jorisvandenbossche commented on code in PR #38472: URL: https://github.com/apache/arrow/pull/38472#discussion_r1425027655
########## cpp/src/arrow/c/dlpack.cc: ########## @@ -0,0 +1,139 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#include "arrow/c/dlpack.h" + +#include "arrow/array/array_base.h" +#include "arrow/c/dlpack_abi.h" +#include "arrow/device.h" +#include "arrow/type.h" +#include "arrow/type_traits.h" + +namespace arrow::dlpack { + +namespace { + +Result<DLDataType> GetDLDataType(const DataType& type) { + DLDataType dtype; + dtype.lanes = 1; + dtype.bits = type.bit_width(); + switch (type.id()) { + case Type::INT8: + case Type::INT16: + case Type::INT32: + case Type::INT64: + dtype.code = DLDataTypeCode::kDLInt; + return dtype; + case Type::UINT8: + case Type::UINT16: + case Type::UINT32: + case Type::UINT64: + dtype.code = DLDataTypeCode::kDLUInt; + return dtype; + case Type::HALF_FLOAT: + case Type::FLOAT: + case Type::DOUBLE: + dtype.code = DLDataTypeCode::kDLFloat; + return dtype; + case Type::BOOL: + // DLPack supports byte-packed boolean values + return Status::TypeError("Bit-packed boolean data type not supported by DLPack."); + default: + return Status::TypeError("DataType is not compatible with DLPack spec: ", + type.ToString()); + } +} + +} // namespace +struct ManagerCtx { + std::shared_ptr<ArrayData> ref; + DLManagedTensor tensor; +}; + +Result<DLManagedTensor*> ExportArray(const std::shared_ptr<Array>& arr) { + // Define DLDevice struct nad check if array type is supported + // by the DLPack protocol at the same time. Raise TypeError if not. + // Supported data types: int, uint, float with no validity buffer. + ARROW_ASSIGN_OR_RAISE(auto device, ExportDevice(arr)) + + // Define the DLDataType struct + const DataType* arrow_type = arr->type().get(); + ARROW_ASSIGN_OR_RAISE(auto dlpack_type, GetDLDataType(*arrow_type)); + + // Create ManagerCtx with the reference to + // the data of the array + std::shared_ptr<ArrayData> array_ref = arr->data(); + std::unique_ptr<ManagerCtx> ctx(new ManagerCtx); Review Comment: Given that we have the explicit `delete` as well, I personally like seeing the `new`+`delete` combo explicitly, even though `make_unique` is exactly equivalent AFAIU -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
