Asynchronously fetch byte ranges from multiple sources

cpp/include/cudf/io/parquet_io_utils.hpp

@@ -109,6 +109,28 @@ fetch_byte_ranges_to_device_async(cudf::io::datasource& datasource,
                                   rmm::cuda_stream_view stream,
                                   rmm::device_async_resource_ref mr);
 
+/**
+ * @brief Fetches lists of byte ranges from multiple datasources into device buffers
+ *
+ * @ingroup io_utils
+ *
+ * @param datasources Input datasources
+ * @param byte_ranges_per_source Vector of byte ranges to fetch, one per datasource
+ * @param stream CUDA stream
+ * @param mr Device memory resource
+ *
+ * @return A tuple containing a vector of device buffers, a vector of vectors of device spans (one
+ * per byte range per datasource), and a future to wait on the read tasks
+ */
+std::tuple<std::vector<rmm::device_buffer>,
+           std::vector<std::vector<cudf::device_span<uint8_t const>>>,
+           std::future<void>>
+fetch_byte_ranges_to_device_async(
+  cudf::host_span<std::reference_wrapper<cudf::io::datasource> const> datasources,
+  cudf::host_span<std::vector<byte_range_info> const> byte_ranges_per_source,
+  rmm::cuda_stream_view stream,
+  rmm::device_async_resource_ref mr);
+
 /** @} */  // end of group
 }  // namespace io::parquet
 }  // namespace CUDF_EXPORT cudf