_, length, out);
      return Status::OK();
    }
  }

  Status LoadType(const DataType& type) {
    DCHECK_NE(out_, nullptr);