Method ReadAsync

cpp/src/arrow/dataset/file_parquet_test.cc:143–153

      : ::arrow::io::BufferReader(buffer) {}

  ::arrow::Future<std::shared_ptr<Buffer>> ReadAsync(
      const ::arrow::io::IOContext& io_context, int64_t position,
      int64_t nbytes) override {
    read_async_count.fetch_add(1);
    auto self = std::dynamic_pointer_cast<DelayedBufferReader>(shared_from_this());
    return DeferNotOk(::arrow::io::internal::SubmitIO(
        io_context, [self, position, nbytes]() -> Result<std::shared_ptr<Buffer>> {
          std::this_thread::sleep_for(std::chrono::seconds(1));
          return self->DoReadAt(position, nbytes);
        }));
  }

  std::atomic<int> read_async_count{0};
};